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A new technique was introduced for sand stabilization and re-vegetation by use of lignin sand stabilizing material (LSSM). LSSM is a reconstructed organic compound with lignin as the most dominant component from the extracts of black-liquor issued by straw pulp paper mills. Unlike the polyvinyl acetate or foamed asphalt commonly used for dune stabilization, the new material is plant-friendly and can be used with virescence actions simultaneously. The field experimental study was conducted since 2001 in China's Northwest Ningxia Hui Autonomous Region and has been proved that LSSM is effective in stabilizing the fugitive dunes, making the arenaceous plants survive and the bare dune vegetative. The advisable solution concentration is 2% and the optimal field spraying quantity is 2.5 L/m^2. The soil nutrients of the stabilized and greened dune, such as organic matter, available phosphorous and total nitrogen are all increased compared with the control treatment, which is certainly helpful to the growth of arenaceous plants. The technique is worthwhile to be popularized because it is provided not only a new method for desertification control but also an outlet for cleaning contaminants issued from the straw paper mills. [ABSTRACT FROM AUTHOR]

Lanzhou City is located in the semi-arid region of northwest China, which experiences serious desertification. Moreover, the high intensity of land development, with the accelerated industrialization and urbanization, causes increasingly aggravated conflict between humans and the environment. Exploring the response of the ecological environment quality to the natural environment and anthropogenic activities is important to protect the sustainable development of urban economic construction and the environment. Based on the Google Earth Engine (GEE) platform, this paper constructed a modified Remote Sensing Ecological Index (MRSEI) model which could reflect the ecological environment quality by integrating the desertification index (DI) into the Remote Sensing Ecological index (RSEI) model. This paper explores the spatiotemporal variation in the environmental quality from 2000 to 2020 in Lanzhou, China, and analyzes the natural and anthropogenic factors affecting the environment quality in terms of temperature, precipitation, gross domestic product (GDP), land use, night lighting, and population. The results showed that the mean value of MRSEI ranged from 0.254 to 0.400. The area undergoing fast growth in ecological quality was in the northwestern part of Lanzhou, and the area of decrease was in the central part. Various factors have different degrees of influence on the ecosystem, with temperature, precipitation, and land use having a greater impact, and GDP and population having a limited impact. Precipitation and temperature showed a strong impact when interacting with other factors, demonstrating that precipitation and temperature were also key factors affecting MRSEI. Overall, climate change and the implementation of ecological restoration projects have led to an improvement in the quality of the ecological environment in Lanzhou. This study provides a reference for understanding the spatiotemporal changes in the ecological environment in semi-arid Lanzhou and is conducive to formulating proper protection strategies. [ABSTRACT FROM AUTHOR]

With the rapid rise of infrastructure construction in southwestern mountainous areas of China, tunnel engineering has become increasingly frequent in crossing faults with strong activity. However, there has been a long-term lack of an effective theoretical method for identifying the stability and controlling the deformation of extremely weak surrounding rocks inside active faults. Therefore, this paper researched stability analysis and deformation control of a tunnel with extremely weak surrounding rocks caused by strike-slip fault activity. Firstly, uniaxial and triaxial compression tests were conducted on completely decomposed granite within active faults under drained and undrained conditions, and the mechanical properties of granite after desertification and argillization were analyzed. Then, based on the upper-bound limit theory and according to the relationship between the safety factor, instability trace, and geo-stress, a theoretical method to evaluate the stability of the unsupported surrounding rock under different geo-stress levels was proposed. Furthermore, a comprehensive deformation control method, including advanced support, excavation face reinforcement, and radial grouting, was proposed, and the applicability of this method was analyzed and verified through field mechanics and deformation measurements. The results showed that under the triaxial stress state, the post-peak stress drop characteristics of completely decomposed granite basically disappear, and the plastic deformation characteristics of rock become prominent. The comprehensive strengthening scheme has a significant deformation control effect, and the surrounding rock deformation can be reduced by over 65%. In addition, the pressure on the supporting structure will be more than 3.2 times higher with no reinforcement scheme. Highlights A comprehensive deformation control scheme has been proposed to prevent and control deformation disasters in extremely weak surrounding rocks caused by strike-slip fault activity. An upper-bound limit theory considering the influence of geo-stress is established to judge the stability of the unsupported surrounding rock. The mechanical properties of completely decomposed granite caused by strike-slip fault activity under drained and undrained conditions are analyzed. [ABSTRACT FROM AUTHOR]

Land desertification is one of the serious ecological and environmental problems facing mankind today, which threatens the survival and development of human society. China is one of the countries with the most serious land desertification problems in the world. Therefore, it is of great theoretical value and practical significance to carry out accurate identification and monitoring of land desertification and its influencing factors in ecologically fragile areas of China. This is conducive to curbing land desertification and ensuring regional ecological security. Minqin County, Gansu Province, located in northwestern China, is one of the most serious areas of land desertification, which is also one of the four sandstorm sources in China. Based on ENVINet5, this paper constructs a high-precision land desertification identification method with an accuracy of 93.71%, which analyzes the trend and reasons of land desertification in this area, provides suggestions for disaster prevention in Minqin County. and provides a reference for other similar areas to make corresponding desertification control policies. [ABSTRACT FROM AUTHOR]

C, N and P are the key biogenic elements of terrestrial ecosystems, and their biogeochemical processes regulate nutrient cycling and play a key role in restoring degraded ecosystems. In this paper, the grassland ecosystem under artificial restoration measures (Dactylis glomerata (DG), Lolium perenne (LP), Lolium perenne + Trifolium repens (LT)), and the natural restoration measures (NG) in a typical karst plateau desertification control area of southwest China, were taken as the research object. The C, N, and P concentrations and the ecological stoichiometry of the plant–soil–microorganism system in grasslands under different restoration measures in the karst desertification area were explored. We established the following findings: (1) Compared with NG, the C, N and P concentrations of plants and soil in DG, LP and LT were higher, and LT was the highest. (2) The microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and microbial biomass phosphorus (MBP) concentrations in LT was also the highest. (3) The C:N ratio of plant and soil indicated that the N mineralization and nutrient release rate of DG, LP and LT were stronger than that of NG, and the plant growth of NG was most seriously limited by nitrogen. The N:P ratio in plant and soil indicated that the grassland was limited by P in the four treatments. (4) The result of correlation analysis showed that the cycling process of C, N and P in the plant–soil–microorganism system was coupled, and that the elements closely affected each other. In general, the effect of artificial restoration on a degraded ecosystem was relatively better than the natural restoration for increasing plant, soil and microbial nutrient concentrations, especially in the mixed-seed ecosystem of leguminous and gramineous forage. However, in the future, grassland management, appropriate N fertilizer or N-fixing plants and P fertilizer should be considered to improve the limitation of plant N and P, so as to realize the sustainable development of grasslands and the restoration of degraded ecosystems in the karst desertification control area. [ABSTRACT FROM AUTHOR]

Synergistically enhancing and realizing the value of grassland ecosystem services (ES) for economic activity is an important but challenging task for achieving sustainability in the karst desertification control (KDC). However, how to use grassland ES value characteristics in the KDC to make decisions on ES improvement, human well-being enhancement, and sustainable development remains unclear. In this paper, we took the contiguous region of karst desertification in Yunnan-Guangxi-Guizhou, China, a global hotspot, as the study area. Based on the valuation of the gross ecosystem product (GEP) and county economic intensity, we analyzed the structural and spatial characteristics of grassland GEP in the KDC using spatial analysis methods. We found that: (1) the grassland GEP in the KDC is mainly distributed in counties with low economic intensity (86.05% of the total number of counties) and vulnerable to losses caused by the livelihood of farmers; (2) the grassland GEP in the KDC is spatially small and scattered (the geographic concentration lies between 0.015 and 0.237), which makes it difficult to form industrial scale advantages; (3) the public product index (66.22–96.77%) and industry scale concentration (97.87–99.86%) of grassland GEP in the KDC are high, and most of the GEP is difficult to transform on the private market. Based on our findings, we proposed three corresponding recommendations for economic decision-making. The results of this study can provide a reference for economic decision-making regarding the management of grassland ES in karst areas with similar conditions and beyond. [ABSTRACT FROM AUTHOR]

In China, backfill mining has been selected as an effective approach to realize the green mining of underground coal resources, where backfill materials are the major factor in the development of backfill mining. In order to provide a better reference for further research and development of backfill mining, the experience and research achievements are reviewed in this paper. Firstly, the backfill materials that have been successfully applied in Chinese underground backfill coal mining are divided into two categories according to whether water is used during the backfill mining operation. Then, the primary considerations of each backfill material during its preparation, transportation and activation stages are discussed and evaluated. Finally, suggestions for backfill material exploration are proposed in terms of the future backfill mining of coal resources in Western China, where there is serious surface desertification. [ABSTRACT FROM AUTHOR]

