Search

Xinjiang is the largest cotton-producing region in China, but it faces a severe shortage of water resources. According to relevant studies, the cotton yield does not significantly decrease under appropriate limited water conditions. Therefore, this paper proposes a water and fertilizer integrated control system to achieve water and fertilizer conservation in the process of cotton field cultivation. This paper designs a fuzzy neural network Proportional–Integral–Derivative controller based on the improved Wild Horse Optimizer to address the water and fertilizer integrated control system's time-varying, lag, and non-linear characteristics. The controller precisely controls fertilizer electrical conductivity (EC) by optimizing parameters through an improved Wild Horse Optimizer for the initial weights from the normalization layer to the output layer, the initial center values of membership functions, and the initial base width of membership functions in the fuzzy neural network. The performance of the controller is validated through MATLAB simulation and experimental tests. The results indicate that, compared with conventional PID controllers and fuzzy PID controllers, this controller exhibits excellent control accuracy and robustness, effectively achieving precise fertilization. [ABSTRACT FROM AUTHOR]

Background: China has made great progress in ecological restoration. However, there have been no analyses on ecological restoration for specific terrestrial ecosystems. This study identified the important knowledge gaps and advances related to terrestrial ecological restoration in China. Results: 7973 papers published between 1978 and 2020 were investigated and about 962 articles were used in this analysis after manually screening. Since the first large national ecological restoration project in 1978, the most frequently studied ecosystem has shifted from farmland ecosystems in 1978–2000 to forest ecosystems after 2000. Forests were the most common ecosystem type investigated, while less attention was paid to wetlands and riparian systems. Meanwhile, the most common ecological issue shifted from environmental pollution in 1978–2000 to the declining resource-carrying capacity of ecosystems after 2000. Studies of ecoregions on the Loess Plateau catchment accounted for more than 40% of papers reviewed in this study, with predominant emphasis on soil and water conservation functionality. Besides, revegetation and afforestation characterized most ecological restoration projects in China, but the natural restoration was relatively less adopted. Additionally, the important tool of reference ecosystem was only used in four studies. Conclusions: Ecological restoration has made significant progress in China. We investigated how the ecological restoration can be implemented more effectively. More projects should be implemented for restorative work in wetlands and riparian systems in future. The tradeoff between restorative activities, water resources, and carbon sink needs further research efforts. More emphasis on biodiversity conservation is warranted. Newly developed theory (e.g., stepwise ecological restoration) and the recently issued Chinese National Guidelines for Ecological Restoration Projects should be more effectively implemented in future restorative works. This study provides essential information for future restorative work in China. It also provides insights into the development of policy relevant to restoration and adaptive management during the U.N. restoration decade. [ABSTRACT FROM AUTHOR]

Scientifically evaluating the influence of ecological restoration projects on the water conservation function (WCF) of regional ecosystems is the foundation for formulating regional ecological restoration policies and optimizing and adjusting ecological restoration projects. In this paper, we considered fully the runoff generation and confluence process in the Qilian Mountains with the actual situation of the basin and re-rated the parameter Z to improve the simulation accuracy of InVEST model. On this basis, the impact of ecological restoration project on the WCF in the upper reaches of Shiyang River Basin (SRB) in the eastern part of Qilian Mountains was quantified. The results showed that, on the whole, the water conservation depth (WCD) of forest land was the largest (138.5 mm) and that of cultivated land was the smallest (24.78 mm), while the water conservation coefficient of forest land was also the largest (93.36%) and that of unused land was the smallest (16.67%). From 1986 to 2018, the WCD showed an increasing trend in the upper reaches of SRB, among them, the WCD in the western tributaries increased faster than that in the eastern tributaries from 1986 to 2000. The significantly increased areas were mainly distributed in the middle reaches of the western tributaries and the river source areas of the eastern tributaries, while the significantly decreased areas were mainly distributed in the river source areas of the western tributaries and the cultivated land expansion area in the middle reaches of the eastern tributaries. From 2000 to 2018, the WCD of the eastern tributaries increased more than that of the western tributaries. The significantly increased areas were mainly distributed in the four eastern tributaries, and the significantly decreased areas were scattered in the middle and lower reaches of each tributary. From 1986 to 2000, the overall influence of land use change on the increase in WCD was negative, while the influence of climate and land use change on the increase in water conservation were both positive from 2000 to 2018. The influence of land use change on WCD was different in different tributaries. Among them, that of the western tributaries (except the Dongda River) was positive in two different periods, while that of the eastern tributaries (except the Xiying River) was changed from negative to positive. The implementation of ecological restoration project was one of the main reasons for the improvement of WCF in Qilian Mountains from 2000 to 2018, with a contribution of 9.04%. In the future, the protection and restoration of decreased areas of WCF should be strengthened, and the Z value determined in this paper is expected to be applied in the arid inland river basins of northwest China. [ABSTRACT FROM AUTHOR]

Forest pests and diseases can diminish forest biodiversity, damage forest ecosystem functions, and have an impact on water conservation. Therefore, it is necessary to analyze the interaction mechanism between plants and pests. In this paper, the prevention and control of a specific pest—namely the larva of Paranthrene tabaniformis (Rott.) (hereinafter referred to as larva)—are studied. Based on the invasion mechanism of the larva in poplar, we establish a delayed differential equation and analyze the existence and stability of equilibria. Next, we assess the existence of a Hopf bifurcation to determine the range of parameters that ensures that the equilibria are stable. Then, we select a set of parameters to verify the results of the stability analysis. Finally, we provide biological explanations and effective theoretical control methods for poplar pests and diseases. [ABSTRACT FROM AUTHOR]

Resource depletion, land-use change, and population growth triggered by the industrial revolution represent serious issues shared globally that have altered the structure, processes, and functions of ecosystems and had significant impacts on human well-being and survival security. This paper assesses changes in ecosystem service values (ESVs) in karst areas based on the perspective of land-use change. Guizhou province, which is typical of the South China Karst (SCK) ecologically fragile areas, was taken as a research subject. The past, current, and future spatial-temporal evolution of karst ESVs were assessed, using equivalence factors and CA-Markov modelling methods. The results show that: (1) from 1980 to 2040, arable land, woodland, and grassland occupy the main land types in the study area; at the same time, the water and built-up areas show a steady growth trend, with dramatic land use shifts occurring in the western, middle, and northern parts. (2) The overall ESVs increased by US$ 31.12 million during the study period, showing a temporal change trend of first decreasing and then increasing; forest land, grassland, and arable land area shift are the main factors of ESVs change; soil conservation, biodiversity conservation, and gas regulation functions are enhanced and play a vital role in the single ESVs increase; ESVs show a basin-type spatial distribution pattern. (3) The sensitivity index is <1, the ESV is inelastic to the VC factor adjustment, and the results are true and valid. This paper found that using quantitative methods to predict land use change of the South China Karst can provide accurate assessment of the differences in supply and demand for natural and social ecosystem services (ES) in a region, clarifying the trade-offs and synergies of ecosystem service functions, contributing to the achievement of sustainable development, and providing a practical reference for global land landscape optimization and land resource planners. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Soil & Water Conservation is the property of Bulletin of Soil & Water Conservation Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Glaciers, known as solid reservoirs, are important water supply sources in northwest China. In this paper, mineral dust collected from a Chinese alpine mining area (Beizhan iron mine) and an ice cube (with a 225 cm2 section and a volume of 1000 mL) were employed via a delicate physical experiment to study the ablation of glaciers covered by mineral dust in alpine regions. After that, the ablation mechanism was revealed using the energy conservation theory. The main findings are as follows: (1) When the solar radiation intensity is 993 W/m2, the glacier ablation rate increases by 13.9% (from 282 to 321.2 mL/h) as the mineral dust coverage rate increases from 0% to 42.7%. (2) When the mineral dust coverage rate remains at 30%, the glacier ablation rate increases by 11.6% (from 291.8 to 325.78 mL/h) as the solar radiation intensity increases from 1007 to 1153 W/m2. (3) When the solar radiation intensity and mineral dust coverage rate remain unchanged, the ablation rate of the glacier covered by the mineral dust inversely increases with the dust particle size. The ablation rates of the particle size gradings C, B, and A (the dust particle sizes of gradings A, B, and C in 0.0375–0.075 mm, 0.075–0.125 mm, and 0.125–0.25 mm accounted for 5%:50%:45%, 30%:40%:30%, and 70%:30%:0%, respectively) were 293.4, 301.2, and 305.6 mL /h, respectively, and the corresponding ablation rates increased by 2.7% and 1.5%. (4) The smaller the average particle size of the mineral dust, the greater the contribution to the ablation rate; a 1 °C temperature increase to the glacier ablation rate is equivalent to 29.1%, 33.6%, and 40.6% increases in dust coverage for particle size classes C, B, and A. (5) The mineral dust covering the glacier surface could not only reduce the reflectivity of the glacier surface to solar radiation but could also continuously transfer the absorbed radiant energy and its own chemical energy to the glacier body, accelerating the glacier's meltwater speed. The findings of this paper can provide the necessary theoretical basis for mineral dust control and glacier water conservation in alpine mining areas. [ABSTRACT FROM AUTHOR]

