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As a politically and culturally important city cluster, the Beijing–Tianjin–Hebei (BTH) region is the most prominent area in China where the imbalance between the supply and demand of water resources restricts the sustainable and healthy development of the regional social economy. In the context of global warming, research into water demand prediction that takes climate change into consideration would be more in line with the strategic goal of the low-carbon sustainable development of future cities. At the same time, the prediction of agricultural water demands against a background of climate change is urgently needed, while industrial water consumption is weakly correlated with climate change, an investigation of the statistical relationship between the two is needed. Thus, in this paper, future climate data from the BTH region under the scenarios RCP2.6, RCP4.5 and RCP8.5 were generated using a statistical downscaling model, and then coupled with agricultural and industrial water demand prediction models to simulate and analyze the impact of climate change on the agricultural and industrial water demands, respectively. The results show that during the forecast period (2020–2035), the reference crop evapotranspiration (ET0) growth rates in the Beijing, Tianjin and Hebei areas under the RCP2.6 scenario are 1.438 mm·a−1, 1.393 mm·a−1 and 2.059 mm·a−1, respectively. Under the RCP4.5 scenario, they are 2.252 mm·a−1, 2.310 mm·a−1 and 2.827 mm·a−1, respectively. Under the RCP8.5 scenario, they are 3.123 mm·a−1, 2.310 mm·a−1 and 2.141 mm·a−1, respectively. Furthermore, under each climate scenario, the increase in evapotranspiration in the Hebei area is the largest, followed by that in the Tianjin area, and that in the Beijing area is the smallest. For water consumption per CNY 10,000 of industrial added value during the forecast period, under the three different climate scenarios, a downward trend is seen in the Beijing area, with rates of 0.158, 0.153 and 0.110, respectively, but in the Tianjin area, there is an upward trend, with an upward tendency in rates of 0.170, 0.087 and 0.071, and an upward trend in the Hebei area, with an upward tendency in rates of 0.254, 0.071 and 0.036, respectively. This study will help the BTH region to rationally allocate agricultural and industrial water against the background of future climate change, and strengthen the coordination and cooperation between the different regions to promote the healthy and sustainable development of the cities. [ABSTRACT FROM AUTHOR]

The South-to-North Water Diversion Project in China is an important measure to promote the ecological civilization construction in the receiving areas. Since the operation of the east and middle routes, the comprehensive benefits are more and more remarkable. It is very significant to quantitatively evaluate the comprehensive benefits of the South-to-North Water Diversion Project. The idea of quantitative evaluation by the improved degree of the carrying capacity of regional water environment after water diversion is put forward in this paper. On the basis, combining with variable fuzzy set and cloud theory, a new comprehensive assessment model is established. According to the evaluation index system of water environmental carrying capacity and the index values of research area, the linear difference function value is generated randomly by triangular forward cloud generator, and then the variable fuzzy comprehensive evaluation is carried out. Taking Haihe River Basin and Beijing City as typical research areas respectively, the comprehensive benefits of water supply from the diversion project in 2030 are analysed. The comprehensive evaluation method with variable cloud model considers both “good” and “bad” aspects and considers both randomness and fuzziness. Results show that the model is feasible and efficient. It is worth popularizing and applying. [ABSTRACT FROM AUTHOR]

It is of great importance to predict or assess the water shortage risk to take some effective measures to reduce risk and losses. A new method of selecting water shortage risk factors is proposed according to the definition of a matrix-based Renyi's α -order entropy in this paper. Important factors were detected in terms of the values of mutual information between water shortage risk and risk factors. Furthermore, a logistic regression model is built to predict water shortage risk. Risks in Beijing during the period of 1979–2017 are evaluated to verify the performance of the model. Water consumption per GDP, water resources per capita and precipitation are the sensitive factors for water shortage risk. Water shortage risks in 2020 under different situations of precipitation are calculated by using the model. The result shows that the water shortage risk is greater than 0.9 with a possibility of 0.56 and greater than 0.5 with a possibility of 0.56 without consideration of the transferred and reclaimed water use. The average water shortage risk declines considerably by using the transferred and reclaimed water. However, the water shortage risk still exceeds 0.9 with a possibility of 0.32. The predicted risks are consistent with the observed risks in 2020 under different conditions of precipitation. [ABSTRACT FROM AUTHOR]

Quantitative predictions of urban domestic water consumption are of great significance for the planning and management of water resources. Aimed at the uncertainty in the process of water consumption forecasting, the kernel density estimation-fractional order reverse accumulative gray model was proposed. Based on the residual error of the fractional order reverse accumulative gray model, the kernel density estimation method was employed for the frequency analysis. According to the design value of residual error at different confidence levels and the predicted value of the fractional order reverse accumulative gray model, the prediction interval of the future water consumption was constructed. The model was validated using the annual urban domestic water consumption data in Beijing, Chongqing, and Qingdao. To test the performance of the model, the model was compared with the gray model with respect to the kernel density estimation—fractional order forward accumulative, kernel density estimation—first-order reverse accumulative, upper and lower bounds partition method—fractional order reverse accumulative and linear model with interval autoregression model. The technique for order of preference by similarity to the ideal solution (TOPSIS) was used to select the optimal model. The results show that the proposed model demonstrates the best performance regarding urban domestic water consumption prediction and can provide powerful decision support for addressing regional urban water consumption forecast issues in the water source sector. The proposed model also provides a new method for the prediction of urban domestic water consumption and other water consumption predictions. [ABSTRACT FROM AUTHOR]