Clues of climate change on the Alashan Plateau since the last glacial period (40 ka) are important for revealing the mechanism of desertification of middle-latitude deserts in the Northern Hemisphere (NH). Studies are still rare for the understanding of the specific relationship of climate changes between the Alashan Plateau and the global. Based on a systematic and comparative analysis of the existing research in China and the international academic community, this paper reviews the environmental evolution history of the Alashan Plateau since the last glacial period from the records of paleo-environment and geomorphological characteristics in different deserts of the plateau (e.g., Badanjilin, Tenggeli, and Wulanbuhe). From about 40 ka to the end of the last glacial maximum, the climate on the plateau was wetter than it is today, and to the end of the Pleistocene, the climate was generally dry and the aeolian activities were enhanced. However, the climate was arid during the whole last glacial period in the Wulanbuhe Desert, evidently different from the overall pattern of the plateau. The Tenggeli Desert was characterized by an arid climate in the early Holocene. The most controversial events for the Alashan Plateau are the drought events in the middle Holocene in the Badanjilin Desert. The role and impact of the westerlies and the East Asian Summer Monsoon (EASM) systems on the climate change of the desert and even the whole plateau is a vexed question that brings different views in different periods. There is still a lack of definite evidence representing the events of global environmental change that occurred on the plateau during the discussed period. The distinctive morphology of dune mountains and the distribution of sand dunes are mutually indicative of the direction and energy of wind systems on the plateau. It is suggested that appropriate wind energy is the significant key to the desertification in these middle-latitude deserts on the plateau. From a global-scale review of climate change, the desertification of the modern-scale sandy desert landscapes on the Alashan Plateau is generally related to the global glacial period and the cold and dry climate during the past 40 ka. [ABSTRACT FROM AUTHOR]

Background: Desertification is one of the main obstacles to global sustainable development. Monitoring, evaluating and mastering its driving factors are very important for the prevention and control of desertification. As one of the largest deserts in China, the development of desertification in Otindag Sandy Land (OSL) resulted in the reduction in land productivity and serious ecological/environmental consequences. Although many ecological restoration projects have been carried out, the vegetation restoration of OSL and the impact mechanism of climate and human activities on desertification remain unclear. Methods: Taking OSL as the research area, this paper constructs the desertification index by using the remote sensing images and meteorological and socio-economic data, between 1986 and 2016, and analyzes the spatio-temporal evolution process and driving factors of desertification by using trend analysis and spearman rank correlation. Results: The results showed that: (1) Desertification in the OSL has fluctuated greatly during the past 30 years. Desertification recovered between 1986 and 1990, expanded and increased between 1990 and 2000, reduced between 2000 and 2004, developed rapidly between 2004 and 2007, and recovered again between 2007 and 2016; (2) The desertification of OSL is dominated by a non-significant change trend, accounting for 73.27%. In the significant change trend, the area of desertification rising trend is 20.32%, which is mainly located in the north and east, and the area of declining trend is 6.41%, which is mainly located in the southwest; (3) Desertification is the result of the superposition of climate and human activities. Climate change is the main influencing factor, followed by human activities, and the superposition effects of the two are spatio-temporal differences. Conclusions: These results shed light on the development of desertification in OSL and the relative importance and complex interrelationship between human activities and climate in regulating the process of desertification. Based on this, we suggest continuing to implement the ecological restoration policy and avoid the destruction of vegetation by large-scale animal husbandry in order to improve the situation of desertification. [ABSTRACT FROM AUTHOR]

Currently, the monitoring of rocky desertification(RD) is concentrated in the karst area, whereas the study in red-bed areas is rare. In this paper, we present a multi-scale classification framework for RD monitoring based on spectral-spatial features. At the pixel scale, we explored several spectral indices based on spectral statistics and separability analysis of land cover samples. The homogeneous land covers were classified by the decision rules from the selected spectral indices (such as NDIOI, NRRI and NDGI); At the patch scale, RD classes were further distinguished by spatial decision rules based on multiple neighborhood features including proximity, linear density, and buffer distance. The method was applied on an OLI image over the red-bed area of northwestern Jiangxi, south central China, and validated using ground-based observations. The experimental results of verification and comparison are satisfactory. This work demonstrates a methodological supplement to the monitoring of red bed RD. [ABSTRACT FROM AUTHOR]

Gully erosion is a major threat to ecosystems, potentially leading to desertification, land degradation, and crop loss. Developing viable gully erosion prevention and remediation strategies requires regular monitoring of the gullies. Nevertheless, it is highly challenging to automatically access the monitoring results of the gullies from the latest monitoring data by training historical data acquired by different sensors at different times. To this end, this paper presents a novel semi-supervised semantic segmentation with boundary-guided pseudo-label generation strategy and adaptive loss function method. This method takes full advantage of the historical data with labels and the latest monitoring data without labels to obtain the latest monitoring results of the gullies. The boundary-guided pseudo-label generation strategy (BPGS), guided by the inherent boundary maps of real geographic objects, fuses multiple evidence data to generate reliable pseudo-labels. Additionally, we propose an adaptive loss function based on centroid similarity (CSIM) to further alleviate the impact of pseudo-label noise. To verify the proposed method, two datasets for gully erosion monitoring are constructed according to the satellite data acquired in northeastern China. Extensive experiments demonstrate that the proposed method is more appropriate for automatic gully erosion monitoring than four state-of-the-art methods, including supervised methods and semi-supervised methods. [ABSTRACT FROM AUTHOR]

Since the 20th century, the resources and environment in Northeast China have changed, and it is one of the typical regions that have short-term or high-intensity environmental impacts in the world. However, due to the excessive consumption of regional resources and strong environmental pollution to the atmospheric environment, development is being greatly affected. Maintaining the natural ecological environment has become a very urgent task. This paper studies the important ecological environment problems in Northeast China from the perspective of double carbon goals. The study points out that there are ecological problems in Northeast China, such as the lack of forest resources, the aggravation of desertification, the decline of black soil quality, and the shrinkage of wetlands, which are severe urban environmental protection problems. At the same time, affected by the trend of world environmental change, policy drivers in Northeast China, and some relatively new environmental pollution problems, the natural environmental quality of Northeast China will still have a significant decline in the future. The future development of Northeast China will be based on the perspective of double carbon goals, constantly improve the ecological environment monitoring system, strengthen the research of scientific and technological system, strengthen innovation, and vigorously develop circular economy and further improve the construction of basic systems. Through a series of ecological environment governance and the coordinated development of economy and ecological environment, the dual growth of economy and ecological environment in Northeast China will be realized, and the overall revitalization of the old industrial zone in Northeast China will be realized. [ABSTRACT FROM AUTHOR]

Surface air temperature is a critical element in the surface–atmosphere interaction, energy exchange, and water cycle. Multi-source fusion reanalysis products (hereafter referred to as reanalysis) have spatiotemporal continuity and broad applicability that can provide key data support for various studies such as glacier melting, soil freeze-thaw and desertification, ecosystem, and climate change in the alpine region of the Qinghai–Tibet Plateau (QTP). Surface air temperature observations collected at 17 weather stations in the High-cold region Observation and Research Network for Land Surface Process and Environment of China (HORN) over the period of 2017–2018 are implemented to evaluate the advanced and widely used surface air temperature reanalysis datasets, which include the European Centre for Medium-Range Weather Forecasts (ECMWF) Fifth Generation Land Surface Reanalysis (ERA5L), the U.S. Global Land Data Assimilation System (GLDAS), and China Meteorological Administration Land Data Assimilation System (CLDAS). Results are as follows: (1) Evaluation results of temporal changes and spatial distribution characteristics indicate that the three reanalysis datasets are consistent with in-situ observations in the alpine region of the QTP. CLDAS is more consistent with observations and can better describe details of temperature distribution and variation than ERA5L and GLDAS. (2) For the evaluation period, CLDAS is 0.53 °C higher than the in-situ observation, while ERA5L and GLDAS are lower than the in-situ observation by −3.45 °C and −1.40 °C, respectively. (3) The accuracy of CLDAS is better than ERA5L and GLDAS under different elevations and land covers. We resampled three reanalysis datasets with a spatial resolution of 0.25° and used the two most common interpolation methods to analyze the impact of spatial resolution and different interpolation methods on the evaluation results. We found that the impact is small. In summary, the three reanalysis datasets all have certain applicability in the alpine region of the QTP, and the accuracy of CLDAS is significantly higher than ERA5L and GLDAS. The results of the present paper have important implications for the selection of reanalysis data in the studies of climate, ecosystem, and sustainable development in the QTP. [ABSTRACT FROM AUTHOR]