The treatment of rural domestic sewage is essential for the comprehensive improvement of the rural environment. At present, the rate of resource utilization of rural domestic sewage is generally low in China, which fits with the actual situation of rural areas, and low cost is becoming the requirement for the development of rural sewage treatment technologies. Adopting a tailored approach based on local conditions for utilising sewage resources is the best option for rural sewage management. Therefore, it is very important and urgent to explore and evaluate the mode of rural domestic sewage resource utilisation. This paper analyzes the current status of sewage resource utilization in rural China. It researches and explores sewage treatment technology and resource utilization models based on 10 study sites in Yongkang City, Zhejiang Province. At the same time, this article evaluates pollution control effectiveness and environmental emission reduction benefits. The results show that the effluent quality of the treated wastewater by the skid-mounted resource utilization equipment met the reuse requirements and maintained stable water quality. The project can save 251,900 tons of high-quality water resources annually, reducing COD by 78.51 tons, reducing NH3-N and TP by 5.62 tons and 0.39 tons, respectively, and reducing carbon emissions by more than 134 tons. The project has achieved significant comprehensive benefits in water conservation, pollution reduction, and carbon reduction. [ABSTRACT FROM AUTHOR]

Freshwater resources are becoming increasingly scarce in coastal areas, limiting crop productivity in coastal farmlands. Although the characteristic of crop water use is an important factor for water conservation in coastal farmlands, it has not been studied extensively. This study aimed to depict the water use process of soil–plant systems under saline stress in coastal ecosystems and optimize water management. An intensive observation experiment was performed within China's Yellow River Delta to identify the water use processes and crop coefficients (KC) and also quantify the impacts of salt stress on crop water use. The results show that shallow groundwater did not contribute to soil water in the whole rotation; KC values for wheat–maize, wheat–sorghum, and wheat–soybean rotation systems were 45.0, 58.4, and 57% less, respectively, than the FAO values. The water use efficiency of the maize (8.70) and sorghum (9.00) in coastal farmlands was higher than that of the soybean (4.37). By identifying the critical periods of water and salt stress, this paper provides suggestions for water-saving and salinity control in coastal farmlands. Our findings can inform the sustainable development of coastal farmlands and provide new insights to cope with aspects of the global food crisis. [ABSTRACT FROM AUTHOR]

Soil water content is an important indicator used to maintain the ecological balance of farmland. The efficient spatial prediction of soil water content is crucial for ensuring crop growth and food production. To this end, 104 farmland soil samples were collected in the Yellow River Delta (YRD) in China, and the soil water content was determined using the drying method. A gradient boosting decision tree (GBDT) model based on a tree-structured Parzen estimator (TPE) hyperparametric optimization was developed, and then the soil water content was predicted and mapped based on the soil texture and vegetation index from Sentinel-2 remote sensing images. The results of statistical analysis showed that the soil water content had a high coefficient of variation (55.30%), a non-normal distribution, and complex spatial variability. Compared with other models, the TPE-GBDT model had the highest prediction accuracy (RMSE = 6.02% and R2 = 0.71), and its mapping results showed that the areas with high soil water content were distributed on both sides of the river and near the estuary. Furthermore, the results of Shapley additive explanation (SHAP) analysis showed that the soil texture (PC2 and PC5), modified normalized difference vegetation index (MNDVI), and Sentinel-2 red edge position (S2REP) index provided important contributions to the spatial prediction of soil water content. We found that the hydraulic physical properties of soil texture and the vegetation characteristics (such as vegetation coverage, root action, and transpiration) are the key factors affecting the spatial migration and heterogeneity of the soil water content in the study area. The above results show that the TPE algorithm can quickly capture the hyperparameters that are most suitable for the GBDT model, so that the GBDT model can ensure prediction accuracy, reduce the loss function with less training data, and accurately learn of the nonlinear relationship between soil water content and environmental factors. This paper proposes a machine learning method for hyperparameter optimization that shows considerable potential to predict the spatial heterogeneity of soil water content, which can effectively support regional farmland soil and water conservation and high-quality agricultural development. [ABSTRACT FROM AUTHOR]

Payment for watershed ecosystem services (PES) has been applied to water conservation and poverty reduction in an increasing number of developing countries. This study evaluates the effect of payment for watershed ecosystem services on farmers' income in conservation intervention areas using a difference-in-differences model and a panel dataset that covers 18 countries in the Xin'an River Basin in China for fourteen consecutive years (2006–2019). The results show that PES programs increase farmers' income and that the poverty reduction effect is sustainable. The PES programs mainly increase the farmers' income in conservation intervention areas through two paths: triggering the transfer of agricultural labor and promoting agricultural restructuring. PES programs are pro-poor and more conducive to increasing the income of farmers in upstream regions and counties with lower levels of economic development. This paper reveals the specific role played by PES in promoting rural poverty reduction in developing countries, providing insights into alleviating the contradiction between poverty and watershed ecosystem protection. [ABSTRACT FROM AUTHOR]

Jiangsu is a major province located in the east of China, consuming a large amount of water resources. It is considered that improving the comprehensive water use efficiency has an important significance to achieve sustainable development of the economy in Jiangsu. Through extensive literature research and investigation of Jiangsu Province, this paper establishes comprehensive water use efficiency index system using water consumption per ten thousand dollar gross domestic product (WC/$104 GDP) as the research target. In the index system, resource factors such as surface water resources (SW), groundwater resources (GW), precipitation (PT), water resources per capita (PW), water consumption per capita (PC) and irrigation area per capita (PI) cannot be artificially altered. Furthermore, the variation amplitude of resource factors is very small. It shows that the linear regression model is not suitable to analyze the resource factors by changing the independent variables. In view of this situation, this paper introduces impulse response function on the basis of vector autoregressive model (VAR) to investigate the intrinsic link between resource factors and WC/$104 GDP in Jiangsu Province. The results show that resource factors have a great impact on WC/$104 GDP in Jiangsu, and the per capita water resources (PW) has the most significant impact. [ABSTRACT FROM AUTHOR]