This study is to analyze the relationship between human settlements system and water resources, select the water resource's carrying capacity index, and construct a system based on the human settlements system theory for the water resource's carrying capacity index. The index weight is determined by the analytic hierarchy process, and the set pair analysis method is used to calculate the connection number and evaluation grade of samples in Beijing, Tianjin, and Hebei Province from 2016 to 2019. The results show that there are differences in water resources carrying capacity from the perspective of human settlements in Beijing, Tianjin, and Hebei Province, and the changing trend of water resources carrying capacity in the three regions is different. The introduction of human settlement theory into the construction of water resource's carrying capacity index system can better reflect the carrying capacity of water resources to human society and can provide a new perspective for other related research in the future. [ABSTRACT FROM AUTHOR]

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With human social and economic development, the problem of consumption and pollution of water resources greatly reduces the quality of human life. The research on the carrying capacity of the water environment can provide a theoretical basis and data support for coordinating the contradiction between man and nature and the green development of the urban economy. The driving force-pressure-stateresponse model evaluation index system, combined with entropy method to strike the index weight, using cloud theory calculated the level of 2004-2017 for each year of the Beijing water environmental carrying capacity. The results show that the water environment carrying capacity of Beijing has been rising in the past 14 years. It is the lowest in 2004 and tends to be stable after reaching a higher level in 2010. Despite Beijing’s water environment carrying capacity has increased, but overall still in the overload state. [ABSTRACT FROM AUTHOR]

From the perspective of value-added trade, this paper divides the virtual water consumption and trade in different provinces of China into five major paths according to the input-output relationship. In 2012 and 2015, most provinces' water resources were implicitly used in the final products to meet the local demand. In addition, the volume of virtual water trade in the complex domestic value chain is greater than that in the traditional domestic trade value chain and the simple domestic trade value chain. In both years, judging from the sum of virtual water trade volumes in the three major value chains, there is virtual water net inflow in Beijing-Tianjin and the northern, eastern and southern coastal areas, and virtual water net outflow in the northeast, central and northwest areas. In the course of this research, the virtual water net outflow turned into net inflow in the southwestern area. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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.)

Li, M.; Li, W.; Xu, Y.Q.; Lin, W., and Li, T., 2020. Evaluation of water resources carrying capacity of Bohai coast Jing-Jin-Ji regions. In: Gong, D.; Zhang, M., and Liu, R. (eds.), Advances in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 106, pp. 414–418. Coconut Creek (Florida), ISSN 0749-0208. Water resources are an irreplaceable natural resource for human survival and economic and social development and an important guarantee for sustainable economic and social development. This study looks at the ecological footprint of the water environment in coastal areas and evaluates the ecological deficit or surplus in the Beijing-Tianjin-Hebei (Jing-Jin-Ji) region based on empirical results. The results showed that the water ecological footprint of the Jing-Jin-Ji region is generally in a state of deficit, with Beijing being the most serious, followed by Tianjin and Hebei. Finally, this paper puts forward countermeasures and suggestions to promote carrying capacity of water resources in coastal areas. [ABSTRACT FROM AUTHOR]

What exactly is the contribution of the South-to-North Water Transfer Project (SNWTP)? This is a subject of much debate. There are concerns about the possible effects on the macroeconomy. Most previous studies have tried to answer this question. In order to answer this question quantitatively, it is necessary to separate the effect of SNWTP from many influencing factors. A computable general equilibrium model (SICGE) was built to estimate the economic effect of the South-to-North Water Transfer Project on Beijing. This CGE model was modified by joining the subdivided water substitution module, the total water constraints module, and the water-capital substitution module. Two scenarios were set: one with SNWTP and one without SNWTP. The what-if scenario (without SNWTP) indicates that the water reduction poses a direct threat to economic growth. Employment, capital, and GDP are lower, largely due to water shortages suffered by many industries by comparative analysis with or without SNWTP. The water utilization for the water-intensive industry will decrease the most, and its output will also decrease the most. Without SNWTP, groundwater extraction will increase, which suggests that SNWTP water will tentatively replace groundwater. [ABSTRACT FROM AUTHOR]