Despite the considerable constraints of karst rocky desertification on the production and life of the locals and the regional economy, few studies have been conducted on areas with karst rocky desertification with the aim of exploring the balance between ecological governance and industrial development. In light of the promotion of featured advantageous industries to ecological governance and industrial development, this study aims to explore the mechanism of industrial revitalization in areas with karst rocky desertification to provide theoretical support for their industrial revitalization. Based on actor‐network theory, this paper presents a case study of Bashan village, a typical area in Guizhou province, China, with karst rocky desertification, to clarify the course of development of its Zanthoxylum bungeanum industry and propose a mechanism for its revitalization. The findings identify the main actors of the revitalization of the Z. bungeanum industry and reveal the driving forces behind it. Moreover, the study found that the industrial revitalization model is a bottom‐up process, which suggests strong endogenous dynamics. Through the revitalization of the featured industries, the results of the management of rocky desertification are transformed into economic output, which improved the livelihood of farmers and consolidated the effectiveness of management. [ABSTRACT FROM AUTHOR]

As an important part of the Earth's environmental system, sandy soils are particularly sensitive to changes in the climatic environment. As one of the four major desert regions in China, the MuUs desert has transformed from a desert to an oasis after more than half a century of ecological management. In this paper, we analyzed the spatial and temporal patterns of surface albedo, evapotranspiration, and fraction vegetation cover in the MuUs desert based on the Global Land Surface Satellite (GLASS) product with high spatial and temporal resolution and assessed the relationships between their variability and snow cover, air temperature, and precipitation. It is of great significance to understand the effect of desertification control and climate change after the conversion of land surface types in the MuUs region. The results show that the desertification control in the MuUs area has achieved remarkable results since 1982. The fraction vegetation coverage of the MuUs desert showed a significant increasing trend, with an interannual change rate of 1.32% each decade−1. The surface albedo of MuUs desert decreased significantly. Affected by vegetation and snow cover, it was lower in summer and higher in winter. The evapotranspiration showed a significant upward trend, higher in summer and lower in winter, which is significantly correlated with the changes in surface albedo, air temperature, and vegetation. In addition, the local-scale biophysical effects caused by vegetation change have influenced the climate of the MuUs region, manifested as the increase in precipitation and air temperature. In general, with the support of relevant policies and human construction projects, the overall ecological environment in the MuUs desert is developing in a good way. [ABSTRACT FROM AUTHOR]

Objectives: Intelligent interpretation based on high-resolution remote sensing is an important way to realize the fine generation and rapid update of geographic information. Based on the background of fine-accurate geographical application using remote sensing, this paper analyzes the limitations of remote sensing information products in production and application. We explain the necessity of remote sensing serving geographical research and the key of coupling the fine shape of the map and the accurate content of the spectrum. Methods: Based on the basic understanding that geography guides the research of intelligent remote sensing, we first put forward the development direction and technical ideas of high-resolution remote sensing geoscience analysis based on fine geographical scenes. Then, we propose an intelligent computing mode via the space-time/satellite-ground collaboration. Furthermore, we take the evaluation of rocky desertification cultivated land in Guanling County, Guizhou Province, China as an application case. Results: Through this case study, three basic models, namely zoning-stratified perception, spatiotemporal synergistically inversion and multi-granular decision-making, are used to show how to carry out fine-accurate application by high-resolution remote sensing collaborative computing in complex mountain areas from a comprehensive perspective of refinement, quantification and topicalization. Conclusions: Combined with the previous work experience and practical cognition, several key scientific problems are discussed, such as spatial expression using irregular grids, multimodal reconstruction of temporal features, multi-source un‐ certainty analysis and iterative optimization guided by uncertainty. We give some potential study directions and research ideas in order to establish a more complete and feasible theoretical system and explore the development paths for the research on intelligent remote sensing under the guidance of geography and the fine-accurate geographical application with remote sensing data. [ABSTRACT FROM AUTHOR]

Rocky desertification is one of the most critical ecological and environmental problems in areas underlain by carbonate rocks globally. Land cover and land use in the region affects large-scale ecosystem processes on a global scale, and many Earth system models rely on accurate land cover information. Therefore, it is important to evaluate current global land cover products and to understand the differences between them, and the findings of these studies can provide guidance to different researchers when using or making land cover products. Whereas there are many studies on the assessment of coarser resolution land cover products, there are few studies on the assessment of higher resolution land cover products (10 m). In order to provide guidance for users of 10 m data, this paper uses the rock deserted southwest region of China as the experimental area. We analyzed the consistency and accuracy of the FROM-GLC, ESA WorldCover 10 and ESRI products using spatial pattern consistency, absolute accuracy assessment of three validation samples, and analyzed their intrinsic relationships among classification systems, classification methods, and validation samples. The results show that (1) the overall accuracy of the FROM-GLC product is the highest, ranging from 49.47 to 62.42%; followed by the overall accuracy of the ESA product, ranging from 45.13 to 64.50%; and the overall accuracy of the ESRI product is the lowest, between 39.03 and 61.94%. (2) The consistency between FROM-GLC and ESA is higher than the consistency between other products, with an area correlation coefficient of 0.94. Analysis of the spatial consistency of the three products shows that the proportion of perfectly consistent areas is low at 44.89%, mainly in areas with low surface heterogeneity and more homogeneous cover types. (3) Across the study area, the main land cover types such as forest and water bodies were the most consistent across the three product species, while the grassland, shrubland, and bareland were lower. All products showed high accuracy in homogeneous areas, with local accuracy varied in other areas, especially at high altitudes in the central and western regions. Therefore, land cover users cannot use these products directly when conducting relevant studies in rocky desertification areas, as their use may introduce serious errors. [ABSTRACT FROM AUTHOR]

Soil wind erosion is the main cause of land degradation in arid and semi-arid areas in northern China, which is mainly affected by surface type, climate and so on. Strong soil wind-erosion will not only accelerate regional desertification and influence the quality of human life, but also cause serious ecological and environmental problems. Since the 2000 s, our country has gradually strengthened the control of land desertification and carried out a series of sand control works, which effectively improved the overall ecological environment of the sandy land. But in recent years, there are some common phenomenon that extensive grassland and brushland was turned into cultivated land in the southeast and southwest of Mu Us sandy land. However, in the dry and windy winter or spring, these new reclaimation land is usually so exposed that it is vulnerable to suffer from strong wind erosion. Therefore, it is great significance to study the characteristics of soil wind erosion in new reclaimation land and find out the control methods. Based on the above question, this paper selected the southern part of Mu Us sandy land (38°05′27″-38°13′58″N, 107°24′28″-107°37′30″E) as the research area, as well as set up 5 observation points on different surfaces, which were represented respectively by A, B, C, D and E. Point A was on the brushland, point B was on the middle of the grassland, and other three points were respectively on different parts of the cultivated land. On the day with strong wind activity, 12 groups simultaneous observation of wind and sand were made at these 5 points (A, B, C, D, E), with each observation time at least 20 minutes. After these observations, the material of the sand samplers were weighed with an electronic balance of 1/1 000, and the material of surface and sand samplers on cultivated land were analyzed by Mastersizer2000 Laser Particle Size Analyzer. The results showed that the soil wind erosion intensity increased exponentially after grassland and shrubland were cultivated; on cultivated land, with the increase of height, the sediment transport rate decreases with exponential function within 0-10 cm height and power function within 10-20 cm height. Due to the height of the sand collector used in this paper is 20cm, lower than the height of the sand flow layer. In order to obtain the total sediment transport rate of the surface of the cultivated land, this paper must calculate it through the function simulation obtained from the above result. After calculating the total sediment transport rate, fitting it with the wind speed. We found that the total sediment transport rate has a good power function relationship with the wind speed in the cultivated land with sufficient erodibility particles. Based on the formula of the relationship between wind speed and total sediment transport rate, as well as the wind speed data of the meteorological stations in the region, the wind erosion modulus of the new reclaimation land can be preliminarily calculated. The result shows that the wind erosion modulus of the new reclaimed land is 9 657 t/(km2·a). Through the results obtained in this paper, combined with the former research results, this paper argues that the emergence of new reclaimed land has an important impact on regional desertification, and its area should be used as an important index when evaluating regional desertification. Meanwhile, Controlling cultivated land area, establishing windbreak and sand fixation forest, as well as retaining stubble at a certain height can effectively control soil wind erosion in newly reclaimed land. [ABSTRACT FROM AUTHOR]

The global urbanization process requires solving the issues of rural and poverty, and research on the coupling patterns and correlational effects of rurality and regional poverty governance change can provide references for promoting regional urban-rural integration and rural revitalization. Based on the analysis of the conceptual relationship and interaction mechanism between rurality and poverty, this paper revealed the spatio-temporal pattern evolution characteristics and correlational effects of the rurality index (RI) and poverty governance level (PGL) in 91 counties of the rocky desertification area of Yunnan-Guangxi-Guizhou (RDAYGG) in China from 2005 to 2020 by using the multi-index comprehensive evaluation, Person correlation coefficient, and fixed effects model. The results showed that (1) there are similarities and differences between rurality and poverty. The logic of rurality affecting poverty governance is that the dynamic trade-offs between the share of positive and negative rurality in a region will come to alter the local capacity for urban-rural coordinated development, and the ideal process is manifested in the weakening of negative rurality and the enhancement of positive rurality. (2) From 2005 to 2020, the RI of counties within the RDAYGG showed a pattern of continuous weakening, while the PGL showed a trend of gradual increase in the whole region, and both were holistically characterized by reverse dynamic change. (3) The regional PGL is closely related to the change of rurality. When other influencing factors remain unchanged, for every 10% reduction in the RI, the PGL will increase by about 0.4%. Future research needs to focus on crucial propositions such as the mixed turn of rurality in the new era, the construction of poverty theory in the latest stage, and the spatial-temporal coupling of rural development and poverty governance. • Governance of rurality and poverty is key to promoting global urban-rural integration and regional development. • Index systems for measuring rurality and regional poverty governance were constructed. • Spatio-temporal pattern and correlation effects of rurality and poverty governance change in the RDAYGG were investigated. • Rurality changes are negatively correlated with regional poverty governance. • Incorporating the perspective of rurality into formulating regional poverty reduction policies is a key breakthrough. [ABSTRACT FROM AUTHOR]