Monitoring of river discharge is a key process for water resources management, soil and water conservation, climate change, water cycling, flood or drought warning, agriculture and transportation, especially for the sustainable development of rivers and their surrounding ecological environment. Continuous and comprehensive discharge monitoring was usually impossible before, due to sparse gauges and gauge deactivation. Satellite remote sensing provides an advanced approach for estimating and monitoring river discharge at regional or even global scales. River morphology is generally considered to be a direct factor that affects the accuracy of remote sensing estimation, but the specific indicators and the extent to which it affects the estimation accuracy have not yet been explored, especially for medium to small rivers (width < 100 m). In this paper, six sites with hydrological gauges in the upper Heihe River Basin (HRB) of northwestern China and the Murray Darling Basin (MDB) of southeastern Australia were selected as the study cases. River discharge was estimated from Landsat imagery using the C/M method accordingly. River gradient, sinuosity, and width were obtained from Digital Elevation Model data for each site. Global Surface Water Dataset (GSWD) was also employed for indicating the dynamic status of river morphology. A series of methods were applied to analyze the influence of river morphology on estimation accuracy qualitatively and quantitatively, based on which we established inference about the theory of selecting satellite virtual gauges (SVGs). The results confirm the feasibility of the C/M method for discharge estimation, with the accuracy affected by multiple river morphological indicators. Among them, river width was found to be the most significant one. Moreover, water occurrence and water extent extracted from GSWD also have impact on the discharge estimation accuracy. Another independent river section in MDB was set as an example to demonstrate the reasonability of the established theory. It is anticipated that this study would promote the application of remote sensing for discharge estimation by providing practical guidance for establishing appropriate SVGs. [ABSTRACT FROM AUTHOR]

This paper analyzes the spatiotemporal patterns, water yield and water conservation function of different land use types in Poyang Lake Region, China, during 1990–2020 by using national land use, meteorological, soil, DEM data, etc., based on the InVEST model. The results showed that: (1) Cultivated land, forestland and water area were the main land use types in Poyang Lake Region during 1990–2020. Construction land and forestland were increasing, while grassland, unused land, cultivated land and water area were decreasing. (2) The increasing construction land was mainly derived from cultivated land. Mutual transfer existed between cultivated land and forestland, as well as between cultivated land and water area. (3) With a downward–upward–downward fluctuating trend, the average annual water yield of Poyang Lake Region was 16.17 × 109 m³, and the water conservation was 53.11 × 108 m³. The average water conservation capacity was 270.98 mm. The vegetation cover area with high water conservation value was mainly concentrated in the northwest of Jiujiang City and the northeast of Poyang County. (4) The average water conservation of different land use types during 1990–2020 was ranked as follows: water area > cultivated land > forestland > construction land > grassland > unused land. The water conservation capacity was ranked as follows: water area > grassland > forestland > cultivated land > construction land > unused land. [ABSTRACT FROM AUTHOR]

To understand the change in irrigation water requirement (IWR) in China under the changing climate conditions and grain planting structures, this paper focused on rice, wheat and maize and analyzed the IWR change in each county under the background of climate change and the adjustment of planting structure by means of the China Agro-Ecological Zones (China-AEZ) model. The results show that: (1) Climate change causes the increase of IWR. Compared with the 1961–1990 period, the average IWR of counties in China increased by 9.31 mm and 16.50% under the climate conditions of the 1981–2010 period. Regionally, the water consumption effect of climate change is stronger in water-poor areas than in water-rich areas. (2) Planting structure change causes the decrease of IWR. Compared with 1990, under the planting structure in 2014, the average IWR of counties in China decreased by 6.61 mm and 11.41%. Regionally, the water-saving effect of the change in planting structure in the north is stronger than that in the south. (3) With the change in climate conditions and planting structure, the average IWR of counties in China first increased and then decreased, with an overall increase of 2.06 mm and 3.56%. Regionally, the IWR in most parts of the country has shown a decreasing trend, while the IWR in northwestern and north China, where water resources are relatively scarce, has increased significantly. (4) Nationally, the change in IWR is dominated by climate change, and the overall trend is in the direction of water consumption. Therefore, adjusting the crop planting structure is a promising way to save irrigation water. To adapt to the pressures on water resources caused by climate change, the proportion of crops with water-saving advantages should be increased in the corresponding areas to achieve regional water savings. In northwest China, which mainly relies on irrigation water, many crops with low IWR should be planted, such as wheat and maize, while the planting proportion of rice should be reduced; furthermore, the planting proportion of wheat should be reduced, and the planting proportion of maize should be increased in north China. Finally, rice with high IWR should be more localized in central, southern and northeastern China. [ABSTRACT FROM AUTHOR]

Driving forces are the factors that lead to the observed changes in the quantity and quality of ecosystem services (ESs). The relationship between driving forces and ESs involves considerable scale-related information. Place-based ecological management requires this information to support local sustainable development. Despite the importance of scale in ES research, most studies have only examined the association between ESs and their drivers at a single level, and few studies have examined this relationship at various scales or analyzed spatial heterogeneity. The purpose of this paper is to explore the significance of the scale-dependent effects of drivers on ESs for localized ecological management. The biophysical values of ESs were calculated using several ecological simulation models. The effects of driving forces on ESs were explored using the geographically weighted regression (GWR) model. Variations in the effects of driving forces on ESs were examined at three scales: provincial, ecoregional, and subecoregional scales. Finally, canonical correlation analysis was used to identify the major environmental factors associated with these variations in each ecoregion. Our results show that (1) the distribution of soil conservation and water yield is highly heterogeneous; (2) four driving forces have significant positive and negative impacts on soil conservation and water yield, and their effects on the two services vary spatially (p < 0.05); (3) the impacts of drivers on ESs vary across different spatial scales, with a corresponding shift in the related environmental factors; and (4) in the study area, at the provincial scale, physical, topographical, and biophysical factors were key factors associated with the variations in the relationship between ESs and drivers, and at the ecoregional and subecoregional scales, physical, socioeconomic, topographical, and biophysical factors all contributed to these changes. Our results suggest that significant differences in topographical conditions (e.g., altitude, slope) can be incorporated for exploring the relationship between drivers and ESs and optimizing ecological management at the provincial scale, whereas significant differences in physical and socioeconomic conditions (e.g., urbanization levels, human activity, vegetation coverage) are more meaningful for localized ecological management at the ecoregional and subecological scales. These findings provide a basis for understanding the relationship between drivers and ESs at multiple scales as well as guidelines for improving localized ecological management and achieving sustainable development. [ABSTRACT FROM AUTHOR]

How and to which extent terrain factors affecting the drainage area threshold (DAT) are disputable. This paper uses principal component analysis (PCA) and correlation analysis to study the influence degree of terrain factors on DAT. Firstly, 22 watersheds, locating in the severe soil erosion region (SSER) of Loess Plateau of China, are picked out as the example areas. The purpose of the mean change point method (MCP) to detect the relationship between DAT and gully density (GD) is to get a reasonable DAT. Secondly, nine terrain factors are calculated, and their statistical values are compared and put in the matrix to clear the different effects on DAT. Finally, the effects of statistical eigenvalues of terrain factors on DAT are compared with PCA and the correlation analysis. According to the PCA, the nine terrain factors are summarized into three principal components, which are slope, height variation, and relief factor. By calculating the score weighted by each factor coefficient matrix and eigenvalue, the result states that slope (S), terrain curvatures (K), and surface roughness (SR) are the factors that have great influence on DAT. Meanwhile, the results of correlation analysis indicate that S, SR, and K have exerted a great influence on the DAT, and the significance level was above 0.05. Both the results of PCA and correlation analysis make clear that the slope is the most direct and influential factor affecting DAT, while other factors are more or less related to slope directly and indirectly. The result implies that the vertical variation of terrain has a strong correlation with the slope, and also has a great influence on DAT. This research not only would be of great significance to recognize the mechanism of gully development, but also able to provide a scientific reference for soil and water conservation in the Loess Plateau. [ABSTRACT FROM AUTHOR]

