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Using datasets on high-tech industries in Beijing as empirical studies, this paper attempts to interpret spatial shift of high-tech manufacturing firms and to examine the main determinants that have had the greatest effect on this spatial evolution. We aimed at merging these two aspects by using firm level databases in 1996 and 2010. To explain spatial change of the high-tech firms in Beijing, the Kernel density estimation method was used for hotspot analysis and detection by comparing their locations in 1996 and 2010, through which spatial features and their temporal changes could be approximately plotted. Furthermore, to provide quantitative results, Ripley's K-function was used as an instrument to reveal spatial shift and the dispersion distance of high-tech manufacturing firms in Beijing. By employing a negative binominal regression model, we evaluated the main determinants that have significantly affected the spatial evolution of high-tech manufacturing firms and compared differential influence of these locational factors on overall high-tech firms and each sub-sectors. The empirical analysis shows that high-tech industries in Beijing, in general, have evident agglomeration characteristics, and that the hotspot has shifted from the central city to suburban areas. In combination with the Ripley index, this study concludes that high-tech firms are now more scattered in metropolitan areas of Beijing as compared with 1996. The results of regression model indicate that the firms' locational decisions are significantly influenced by the spatial planning and regulation policies of the municipal government. In addition, market processes involving transportation accessibility and agglomeration economy have been found to be important in explaining the dynamics of locational variation of high-tech manufacturing firms in Beijing. Research into how markets and the government interact to determine the location of high-tech manufacturing production will be helpful for policymakers to enact effective policies toward a more efficient urban spatial structure. [ABSTRACT FROM AUTHOR]

The northeastern China, the United States, and the western Europe are important agricultural regions both on the global and regional scales. The western Europe has a longer history of agricultural land development than the eastern United States. These two regions have changed from the deforestation and reclamation phase in the past to the current land abandonment and reforestation phase. Compared with the two regions, large-scale land exploitation has only been practiced in the northeastern China during the last century. After a short high-intensity deforestation and reclamation period, agricultural and forest lands are basically in a dynamic steady state. By comparing domestic and international agro-forestry development and considering the ecological environment and socio-economic benefits that can be derived from agro-forestry, this paper suggests that large area of reforestation would be inevitable in future though persistent and large agricultural demand in coming decades even more. And local reforestation at slope farmland with ecological vulnerability should be imperative at present to avoid severer damage. At the same time, from the perspective of Land Change Science, the results demonstrate that the research on land use change in the agro-forestry ecotone is typical and critical, particularly those dealing with the analysis of spatial and temporal characteristics and the simulation of climate, hydrology, and other environmental effects. [ABSTRACT FROM AUTHOR]

Mechanism and modeling of the land subsidence are complex because of the complicate geological background in Beijing, China. This paper analyzed the spatial relationship between land subsidence and three factors, including the change of groundwater level, the thickness of compressible sediments and the building area by using remote sensing and GIS tools in the upper-middle part of alluvial-proluvial plain fan of the Chaobai River in Beijing. Based on the spatial analysis of the land subsidence and three factors, there exist significant non-linear relationship between the vertical displacement and three factors. The Back Propagation Neural Network (BPN) model combined with Genetic Algorithm (GA) was used to simulate regional distribution of the land subsidence. Results showed that at field scale, the groundwater level and land subsidence showed a significant linear relationship. However, at regional scale, the spatial distribution of groundwater depletion funnel did not overlap with the land subsidence funnel. As to the factor of compressible strata, the places with the biggest compressible strata thickness did not have the largest vertical displacement. The distributions of building area and land subsidence have no obvious spatial relationships. The BPN-GA model simulation results illustrated that the accuracy of the trained model during fifty years is acceptable with an error of 51% of verification data less than 20 mm and the average of the absolute error about 32 mm. The BPN model could be utilized to simulate the general distribution of land subsidence in the study area. Overall, this work contributes to better understand the complex relationship between the land subsidence and three influencing factors. And the distribution of the land subsidence can be simulated by the trained BPN-GA model with the limited available dada and acceptable accuracy. [ABSTRACT FROM AUTHOR]

In this paper, we proposed a framework for evaluating the performance of ecosystem strategies prepared for enhancing vulnerability reduction in the face of hazards due to climate change. The framework highlights the positive effects of human activities in the coupled human and natural system (CHANS) by introducing adaptive capacity as an evaluation criterion. A built-in regional vulnerability to a certain hazard was generated based upon interaction of three dimensions of vulnerability: exposure, sensitivity and adaptive capacity. We illustrated the application of this framework in the temperate farming-grazing transitional zone in the middle Inner Mongolia of the northern China, where drought hazard is the key threat to the CHANS. Specific indices were produced to translate such climate variance and social-economic differences into specific indicators. The results showed that the most exposed regions are the inner land areas, while counties located in the eastern part are potentially the most adaptive ones. Ordos City and Bayannur City are most frequently influenced by multiple climate variances, showing highest sensitivity. Analysis also indicated that differences in the ability to adapt to changes are the main causes of spatial differences. After depiction of the spatial differentiations and analysis of the reasons, climate zones were divided to depict the differences in facing to the drought threats. The climate zones were shown to be similar to vulnerability zones based on the quantitative structure of indexes drafted by a triangular map. Further analysis of the composition of the vulnerability index showed that the evaluation criteria were effective in validating the spatial differentiation but potentially ineffective because of their limited time scope. This research will be a demonstration of how to combine the three dimensions by quantitative methods and will thus provide a guide for government to vulnerability reduction management. [ABSTRACT FROM AUTHOR]

Microorganisms are nutritious resources for various soil fauna. Although soil fauna grazing affects microorganism composition and decomposition rate, the responses of soil fauna and leaf litter decomposition to added microorganism is little understood. In this study, in the coniferous and broad-leaved mixed forest of Tahe County in the northern Da Hinggan Mountains, China, three sampling sites (each has an area of 10 m) were selected. The first two sites were sprinkled with 250 times (EM1) and 1000 times (EM2) diluted effective microorganism (EM) preparations evenly, and the third site was sprinkled with the same volume of water as a control site. The responses of soil fauna structure and leaf litter decomposition to EM treatment were conducted during three years. The results revealed that EM treatment resulted in significant increase of soil organic matter. The number of soil fauna in the EM1 and EM2 sites increased by 12.88% and 2.23% compared to the control site, and among them springtails and mites showed the highest increase. However, the groups of soil fauna in the EM1 and EM2 sites decreased by 6 and 9, respectively. And the changes in the diversity and evenness index were relatively complicated. EM treatment slowed the decomposition of broad-leaved litter, but accelerated the decomposition of coniferous litter. However, the decomposition rate of broad-leaved litter was still higher than that of coniferous litter. The results of this study suggested that the added microorganisms could help individual growth of soil fauna, and this method led to a change in the process of leaf litter decomposition. This paper did not analyze the activity of soil microorganisms, thus it is difficult to clearly explain the complex relationships among litter type, soil fauna and soil microorganisms. Further research on this subject is needed. [ABSTRACT FROM AUTHOR]

The studies on environmental effects of foreign trade and its spatial variations are helpful to design and implement environmental protection countermeasures. In order to eliminate the adverse effects of insufficient observation values on the accuracy of regression results and dynamic information quantity of fitting equation during empirical study, panel data of the mid-eastern provinces and cities of China from 1985 to 2007 were selected based on the adjustment of classical regression model in this paper. Panel unit root test and panel cointegration analysis method were applied to investigating the environmental effects of foreign trade and its spatial variations in the mid-eastern provinces and cities of China and its three groups divided by foreign trade dependence. The results show that all scale effects are positive, while all technical effects are negative and unable to counteract positive scale effects. Foreign trade development is regarded as an important cause for outstanding eco-environmental problems in the mid-eastern provinces and cities of China. Total effects and structural effects are significantly different among different groups because of spatial variations in environmental policies, export destinations, source of FDI, etc. Following the principle of 'coordinating generality and considering differences comprehensively', it is essential to issue a series of policies and countermeasures corresponding to differences in regional environmental effect of foreign trade, in order to coordinate the relationship between foreign trade development and eco-environment in each region. [ABSTRACT FROM AUTHOR]