Due to the complex geographical situation in China, in this paper, the area of land desertification is 98.5% of the total land desertification area in China. Based on the measured data of GIS and remote sensing images, we will discuss the spatial and temporal distribution characteristics of land desertification in China by calculating standardized precipitation evapotranspiration index (SPEI) and normalized vegetation index and establishing the CA model. The results show the following. (1) The trend of desertification in China has decreased as a whole, and the percentage of nondesertification has increased from 36.91% in 1991 to 44.46% in 2020, an increase of 7.55%. Extremely severe desertification increased from 21.72% to 24.25%, an increase of 2.53%. (2) The drought situation in the study area gradually improved, and the change trend of SPEI decreased by 74%. (3) In recent ten years (2011–2020), the vegetation grew well gradually, and it was in the best state in 2018. The NDVI index value increased by 5.9% compared with the average value in this decade. (4) The model designed by us works very well, and the results of simulating and testing the Three Rivers Source region are very little different from the actual situation, which meets our research requirements. [ABSTRACT FROM AUTHOR]

• Synergistic effects of surface and groundwater on desert riparian vegetation were analyzed. • The cautionary depth to groundwater for vegetation expansion in the lower Tarim River is 4.0–5.0 m. • Flooding by surface water (lateral water transfer coverage) acts as the main driver for the expansion of vegetation in arid areas. • A zonal ecological water transfer strategy helps to promote effective ecosystem restoration in the region. Restoring degraded ecosystems in drylands is challenging because of low precipitation and high evapotranspiration. Water availability determines the existence and spatiotemporal distribution patterns of key endangered species struggling to survive in the severely damaged desert riparian ecosystem of the lower Tarim River (LTR) in NW China. Ecological water flow restoration measures with high costs and uncertainties have been implemented since 2000. The key task for scientists is to assess the success and drawbacks of this restoration project and propose specific recommendations for stakeholders to optimize the ecological benefits of the project in a cost-effective manner. In this study, Landsat time-series data from 1990 to 2020 were used to extract vegetation index values from river corridors along the LTR and explore the spatiotemporal patterns of desert riparian forest (DRF) vegetation. Based on land use and surface water data, we extracted the interannual spatial distribution range of vegetation and surface water, and selected several sample plots to demonstrate the influence of surface water and groundwater on vegetation change trends. The study results showed the following. 1) From 1990 to 1999, the vegetation slowly degraded; from 2000 to 2012, the extent of vegetation restoration was approximately 1 km from the river; and from 2013 to 2020, the extent of vegetation restoration at the Yingsu and Karday sections increased to 4.5–6.0 km, while that at the Arghan and Yiganbujima sections remained within 1 km from the river. 2) The vegetation growth rate increased substantially and was spatially heterogeneous when the groundwater level reached 4.0–5.0 m and was influenced by surface water divergence; the average vegetation expansion rates per square km for P 1 –P 4 were 0.017 km2/a, 0.011 km2/a, 0.005 km2/a, and 0.002 km2/a, respectively. 3) Flooding by surface water was the main driver of vegetation expansion when groundwater was stable and elevations in surface vegetation area were often accompanied by the spreading of surface water. Surface water was significantly correlated with vegetation cover and normalized difference vegetation index (NDVI) (Water pixels–Vegetation cover [P 1 : R2 = 0.57, P < 0.001; P 2 : R2 = 0.45, P < 0.01]; Water pixels–NDVI [P 1 : R2 = 0.22, P < 0.05; P 2 : R2 = 0.40, P < 0.01]). The increase in surface vegetation has alleviated the desertification process in the LTR, and the survival of the poplar has been mitigated. The results of this paper can help decision makers to formulate reasonable ecological water conveyance strategies and realize sustainable management of DRF ecosystems in arid zones. [ABSTRACT FROM AUTHOR]

This paper examines the acute socioecological crisis in the Minqin region of China's Gansu province beginning in the 1980s and the multilevel, governmental response to that crisis in the first two decades of the 21st century. Drawing on extensive field research and interviews in the area, supplemented by analysis of available data, the paper presents a detailed case study of the development and implementation of the Shiyang River Watershed Restoration Plan in the period 2007-15. The case illustrates how conflicting policy objectives of the central state-led conservation project shaped patterns of interaction between local government officials, cadres, and farmers in Minqin County as well as ensuing outcomes and challenges in policy implementation. The study finds that top-level declaration of ecological and social issues in the watershed as a national security issue incentivized local government officials and cadres to overlook the Plan's provision for local consultation, in favor of meeting binding ecological and economic targets. It contributes to scholarship on environmental authoritarianism, illuminating structural factors and institutional constraints that shape local government officials' and cadres' behavior in a centrally administered environmental policy context. [ABSTRACT FROM AUTHOR]

• Seasonal variations of δ18O and δD in precipitation can be conserved in groundwater. • Amount-weighted isotopic input of rainfall affects seasonal amplitude of groundwater. • The seasonal isotopic strength conserved in groundwater varies with land cover. • Land cover impacts on evaporation loss and hydrodynamic conditions in groundwater. • To land cover, soil has the most important effect on dampening isotopic seasonality. δ18O and δD values in meteoric groundwaters reflect those in their source precipitation, which normally displays seasonal ranges of several to many permil. Normally there are substantial reductions in the groundwater isotopic ranges due to mixing in any vegetation, soil cover and the aquifer itself, plus the distortions that can be introduced by evaporation. Nevertheless, in carbonate karst regions (and others) many spring waters are found to preserve significant proportions of these seasonal signals. They are of current interest because they may also be detected in calcite speleothems precipitated from groundwater in caves, in calcretes and calcareous nodules in soils, etc. thus permitting detailed paleoclimate reconstructions. This paper presents some baseline data on reduction of isotope seasonal signals in groundwater that are pertinent to such speleothem studies. They are from artificial tank experiments at Shawan Karst Test Site, Guizhou, China. The climate is humid subtropical with mean annual precipitation of 1340 mm, >80% falling between May and October. The concrete tanks measure 20 × 5 m, 3 m deep each, point-drained at one end to simulate a spring. They are filled with 2.5 m of local limestone quarry gravel, creating carbonate aquifers with primary porosities ∼ 50%. A first tank is left bare, simulating the rocky desertification found in parts of the region. The other tanks are topped with 0.5 m of local, clay-rich residual soil, one left bare, the other three sown with rainy season corn, permanent grass and permanent shrubs respectively. Measurements cover the three climatic years, November 2015-November 2018. > 90% of the rainfall events were sampled, and the drains every ten days. δ18O and δD in the rainfall displayed strong and regular sinusoidal oscillations with the successive seasons. In the bare rock tank these were reduced (damped) by 56~74% in the different years, with phase (time) lags of 127~134 days at the drain. In the soil-topped tanks damping ranged from 61% to 93% and the time lags from 164 to 202 days: differences between them are not statistically significant but all do differ significantly from the bare rock. In all cases, the responses of the two isotopes were similar in direction and magnitude. The 0.5 m soil cover had the most important effect. The bare rock aquifer conserved the most information. Losses were similar in the four soil-topped tanks, responding to stronger evaporation and obstruction of flow in the soil. These findings are briefly compared to seasonal isotope variations reported in speleothem drip waters in limestone caves in China and elsewhere in the world. [ABSTRACT FROM AUTHOR]