Mastering the spatial distribution of water retention capacity and scientifically delineating the ecological space for water conservation are of great significance to the management of regional land and water resources. In this paper, a water conservation ecological spatial delimitation framework suitable for water-deficient areas was put forward. The water retention capacity of the study area in 1983, 1990, 2000, 2010, and 2016 was evaluated by using the InVEST Water Yield model and water balance method, respectively. On this basis, a flexible inflection point model based on the contribution degree of functional units was established. Then the ecological space for water conservation was delimited. The framework was applied to the delimitation of the key water conservation areas in Jilin province, China. The results showed that: (1) the spatial distribution pattern of water conservation in Jilin province gradually decreased from east to west. The spatial difference was significant. The maximum value of water conservation in Jilin province was 730 mm. From 1983 to 2016, water conservation, which accounted for 75.71% of the area, showed an upward trend. The overall water retention capacity showed the characteristics of the overall increase and the local decline. (2) From the absolute amount of the effect of unit area change on water conservation, the intensity from the high to the low was forestland, cultivated land, grassland, unused land, buildings, and water. (3) The area of water conservation less than 474 mm accounted for more than 80% of the total study area. The overall water retention capacity was low. High importance ecological space area of water conservation was comprehensively defined as 36.97%, which was mainly distributed in the natural forest area of Changbai Mountain in the east and the south of Song Liao Plain. Therefore, this study provided a basic layout of relatively concentrated ecological spatial distribution for water conservation types at different levels in Jilin province. The study results and conclusions of this paper will provide a reference for water conservation assessment and the regional land’s natural resources management. [ABSTRACT FROM AUTHOR]

This paper used original survey data in Shandong province of China to depict local farmers' perceptions of combined climatic and market risks, and their adaptive behaviors. Two Logit models were developed to capture the empirical relationship between farmers' risk perception of the combined risks and adaptive behaviors. Results show that farmer's risk perception of climate change and market significantly affected their adoption behavior of adaptive measures, including perception of rainfall decrease, gale decrease, drought increase, and price fall of agricultural products. Moreover farmers' adaptive behaviors are more sensitive to their perceptions of extreme climatic events. Addition of demographic factors can improve the explanatory capacity of the Logit model. As illustrated by the models, male and better educated farmers have greater willingness to take actions for averting risks, while household heads with bigger farm are more reluctant. A majority of respondents chose to construct farm structure for irrigation and water conservation to avert climatic risks. Insurance, which is regarded as an effective tool to help farmers mitigate risks and avoid losses, has not been sufficiently accepted by farmers in rural areas in Shandong province. This underscores the need of effective communication of knowledge to enhance farmers' coping capacity and to encourage their active response to risk. [ABSTRACT FROM AUTHOR]

Over-exploitation of groundwater in China has severely affected irrigation agriculture, especially in the North China Plain, and it also threatens the environment. Although water-saving technologies (WSTs) have been introduced for decades, sustained commitment to WST is not being met. This paper investigates factors affecting adoption and sustained adoption of WST based on 261 households in the North China Plain. We employ Heckman's two-stage sample selection process: (1) households decide whether to adopt WST or not and (2) households decide whether to sustainably adopt (adopt for a long time) WST or not. Particular attention is paid to the role of water scarcity in the initial adoption and sustained adoption stages. Several indicators relating to water scarcity are used to calculate a water scarcity index based on principal component analysis. The results showed that water scarcity exerts a significant and positive effect on both adoption and sustained adoption of WST. Non-adopters and non-sustained adopters face less severe water scarcity than adopters. Membership in cooperative organizations significantly improves the likelihood of sustained adoption; 63.6% of sustained adopters have a membership in cooperative organizations, compared with 18.2% of non-sustained adopters. The number of plots negatively affects the sustained adoption of WST; sustained adopters on average have 3.0 plots, and non-sustained adopters have 5.3 plots. Education, extension service, farm size, off-farm work, relatives working in the local government and irrigation costs are positively and significantly associated with adoption and sustained adoption decisions. Finally, we find that labor-saving capacity significantly influences both stages, whereas capital-saving capacity is only significant in the adoption stage. Only 10% of non-adopters consider adoption of WST as more labor- and capital-saving than conventional irrigation practices, in comparison with nearly 50% of adopters. These results imply that the extension of WST should consider focusing more on cooperative organizations and hold more demonstrations for farmers. Moreover, given that the degree of water shortage varies from region to region, the WST extension standards should vary accordingly. Governments should strengthen awareness by enhancing education and publicity concerning water scarcity and conservation. [ABSTRACT FROM AUTHOR]

In order to address the serious water shortage problem in northern China, China has launched the South-to-North Water Diversion Scheme, which is a large-scale inter-basin water diversion project. With Beijing as an example and using input-output analysis, this paper analyzes the macroeconomic impact of the increased water supply on the affected areas in the industrial sector. Our empirical results show that the increased water supply has brought about direct economic benefits to Beijing, which had increased from RMB 4.39 billion in 2008 to RMB 55.99 billion in 2013. The estimated full value of economic benefits had increased from RMB 14.07 billion in 2008 to RMB 231.86 billion in 2013. In addition, management of water conservancy, environment and public facilities, and public management, social security and social organization are the two main industrial sectors which drive the most direct economical benefits. This paper also forecasts the impact of the South-to-North Water Division Project on Beijing's various industrial sectors by 2020. Based on our analysis, this paper puts forward policy recommendations to further improve the efficiency of water usage in Beijing. [ABSTRACT FROM AUTHOR]

Corporate water performance and sustainable development are currently vital focus areas for scholars. Therefore, this paper investigates the experience of Chief Executive Officers (CEOs) with water shortage influences corporate water performance by focusing on listed companies in water-intensive and high-water-risk industries in China between 2014 and 2019. This paper manually collected information relative to the cities and provinces where CEOs grew up to evaluate their early exposure to water shortages. Furthermore, this paper develops an evaluation scale, based on the Enterprise Water Conservation Evaluation Guide (GB/T 7119-2006), to compute the enterprise water management practices scores. These results will constitute the enterprise water performance evaluation score. Moreover, this paper focuses on CEOs who have experienced water resource shortages through a positive impact on the water resource performance of their companies. As for the findings, they demonstrate that CEOs who grew up in regions with higher water scarcity have a more pronounced positive effect on their water shortage experience through corporate water performance. Furthermore, CEO power intensity positively moderates the relationship between the CEO's water shortage experience and corporate water resource performance. Further investigation reveals generational differences in the impact of CEO water shortage experience on company water performance. CEOs, who grew up during periods with a higher incidence of droughts, demonstrate a more significant promoting effect on corporate water performance. To sum up, this study expands the understanding of factors influencing corporate water resource performance and deepens the knowledge of the early life experiences of CEOs. • We construct a set of scales to measure corporate water performance. • We explore the relationship between CEO water shortage experience and corporate water resource performance. • CEO water shortage experience has a positive effect on corporate water performance. • CEO power intensity plays a positive moderating role. [ABSTRACT FROM AUTHOR]