This paper principally focuses on land use dynamics, urban expansion and underlying driving forces in the Natural Wetland Distribution Area (NWDA) of Fuzhou City in the southeastern China. Based on time series Landsat TM/ETM+ imageries and historical data, relationships between urban land expansion and its influencing factors from 1989 to 2009 were analyzed by using an integrated approach of remote sensing (RS) and geographic information system (GIS) techniques. The results showed that built-up land increased from 151.16 km in 1989 to 383.76 km in 2009. Approximately 64.25% of the newly emerging built-up land was converted from cropland (29.47%), forest and shrub (25.78%), water (3.73%), wetland (4.61%), and bare land (0.66%) during 1989 and 2009. With a remarkable decrease in cropland, the proportion of non-agricultural population increased by 23.6%. Moreover, rapid development of infrastructures, facilities, industrial parks, and urban and rural settlements along the Minjiang River resulted in the eastward and southward expansion of built-up land. Additionally, the growth pattern of built-up land in the NWDA is highly correlated with socio-economic factors, including the gross domestic product (GDP), GDP per capita, and structure of industry. As a result, the observed environmental degradation such as loss of cropland and wetland due to heavy pressure of rapid urbanization have greatly impaired the carrying capacity of city. Thus, in addition to scientific and rational policies towards minimizing the adverse effects of urbanization, coordination between the administrative agencies should be urgently strengthened to balance the conflicts between urban development and ecological conservation to make sure the sustainable land use. [ABSTRACT FROM AUTHOR]

China is entering a critical and accelerating phase of urbanization. As one of the most urbanized regions in China, the Changjiang (Yangtze) River Delta has experienced dramatic urbanization and urban transformation. However, in the recent years, many changes have taken place in this region and there is limited attention to the regional urbanization path evolution, its problems and the way to solve these problems. Therefore, we should revisit the urbanization process in the Changjiang River Delta again. In this paper, we revisited urbanization paths of the Changjiang River Delta by data analysis, influence factors of urbanization by the Gray Relational Analysis, and major challenges to urbanization of the Changjiang River Delta by theoretical considerations. We found that the urbanization of the Changjiang River Delta had experienced several stages of large-scale spatial and urban system restructuring. Within the Changjiang River Delta, Shanghai, Zhejiang and Jiangshu had experienced different urbanization path with local characteristics. But with their development model gradually converging, their urbanization model is also converging. We also found that the major influence factors affecting the Changjiang River Delta urbanization were dynamic change and urbanization was driven by different key factors in different socio-economic development stages. Meanwhile, the Changjiang River Delta urbanization is facing many problems such as existing institutional arrangements, including the hukou (household registration) system and others which can not meet the needs of current socio-economic development and urbanization. Therefore, it is imperative to promote institutional innovation and adopt a new urbanization development strategy for the sake of the orderly and sustainable urbanization development in the Changjiang River Delta. [ABSTRACT FROM AUTHOR]

Three-River Headwaters (TRH) region involved in this paper refers to the source region of the Changjiang (Yangtze) River, the Huanghe (Yellow) River and the Lancang River in China. Taking the TRH region of the Qinghai-Tibet Plateau as a case, the annual evapotranspiration (ET) model developed by Zhang et al. (2001) was applied to evaluate mean annual ET in the alpine area, and the response of annual ET to land use change was analyzed. The plant-available water coefficient ( w) of Zhang's model was revised by using vegetation-temperature condition index (VTCI) before annual ET was calculated in alpine area. The future land use scenario, an input of ET model, was spatially simulated by using the conversion of land use and its effects at small regional extent (CLUE-S) to study the response of ET to land use change. Results show that the relative errors between the simulated ET and that calculated by using water balance equation were 3.81% and the index of agreement was 0.69. This indicates that Zhang's ET model based on revised plant-available water coefficient is a scientific and practical tool to estimate the annual ET in the alpine area. The annual ET in 2000 in the study area was 221.2 mm, 11.6 mm more than that in 1980. Average annual ET decreased from southeast to northwest, but the change of annual ET between 1980 and 2000 increased from southeast to northwest. As a vast and sparsely populated area, the population in the TRH region was extremely unbalanced and land use change was concentrated in very small regions. Thus, land use change had little effect on total annual ET in the study area but a great impact on its spatial distribution, and the effect of land use change on ET decreased with increasing precipitation. ET was most sensitive to the interconversion between forest and unused land, and was least sensitive to the interconversion between cropland and low-covered grassland. [ABSTRACT FROM AUTHOR]

Hong Kong has undergone substantial economic transformations and developed into a sophisticated business and financial center in the Asia-Pacific region, since the return of sovereignty to China as a Special Administrative Region under the One Country Two Systems (OCTS) in 1997. This paper discusses and analyzes the industrial structural changes of Hong Kong in recent decades as well as its future challenges and opportunities. The data and finding reveal that even though Hong Kong will face fierce competition from the Mainland's cities as the rise of China, the important role as a bridge between China and the rest of the world will brace Hong Kong itself under the OCTS for developing into a service hub for business and trade in the Asia-Pacific region. [ABSTRACT FROM AUTHOR]

The global economic downturn caused primarily by the US sub-prime mortgage crisis in 2007 engendered revenue loss of the multinational corporations. Existing studies have yet to depict the detrimental impacts on city's command and control functions induced by the sub-prime mortgage crisis together with its residual wave of global economic recession on the global spatial economy. Recent and previous studies have produced an 'instant history' of the global spatial economy before the global economic downturn undermines the global economy in late 2008. However, the waxes and wanes of major cities' command and control functions on the global economic arena before and after the outbreak of financial crisis and its associated geo-economic transitions are still poorly understood. This paper attempts to contribute a new set of customized data to update and fill in the gap in the literature with the investigation of the command and control functions of cities around the world from 2005 to 2009. Particular attentions are paid to the time-space relationship of the geo-economic transition that can capture the recent historical images of the command and control situation of different cities in the world. [ABSTRACT FROM AUTHOR]

Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA), this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Basin, which is situated in the easternmost end of the Tianshan Mountains, Xinjiang Uygur Autonomous Region, China. For the zonal vegetation, community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors. The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude, soil pH and soil salt content. With increasing elevation, the soil pH and total salt content decrease but the contents of soil organic matter, soil water, total nitrogen and total phosphorus increase gradually. In the CCA ordination diagrams, the sample plots and main species can be divided into five types according to their adaptations to the environmental factors. Type I is composed of desert vegetation distributed on the low mountains, hills, plains and deserts below an elevation of 1900 m; type II is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m, and includes steppe desert, desert steppe and wetland meadow; type III is very simply composed of only salinized meadow; type IV is distributed above an elevation of 2300 m, containing mountain steppe, meadow steppe, subalpine meadow and alpine meadow; type V only contains salinized meadow. The results show that with increasing elevation, species combination changes from the xerophytic shrubs, semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate. [ABSTRACT FROM AUTHOR]

Spatial heterogeneity is widely used in diverse applications, such as recognizing ecological process, guiding ecological restoration, managing land use, etc. Many researches have focused on the inherent scale multiplicity of spatial heterogeneity by using various environmental variables. How these variables affect their corresponding spatial heterogeneities, however, have received little attention. In this paper, we examined the effects of characteristics of normalized difference vegetation index (NDVI) and its related bands variable images, namely red and near infrared (NIR), on their corresponding spatial heterogeneity detection based on variogram models. In a coastal wetland region, two groups of study sites with distinct fractal vegetation cover were tested and analyzed. The results show that: 1) in high fractal vegetation cover (H-FVC) area, NDVI and NIR variables display a similar ability in detecting the spatial heterogeneity caused by vegetation growing status structure; 2) in low fractal vegetation cover (L-FVC) area, the NIR and red variables outperform NDVI in the survey of soil spatial heterogeneity; and 3) generally, NIR variable is ubiquitously applicable for vegetation spatial heterogeneity investigation in different fractal vegetation covers. Moreover, as variable selection for remote sensing applications should fully take the characteristics of variables and the study object into account, the proposed variogram analysis method can make the variable selection objectively and scientifically, especially in studies related to spatial heterogeneity using remotely sensed data. [ABSTRACT FROM AUTHOR]