The Yunnan–Guizhou Plateau (YGP) is a typical ecologically fragile region in southwest China. Water-erosion desertification (WED) is one of the most significant environmental and socio-economic issues on the YGP and has seriously restricted the socio-economic development of this region. However, the research on monitoring of the desertification trends in this region has been limited to long time-series Landsat imagery. The objectives of this research were to monitor the WED trends on the YGP using time-series Landsat imagery data from 1989 to 2016. In this paper, we present a multi-indicator rule-based method, which was used to map the WED on the YGP during this period. The results show that the addition of multiple indicators improved the WED classification accuracy to 90.61%. Overall, the following results were obtained by using the proposed method. (1) The slight desertification area on the YGP increased from 89,617.09 km2 in 1989 to 100,976.47 km2 in 2016 with an annual growth ratio (AGR) of 0.48%, the moderate desertification area increased from 80,276.65 km2 in 1989 to 90,768.39 km2 in 2016 with an AGR of 0.50%, and the severe desertification area increased from 8149.3 km2 in 1989 to 13,220.16 km2 in 2016 with an AGR of 2.39%. (2) The WED expansion on the YGP can be divided into three stages. Firstly, the total WED area increased slowly from 17.80×104 km2 in 1989 to 17.98×104 km2 in 2010 with an AGR of 0.05%. Then, the WED rapidly expanded from 17.98×104 km2 in 2010 to 20.28×104 km2 in 2013 with an AGR of 4.26%. Finally, the WED increased slightly from 20.28×104 km2 in 2013 to 20.50×104 km2 in 2016 with an AGR of 0.36%. The total areas of the different degrees of WED decreased in 1992, 1998, 2001, and 2004. (3) The driving factors of WED were analyzed based on the Geographically Weighted Regression (GWR) model. We found that precipitation, vegetation area, and gross domestic product have key roles in the processes of desertification reversion and development. However, the regression coefficients between WED and these factors exhibited considerable spatial variations. The regression coefficients of the key driving factors showed different spatial distributions based on the GWR model in the YGP. The research results can provide scientific reference information for the prevention and control of WED in the YGP. [ABSTRACT FROM AUTHOR]

In order to ensure China's food and ecological security, it's particularly necessary to perform desertification monitoring and early warning during the land consolidation projects execution. The study area was located in Kezuohouqi which is famous for the sandy land. Based on Landsat 8 OLI image data, desertification monitoring was achieved by the decision tree classification method. The desertification early warning system was constructed by PSR (pressure-state-response) model; the natural and human influencing factors of desertification were regarded as "pressure", the desertification monitoring results were regarded as "state", and the land consolidation projects were regarded as "response". The weight of each factor in the PSR model was set by expert scoring method, and DESI (desertification ecological security index) was adopted in this paper; the greater the index, the lower the risks of desertification. Based on the DESI, the results of desertification early warning were divided into 4 different levels through natural breakpoint method, namely, no desertification warning, slight desertification warning, medium desertification warning and severe desertification warning. In the end, the validity of land consolidation could be evaluated through calculating the area of different desertification early warning results in the land consolidation projects and conducting the comparison. The results showed that: 1) The area of desertification accounted for 88% of study area. To be exact, the area of medium and severe desertification accounted for 61% of the total area, and the extremely severe desertification was mainly concentrated in the western part of the study area whose area accounted for 6% of the total area. 2) The zonal differentiation of desertification early warning results was clear; the spatial distribution from east to west in Kezuohouqi in turn was no desertification warning, medium desertification warning, slight desertification warning, medium desertification warning, severe desertification warning, and then medium desertification warning. The area of medium desertification warning was the largest, and the distribution laws of severe warning desertification and extremely severe desertification were similar, but the severe warning desertification tended to gather in the northwest pastoral areas of Kezuohouqi, the slight warning and no warning areas were located in the eastern part of Kezuohouqi, and the land use pattern was mainly agricultural land. 3) In the land consolidation projects, high quality capital farmland construction and arable land consolidation were mainly distributed in the areas with no desertification warning. The potential land suitable for agriculture and the project of land reclamation were mainly distributed in slight desertification warning area and medium desertification warning area. There was the sever desertification warning land among the farmland consolidation, the potential land resources suitable for agriculture, and forage grass base construction projects, whose distribution style was sporadic. However, the severe desertification warning area in high quality capital farmland was not up to the mark and should be eliminated from the projects. Overall, in the context of land consolidation, the risk of further desertification is small. The severe desertification warning area would be a key point for land consolidation projects, and the government must put a high premium on the sever warning area. The results of desertification early warning in this paper can provide the reference for land consolidation and adjustment. [ABSTRACT FROM AUTHOR]

Oasification is a complex oasis expansion and ecological processes caused by climate changes and human activities under available water supply in arid and semiarid regions. The process can effectively improve soil productivity, vegetation cover, and biomass production in fighting against land degradation, such as desertification and soil erosion. However, the significance of oasification has not yet reached the general cognition compared to desertification, which is regarded as one of the most severe global eco-environmental issues. This paper identifies desertification and oasification processes and their perspectives in cognition. The implication of oasification in combating desertification and controlling land degradation is emphasized by the justification between desertification and oasification processes. As opposite process of desertification, the oasification is an unable evasive process that can provide positive environmental effects in the control of desertification, ecological restoration, and land rehabilitation. According to the interaction of climatic variations and human activities, the oasification processes is classified into six main forms: natural oasis evolution process, engineering forest construction, conversion of natural landforms into farmlands, urban encroachment, constructed environments, and coupled ecosystems. These processes gradually modify the productive capacity of soils, increase vegetation cover for restoring degraded lands, and improve the living environment for human settlement and sustainability of an oasis ecosystem. Moreover, an overview of oasification research is detailed, and Northwest China as an example is used to illustrate the progress of the oasification research in recent decades. Currently, the oasification process and its mechanistic research still remain less concern in the arid and semiarid regions. A new science framework of the oasification research is proposed to effectively deal with ecological and environmental issues in the arid and semiarid regions. • Desertification and oasification and their perspectives are identified. • Implication of oasification is emphasized in comparison with desertification. • Oasification processes are classified into six main forms. • Overview of oasification research is detailed and illustrated in Northwest China. • A new science framework of the oasification research is proposed. [ABSTRACT FROM AUTHOR]

Land desertification and sandstorms have been affecting cities worldwide on the edge of sandstorms, so humans have been seeking for ways to strengthen their defenses against wind and sand. High water retention capacity can improve human well-being in sandy areas. Several measures and cases have been already developed. To systematically find the differences between different ecosystem restoration models according to integrated benefits (e.g., ecological, economic and social benefits), this paper proposes an effective technical methodology to quantitatively identify sand control projects in a certain area. With the Southern edge of Tengger Desert-Shapotou in China as an example, this paper uses land use change and NDVI change rates to identify areas of wind and sand management. In addition, this paper uses actual evaporation (ET), soil moisture (SM), temperature vegetation dryness index (TVDI) and sand fixation service to compare the advantages and disadvantages of two typical sand management models in China according to their wind and sand control benefits, resource conservation, as well as socio-economic benefits. As indicated by the results, the straw checkboard engineering model has sustainable ecological and socio-economic benefits in water retention, cost consumption, as well as wind and sand control. Besides, the afforestation model achieves higher ecological benefits in the short term, whereas it has higher operating costs and poor sustainability, which makes this model difficult in maintaining ecological stability. On the whole, both types of sand control projects show their advantages and disadvantages in wind and sand control functions, resource recycling and socio-economic benefits. Furthermore, fast-growing afforestation combined with straw checkboards is capable of sustainably resisting wind and sand attacks and preventing land desertification. Accordingly, the finding of this paper can be referenced widely for wind and sand control. [ABSTRACT FROM AUTHOR]

The most serious desertification in China occurs in the agro-pastoral ecotone of Northeast China and in the oases in Northwest China. It has resulted in the reduce of land productivity and serious ecological/environmental consequences. In this paper, we assessed the mechanisms of land desertification and the key strategies to monitor, control and mitigate land desertification in China, which will provide unique experiences and schemes to support academics and industrialists in other developing countries to reverse desertification. In aspect of monitoring desertification, satellite remote sensing can detect and characterize large-scale desertification, and in-situ field work can measure changes of soil physical & chemical properties induced by desertification. In aspect of desertification control and mitigation, the implementation of sustainable cultivation/grazing practices and wind-shelter forests are the key measures in Northeast China, while water use quotas and sustainable water management are the key measures in Northwest China. Finally, we suggested big-data-based water resource management, regional-climate-model-based agricultural planning, CO 2 storage with deep saline water recovery and desert geoengineering as possible solutions to future, large-scale reversal of deserts and desertification regions in China and other developing countries. [ABSTRACT FROM AUTHOR]

The arid region in the northern part of China is a bridge between China and neighbouring countries in the Silk Road Economic Belt, and the severe desertification in this region restricts its sustainable development. In this paper, MODIS data, including albedo, reflectance, normalized vegetation index, and land surface temperature, were selected in 2000, 2005, 2010, and 2015 to construct a decision tree to extract spatio‐temporal information of the desertified land in the arid area. The trend in desertification and transfer directions was analysed by the GIS method, and the dynamic characteristics of the desertification at different units (provincial administrative unit and typical sandy land) and with different topographic factors (slope and aspect) are discussed. Our conclusions include (a) desertification in the arid region in the northern part of China showed improvement overall and local deterioration. The deteriorating areas were located primarily in the western region of the Hunshandake Sandy Land, the tectonic zone of the Taklimakan Desert, and the Qaidam Basin; (b) the degree of desertification transfer occurred primarily at adjacent levels; (c) the desertified area in each province showed a different trend in fluctuation, and Maowusu Sandy Land recovered better among the 4 large sands; and (d) the desertified area was distributed primarily along 0o–3o slopes and showed a rapid decline at increased slopes. The change in the degree of desertification in each aspect largely was a general reversal, and the area of the north aspect was larger than that of other areas of aspects. This study provides some theoretical support for the control of desertification in the Silk Road Economic Belt. [ABSTRACT FROM AUTHOR]