The source region of the Yellow River, located in the north-eastern edge of the Qinghai-Tibet Plateau, is an important water conservation region and ecological barrier of the Yellow River. In this paper, based on remote sensing technology, multi-period Landsat remote sensing images in the source region were taken as the main information source. With the assistance of field investigation, we monitored the spatial and temporal changes of desertification in the source region from 2000 to 2019. The results show that the area of desertification in the source region has accounted for 9.36% of the total area, of which the light desertification land is the major portion. The desertification is mainly distributed between the southern margin of Madoi Valley basin and the northern margin of Heihe Valley basin, and is distributed on the river valleys, lakesides, ancient rivers and piedmont proluvial fan, showing the form of patches, sheets and belts. The growth rate of desertification in the source region was 87.47% from 2000 to 2010. With a high growth rate, the process of desertification was represented by the rapid spread of desertification. From 2010 to 2019, the growth rate of desertification was 37.32%, which was relatively slow. But the moderate desertification land maintained a straight linear growth trend, showing an increasing trend of desertification degree. Through the analysis of the driving factors of desertification in the source region of the Yellow River, this paper argues that the special geographical location, climatic factors, rodent damages and human activities are the main causes of desertification. [ABSTRACT FROM AUTHOR]

The Chinese Mollisol region is affected by soil erosion. Soil and water conservation (SWC) measures are effective in preventing these phenomena. However, few studies have systematically reviewed soil erosion and SWC measures in this region. The objectives of this paper were to analyze soil erosion and identify typical SWC measures on hillslopes in this Mollisol region. A literature review and analysis were conducted. Soil erosion is widespread in this region and is dominated by snowmelt and wind erosion in winter and spring, rainfall in summer and wind erosion in autumn. The A-horizon thicknesses and organic matter content of the Mollisol decreased with an increase in the number of years of cultivation. Therefore, controlling soil erosion is a means to protect this precious Mollisol resource. The characteristics of 39 SWC measures used on hillslopes were summarized. Among these measures, the contour ridge, large ridge, minimal tillage with residue mulching, no-tillage, straw returning, slope terrace, ridge belt, and agricultural protection forest approaches were the most typical SWC measures. Furthermore, the new tillage measure of half-ridge planting needs to be examined in future studies. In conclusion, it is of practical significance to select suitable SWC measures for different hillslopes in the Mollisol region. [ABSTRACT FROM AUTHOR]

The aim of this paper is to deal with resource-constrained multiple project scheduling problems (rc-mPSP) under a fuzzy random environment by a hybrid genetic algorithm with fuzzy logic controller (flc-hGA), to a large-scale water conservancy and hydropower construction project in the southwest region of China, whose main project is a dam embankment. The objective functions in this paper are to minimize the total project time (that is the sum of the completion time for all projects) and to minimize the total tardiness penalty of multiple projects, which is the sum of penalty costs for all the projects. After describing the problem of the working procedure in the project and presenting the mathematical formulation model of a resource-constrained project scheduling problem under a fuzzy random environment, we give some definitions and discuss some properties of fuzzy random variables. Then, a method of solving solution sets of fuzzy random multiple objective programming problems is proposed. Because traditional optimization techniques could not cope with the rc-mPSP under a fuzzy random environment effectively, we present a new approach based on the hybrid genetic algorithm (hGA). In order to improve its efficiency, the proposed method hybridized with the fuzzy logic controller (flc) concept for auto-tuning the GA parameters is presented. For the practical problems in this paper, flc-hGA is proved the most effective and most appropriate compared with other approaches. The computer generated results validate the effectiveness of the proposed model and algorithm in solving large-scale practical problems. [ABSTRACT FROM AUTHOR]

Loess tunnel erosion is a distinctive soil erosion pattern that commonly occurs in collapsible loess areas. The resulting soil erosion is a serious and complex problem. At present, most of the research methods on loess tunnel erosion are based on field investigation, and the knowledge obtained is, therefore, mostly qualitative. Erosion characteristics and erosion rates of loess tunnels are rarely revealed quantitatively by laboratory physical modeling or field investigation. In this paper, we report the results of a small model test based on three types of archetypal geological structures that are recognized by field investigation, i.e., vertical fractures, horizontal fractures, and round holes, These results reveal the effect of different initial flow cross sections on the erosion characteristics of loess tunnels. We found that, where water crosses an area of loess, waterfalls dominate initial erosion. We also studied the mud erosion rate to quantitatively reveal tunnel-erosion rates and their variation with time and found that tunnel erosion occurs in three stages: a rapid-erosion stage, an erosion slow-down stage, and a slow uniform-erosion stage. Using a model test to undertake quantitative studies into the relationship between the erosion rate of a loess tunnel and both initial dry density and initial water content, we demonstrated a significant linear negative correlation between these parameters. Through physical simulations combined with field investigation and analysis of survey results, we found that the erosion of loess tunnels occurs with a certain periodicity and that the tunnel-erosion base level plays a decisive role in the erosional features and final morphology of loess tunnels. By increasing our understanding of the internal mechanisms of loess tunnel erosion, our work will contribute to the prevention of cave erosion and reduction in the risks of associated disasters in the Loess Plateau of the Yellow River in China and in other loess-containing areas around the world. Our studies also provide a theoretical basis for carrying out soil and water conservation work in similar areas. [ABSTRACT FROM AUTHOR]

The water source area of the middle route of the South-to-North Water Diversion Project is an important water conservation and ecological protection area in China. Based on remote sensing data, this paper analyzed the evolution process of land use/cover change in water source region in the past 35 years. Then, based on the InVEST model, the spatial-temporal patterns of water yield in the water source region were calculated with land use cover, meteorology and soil data as inputs. The impacts of climate factors such as precipitation and temperature and land use change on water yield were discussed, and the responses of water yield to these two changes were also discussed. The results show that from 1985 to 2020, the average water yield depth in the middle route of the South-to-North Water Diversion Project increases first and then decreases, from 615 mm in 1985 to 738 mm in 2000, and then decreases to 521 mm in 2020. The spatial heterogeneity of the water-producing capacity is obvious. The high value of the water-producing capacity is concentrated in the Daba Mountain area in the south, while the low values are concentrated in the Hanzhong Basin, Ankang Basin and the eastern plain area. The spatial pattern of water producing depth has no obvious change. The average water yield depth of forest, grassland and shrub in the region was the largest, and forest and cultivated land were the main contributors to the total water yield of the region, providing 82% and 14% of the total water yield in 2020. Precipitation has a significant effect on water yield, while land use/cover change has a small effect on water yield. [ABSTRACT FROM AUTHOR]

Coal power generation capacity is expanding rapidly in the arid northwest regions in China. Its impact on water resources is attracting growing concerns from policy-makers, researchers, as well as mass media. This paper briefly describes the situation of electricity-water conflict in China and provides a comprehensive review on a variety of water resources management policies in China's coal power industry. These policies range from mandatory regulations to incentive-based instruments, covering water withdrawal standards, technological requirements on water saving, unconventional water resources utilization (such as reclaimed municipal wastewater, seawater, and mine water), water resources fee, and water permit transfer. Implementing these policies jointly is of crucial importance for alleviating the water stress from the expanding coal power industry in China. [ABSTRACT FROM AUTHOR]