Different types of vegetation occupy different geomorphology and water gradient environments in the Sanjiang Plain, indicating that the soil moisture dynamics and water balance patterns of the different vegetation communities might differ from each other. In this paper, a lowland system, perpendicular to the Nongjiang River in the Honghe National Nature Reserve (HNNR), was selected as the study area. The area was occupied by the non-wetland plant forest and the typical wetland plant meadow. The Microsoft Windows-based finite element analysis software package for simulating water, heat, and solute transport in variably saturated porous media (HYDRUS), which can quantitatively simulate water, heat, and/or solute movement in variably-saturated porous media, was used to simulate soil moisture dynamics in the root zone (20-40 cm) of those two plant communities during the growing season in 2005. The simulation results for soil moisture were in a good agreement with measured data, with the coefficient of determination ( R) of 0.44-0.69 and root mean square error (RMSE) ranging between 0.0291 cm/cm and 0.0457 cm/cm, and index of agreement ( d) being from 0.612 to 0.968. During the study period, the volumetric soil moisture content of meadow increased with the depth and its coefficient of variation decreased with the depth (from 20 cm to 40 cm), while under the forest the soil moisture content at different depths varied irregularly. The calculated result of water budget showed that the water budget deficit of the meadow was higher than that of the forest, suggesting that the meadow is more likely to suffer from water stress than the forest. The quantitative simulation by HYDRUS in this study did not take surface runoff and plant growth processes into account. Improved root water uptake and surface runoff models will be needed for higher accuracy in further researches. [ABSTRACT FROM AUTHOR]

Spectral remote sensing technique is usually used to monitor flood and waterlogging disaster. Although spectral remote sensing data have many advantages for ground information observation, such as real time and high spatial resolution, they are often interfered by clouds, haze and rain. As a result, it is very difficult to retrieve ground information from spectral remote sensing data under those conditions. Compared with spectral remote sensing technique, passive microwave remote sensing technique has obvious superiority in most weather conditions. However, the main drawback of passive microwave remote sensing is the extreme low spatial resolution. Considering the wide application of the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) data, an AMSR-E data unmixing method was proposed in this paper based on Bellerby's algorithm. By utilizing the surface type classification results with high spatial resolution, the proposed unmixing method can obtain the component brightness temperature and corresponding spatial position distribution, which effectively improve the spatial resolution of passive microwave remote sensing data. Through researching the AMSR-E unmixed data of Yongji County, Jilin Provinc, Northeast China after the worst flood and waterlogging disaster occurred on July 28, 2010, the experimental results demonstrated that the AMSR-E unmixed data could effectively evaluate the flood and waterlogging disaster. [ABSTRACT FROM AUTHOR]

Food safety and its related influencing factors in China are the hot research topics currently, and cultivated land conversion is one of the significant factors influencing food safety in China. Taking the North China Plain as the study area, this paper examines the changes of cultivated land area using satellite images, estimates land productivity from 1985 to 2005 using the model of Estimation System for Land Productivity (ESLP), and analyzes the impact of cultivated land conversion on the land production. Compared with the grain yield data from statistical yearbooks, the results indicate that ESLP model is an effective tool for estimating land productivity. Land productivity in the North China Plain showed a slight decreasing trend from 1985 to 2005, spatially, increased from the north to the south gradually, and the net changes varied in different areas. Cultivated land area recorded a marginal decrease of 8.0 × 10 ha, mainly converted to other land uses. Cultivated land conversion had more significant negative impacts on land production than land productivity did. Land production decreased by about 6.48 × 10 t caused by cultivated land conversion between 1985 and 2005, accounting for 91.9% of the total land production reduction. Although the land productivity increased in Anhui and Jiangsu provinces, it can not offset the overall adverse effects caused by cultivated land conversion. Therefore, there are significant meanings to control the cultivated land conversion and improve the land productivity for ensuring the land production in the North China Plain. [ABSTRACT FROM AUTHOR]

Comprehending regional characteristics and influencing factors of China's inbound tourism economy is important to make effective policies that will help inbound tourism develop harmoniously and shrink regional disparity. This paper studied the regional disparity and convergence of China's inbound tourism economy during 1996-2008 with the methods of σ-convergence, club convergence and β-convergence. The results indicate that 1) inbound tourism receipts per capita (ITRPC) of the whole country, the eastern, central and western regions presented the rapid increasing trend; 2) ITRPC of the whole country was characterized by convergence; 3) the eastern region presented club convergence, but the central and western regions did not show this trend; 4) the star-hotel levels and investment in fixed assets for the tourism industry per capita had a same trend to growth rates of ITRPC, promoting inbound tourism development, and there was no difference among the 31 provinces (municipalities) in the mainland of China; 5) but the proportion of employed persons in the tourism industry accounting for total population and the proportion of the tertiary industry accounting for GDP had a reversal trend to growth rates of ITRPC, shrinking the provincial disparity in inbound tourism economy, and there were differences between the developed provinces and the developing provinces. Based on these analyses, we put forward some suggestions for the developing provinces to speed up inbound tourism economy. [ABSTRACT FROM AUTHOR]

The responses of spatiotemporal variation of ecosystem service values (ESVs) to landscape pattern from 1985 to 2005 in a typical Karst area of the northwest Guangxi Zhuang Autonomous Region, China, were examined using remote sensing and geographic information system techniques in this paper. The total ecosystem service values declined significantly from 1985 to 1990, and then increased slowly from 1990 to 2005, almost equaled to the 1985 level. The ecosystem service values tended to decline from the west to the east and from mountainous regions to peak-cluster depression areas in 1985, 1990, 2000 and 2005 respectively. During the period from 1985 to 2005, the ecosystem service values have increased in the middle and eastern parts of the study area. Landscape pattern indices, such as total area, largest patch index, contagion, aggregative index, effective mesh and proportion of like adjacencies, are significantly correlated with ecosystem service values. This suggests that ecosystem service values tend to increase with the growth of patch area and patch connectivity. However, there are negative correlations between ecosystem service values and landscape pattern indices, such as division index and patch richness. It indicates that ecosystem service values decrease with patch fragmentation and patch size shrinkage. The ecosystem conditions in the typical Karst area have been improved because of the control measures of rocky desertification. It is important to protect key landscape types, such as woodland, shrub and grassland, and to increase patch size and connectivity to avoid further fragmentation. Furthermore, it is necessary to reduce disturbances to ensure the growth of ecosystem service values and to facilitate the sustainable development in this region. [ABSTRACT FROM AUTHOR]

Urban agglomeration (UA) is an advanced spatial economic form formed and developed in the process of rapid industrialization and urbanization, and an important carrier of urbanization and economic development. The economy has developed rapidly in the recent decades of China, and the UAs have also developed rapidly. However, as a large population country, the population distribution and changes of UAs in China has unique characteristics. Using the fifth, sixth and seventh population census data, spatial auto-correlation and spatial econometric models, we analyzed the spatial-temporal evolution characteristics and influencing factors of population agglomeration in China's UAs. Results revealed that: 1) from 2000 to 2020, the population gradually converged into UAs, and the characteristics of population agglomeration in different development degree of UAs differ. The higher the development degree of UA, the higher the population agglomeration degree. Besides, UAs are the main area with the most significant population agglomeration degree, and the spatial autocorrelation show that the cities with similar degree tend to be concentrated in space. The urban population gathering in UAs has a certain positive spillover effect on population size of neighboring cities. 2) Economic development and social conditions factors are important factors affecting population agglomeration degree in UAs. The main factors of population gather into UAs are similar with the outside UAs, but the positive promotion of urbanization rate and proportion of tertiary industry in GDP on population agglomeration of UAs in China are enhancing from 2000 to 2020. Meanwhile, the other factors, such as high-quality public services, good urban living environment conditions, high-quality medical and educational resources, are also important factors to promote urban population gather into UAs. This study provides a basis for formulating the development planning of UAs in China, and enriches the relevant theoretical research of population evolution and influencing factors of UAs. [ABSTRACT FROM AUTHOR]