Abstract: Arid and semiarid China have experienced multiple arid phases throughout the Quaternary, and over the past five decades, there have been several periods with relatively high or low rates of desertification and rehabilitation. The causes of these changes and their historical trends have been debated by scientists because of their potentially huge significance for China, as well as for the global ecology and food supply. This paper reviews recent studies of desertification in different regions of arid and semiarid China. In general, the results of systematic monitoring, and analyses of the causes of desertification and the contemporaneous human impacts, suggest that desertification in China has been primarily caused by climate change, and particularly by strong wind regimes (with high sand transport potential) accompanied by decreased spring precipitation. Unfortunately, although numerous scientists have claimed that desertification in China is primarily due to human impacts; there is surprisingly little unassailable evidence to support this claim. The review presented in this paper show that desertification in China is likely to be controlled by climate change and geomorphological processes, even though human impacts have undeniably exacerbated their effects. Our arguments for both climate change and human activity as factors responsible for the observed changes in desertification rely primarily on inferences based on correlations between trends, thus future research must seek stronger and more direct evidence for the causal relationships that we have proposed as possibilities. This improved information is essential to provide a firm basis for future policy decisions on how best to combat desertification. [Copyright &y& Elsevier]

Desertification and salinization are both threats to the ecosystem services in inland river oases of arid regions. Previous studies focus on either desertification or salinization, and there is a lack of joint studies on the two issues. The essential cause of desertification in a transition zone is usually concentrated irrigation water use, which leads to shrink of the subsurface flow field of groundwater, decline of the groundwater level, and loss of groundwater supply to the vegetation. The salinization problem in an oasis area is mainly caused by the local excess groundwater in the oasis, referring to secondary salinization, which leads to salt migration with the groundwater level rise to form salt crystallization at the land surface. Thus, the processes of desertification and secondary salinization are connected, and the solutions to the two problems can be complementary, i.e., by transporting the excess groundwater in the local secondary salinization area to the transition zone area where water is scarce. This paper, taking Luocheng Irrigation District in the Heihe River Basin of northwestern China as an example, estimates 1.76–4.70 million m3 of excess groundwater that can be extracted in the salinized area. Using this amount of water through engineering regulation, it is estimated that the transition zone nearby the irrigation district, which is under desertification threat, can be restored with an area of 23–212 km2. An engineering system is designed for coordinated groundwater regulation and the implementation with an experimental farm in the irrigation district is demonstrated. • Providing a new method to mitigate salinization and desertification in arid areas through groundwater regulation. • Estimating the amount of drainage from salinized oasis area in an irrigation district and the transition zone area to be recovered from desert. • Designing an engineering system for coordinated groundwater regulation. [ABSTRACT FROM AUTHOR]

It has been widely accepted that high land use intensity contributes to sandy desertification in Northern China. However, it is surprising that it is even not easy to find an explicit definition and proper indicator for the term “land use intensity” in the sandy desertification related literatures. To better understand the association between sandy desertification and its driving factors, especially in the context of the synergistic roles of both climatic and anthropogenic variables, an indicator for land use intensity was developed in this paper for quantifying the relative role of land use output on different kinds of vegetation cover. The results indicated land use intensity increased rapidly from 1980 to 1995, obviously decreased from 1995 to 2000, and increased slowly after 2000 as a result of the continued increase of socioeconomic pressures and the fluctuating changes in vegetative cover. An ARDL model was established and applied to analyze the correlation between the area of bare sand land and land use intensity with the influence of annual precipitation in temporal dimension. The area of bare sand land was significantly affected by land use intensity in the long run. However, in the short run, the area of bare sand land was mainly impacted by the auto-correlation effect of itself in temporal dimension and by the annual precipitation. The improvement of the sand dunes obviously reduced the risk of sandy desertification under the condition of specific land use intensity. Before analyzing the correlation between land use intensity and sandy desertification, specific skills were applied to improve the model, including data interpolation and regression verification, since there would be regression biases resulting from the acquisition and processing of time-series data of different sources. Results showed that the area of bare sand land ( S t )and the land use intensity ( LI t ) were time-independent. Lag terms of these two variables were added to improve original model. Changes in socioeconomic pressures and ecological restoration projects had obvious influences on land use intensity. Along with the steady increase of socioecological pressures on land and the changes in vegetative cover resulting from various ecological protection strategies and ecological restoration projects, shifts in land use intensity followed a different trend with the population and the social-economic demands. Nonetheless, the continuous increase of socioeconomic demands will increase land use intensity in the long run, so that the risk of sandy desertification remains high. [ABSTRACT FROM AUTHOR]

Karst rocky desertification occurs after vegetation deteriorates as a result of intensive land use, which leads to severe water loss and soil erosion and exposes basement rocks, creating a rocky landscape. Karst rocky desertification is found in humid areas in southwest China, the region most seriously affected by rocky desertification in the world. In order to promote ecological restoration and help peasants out of poverty, the Chinese government carried out the first phase of a rocky desertification control project from 2006 to 2015, which initially contained the expansion of rocky desertification. Currently, the Chinese government is prepared to implement the second phase of the rocky desertification control project, and therefore it is essential to summarise the lessons learned over the last 10 years of the first phase. In this paper, we analyse the driving social and economic factors behind rocky desertification, summarise the scientific research on rocky desertification in the region, and finally identify the main problems facing rocky desertification control. In addition, we put forward several policy suggestions that take into account the perspective of local peasants, scientific research, and China's economic development and urbanisation process. These suggestions include promoting the non-agriculturalization of household livelihoods, improving ecological compensation, strengthening the evaluation of rocky desertification control and dynamic monitoring, and strengthening research on key ecological function recovery technologies and supporting technologies. [ABSTRACT FROM AUTHOR]

This paper is based on a case study in the Beipan River basin, which aims to assess the success of environmental initiatives in southwest China under the national Western Development Strategy. The research uses data searching, interviews and in situ observation. The results of erosion, Karst stony-desertification, reforestation and the water quality of the Beipan River reveal that the ecosystems in the basin were improved during 2000–2012. Geology, topography, hydrology, climate and human impacts will remain major challenges to the future ecological conservation and environmental protection. Future environmental development in the basin and southwest China will demand a long-term, holistic approach to overcome both natural and human impacts. [ABSTRACT FROM AUTHOR]

he thematic focus of this paper is to introduce a way to prevent desertification in the steppe climatic region by reducing wind velocity on ground surface and introducing a know-how of a specially designed driprrigation system that is sustainable in arid climate. he current desertification processes are rapidly expanding over the steppe climatic region worldwide, closely overlapping with Steppe Climatic Region (BS) of Koppen Climatic Classification. he basic thought in my study is to prevent desertification in the steppe climatic region by reducing wind velocity so that evaporation does not exceed precipitation. By applying Bernoulli' s equation for a one-kilometer-square pilot project in Fengning County, Hebei Province, China, it is estimated that four layers of tree windbreak in a square shape are sufficient to reduce wind velocity for the reforestation (Kim 2011). To avoid frequent failure of reforestation in the arid area owing to buildup of calcium layers and salt lat, a specially designed drip-irrigation system is introduced. Utilizing the favorable physical settings in the high altitude in arid area, a rotating solar power plant is planned to provide for pumping underground water for the drip irrigation. It is estimated that six kilowatts are sufficient power to support irrigation for a one-kilometer-square area, with a few dwelling units in the innermost 400-square-meter area. Once the Fengning pilot project is proven to be successful, it is hoped that the same system may be extended to the adjacent arid region and beyond. [ABSTRACT FROM AUTHOR]