Background and objectives: Land use and land cover change (LULCC) directly affects the human living environment and economic society by influencing ecosystem services. This study explores the complex relationship between LULCC and ecosystem services in the Dongting Lake region of China. Methods: The analysis incorporates the transfer matrix analysis of LULCC, ecosystem service value (ESV) accounting, Mann-Kendall mutation test, gray correlation, and path analysis. This study explored the spatial and temporal characteristics of LULCC and ecosystem services and revealed the comprehensive impacts of LULCC on ecosystem services from the perspective of factor interactions. Findings: The findings reveal that open water (OW) area and farmable land are the dominant land use types transferring in and out of the study area, with significant interconversion observed among open water area, wetland (WL), arable land (AL), and forest land (FL). Water conservation, waste disposal, climate regulation, and biodiversity conservation emerge as the most crucial ecosystem services in the study area. The study identifies consistent patterns of abrupt changes in LULCC and ESV across six analyzed time periods. Forest land exhibits the most substantial direct influence on climate regulation, gas exchange, soil formation and protection, conservation of biodiversity, rawmaterials, and recreation and leisure. Additionally, forest land, wetland, arable land, and openwater area contribute significantly to the total ESV, with forest land being the dominant factor influencing the spatial differentiation of ecosystem services in the Dongting Lake region. Conclusion: The research reveals the consistency of ecosystem services and LULCC trends in the Dongting Lake area. LULCC is a complex process influenced by multiple factors, in which the conversion between ecological and nonecological land use has a significant impact, and the complex coupling and coordination among LULCC drivers together influence ecosystem services. Furthermore, LULCC alters the structure and scale of ecosystems, resulting in alterations in the ESV. [ABSTRACT FROM AUTHOR]

Natural vegetation protects, maintains, and improves the environment through its ecological functions and is, thus, an important component of Earth's ecosystems. The distribution of natural vegetation and its corresponding ecological roles vary with the topographic gradient. Understanding this role is essential for effective ecosystem management and conservation efforts. This study analyzes vegetation composition across altitude gradients and the spatiotemporal evolution of water conservation, soil conservation, and carbon storage in the southern hill and mountain belt of China. We then explored the drivers of the ecological functions of vegetation at different altitude gradients. The results showed that water conservation increased by 108.56%, soil conservation increased by 97.04%, and carbon storage increased only slightly. The ecological functions of vegetation varied across altitude gradients, with the 500–800 m gradient exhibiting markedly higher ecological functions than the other gradients. The effect of precipitation on soil conservation increases with altitude. In addition, at higher altitudes, evergreen coniferous forests had a greater effect on carbon storage. Based on the results, we propose vegetation management measures for different altitudes. This study provides a reference for decision-makers to develop and adjust ecological restoration programs in mountainous areas for the improvement of the local ecological environment. [ABSTRACT FROM AUTHOR]

Strong soil erosion and increasing human activities have made Loess Plateau areas ecologically fragile regions. Constructing the ecological security pattern (ESP) is imperative to maintain their ecosystem functions and sustainable development. However, it is still challenging to establish the ESP in such an unstable and scattered ecological environment. In this study, we take Shanxi Province, which suffers severe ecological problems in Loess Plateau areas, as an example to construct the ESP in a pattern of "source-resistance-corridor". The proposed methods include the following steps: (1) potential ecological sources are selected with important ecosystem functions based on contributions of soil and water conservation, habitat quality, and carbon storage; (2) ecological sources are determined by considering core areas at the landscape scale based on morphological spatial pattern analysis (MSPA) along with stability based on dynamic assessment on previous sources; (3) the comprehensive resistance surface is constructed by multiple resistance factors and remotely sensed nighttime light data; (4) ecological corridors are simulated and extracted based on circuit theory. As a result, the proposed ESP in our study area mainly includes 13,592 km2 of ecological sources, 8519.64 km of ecological corridors, and 277 ecological nodes. Meanwhile, an ecological framework of "two axes, three belts, and three zones" was proposed based on the optimization and reorganization of ecological components within the ESP. Our research lays a methodological and practical foundation for regional ESP construction and sustainable development in Loess Plateau areas. [ABSTRACT FROM AUTHOR]

The term "One Belt and One Road", firstly initiated by the Chinese Government, has brought new opportunities for the effect of China on South Asian countries in the economic and trade cooperation. From 2005 to 2016, the scale of goods trade between South Asian countries and China increased significantly, and South Asia gradually became an important trading partner of China. The structure of China's export products to South Asian countries has not changed much and most of which are technology and capital-intensive processed products. However, the elements of China's import products has changed a lot under marine water conservation and tends to be diversified and rationalized. This paper analyzes the complementarity and competitiveness of trade between China and South Asian countries by applying existing indicators, e.g., revealed comparative advantage index (RCA), trade integration index (TII), trade complementarity index (TCI), export similarity index (ESI) and trade competitiveness index (CI).The results show that China's trade with South Asian countries is more complementary than competitive, and there is great potential for international logistics between China and South Asian countries. According to the situation of marine water conservation, we should make use of trade complementarity to improve the structure of foreign trade, strengthen trade negotiations and advance the development of free trade zones, as well as strengthen infrastructure construction and promote connectivity, in order to increase international trade value and promote logistics industry in China and South Asian countries. [ABSTRACT FROM AUTHOR]

Groundwater reservoir technology is a vital way to achieve both efficient mining and water conservation in western coalfields in China. The stability of coal pillar dam is an emphasis of reservoir design, which plays an important role in the stability of groundwater reservoirs. Coal pillar dam should ensure the safety of coal mining, as well as the safe operation of groundwater reservoirs. The stability of coal pillar dam is closely related to water weakening and engineering geological conditions, such as buried depth, mining stress, geological structure and so on. In order to study the strength weakening law of coal pillar dam of groundwater reservoirs under water, this paper took Madiliang mine No.5 in western mining area as the research object, carried out a non-destructive water immersion test on coal sample and a uniaxial compression test on coal sample under various water content and repeated soaking. The results show that the water content of coal samples with various water content increased rapidly within 0-20 h; after 20 h, the grew rate slowed down; and in 20-70 h, the water content grew slowly; in 70-140 h, the growth of water content of coal sample was nearly stable. In conclusion, the water content of coal sample increases with the soaking time, but the increase rate gradually decreases, and finally tends to be flat. With the increase of water content( the number of times of soaking), the uniaxial compressive strength of coal sample decreases gradually, but the peak strain increases gradually, and the elastic modulus decreases gradually. Compared with the dry coal sample, the uniaxial compressive strength of the first water-saturation coal sample and the coal sample with the third soaking decreased by 27.1% and 50.0% respectively, and the elastic modulus decreased by 34.6% and 58.5% respectively. Combined with the above results and the elasticplastic mechanics theory, this paper discussed the damage zone and plastic zone width of coal pillar dam under various water content, carried out the research of coal pillar dam width considering overburden rock pressure, water pressure and water weakening, and designed the width of the groundwater reservoir combining with the engineering geological conditions of Madiliang mine. At the same time, the paper further analyzed the influencing factors of the width of coal pillar dam, concluding that the width of coal pillar dam is closely affected by water content, buried depth, and mining thickness. [ABSTRACT FROM AUTHOR]

This paper measured province-level water resource efficiencies in China from both static and dynamic perspectives, applying the undesirable-output-based Malmquist-Luenberger productivity index to panel data of 30 provinces in China from 2006 to 2015. Then, the paper analyzed factors that affect water resource efficiency by using a panel Tobit model. Research results showed significant lack of water resource efficiency with notable differences among provinces; water resource efficiency was somehow related to the level of economic development. Technical improvement was an important factor in water resource efficiency. The level of economic development had a non-linear influence on water resource efficiency. Industrial structure upgrading and population expansion could significantly improve water resource efficiency while the effects of water supply and per capita educational level were insignificant. [ABSTRACT FROM AUTHOR]