As the population continues to shrink in the black soil region of Northeast China since 2000, it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainable development. In this study, we focused on the impacts of depopulation on the evolution and interrelationship of rural subfunctions. Based on the rural function indexes system, the TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) method, spatial analysis method, and mathematical statistics analysis method were used to summarize the spatial and temporal characteristics of rural function development, as well as the effect of population shrinkage in the typical black soil region of Northeast China. The results showed that depopulation varied in the extent and duration between the forested region and plain areas, which both impacted the trajectories of rural subfunctions evolution. For the economic development function and ecological conservation function, the effect of continuous slight depopulation was beneficial, while the effect of rapid depopulation was adverse, which was exactly opposite to the agricultural production function. All forms of population shrinkage were conducive to the development of the social security function. With the deepening population shrinkage, depopulation mainly promoted the collaborative development between subfunctions in this study, except the relationship between agricultural production and social security function. But effects of depopulation on the interrelationship of rural subfunctions varied between the forested region and plain areas in some cases. The results provided evidence for the cognition that population shrinkage had complicated effects on rural subfunctions. [ABSTRACT FROM AUTHOR]

Cultivated land is an important natural resource to ensure food, ecological and economic security. The cultivated land quality evaluation (CQE) is greatly significant for protecting and managing cultivated land. In this study, 320 counties in the black soil region of Northeast China (BSRNC) represent the research units used to construct the CQE system measuring the soil properties (SP), cultivated land productivity (CLP), ecological environment (EE) and social economy (SE). The total of 19 factors were selected to calculate the integrated fertility index (IFI) and divided into grades. Simultaneously, we used the coupling coordination degree model to comprehensively analyze the spatial pattern of the cultivated land quality (CLQ) in the BSRNC, and use the structural equation model (SEM) to analyze the driving mechanism. The results show the following: 1) The CLQ of 262 counties in the BSRNC is in a state of coupling and coordination, and the coupling and coordination degree presents a spatial distribution pattern of 'high in the southwest and northeast, low in the northwest and southeast'. The coordinated development degree of 271 counties is between 0.4 and 0.6, which is in a transitional state between coordination and disorder. 2) The CLQ in the BSRNC is generally good, with an average grade of 3. High-quality cultivated land accounts for 58.45% of all counties, middle- and upper-quality cultivated land accounts for 27.05%, and poor-quality cultivated land accounts for 14.49%. 3) The SEM analysis shows that the SP, CLP, EE, and SE all influence the CLQ. Among them, the SP has the largest driving force on the CLQ, while the SE has the smallest driving force on it. The results confirm that the main factors affecting the evaluation results are crop productivity level, normalized difference vegetation index, ratio vegetation index, difference vegetation index, and organic carbon content. When implementing protection measures in counties with a low CLQ, considering a balanced coordination of multiple systems and reasonably controlling the quality degradation are important. This study provides the current situation and driving factors of the CLQ in the BSRNC and will play an important role in black soil governance and utilization. [ABSTRACT FROM AUTHOR]

The coordinated development of Beijing, Tianjin and Hebei has been elevated as China's important strategy. And, the priority in considering how to bring the maximum effect of their coordinated development into play is to delineate the spheres of urban influence with regard to the cities in the Beijing-Tianjin-Hebei Metropolitan Region. By building an evaluation index system of urban comprehensive strength, this paper applies the principal component analysis method to determine centrality strength of the cities, and the breakpoint theory and weighted Voronoi diagram to identify the spheres of urban influence in all central cities of the region. Results show that 13 central cities within the region greatly differ in strength, which can be classified into four tiers and that the spheres of urban influence do not have a high goodness of fit with administrative jurisdiction scope. Cities like Beijing, Tianjin, Shijiazhuang and Handan have larger spheres of urban, spheres of urban influence in Tangshan and Qinhuangdao are basically consistent with their administrative jurisdiction scopes, and seven cities including Langfang and Baoding have smaller spheres of urban influence. So according to these cities' comprehensive strength and spheres of influence, the region can be divided into five plates: Beijing, Tianjin, Shijiazhuang, Tangshan and Handan. The major influence factors for inconsistency between spheres of urban influence and spheres of jurisdiction include difference in urban administrative ranking, small number of central cities with weak strength, discrepancy in the number of counties under jurisdiction, unreasonable spheres of jurisdiction and diversity in topographical conditions. In order to solve the imbalance in the spheres of urban influence and those of jurisdiction and better facilitate the coordinated development of the region, it is advised to adjust administrative areas so as to obtain more optimized urban spatial layout and more reasonable urban scale hierarchy system. [ABSTRACT FROM AUTHOR]

Cultivated land pressure represents a direct reflection of grain security. Existing relevant studies rarely approached the spatiotemporal pattern of cultivated land pressure or the spatial heterogeneity of its influencing factors from the level of economic zones. Taking the Huaihai Economic Zone (HEZ), China for case analysis, this study investigated the spatiotemporal pattern of cultivated land pressure in diverse periods from 2000 to 2018 based on a modified cultivated land pressure index and spatial correlation models. On this basis, it explored the influencing factors of the spatial differentiation of cultivated land pressure in the late stage of the study using geographical detector as well as multi-scale geographically weighted regression model. The results indicated that: 1) in the study period, the global cultivated land pressure index of the study area decreased gradually, but cultivated land pressure increased locally in a significant way, especially in the central and southern Shandong Province; 2) the spatial pattern of cultivated land pressure manifested global clustering features. Hot and secondary-hot spots presented a narrowing and clustering trend, whereas cold and secondary-cold spots manifested a spreading and clustering trend; 3) average slope, the proportion of non-grain crops, population urbanization rate, and multiple cropping index have significant effects on the spatial differentiation of cultivated land pressure. The former three factors were positively correlated with cultivated land pressure, and the last factor was negatively correlated with cultivated land pressure; and 4) the amount of cultivated land has increased in the central and southern Shandong Province through land consolidation which, nonetheless, failed to improve the grain production. In regards to major grain producing areas similar to the HEZ in China, the authors suggest that great importance should be given to the balance of the quality and quantity of cultivated land, the optimization of agricultural production factors and the rational control of non-grain crops, thus providing a powerful guarantee for grain security in China. [ABSTRACT FROM AUTHOR]

Mastering the pattern of food loss caused by droughts and floods aids in planning the layout of agricultural production, determining the scale of drought and flood control projects, and reducing food loss. The Standardized Precipitation Evapotranspiration Index is calculated using monthly meteorological data from 1984 to 2020 in Shandong Province of China and is used to identify the province's drought and flood characteristics. Then, food losses due to droughts and floods are estimated separately from disaster loss data. Finally, the relationship between drought/flood-related factors and food losses is quantified using methods such as the Pearson correlation coefficient and linear regression. The results show that: 1) there is a trend of aridity in Shandong Province, and the drought characteristic variables are increasing yearly while flood duration and severity are decreasing. 2) The food losses caused by droughts in Shandong Province are more than those caused by floods, and the area where droughts and floods occur frequently is located in Linyi City. 3) The impact of precipitation on food loss due to drought/flood is significant, followed by potential evapotranspiration and temperature. 4) The relationship between drought and flood conditions and food losses can be precisely quantified. The accumulated drought duration of one month led to 1.939 × 104 t of grain loss, and an increase in cumulative flood duration of one month resulted in 1.134 × 104 t of grain loss. If the cumulative drought severity and average drought peak increased by one unit, food loss due to drought will increase by 1.562 × 104 t and 1.511 × 106 t, respectively. If the cumulative flood severity and average flood peak increase by one unit, food loss will increase by 8.470 × 103 t and 1.034 × 106 t, respectively. [ABSTRACT FROM AUTHOR]

The extant literature on international immigrants has discussed migrants' entrepreneurial activities in the context of Western countries but has paid little attention to return-home entrepreneurial intention (RHEI). Rural migrant workers (RMWs) in China, who used to promote rural development by remittances and were characterized by similarities with early international migrants, have gradually returned to their hometowns to initiate entrepreneurial activities. Based on the structured questionnaire conducted in 2015 and 2020 in Anhui Province, China, this article combines the concept of mixed embeddedness with the idea of double-layered embeddedness and analyzes the impacts of the social, economic and institutional context in RMWs' hometowns and migration destinations on RMWs' RHEI by using binary logistic regression. The article shows that the social, economic, and institutional environments of RMWs' hometowns and migration destinations have effects on their RHEI. The embeddedness in the economic and informal institutional context in RMWs' RHEI is even more important than personal characteristics. Compared with migration destinations, RMWs' hometowns exert a more influential effect on their RHEI. However, that does not mean that the role of migration destinations can be undervalued. Actually, the better the social, economic, and institutional environments of migration destinations RMWs moved into is, the higher entrepreneurial intention they will have after returning to their hometowns. The article proposes a modified framework in combination of mixed embeddedness with double-layer embeddedness and proves that it is suitable for analyzing RMWs' RHEI. The framework has important implications for strengthening China's RMWs to return home to start their own businesses. [ABSTRACT FROM AUTHOR]