The farming-pastoral region of North China is a region that has suffered from serious desertification, and the multiple transitional characteristics in this region make it very difficult to link the progress of desertification to the driving forces behind it. This paper mainly focuses on the dynamics of desertification over the past 10 years and their relationship to climate change and human activity. According to the MODIS images in 2000 and 2010, the farming-pastoral region had experienced significant desertification dynamics over the past 10 years. The area of regions that had undergone desertification reversion and expansion were 186,240 km 2 and 199,525 km 2 respectively, and the spatial distribution of these regions showed great heterogeneity. The relationship between desertification dynamics and their driving forces was investigated by comparing the change in the NPP that was induced by climate change and human activity for each pixel that experienced desertification reversion and expansion. From 2000 to 2010, the coupling of climate change and human activity was the dominant factor behind desertification reversion. However, the human activity was the dominant factor that controlled the desertification expansion process between 2000 and 2010. The driving processes of desertification also had considerable spatial heterogeneity, and the dominant factors behind desertification reversion and expansion in each sub-region were not completely the same. So, the scale effect must be considered when explaining the results from similar studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Quantifying the restoration progress of ecological quality. • Ecological quality showed an increasing trend with an interannual change of 2.46%. • The spatial aggregation effect of ecological quality levels gradually diminishes. • Agricultural land has the most significant impact on regional ecological quality. Human uncontrolled land use is the main cause of ecosystem degradation and increased rock desertification in karst areas of Southern China. Landscape ecological quality assessment (LEQA) based on land use plays a significant role in promoting sustainable ecological restoration in karst rocky desertification areas. This paper selects the karst plateau canyon rocky desertification comprehensive control demonstration area in South China as the research object to accurately quantify the impact of ecological management on landscape ecological quality changes (LEQ). Based on the characteristics of the karst ecological environment, the basic theory of spatial heterogeneity and landscape pattern is applied to evaluate the ecological quality of the study area at three levels: landscape stability, landscape disturbance degree, and ecological restoration and reconstruction ability. The results showed that the comprehensive score of regional ecological quality increased from 0.539 to 0.662 from 2015-2020. However, the ecological quality level of unused land and mining areas was still poor, and unsound production activities such as ore mining were the main hindrances to improvements in landscape ecological quality. Areas of better ecological quality were mainly distributed to the north and south of the study area. Treatment measures such as returning farmland to forest and agroforestry effectively improved the ecological environment quality of these areas, but the ecological benefits brought by the treatment in different areas varied significantly. The current analysis results show that the land use-based landscape ecological quality evaluation method is applicable in karst areas with special ecological environments. This work provides a new quantitative research method for the unique ecological environment in karst areas; it can accurately identify trends in ecological environment quality changes and provide a basis for sustainable ecological restoration. [ABSTRACT FROM AUTHOR]

[Display omitted] • SIF data that characterizes the growth of sandy vegetation is more sensitive. • SIF can well capture the changes in surface moisture and groundwater. • Vegetation growth has a strong correspondence with SM and a relatively weak correlation with TWS. • Vegetation growth in the late period of the mutation year is generally better than that in the early period. • Similarities and differences of vegetation-moisture relationship in four sandy lands. Hulunbuir, Otindag, Horqin and Mu Us are the four greater sandy lands in China. They are typical ecologically fragile areas with limited ability to resist interference and are susceptible to changes in the external environment. With climate change in recent decades, these areas have experienced severe land desertification and decreased groundwater levels. The ecological environment is at risk of further deterioration, and continuous vegetation restoration and management should be adapted to the local climate and maintain the water balance with natural precipitation. This paper combines multi-source satellite observations to explore the relationship between vegetation growth and water supply. The results show four main points. (1) Although the vegetation growth in Otindag and Horqin had degraded before 2010, it improved after 2010. The vegetation growth and soil moisture (SM) of the four sandy lands both generally increased from 2003 to 2016. The SM of the Horqin increased significantly (84% anomaly > 1.4 × 10−2 cm3/cm3). Other than the Hulunbuir, the other sandy lands show a downward trend in terrestrial water storage (TWS), especially the Mu Us declined the most (97% anomaly < −40 mm). (2) Solar-induced chlorophyll fluorescence (SIF) has specific advantages in characterizing the sandy vegetation productivity and water composition changes compared to vegetation index (EVI) or gross primary productivity (GPP). (3) The regional pattern of the vegetation-moisture relationship is mainly affected by the precipitation-driven SM and depends on the types of underlying vegetation functions. (4) Both SM and TWS have approximately one-month persistence in the four sandy lands, especially the Mu Us has the longest persistence (0.94 months and 1.1 months). The persistence in the early period is generally longer than that in the late period, implying that the resilience of water components after the mutation year is stronger than before it. This study provides a scientific basis for the management and restoration of sandy lands. It is recommended that different vegetation restoration and protection strategies should be developed for specific sandy land moisture conditions in arid/semi-arid regions of northern China, which includes the improvement of water use efficiency to maintain soil moisture and the reduction of excessive groundwater uses. [ABSTRACT FROM AUTHOR]

This paper is aimed to analyze the current situation and problems about use of various karst environments via filed survey, documentation and comparison methods, and to make reasonable recommendations about land use and management for different karst types in a bid to provide theoretical and practical basis for optimization of karst land use and the comprehensive control of karst rock desertification. The results show that, ① as the bare karst areas are lack of water and soil and highly prone to droughts and floods, land utilization in such areas should follow the principle of soil and water conservation and ecological restoration, emphasize both the ecological benefit and the economic benefit and reasonably configure the land resources to achieve the virtuous circle; ②in covered karst areas, the most important task is to take measures to prevent the appearance of secondary kast rock desertification, water exhaustion and karst collapse; ③ the buried karst areas shall mainly focus on prevention of overlaying sand shale collapse, and possible pollution of deep karst water and the surface land resulted from exploration and exploitation of oil and gas and geothermal water. ④ The final conclusion is that features and problems of land utilization of the three karst types are different from each other, and that the general principle for land use in karst regions shall be based on the local conditions. [ABSTRACT FROM AUTHOR]

The first successful sand-control was achieved in the Mu Us Desert by local people in the 1950–1960s, and their experience and approach have been extended to the whole Ordos and Northern China since then. The objective of this paper is to assess comprehensively the effectiveness of sand-control in 15 counties in and around Mu Us using multitemporal satellite images and socioeconomic data. After atmospheric correction, Landsat TM and OLI images were harnessed for land cover classification based on the ground-truth data and for derivation of the GDVI (generalized difference vegetation index) to extract the biophysical changes of the managed desert and desertification. Climatic, socioeconomic, environmental and spatial factors were selected for coupling analysis by multiple linear and logistic regression models to reveal the driving forces of desertification and their spatial determinants. The results show that from 1991 to 2020, 8712 km2 or 63% of the desert has been converted into pastures and shrublands with a greenness increase of 0.3509 in GDVI; the effectiveness of sand-control is favored by the rational agropastoral activities and policies; though desertification occurs locally, it is associated with both climatic and socioeconomic factors, such as wind speed, precipitation, water availability, distance to roads and animal husbandry. [ABSTRACT FROM AUTHOR]

Abstract: Efforts to control aeolian desertification in China have focused on the arid and semiarid regions. However, the direct dust emission rates, sediment characteristics and local-scale controls, as well as the measures needed to combat desertification, remain poorly understood in northwest Shanxi Province. Aeolian desertification is regarded as an obstacle to local sustainable socioeconomic development. This paper investigated changes in aeolian desertification between 1975 and 2010 on the northwestern Shanxi Plateau. In this study, remote sensing images were used to classify land suffering from aeolian desertification into four categories: light, moderate, severe, and extremely severe. To evaluate the evolution and status of aeolian desertification as well as its causes, we interpreted and analyzed Landsat multi-spectral scanner (MSS) image (acquired in 1975) and Landsat Thematic Mapper (TM) images (acquired in 1991, 2000, 2006, and 2010) as well as meteorological and socioeconomic data. Results revealed 11,866km2, 13,362km2, 14,051km2, 13,613km2, and 12,318km2 of aeolian desertified land (ADL) in the above 5 periods, respectively. The spatial dynamics and patterns showed two stages: expansion during 1975–2000 at a rate of 87.37km2 a−1, and spatial transfer of affected areas during 2000–2010 with a net decrease of 173.27km2 a−1. During the evolution of aeolian desertification, areas of moderate ADL had the greatest dynamic response (11.45%). The factors controlling ADL dynamics were analyzed from the perspectives of two groups of factors: natural factors and human activities. Our results indicated that the climate-dominated natural factors contribute greatly to the occurrence and development of ADL. However, they are not the fundamental causes of its development. The human factors are the primary and direct driving forces responsible for the increase in ADL area. More thorough quantitative analysis, with more frequent remotely sensed data is needed to assess the driving forces in more detail. [Copyright &y& Elsevier]

Abstract: Assessing the driving forces of sandy desertification is fundamental and important for its control. It has been widely accepted that both climatic conditions and land use have great impact on sandy desertification in northern China. However, the relative role and synergistic effect of each driving force of sandy desertification are still not clear. In this paper, an indicator named as SI was defined to represent the integrated probability of sandy desertification caused by land use. A quantitative method was developed for characterizing the relative roles of annual precipitation and land use to sandy desertification in both spatial and temporal dimensions at county level. Results showed that, at county level, land use was the main cause of sandy desertification for Naiman Banner since 1987–2009. In the case of spatial dimension, the different combination of land use types decided the distribution of sandy desertification probability and finally decided the spatial pattern of bared sand land. In the case of temporal dimension, the synergistic effect of land use and precipitation highly influenced the spatial distribution of sandy desertification. [Copyright &y& Elsevier]