Climate variability and human activities are two main contributing attributions for runoff changes in the Yellow River, China. In the loess hilly-gully regions of the middle Yellow River, water shortage has been a serious problem, and this results in large-scale constructions of soil and water conservation (SWC) measures in the past decades in order to retain water for agricultural irrigation and industrial production. This disturbed the natural runoff characteristics. In this paper, we focused on a typical loess hilly-gully region (Wudinghe and Luhe River basins) and investigated the effects of SWC measures and climate variability on runoff during the period of 1961-2013, while the SWC measures were the main representative of human activities in this region. The nonparametric Mann-Kendall test was used to analyze the changes of annual precipitation, air temperature, potential evapotranspiration (PET), and runoff. The analysis revealed the decrease in precipitation, significant rise in temperature, and remarkable runoff reduction with a rate of more than 0.4 mm per year. It was found that runoff capacity in this region also decreased. Using the change point detection methods, the abrupt change point of annual runoff series was found at 1970, and thus, the study period was divided into the baseline period (1961-1970) and changed period (1971-2013). A conceptual framework based on four statistical runoff methods was used for attribution analysis of runoff decline in the Wudinghe and Luhe River basins (−37.3 and −56.4%, respectively). Results showed that runoff reduction can be explained by 85.2-90.3% (83.3-85.7%) with the SWC measures in the Wudinghe (Luhe) River basin while the remaining proportions were caused by climate variability. The findings suggested that the large-scale SWC measures demonstrated a dominant influence on runoff decline, and the change of precipitation extreme was also a promoting factor of the upward trending of SWC measures' contribution to runoff decline. This study enhances our understanding of runoff changes caused by SWC measures and climate variability in the typical semiarid region of Loess Plateau, China. [ABSTRACT FROM AUTHOR]

The mining of coal mines in western China needs to focus on protecting groundwater. A non-hydrophilic similar material for simulating the development and hydraulic conductivity of weakly cemented overlying strata fractures was developed. Fine sand, coarse sand, and gypsum are used as aggregates. Paraffin and Vaseline are used as binders. The non-hydrophilic material ratios of weakly cemented sandy mudstone and medium-grained sandstone were determined by orthogonal experiments, and used for similar simulation tests. The results show that the non-hydrophilicity of rock-like materials can be adjusted to prevent them from softening and collapsing under the action of water. Non-hydrophilic materials of higher strength and brittleness of rocks can be achieved by adjusting the content of paraffin, fine sand, and gypsum. The non-hydrophilic materials of soft and large particle rocks can be achieved by adjusting the content of paraffin, fine sand, and gypsum. After the coal seam in a similar simulation experiment was extracted, the large area of weakly cemented rock above it underwent overall settlement and fracture. Although this part was located within the failure zone, there was no macroscopic water-conducting cracks generated. The height of the water-conducting fracture zone was lower than the height of the fracture zone classified by the traditional 'three zone' theory, which is consistent with the on-site measurements. This indicates that the prepared non-hydrophilic material is reliable. The similarity simulation method based on non-hydrophilic materials can enrich the means for studying the fracture and permeability of weakly cemented overlying rocks in coal mines. [ABSTRACT FROM AUTHOR]

Irrigation districts are a pivotal infrastructure of agricultural water conservancy engineering. Implementing modernization will be the main task of large-scale irrigation districts for a considerable amount of time in the future. In this study, four typical large-scale irrigation districts in North China were investigated: the Renmin Shengliqu, Weishan, Shijin, and Zuncun irrigation districts. The concept of a modern irrigation district was deconstructed to establish an evaluation index system which includes four second-level indicators, twelve third-level indicators, and thirty fourth-level indicators. A hybrid approach based on AHP and OWA was used to quantify indicator weights used in group decision making. TOPSIS was introduced to measure the modernization level of the four irrigation districts. An obstacle factor diagnosis model was applied to search for key obstacle factors that will affect the modernization and improvement of the irrigation districts. The results showed that (1) the modernization levels of the Renmin Shengliqu, Weishan, Shijin, and Zuncun irrigation districts in 2020 and 2025 were 0.3916 and 0.5755, 0.3748 and 0.5396, 0.4493 and 0.6012, and 0.2343 and 0.6166, respectively. The evaluation results indicate that the four irrigation districts are still in the beginning phase (or even preparation phase) of the modernization process. (2) Eight indicators were identified as the main common obstacle factors for the four evaluated irrigation districts, including the irrigation water-use efficiency factor, the coverage proportion of information technology, the proportion of efficient water conservation irrigation areas, and so on. (3) There are two effective methods to enhance the modernization level of the four irrigation districts: improving water resource utilization efficiency and strengthening the management system with an emphasis on informatization. The present study can enrich the theoretical evaluation of irrigation districts and provide a scientific basis for the modernized construction and management of irrigation districts in China. [ABSTRACT FROM AUTHOR]

The Three-River Headstreams Region (TRHR) serves as the cradle of China's three major rivers—the Yangtze, Yellow, and Lancang—rendering its water conservation (WC) capacity quintessentially significant for Asian water resource security. This study integrated the InVEST model and random forest model to holistically elucidate the spatiotemporal characteristics and factors influencing WC in the TRHR from 1980 to 2018. The results revealed that the WC growth rate was 5.65 mm/10a in the TRHR during the study period, yet pronounced regional disparities were observed among different basins, especially with the Lancang River Basin (LRB), which exhibited a decrease at a rate of 5.08 mm per decade despite having the highest WC. Through Theil–Sen trend analysis, the Mann–Kendall abrupt change test, and the cumulative deviation method, meteorological, vegetative, and land use abrupt changes in approximately 2000 were identified as the primary drivers for the abrupt surge in WC within the TRHR. Furthermore, precipitation and the aridity index were the core feature variables affecting WC. However, a positive transition in land use patterns post-2000 was also revealed, and its favorable effect on WC was not as significant as the abrupt climatic changes. This study offers new perspectives on managing multidimensional spatiotemporal data and contributes to laying the groundwork for machine learning applications in water conservation. Additionally, it potentially provides useful references for decision-making processes related to ecosystem security. [ABSTRACT FROM AUTHOR]

In the realm of agriculture, biodegradable films are emerging as a promising substitute for traditional polyethylene (PE) films. Despite their potential, there has been a notable lack of extensive research on their effectiveness in the context of dry direct-seeded rice cultivation. Addressing this gap, a comprehensive biennial study was conducted in the northeastern regions of China, focusing on the 'Baonong 5' rice variety. This study meticulously compared three distinct cultivation methods: (1) employing biodegradable film mulching, (2) using conventional plastic film mulching, and (3) cultivating without any mulch. The findings revealed that biodegradable film mulching significantly enhanced soil moisture control, increased leaf area, and improved rice yield and water utilization efficiency (p < 0.05) compared to the plots without mulch. Notably, there was no marked difference in outcomes between the plastic film mulching and the unmulched plots. This research underscores the profound benefits of biodegradable film in rice cultivation, particularly from an environmental sustainability perspective. This innovative method not only boosts agricultural productivity but also addresses critical environmental challenges like climate change and water conservation. The application of biodegradable mulch has proven to be remarkably effective in improving irrigation efficiency and crop water conservation, leading to enhanced rice development and higher yields. The study recorded a substantial increase in water productivity—30% in 2021 and between 52.85% and 60% in 2022—compared to traditional cultivation practices. Furthermore, the use of biodegradable mulch resulted in significantly higher rice yields than the non-mulched plots, thus contributing to increased profitability. Such methods not only yield higher crop outputs but also mitigate environmental issues like water pollution and help alleviate prevalent water shortages in rice farming. [ABSTRACT FROM AUTHOR]