Wetland databases can provide the basic data that necessary for the protection and management of wetlands. A large number of wetland databases have been established in the world as well as in China. In this paper, we review China's wetland databases based on remote sensing (RS) technology after introducing the background theory to the application of RS technology in wetland surveys. A key conclusion is that China's wetland databases are far from sufficient in fulfilling protection and management needs. Our recommendations focus on the use of the hyper-spectral imagery, microwave data, multi-temporal images, and automatic classifications in order to improve the accuracy and efficiency of wetland inventory. Further, attention should also be paid to detect major biophysical features of wetlands and build wetland databases in years after the 1980s in China. Considering that great gap exists between RS experts and wetland experts, further cooperation between wetland scientists and RS scientists are needed to promote the application of RS in the foundation of wetland databases. [ABSTRACT FROM AUTHOR]

Analyzing spatiotemporal dynamics of land use and land cover over time is widely recognized as important to better understand and provide solutions for social, economic, and environmental problems, especially in ecologically fragile region. In this paper, a case study was taken in Zhenlai County, which is a part of farming-pastoral ecotone of Northeast China. This study seeks to use multi-temporal satellite images and other data from various sources to analyze spatiotemporal changes from 1932 to 2005, and applied a quantitative methodology named intensity analysis in the time scale of decades at three levels: time interval, category, and transition. The findings of the case study are as follows: 1) the interval level of intensity analysis revealed that the annual rate of overall change was relatively fast in 1932-1954 and 1954-1976 time intervals. 2) The category level showed that arable land experienced less intensively gains and losses if the overall change was to have been distributed uniformly across the landscape while the gains and losses of forest land, grassland, water, settlement, wetland and other unused land were not consistent and stationary across the four time intervals. 3) The transition level illustrated that arable land expanded at the expense of grassland before 2000 while it gained intensively from wetland from 2000 to 2005. Settlement targets arable land and avoids grassland, water, wetland and other unused land. Besides, the loss of grassland was intensively targeted by arable land, forest land and wetland in the study period while the loss of wetland was targeted by water except for the time interval of 1976-2000. 4) During the early reclamation period, land use change of the study area was mainly affected by the policy, institutional and political factors, followed by the natural disasters. [ABSTRACT FROM AUTHOR]

Association rule mining methods, as a set of important data mining tools, could be used for mining spatial association rules of spatial data. However, applications of these methods are limited for mining results containing large number of redundant rules. In this paper, a new method named Geo-Filtered Association Rules Mining (GFARM) is proposed to effectively eliminate the redundant rules. An application of GFARM is performed as a case study in which association rules are discovered between building land distribution and potential driving factors in Wuhan, China from 1995 to 2015. Ten sets of regular sampling grids with different sizes are used for detecting the influence of multi-scales on GFARM. Results show that the proposed method can filter 50%-70% of redundant rules. GFARM is also successful in discovering spatial association pattern between building land distribution and driving factors. [ABSTRACT FROM AUTHOR]

Quality of life (QOL) is a hotspot issue that has attracted increasing attention from the Chinese Government and scholars, it is also a vital issue that should be addressed during the cause of ′establishing overall well-off society′. Northeast China is one of the most import old industrial bases in China, however, the industrial structure of heavy chemical industry and the development mode of ′production first, living last′ have leaded to series of social problems, which have also become a serious bottleneck to social stability and economic sustainable development. Through applying the methods of BP neural network, exploratory spatial data analysis (ESDA) and spatial regression model, this paper examines the space-time dynamics of QOL of the residents in Northeast China. We first investigate the indexes of QOL of the residents and then use ESDA methods to visualize its space-time relationship. We have found a spatial agglomeration of QOL of the residents in middle-southern Liaoning Province, central Jilin Province and Harbin-Qiqihar-Daqing area of Heilongjiang Province. Two third of the counties are low-low spatial correlation, and the correlative type of about 60% of the prefecture level areas keeps stable, indicating QOL of the residents in Northeast China shows a certain character of path dependence or spatial locked. We have also found that economic strength and development levels of service industry have positive and obvious effect on QOL of the residents, while the effect of such indexes as the social service level and the proportion of the tertiary industries are less. [ABSTRACT FROM AUTHOR]

As a traditional agricultural country, China has always prioritized agricultural development, and has increasingly focused on green and sustainable agricultural development. Based on the inter-provincial panel data for China from 1997 to 2019, this study divided these data into five periods according to the Five-Year Plan (FYP) of China, measured the agricultural eco-efficiency (AEE) values using the Super-SBM model, and then determined the spatial association network of the inter-provincial AEE of China using the improved gravity model. Finally, social network analysis (SNA) was used to further analyze the evolution process of AEE, and we developed a framework of how multidimensional proximity, which includes geographical, economic, technological, cognitive, and institutional proximity, made an influence on the formation of AEE spatial relation network. The findings indicated that: 1) in 1997–2019, the AEE in China was present in some spatial and temporal differences characteristics at the provincial scale, and we specifically found that national macro-regulation and policy incentives played a positive role in the long-term development of AEE. 2) The spatial correlation of AEE development among provincial regions were becoming closer and exhibits obvious spatial correlation and spillover effects. The evolution of the AEE network has clearly observable trends of hierarchization and aggregation, and the complexity of the correlation network continues to increase and exhibits spatial clustering characteristics that are dense in the east and sparse in the west. The network structure has changed from monocentric radiation to a multicentric network, and network nodes select the more advantageous nodes with which to connect. 3) Finally, the geographical proximity had a significant negative effect; the economic, technological, and institutional proximities were all observed to contribute to the AEE network formation, and cognitive proximity did not significantly influence this network formation. [ABSTRACT FROM AUTHOR]

Changes in natural geographic features and landscape patterns directly influence the hydrology and non-point source pollution processes in the watershed; however, to slow down non-point source pollution, it is necessary to distinguish their effects. But the non-point source pollution process is interactional as a result of multiple factors, and the collinearity between multiple independent variables limits our ability of reason diagnosis. Thus, taking the Burhatong River Basin, Northeast China as an example, the methods of hydrological simulation, geographic detectors, and redundancy analysis have been combined to determine the impact of natural geographic features and landscape patterns on non-point source pollution in the watershed. The Soil & Water Assessment Tool (SWAT) has been adopted to simulate the spatial and temporal distribution characteristics of total nitrogen and total phosphorus in the watershed. The results show that the proportions of agricultural land and forest area and the location-weighted landscape contrast index (LWLI) are the main indicators influencing the rivers total nitrogen and total phosphorus. The interaction of these indicators with natural geographic features and landscape configuration indicators also significantly influences the changes in total nitrogen (TN) and total phosphorus (TP). Natural geographical features and landscape patterns have different comprehensive effects on non-point source pollution in the dry and wet seasons. TN and TP loads are affected mainly by the change in landscape pattern, especially in the wet season. Although the ecological restoration program has improved forest coverage, the purification effect of increased forest coverage on the water quality in the watershed may be offset by the negative impact of increased forest fragmentation. The high concentration and complexity of farmland patches increase the risk of non-point source pollution spread to a certain extent. [ABSTRACT FROM AUTHOR]

Climate change can affect wind erosion power and hence induce changes in wind erosion rates. In this study, the wind erosion climate factor (C-factor), proposed by the Food and Agriculture Organization of the United Nations, was used to assess the impact of changes in climate on wind erosion climatic erosivity. The Mann-Kendall test was employed to detect trends in the C-factor during the period of 1961–2017 in the farming-pastoral zone of northern China. Sensitivity analysis was used to determine the sensitivity of the C-factor to changes in key climate factors. Furthermore, a comparison of the contributions of different climate factors was carried out to understand their impact on changes in the C-factor. The results indicated that most of the surveyed region exhibited decreasing trends in wind speed at a confidence level of 90%, while maximum and minimum temperatures showed increasing trends throughout the study area. As a consequence of decreasing wind speed, the annual C-factor exhibited significant decreasing trends, with a mean slope of −0.58/yr. Seasonal analysis revealed that in most regions, the changes in the C-factor had significant decreasing trends in spring, winter, and autumn, while in more than two-thirds of the study area, no significant change trends in the C-factor were detected in summer at a confidence level of 90%. Sensitivity analysis showed that the C-factor was most sensitive to wind speed, and that the sensitivity coefficients from July to September were much higher than those in other months. Contribution analysis revealed that, for most stations, wind speed (with greater values of sensitivity coefficients) was the dominant factor in the change of C-factor, while for some stations, the minimum temperature made the most contribution to the C-factor's change due to its dramatic changes during the study period. Although the minimum temperature sensitivity coefficient was the lowest of all the sensitivity coefficients, it is urgent to evaluate the expected impact of minimum temperature due to its possible changes in the future. [ABSTRACT FROM AUTHOR]