Rocky desertification of karst in Southwest China has seriously influenced the normal life of local people. Soil erosion is the key process for inducing rocky desertification. This paper analyzes the stability and variation of shear strength under different of water contents of the brownish clay soil in carbonate rock area Chenqi of Puding in Guizhou province. Results show that the cracking of brownish clay soil aggregates occurs in the early soaked stage. The lower the initial water content of soil aggregates, the faster and more completely large particles disintegrate. Stability of soil aggregates is stronger with higher water content, but the entire shear strength decreases significantly; it will collapse entirely in the rainy season. Therefore, for desertification prevention and control in carbonate rock areas, greater attention should be given to effective protection measures during the rainy periods after long-term dry weather. The control during this period is essential in the whole process of desertification mitigation. [ABSTRACT FROM AUTHOR]

Abstract: Soil salinization is an important desertification process that threatens the stability of ecosystems, especially in arid lands. Quantifying and mapping soil salinity to monitor soil salinization is difficult because of its large spatial and temporal variability. There has been a growing interest in the use of hyperspectral reflectance as a rapid and inexpensive tool for soil salinity characterization in the recent past. However, as soil moisture often jointly affects soil reflectance, a moisture-insensitive reflectance model is needed to provide the base for soil salinity monitoring from soil reflectance. In this paper, we developed an exponent reflectance model to estimate soil salt contents inversely under various soil moisture conditions, based on a control laboratory experiment on the two factors (soil salinity and soil moisture) to soil reflectance. Main soil salt types (Na2SO4, NaCl, Na2CO3) with wide soil salinity (0% to 20%) and soil moisture (1.75% to 20%) levels (in weight base) from Western China were examined for their effects on soil reflectance through a model based approach. Moisture resistant but salt sensitive bands of reflected spectra have been identified for the model before being applied to inversely estimate soil salt content. Sensitive bands for Na2SO4 type of salt affected soils were identified as from 1920 to 2230nm, and 1970 to 2450nm for NaCl, 350 to 400nm for Na2CO3 type of salt affected soils, respectively. The sensitive bands focused on ranged from 1950 to 2450nm when all data were considered when ignoring salt types. The model was then applied to inversely estimate soil salt contents. High R2 of 0.87, 0.79, and 0.66, and low mean relative error (MRE) of 16.42%, 21.17%, and 27.16%; have been obtained for NaCl, Na2SO4 and Na2CO3, respectively. Performance of the inverse model dropped but remained significant when ignoring salt types with an R2 of 0.56 and a MRE of 33.25%. The approach proposed in this study should thus provide a new direction for estimating salinity from reflectance under various soil moisture conditions and should have wide applications in future monitoring of soil salinization. [Copyright &y& Elsevier]

It appears that two main factors hinder the effective incorporation of ecological information derived from computer modeling in resource management at large spatial scales: (1) some models are not ecologically sound and (2) most models based on ecological principles are often too sophisticated or detailed, having complex structures and requiring a large range of input data. This paper employs a generic model based on well-established ecological principles, but with appropriate detail, to better serve decision-making in sustainable resource management. The model was used to simulate aboveground net primary productivity (ANPP), foliage projective cover (FPC), and the evaporation coefficient (k) for large arid areas in northwest China, where there has been serious desertification recently. Observation data of ANPP and FPC in the study area were used to validate the model, and the model results were in good agreement with observation data and other published data. The model was then used to simulate the evaporation coefficient, FPC, and ANPP for the study area. The simulation results indicated that except for several sites, the k parameter was lower than 0.35 × 10-2 and implied a typical arid climate in the study area. Estimated FPC of the plant community was lower than 50% at most sites, and the annual ANPP was very low-less than 1 tons · ha-1 · yr-1 at 93.8% of sites. These simulation results could serve as references for vegetation restoration and livestock husbandry management in arid areas of China. [ABSTRACT FROM AUTHOR]

Abstract: Afforestation is a primary tool for controlling desertification and soil erosion in China. Large-scale afforestation, however, has complex and poorly understood consequences for the structure and composition of future ecosystems. Here, we discuss the potential links between China''s historical large-scale afforestation practices and the program''s effects on environmental restoration in arid and semi-arid regions in northern China based on a review of data from published papers, and offer recommendations to overcome the shortcomings of current environmental policy. Although afforestation is potentially an important approach for environmental restoration, current Chinese policy has not been tailored to local environmental conditions, leading to the use of inappropriate species and an overemphasis on tree and shrub planting, thereby compromising the ability to achieve environmental policy goals. China''s huge investment to increase forest cover seems likely to exacerbate environmental degradation in environmentally fragile areas because it has ignored climate, pedological, hydrological, and landscape factors that would make a site unsuitable for afforestation. This has, in many cases, led to the deterioration of soil ecosystems and decreased vegetation cover, and has exacerbated water shortages. Large-scale and long-term research is urgently needed to provide information that supports a more effective and flexible environmental restoration policy. [Copyright &y& Elsevier]

Abstract: Wind erosion near soil surface is one of the major causes of farmland degradation and desertification in arid and semiarid areas. Intercropping wheat and potato can effectively reduce wind erosion, soil desertification and degradation. In this paper, a quantitative research on effective resistance width to wind erosion for the wheat and potato intercropping farmland was performed using several 8-channel wind speed samplers and a movable wind tunnel. As can be seen from the test results, the effective width to control wind erosion for conventional tillage strips on wheat and potato intercropping farmland was lower than or equal to 5m as the wind speed at 2m height was 6–7m·s−1. Moreover, the effective width to control wind erosion of conservation tillage strips on wheat and potato intercropping farmland should be greater than or equal to 5.5m. Therefore, wheat and potato intercropping with suitable strip width is a cropping mode that not only protects farmland soil from wind erosion to the utmost but also satisfies the requirements of regional planting structure. [Copyright &y& Elsevier]

Use of the fallout radionuclide cesium-137 (137Cs) as a tracer has been widely employed for assessment of soil losses and dating of deposited sediment; however, few studies have been conducted in karst environments using this technique. In this study, the 137Cs technique was employed to assess sediment deposition rates in a depression in a small catchment of southwest China. Information derived from the 137Cs measurement of sediment samples collected from a depression in a small catchment in southwest China was used to estimate the sediment deposition rate since 1963, and the rate of soil erosion in the study catchment was also discussed. The results presented in this paper indicated that the depression acted as a sink of soils being eroded from the upland slopes. The mean sediment deposition rate and specific sediment yield of the study depression since 1963 were estimated to be 0.37 cm y-1 (0.15 in yr-1) and 50.2 t km-2 y-1 (0.184 tn ac-1 yr-1), respectively. Analysis of the topographic characteristics of the catchment revealed that the rate of soil redistribution of the catchment was very close to the sediment deposition rate of the depression because no significant sediment accumulation occurred upstream of the depression and in the meantime, very few sediments drained out through the sinkhole with the runoff. Therefore, it was inferred that the rate of soil redistribution in the study area was 55.8 t km-2 y-1 (0.205 tn ac-1 yr-1). Overall, the results revealed that there was a low background rate of soil loss in the karst mountain area suffering from severe land desertification in Southwest China. Furthermore, the results illuminated the potential for use of the 137Cs technique to evaluate the sediment deposition and soil erosion rates in karst areas of southwest China, where limited information regarding soil erosion and sedimentation exists. [ABSTRACT FROM AUTHOR]

This paper explores the relationship between vegetation in the Liangzhou Oasis in the Upper Shiyang River watershed (USRW) of west-central Gansu, China, and within-watershed precipitation, soil water storage, and oasis self-support. Oases along the base of the Qilian Mountains receive a significant portion of their water supply (over 90%) from surface and subsurface flow originating from the Qilian Mountains. Investigation of vegetation control on oasis water conditions in the USRW is based on an application of a process model of soil water hydrology. The model is used to simulate long-term soil water content (SWC) in the Liangzhou Oasis as a function of (i) monthly composites of Moderate Resolution Imaging Spectroradiometer (MODIS) images of land surface and mean air temperature, (ii) spatiotemporal calculations of monthly precipitation and relative humidity generated with the assistance of genetic algorithms (GAs), and (iii) a 80-m-resolution digital elevation model (DEM) of the area. Modeled removal of vegetation is shown to affect within-watershed precipitation and soil water storage by reducing the exchange of water vapor from the land surface to the air, increasing the air’s lifting condensation level by promoting drier air conditions, and causing the high-intensity precipitation band in the Qilian Mountains to weaken and to be displaced upward, leading to an overall reduction of water to the Liangzhou Oasis. [ABSTRACT FROM AUTHOR]

Abstract: The problem of historical desertification of the Mu Us desert, northern China has been paid considerable attention during the past several decades. Through the analysis of stratigraphic evidence, historical records and archaeological discoveries, this paper studied the problem using a multidisciplinary approach. The results show that two phases of serious desertification occurred during the last two millennia, one is during the mid-to-late Tang dynasty (about A.D. 800) and the other during the late Ming dynasty (about A.D. 1500–1600). Further investigation of the cause of each phase of desertification demonstrates that the former phase of desertification is closely related to abrupt climate change occurring in the mid-eighth century, but the latter, which started during the Ming dynasty and stopped at late 1980s, is not consistent with climatic causation. Therefore, we suggest that human activities contributed to the development of the latter phase of desertification. [Copyright &y& Elsevier]