• NR has an amplifier effect on the trade-off and synergy strength relationship of other services. • There were five constraining effects types between environmental factors and four types of ESs. • 70 % vegetation cover, 2000 mm annual precipitation and 0.4 landscape diversity maximize the supply of ESs in the study area. Identifying the multiscale relationships of ecosystem services (ESs) and their influencing factors is helpful for scientific decision-making and regional sustainable development. Different from previous studies on trade-off and synergy relationships, this paper introduced a new perspective of the constraint effect and reports a third type of service relationship. This paper first assessed four typical ESs in the Pearl River Delta region, including water conservation (WC), soil conservation (SC), habitat quality (HQ), and natural recreation (NR). Applying segmented quantile regression, constraint lines for scatter plots of NR and three other ESs were extracted on 8 scale series. The key features of constraint lines were analyzed, and the multiscale constraint effects of four types of environmental factors on ESs were identified. The results showed that (1) NR-SC and NR-WC had a hump-shaped constraint relationship, while NR-HQ had a linear constraint relationship. The NR service not only has an amplifier effect on the trade-off and synergy strength relationship of other services, but its threshold range is also an important reference for realizing a win–win situation; (2) The threshold and key characteristics of the constraint line are closely related to the maximum and range values of vegetation coverage, slope, and landscape diversity; (3) Environmental factors had five constraining effects on ESs: hump-shaped, positive convex, negative convex, U-shaped and exponential, which not only limited the upper boundary of the ES supply but also had lower boundary constraint effects on specific services; and (4) When the vegetation coverage reached 70 %, the average annual precipitation reached 2000 mm, and the landscape diversity reached approximately 0.4, the total amount of ESs approached the maximum value. When the slope is close to 7.5°, monitoring of vegetation and soil erosion needs to be strengthened to reduce ecological risks. The application of the constraint line method in analyzing complex influence relationships has been proven to visualize nonlinear relationships and quantify the optimal values of influencing factors. It will help maintain the long-term stability of the entire ecosystem and become an effective tool for multiscale regional ecological planning. [ABSTRACT FROM AUTHOR]

Water security is an integral aspect of the socio-economic development in China. Nevertheless, water resources are under persistent pressures because of the growing population, heavy irrigation, climate change effects and short-term policies. Traditional management approaches narrowly focus on increasing supply and reducing demand without considering the complex interactions and feedback loops that govern water resource behaviour. Whereas these approaches may provide quick fix solutions, they often lead to unanticipated, sometimes catastrophic, delayed outcomes. Therefore, water management needs to take a holistic approach that caters to the interdependent physical (e.g. water inflows, outflows) and behavioural (e.g. decision rules, perceptions) processes in the system. Unlike reductionist approaches, System Dynamics (SD) takes a system-level view for modelling and analysing the complex structure (cause-effect relationships, feedback loops, delays) that generates the systemic behaviour. Simulating the SD model allows assessing long-term system-wide impacts, exploring leverage points and communicating results to decision makers. In this paper, we follow an SD modelling approach to examine the future of water security in Yulin City. First, we present a conceptual model for integrating water supply and demand. Based on this, we build an SD model to simulate and analyse the dynamics of water resource over time. The model output is tested to ensure that it satisfactorily replicates the historical behaviour of the system. The model is used to quantitatively assess the effectiveness of various supply/demand management options. Three scenarios are designed and examined: business-as-usual, supply management, and demand management. Results show that current management regime cannot effectively meet the future water demand. Whereas supply acquisition provides short-term benefits, it cannot cope with the growing population. A combination of conservation measures and demand-management instruments is regarded the most effective strategy for balancing supply and demand. [ABSTRACT FROM AUTHOR]

The definition of "Digital Water Conservancy" is proposed on the basis of "Digital Earth" in this paper. The necessity, feasibility, construction principles of "Digital Water Conservancy" are analysed, and the framework of it is proposed, that is: key technology, basic infrastructure, and comprehensive applications. The key technology is composed of spatial information technology, management information technology, and comprehensive information technology; the basic infrastructure consists of National Information Infrastructure (Nil), National Spatial Data Infrastructure (NSDI), special data of water conservancy and security measures; the comprehensive applications are made up of the management system, decision-making models, and application systems. The above three levels supply hardware and solftware to water conservancy around data acquisition and updating, processing and accessing, information extraction and analysis, propagation of information, building and updating of databases, web and transmission, and decision-making support. A spatial information infrastructure, special data of water conservancy, and decision-making models are the core and are discussed in detail. Digital Water Conservancy is a large and complex systematic engineering, but it can be regarded as being composed of points (reservoirs and lakes), lines (rivers and their watersheds), and regions (oceans). A digital reservoir analysis is carried out in Xue Ye Reservoir, Shandong Province to provide experience for informatisation of water conservancy in China. [ABSTRACT FROM AUTHOR]

The development of the leather industry in the Aojiang watershed of Zhejiang province increased the release of waste water. In the waste water, ammonium nitrogen (NH+ 4-N and Ge harms human health and biological species. This paper focuses on assessing the trends of NH+-N and Ge concentrations in the released waste water in Aojiang watershed and on understanding their relationships with the released waste water using regression and correlation statistics. The paper also utilizes the integrated pollution index to evaluate the water quality in the watershed. Preliminary results show that, from 1992 to 1998, the concentrations of NH4-N and Ge harms human health and biological species. This paper focuses on assessing the trends of NH+ 4-N and Ge concentrations in the released waste water in Aojiang watershed and on understanding their relationships with the released waste water using regression and correlation statistics. The paper also utilizes the integrated pollution index to evaluate the water quality in the watershed. Preliminary results show that, from 1992 to 1998, the concentrations of NH+ 4-N and total Ge increased 13 and 14 times, respectively, and they decreased somewhat after 1998. The concentrations of NH+ 4-N and total Ge are positively correlated to the amount of released waste water. These concentrations of NH+ 4-N and Ge, respectively, exceed 12 and 3 times, of the water standards. The water quality in the watershed degraded from Type III in 1992 to over Type V in 2003 when they were compared with the national water quality standards. It appeared that the pollution had positive correlation with leather industry production. The degraded water has no doubt affected human health and the ecosystem health. These results can provide scientific information for the local government to reasonably adjust the industry structure and reduce the pollution to protect the environment. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The adoption of soil and water conservation (SWC) technology is a key strategy for reducing global land degradation and improving agricultural productivity. This study uses survey data from households in the Loess Plateau in 2017 to evaluate the impact of social interaction on the decision-making process of SWC adoption by farmers. It measures the mediating effect of information acquisition and the moderating effect of internet use and deploys the probit model, general decomposition (KHB) model, and moderated effect model for analysis. The study found that the level of SWC adoption by farmers in the Loess Plateau of China remains relatively low, with only 57.3% of farmers adopting SWC, whereas social interaction increases the possibility of farmers adopting SWC by 10.0%. Accordingly, the paper argues that social interaction can encourage farmers to adopt SWC by improving their ability to acquire information, while internet use can positively moderate the impact of social interaction on farmers' adoption of SWC. Furthermore, the study found the positive impact of social interaction on SWC adoption is more pronounced for farmers in larger villages and those who join cooperative societies. Therefore, the research results provide a new perspective for promoting SWC in China, emphasizing the importance of enhancing social interaction improving farmers' ability to acquire information, and accelerating internet use. • Social interaction plays a crucial role in promoting SWC adoption. • Improving farmers' ability to acquire information can promote SWC adoption. • Internet use can moderate the impact of social interaction on SWC adoption. [ABSTRACT FROM AUTHOR]