Reference evapotranspiration (ET0) is a vital component in hydrometeorological research and is widely applied to various aspects, such as water resource management, hydrological modeling, irrigation deployment, and understanding and predicting the influence of hydrologic cycle variations on future climate and land use changes. Quantifying the influence of various meteorological variables on ET0 is not only helpful for predicting actual evapotranspiration but also has important implications for understanding the impact of global climate change on regional water resources. Based on daily data from 69 meteorological stations, the present study analyzed the spatiotemporal pattern of ET0 and major contributing meteorological variables to ET0 from 1960 to 2017 by the segmented regression model, Mann-Kendall test, wavelet analysis, generalized linear model, and detrending method. The results showed that the annual ET0 declined slightly because of the combined effects of the reduction in solar radiation and wind speed and the increase in vapor pressure deficit (VPD) and average air temperature in the Loess Plateau (LP) during the past 58 yr. Four change points were detected in 1972, 1990, 1999, and 2010, and the annual ET0 showed a zigzag change trend of 'increasing-decreasing-increasing-decreasing-increasing'. Wind speed and VPD played a leading role in the ET0 changes from 1960 to 1990 and from 1991 to 2017, respectively. This study confirms that the dominant meteorological factors affecting ET0 had undergone significant changes due to global climate change and vegetation greening in the past 58 years, and VPD had become the major factor controlling the ET0 changes on the LP. The data presented herein will contribute to increasing the accuracy of predictions on future changes in ET0. [ABSTRACT FROM AUTHOR]

With an increase in population and economic development, water withdrawals are close to or even exceed the amount of water available in many regions of the world. Modelling water withdrawals could help water planners improve the efficiency of water use, water resources allocation, and management in order to alleviate water crises. However, minimal information has been obtained on how water withdrawals have changed over space and time, especially on a regional or local scale. This research proposes a data-driven framework to help estimate county-level distribution of water withdrawals. Using this framework, spatial statistical methods are used to estimate water withdrawals for agricultural, industrial, and domestic purposes in the Huaihe River watershed in China for the period 1978–2018. Total water withdrawals were found to have more than doubled, from 292.55 × 108 m3 in 1978 to 642.93 × 108 m3 in 2009, and decreased to 602.63 × 108 m3 in 2018. Agricultural water increased from 208.17 × 108 m3 in 1978 to 435.80 × 108 m3 in 2009 and decreased to 360.84 × 108 m3 in 2018. Industrial and domestic water usage constantly increased throughout the 1978–2018 period. In 1978, industrial and domestic demands were 20.35 × 108 m3 and 60.04 × 108 m3, respectively, and up until 2018, the figures were 105.58 × 108 m3 and 136.20 × 108 m3. From a spatial distribution perspective, Moran's I statistical results show that the total water withdrawal has significant spatial autocorrelation during 1978–2018. The overall trend was a gradual increase in 1978–2010 with withdrawal beginning to decline in 2010–2018. The results of Getis-Ord Gi* statistical calculations showed spatially contiguous clusters of total water withdrawal in the Huaihe River watershed during 1978–2010, and the spatial agglomeration weakened from 2010 to 2018. This study provides a data-driven framework for assessing water withdrawals to enable a deeper understanding of competing water use among economic sectors as well as water withdrawal modelled with proper data resource and method. [ABSTRACT FROM AUTHOR]

Biodiversity is vital for the integrity and stability of ecosystems and sustainable development. Karst regions of Southwest China is featured for undulating and broken karst terrain as well as high plant diversity. Land use changes induced by the growing population and expanding human settlement have threatened biodiversity preservation in this region. However, the impact of urban expansion on plant diversity remains unclear here. This study focuses on how expanding countryside landscapes affect the recovery rate of plant diversity and demonstrate how urban expansion affects plant diversity conservation in karst regions of Southwest China. In situ biodiversity investigations and multisource remote sensing images were combined to analyze the role of human settlement evolution in the conservation of plant diversity using descriptive statistics and regression analysis. Unmanned vehicle images, historical aerial photographs, and long-term remote sensing images were used to observe the human settlement pattern changes over 40 yr and found that plant diversity is restored faster in countryside ecosystems than in island ecosystems restricted by water. Forests, however, contribute the most to plant diversity conservation in both ecosystems. While the forest area is stable during urban expansion, massive forest patches play an essential role in plant diversity conservation. Arable lands and grasslands shrank but with a fragmenting trend, which was conducive to preserving plant diversity, whereas increased and regularized large patches of built-up areas were not beneficial to plant diversity. Accordingly, forest protection should be prioritized to coordinate future socioeconomic development and plant diversity conservation in karst and broader regions. Furthermore, large built-up patches should be limited, and the irregularity should be improved during urban expansion. Irregular shaped cultivated land and grassland were suggested to promote biological information exchanges as landscape corridors. [ABSTRACT FROM AUTHOR]

The cold-island effect of urban wetlands has received increasing attention in recent years due to its important role in the alleviation of urban heat islands. Hangzhou, a representative rapidly urbanizing city with rich wetlands in China, was selected as a case study for researching the changes that the urban wetlands have undergone and their impact on the urban thermal environment. Land surface temperature (LST) was acquired from the thermal infrared data of Landsat 5 Thematic Mapper (TM) images in 1990, 1995, 2000, 2006, and 2010, using the single-channel method. The results are as follows: 1) considering the changes in land use, the urban wetlands located to the west of Hangzhou have decreased significantly during 1990-2010 because of rapid urbanization. In the Xixi Wetland, the change in land use was relatively small and most of the water body and vegetation were preserved. However, to the east of the Xixi Wetland, large areas of water body and vegetation have been replaced by built-up land as a result of the urbanization process; 2) considering the change in LST, it was found from land surface temperature retrieval that the changing spatial pattern of the thermal field was highly correlated with land use changes. Low temperature regions of the eastern Xixi Wetland were gradually eroded by high temperature regions, and the centroid of the heat island in East Xixi was found to be constantly shifting westward. In addition, the difference in LST between the Xixi Wetland and East Xixi has increased; 3) considering the impact factors for this area, land use structure and patch shape were found to have a significant impact on LST, shown by the results of multiple linear stepwise regressions. Increasing the size of the wetlands in urban planning is considered to be the most effective measure in alleviating the urban heat island effect. Moreover, reducing the spatial complexity of landscape patches also contributes to the alleviation of the urban heat island effect. [ABSTRACT FROM AUTHOR]

With global warming, the great changes in the patterns of plant growth have occurred. The conditions in early spring and late autumn have changed the process of vegetation photosynthesis, which are expected to have a significant impact on net primary productivity (NPP) and affect the global carbon cycle. Currently, the seasonal response characteristics of NPP to phenological changes in dryland ecosystems are still not well defined. This article calibrated and analyzed the normalized difference vegetation index (NDVI) time series of Advanced Very-High-Resolution Radiometer (AVHRR) data from 1982 to 2015 in the Loess Plateau, China. The spatial and temporal distributions of vegetation phenology and NPP in the Loess Plateau under semihumid and semiarid conditions were investigated. The seasonal variation in the NPP response to vegetation phenology under the climate change was also analyzed. The results showed that, different from the northern forest, there was distinct spatial heterogeneity in the effect of climate change on the dynamic change in vegetation growth in the Loess Plateau: 1) an advance of the start of the growing season (SOS) and a delay of the end of the growing season (EOS) significantly increased the NPP in spring and autumn, respectively, in the humid southeast; 2) in the arid northwest, the NPP did not significantly increase in spring and autumn but significantly decreased in summer. [ABSTRACT FROM AUTHOR]

Extreme precipitation events bring considerable risks to the natural ecosystem and human life. Investigating the spatial-temporal characteristics of extreme precipitation and predicting it quantitatively are critical for the flood prevention and water resources planning and management. In this study, daily precipitation data (1957–2019) were collected from 24 meteorological stations in the Weihe River Basin (WRB), Northwest China and its surrounding areas. We first analyzed the spatial-temporal change of precipitation extremes in the WRB based on space- time cube (STC), and then predicted precipitation extremes using long short-term memory (LSTM) network, auto-regressive integrated moving average (ARIMA), and hybrid ensemble empirical mode decomposition (EEMD)-LSTM-ARIMA models. The precipitation extremes increased as the spatial variation from northwest to southeast of the WRB. There were two clusters for each extreme precipitation index, which were distributed in the northwestern and southeastern or northern and southern of the WRB. The precipitation extremes in the WRB present a strong clustering pattern. Spatially, the pattern of only high-high cluster and only low-low cluster were primarily located in lower reaches and upper reaches of the WRB, respectively. Hot spots (25.00%–50.00%) were more than cold spots (4.17%–25.00%) in the WRB. Cold spots were mainly concentrated in the northwestern part, while hot spots were mostly located in the eastern and southern parts. For different extreme precipitation indices, the performances of the different models were different. The accuracy ranking was EEMD-LSTM-ARIMA > LSTM > ARIMA in predicting simple daily intensity index (SDII) and consecutive wet days (CWD), while the accuracy ranking was LSTM > EEMD-LSTM-ARIMA > ARIMA in predicting very wet days (R95P). The hybrid EEMD-LSTM-ARIMA model proposed was generally superior to single models in the prediction of precipitation extremes. [ABSTRACT FROM AUTHOR]

Demographic and economic development can be seen as two sides of one coin in the process of regional development. This article deals with how economic and demographic changes influence the settlement structure and development of the Pearl River Delta (PRD) and lead to regionalization processes within the large agglomerations. The aim of the study was to understand the interrelation between the three aspects: economic change, demographic change and change of spatial structures. Based on population age and occupational data, spatial changes in demographic structure and economic activities from 2000 to 2010 were analyzed. It was found that the demographic and economic change reflected changing spatial patterns between the urban centers and the hinterland in the PRD. Two processes were apparent during the studied period in the hinterlands and the high-density areas of the PRD. On one hand, the hinterlands in the PRD attracted more manufacturing activities, while the inner high-density areas experienced a decrease in manufacturing, associated with an increase in young labor in regions where workplaces that only required limited education expanded. On the other hand, specialization in knowledge-intensive business services increased in the inner high-density areas, which also saw an increased share in the older population. This finding suggests that increasing knowledge-intensive work correlates with higher age structures due to the longer formal education required and also the benefits knowledge workers accrue through experience and gained knowledge over time. Therefore, based on a transformation process, we tentatively conclude that the populations in high-density areas in the PRD became more middle-aged and were represented by more knowledge workers. [ABSTRACT FROM AUTHOR]

China is in a transitional period between urban renewal and industrial change. In this period, the focus has been on the suburbanization of enterprises and land transformation in old industrial areas, particularly areas with chemical industries. A life cycle theoretical framework was established to develop chemical industrial zones in the context of urban expansion and land function conversion. The long-term historical processes and mechanisms that transformed a typical old chemical industry area along the Yangtze River, Yanziji Area of Nanjing City were unveiled and comparatively analyzed. The study found that the entire life cycle of the case study area was formed through the combined action of different influencing factors. Traditional industrial location factors played important roles during the rise and continuity of the chemical industry zone, while unconventional environmental regulations and government policies drove its decline and transformation. In the transformation of the old chemical zone, the renewal and redevelopment of industrial land into higher-value residential land is a key link determining the feasibility of government fund compensation and the circulation of capital. These findings demonstrate that regional control and environmental regulation play crucial roles in determining the location of polluting industries and the renewal of urban industrial areas. This research enhances the understanding of the development history and reconstruction of chemical industry clusters and plots within megacities at a finer geographic scale. [ABSTRACT FROM AUTHOR]

As an important and typical arid inland region in China, Shiyang River Basin plays an important role in maintaining the sustainable development of eco-environment, whose ecological land suitability restricts the development of the local human activities. Therefore, Shiyang River Basin was selected as the case study, the minimum cumulative resistance (MCR) model and GIS technique were integrated to create land suitability evaluation map. We calculated the MCR value of ecological source and living source, and divided the whole basin into five partitions according to the difference between ecological source and living source, and analyzed the patterns and characteristics of the ecological land suitability evaluation (ELSE) regions, respectively. The results showed that: 1) The suitable ecological land includes prohibited development region and restricted development region, which accounts for 15.45% and 23.35% of the total land area of the Shiyang River Basin, respectively. These two regions mainly distributed high altitude region in the southern Qilian Mountain and low altitude region where had high density of rivers. 2) The protection of ecological land requires not only conserving existing ecological land but also focusing on ecological buffer belts around ecological sources and improving ecological land service ability. 3) Ecological networks should be constructed through artificial planting trees around the boundary of oasis and ecological restoration region. Buffer greenbelts should also be established between optimized development region and ecological restoration region. [ABSTRACT FROM AUTHOR]

Inspired by recent significant agricultural yield losses in the eastern China and a missing operational monitoring system, we developed a comprehensive drought monitoring model to better understand the impact of individual key factors contributing to this issue. The resulting model, the 'Humidity calibrated Drought Condition Index' (HcDCI) was applied for the years 2001 to 2019 in form of a case study to Weihai County, Shandong Province in East China. Design and development are based on a linear combination of the Vegetation Condition Index (VCI), the Temperature Condition Index (TCI), and the Rainfall Condition Index (RCI) using multi-source satellite data to create a basic Drought Condition Index (DCI). VCI and TCI were derived from MODIS (Moderate Resolution Imaging Spectroradiometer) data, while precipitation is taken from CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) data. For reasons of accuracy, the decisive coefficients were determined by the relative humidity of soils at depth of 10–20 cm of particular areas collected by an agrometeorological ground station. The correlation between DCI and soil humidity was optimized with the factors of 0.53, 0.33, and 0.14 for VCI, TCI, and RCI, respectively. The model revealed, light agricultural droughts from 2003 to 2013 and in 2018, while more severe droughts occurred in 2001 and 2002, 2014–2017, and 2019. The droughts were most severe in January, March, and December, and our findings coincide with historical records. The average temperature during 2012–2019 is 1°C higher than that during the period 2001–2011 and the average precipitation during 2014–2019 is 192.77 mm less than that during 2008–2013. The spatio-temporal accuracy of the HcDCI model was positively validated by correlation with agricultural crop yield quantities. The model thus, demonstrates its capability to reveal drought periods in detail, its transferability to other regions and its usefulness to take future measures. [ABSTRACT FROM AUTHOR]

Eco-geographical regionalization involves dividing land into regions by considering both intra-regional consistency and interregional disparity and is based on the pattern of differentiation of eco-geographical elements. Owing to the complexity of the land surface, and the limitation of data and appropriate methods, regions in China have hitherto been mapped manually, meaning that the process of mapping was non-repeatable. To make the regionalization technique repeatable, this study aimed to extract and quantify the expert knowledge of regionalization using an automated method. The rough set method was adopted to extract rules of regionalization based on the existing eco-geographical regionalization map of China, as well as its corresponding meteorological and geological datasets. Then, the rules for regionalization were obtained hierarchically for each natural domain, each temperature zone, and each humidity region. Owing to differences in zonal differentiation, the rule extraction sequence for the eastern monsoon zone and Tibetan Alpine zone was temperature zone first followed by humidity region, with the reverse order being applied for the northwest arid/semi-arid zone. Results show that the extracted indicators were similar to those of the existing (expert-produced) regionalization scheme but more comprehensive. The primary indicator for defining temperature zones was the ≥10°C growing season, and the secondary indicators were the January and July mean temperatures. The primary and secondary indicators for identifying humid regions were aridity index and precipitation, respectively. Eco-geographical regions were mapped over China using these rules and the gridded indicators. Both the temperature zones and humidity regions mapped by the rules show ≥85% consistency with the existing regionalization, which is higher than values for mapping by the commonly used simplified method that uses the classification of one indicator. This study demonstrates that the proposed rough set method can establish eco-geographical regionalization that is quantitative and repeatable and able to dynamically updated. [ABSTRACT FROM AUTHOR]

Although the development of energy and mineral resources strongly supports China's rapid industrialization and urbanization, it has led to a series of ecological and environmental problems. Strengthening the spatial regulation considering the ecological and environmental protection on energy and mineral resource development areas is an important aspect of realizing China's sustainable development. In this study, we mapped, categorized, and analyzed the ecological cumulative effects of the Chinese 134 prefectural mining units based on the pressure-state-response model, which is demonstrated as impact of mining activities on ecological environment, ecological environmental fragility, and ecological function. This investigation developed a stress zoning typology of the mining units based on scores of three dimensions of the ecological cumulative effects and classified 134 prefectural mining units into eight types of stress zones. A series of regulation and policy suggestions have been proposed to different types of zones from three aspects: space control, intensity control, and development mode control. The application of this evaluation and spatial zoning system will contribute to the refined spatial management of China's mining areas. [ABSTRACT FROM AUTHOR]

The research on ecosystem service values (ESVs) estimation in arid region is weak. We took the Alxa League of China's Inner Mongolia Autonomous Region, an extreme arid region, as an example and constructed an equivalent coefficient method to assess its ESVs from 1975 to 2015, by determining the standard unit of ESVs and the basic equivalent of the value of different ecosystem services per unit area based on the regional characteristics, literature research, expert knowledge and land use data. The results show that the ESVs first decreased from 83 170.4 million yuan (RMB) in 1975 to 82 337.8 million yuan (RMB) in 2000 and then increased to 84 033.6 million yuan (RMB) in 2015, and the ESV of sparse grassland and desert account for about 33% and 29% of the total ESVs, respectively. Among the four service types, the regulating services, support services, supply services and cultural services account for 66.5%, 22.8%, 6.0% and 4.7%, respectively. The changes of ESVs in Alxa League are determined by the socio-economic development and ecological changes. This study provides a new method to estimate the ESVs in arid region by integrating existing methods and regional characteristics, such as the cost of water for arid ecosystems. [ABSTRACT FROM AUTHOR]

The article discusses empirical research investigating the connectivity of Chinese cities in the world city network (WCN) in 2010. Topics include an overview of the WCN, which is a regional approach developed by research institute the Globalization and World Cities Research Network (GaWC) to understand cities in relation to globalization, the role of business services firms in city network formation, and the significance of the uneven integration of Chinese cities in the WCN.

Rapid urbanization leads to dramatic changes in land use patterns, and the land use/cover change (LUCC) can reflect the spatial impact of urbanization on the ecological environment. Simulating the process of LUCC and predicting the ecological risk future changes can provide supports for urban ecological management. Taking the Yangtze River Delta Urban Agglomeration (YRDUA), China as the study area, four developmental scenarios were set on the basis of the land use data from 2005 to 2015. The temporal land use changes were predicted by the integration of the system dynamic and the future land use simulation (SD-FLUS) model, and the geographically weighted regression (GWR) model was used to identify the spatial heterogeneity and evolution characteristics between ecological risk index (ERI) and socio-economic driving forces. Results showed that: 1) From 2005 to 2015, the expansion of construction land (7670.24 km2) mainly came from the occupation of cultivated land (7854.22 km2). The Kappa coefficient of the SD-FLUS model was 0.886, indicating that this model could be used to predict the future land use changes in the YRDUA. 2) Gross domestic production (GDP) and population density (POP) showed a positive effect on the ERI, and the impact of POP exceeded that of GDP. The ERI showed the characteristics of zonal diffusion and a slight upward trend, and the high ecological risk region increased by 6.09%, with the largest increase. 3) Under different developmental scenarios, the land use and ecological risk patterns varied. The construction land is increased by 5.76%, 7.41%, 5.25% and 6.06%, respectively. And the high ecological risk region accounted for 12.71%, 15.06%, 11.89%, and 12.94%, correspondingly. In Scenario D, the structure of land use and ecological risk pattern was better compared with other scenarios considering the needs of rapid economic and ecological protection. This study is helpful to understand the spatio-temporal pattern and demand of land use types, grasp the ecological security pattern of large-scale areas, and provide scientific basis for the territory development of urban agglomeration in the future. [ABSTRACT FROM AUTHOR]

Baseflow, a component of the total streamflow, plays a key role in maintaining aquatic habitats, particularly during extreme drought events. This study investigated baseflow response to a prolonged and extreme meteorological drought event in the Baiyangdian Basin (BYD basin), a temperate water-limited basin in North China. Applying a precipitation series, piecewise regression was used to determine this extreme meteorological drought event, while the Automatic Baseflow Identification Technique (ABIT) was used to estimate a recession parameter (α), which was used to isolate baseflow from total streamflow. Results showed that: 1) annual precipitation exhibited significant decreasing trends (P < 0.05) with an average change of −1.81 mm/yr2. The precipitation deficit revealed that the start and end date of the extreme meteorological drought event was from August 1996 to May 2011, respectively, persisting for a total of 178 months (roughly 15 yr); 2) hydrological drought (including streamflow and baseflow) lagged behind meteorological drought while predictably persisting longer than extreme meteorological drought (i.e., precipitation); and 3) baseflow decreased dramatically under meteorological drought at both seasonal and annual scales, resulting in significantly decreasing trends during drought periods. Findings from this study confirmed that hydrological events caused by extreme meteorological drought can alter the magnitude and duration of baseflow and total streamflow, which will have an inevitable influence on aquatic ecosystems. [ABSTRACT FROM AUTHOR]

To solve the problems caused by irrational land-use, studying the functions of land-use, its changing characteristics, and the relationship between each land-use function will be beneficial for achieving sustainable land development. In this research, we constructed an evaluation framework of multiple land-use functions (LUFs) based on sustainable land-use theory. Specifically, we classified the multiple LUFs into three types: agricultural production function (APF), living function (LVF), and ecological service function (ESF). We then spatialized the economic and social data, and implemented the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model and RUSLE (Revised Universal Soil Loss Equation) model to evaluate each sub-LUF (crop production, aquatic production, woodlands production, livestock production, living space, life quality, water supply, soil conservation, climate regulation, biological conservation) in central China in 2000 and again in 2015. Moreover, by analyzing the changes to LUFs and the relationships between each LUF change, we were able to discern patterns of LUF change in central China. The results show that: 1) 42.12% of total territory in the study area increased their APF from 2000 to 2015, while 43.41% of the lands increased their ESF yet only 8.98% of the lands increased their LVF; 2) in Hubei and Hunan, there was more land with an increase of APF than in Anhui or Jiangxi. The APF in Jiangxi exhibited the greatest decline over time period, the LVF increased more in the provincial capital cities than in other regions, and the ESF expanded more in Jiangxi than in the other provinces; and 3) the changes in APF were significantly and positively correlated with changes in LVF. Additionally, changes in ESF were negatively but non-significantly correlated with changes in APF and LVF. [ABSTRACT FROM AUTHOR]

Agricultural science and technology parks (ASTPs) represent an important growth pole in China's agricultural modernization. Clarifying their diffusion laws can optimize the technological diffusion process and improve its efficiency. Our study uses disaggregated spatial information in its model to analyze ASTP technology diffusion in a heterogeneous space. We constructed a comprehensive index system to evaluate the diffusion environmental quality and introduced the heterogeneous diffusion equation to calculate the technological diffusion probability. We applied this framework to a real-world scenario: the apple planting technology diffusion of the Yangling ASTP in the Loess Plateau, China. The results indicated: 1) the technological diffusion environment of the Loess Plateau advantageous apple producing area showed strong spatial heterogeneity caused by climate, topography, and external transportation links. 2) Under the combined effects of distance and spatial heterogeneity, the spatial diffusion pattern of the Yangling ASTP apple technology was expansion diffusion supplemented by hierarchical diffusion and banded diffusion, and 3) ASTP technology diffusion showed a strong distance attenuation effect, and the frictional effect of distance can be decreased by improving the diffusion environmental quality. These laws can promote regional balanced ASTP-driven development. [ABSTRACT FROM AUTHOR]