• Water use efficiency evaluation based on 3D water footprint using SBM model. • Two scenarios for water use efficiency evaluation. • Analyzing the driving forces affecting water footprint change using the LMDI model. Water shortage and the conflict between water supply and demand have become the main constraints to the sustainable development of sustainable societies in Beijing-Tianjin-Hebei (BTH) region. Scientific evaluation of water usage efficiency and clarification of the three-dimensional water ecological footprint (EF 3D) drivers are of great significance for the collaborative environmental management of BTH region. This paper firstly explores the evolution of water footprint breadth (EF size), depth (EF depth) and EF 3D in BTH region from 2004 to 2020. Using the super-efficient SBM (Slacks-Based Measure) model with EF 3D to evaluate the water use efficiency of BTH region in two scenarios. 22 impact factors were selected to analyze the dynamics affecting the change of EF 3D in BTH region by using the LMDI (Logistic Mean Divided Index) model. The results show that: (1) The water resources pressure of the three provinces are in the overload state from 2004 to 2020, and the EF 3D is at its maximum in 2011–2015. The EF depth of BTH region is fluctuating up and then fluctuating down around 2012, and the most serious capital consumption of water resources stock is in Tianjin. (2) The water resources in Hebei are all in inefficient use. The water resources in Tianjin are in a state of inefficient use in some study years, and since 2014, the water resources are in a state of fluctuating increase and high efficiency. As for Beijing, the water resources are in a state of efficient use in the study years. On the whole, scenario 2 better reflects the water resources utilization efficiency situation and is more in line with the real situation. (3) The water structure and endowment of water resources are pivotal factors positively influencing the EF 3D. To mitigate EF 3D and achieve sustainable utilization of water resources, both Hebei and Tianjin have ample room for progress in elevating agricultural water-saving technologies, optimizing industrial structure, and enhancing water usage patterns. Agricultural water consumption is no longer the primary driver of water resource depletion in Beijing, necessitating focused attention on the impact of external water diversions in terms of local water displacement, optimization of water usage structures, and their role in supporting socio-economic development. Additionally, excessive reliance on external water diversions may entail associated risks that warrant consideration. [ABSTRACT FROM AUTHOR]

River water plays a critical role in riparian plant water use and riparian ecosystem restoration along losing rivers (i.e., river water recharging underlying groundwater). How to quantify the contributions of river water to the transpiration of riparian plants under different groundwater levels and the related responses of plant water use efficiency is a great challenge. In this study, observations of stable isotopes of water (δ2H and δ18O), 222Rn , and leaf δ13C were conducted for the deep-rooted riparian weeping willow (Salix babylonica L.) in 2019 (dry year) and 2021 (wet year) along the Chaobai River in Beijing, China. We proposed an iteration method in combination with the MixSIAR model to quantify the river water contribution to the transpiration of riparian S. babylonica and its correlations with the water table depth and leaf δ13C. Our results demonstrated that riparian S. babylonica took up deep water (in the 80–170 cm soil layer and groundwater) by 56.5 % ± 10.8 %. River water recharging riparian deep water was an indirect water source and contributed 20.3 % of water to the transpiration of riparian trees near the losing river. Significantly increasing river water uptake (by 7.0 %) and decreasing leaf δ13C (by - 2.0 ‰) of riparian trees were observed as the water table depth changed from 2.7 m in the dry year of 2019 to 1.7 m in the wet year of 2021 (p<0.05). The higher water availability probably promoted stomatal opening and thus increased transpiration water loss, leading to the decreasing leaf δ13C in the wet year compared to the dry year. The river water contribution to the transpiration of riparian S. babylonica was found to be negatively linearly correlated with the water table depth and leaf δ13C (p<0.01). The rising groundwater level may increase the water extraction from the groundwater and/or river and produce a consumptive river-water-use pattern of riparian trees, which can have an adverse impact on the conservation of both river flow and riparian vegetation. This study provides new insights into understanding the mechanisms of the water cycle in a groundwater–soil–plant–atmosphere continuum and managing water resources and riparian afforestation along losing rivers. [ABSTRACT FROM AUTHOR]

Ecological security and sustainable utilization of water resources have become increasingly important focal areas in today's conversation about water resource management. Ecological footprint models of water resources are commonly used to analyze these factors; however, traditional models do not consider regional and interannual differences. Here, an improved model by calculating water resource equilibrium factors (γw) was used to simulate the water resources ecological footprint (EFw) and water resources ecological carrying capacity (ECw) of Beijing, Tianjin, and Hebei. Ecological deficit and surplus (EDS), water load index (WRL), and ecological footprint of water resources per 104 Chinese yuan (WFG) were used to evaluate sustainable water usage. The findings reveal that γw is discrepant in across regions and years, as were EFw and ECw. Over the course of the study, EFw and ECw of Beijing–Tianjin–Hebei increased by > 25 and 46%, respectively. The sustainable utilization of water resources in the Beijing–Tianjin–Hebei region was found to be poor, but the utilization efficiency had improved through time. Finally, an uncertainty analysis was performed to determine how to improve sustainable development of water resources in Beijing–Tianjin–Hebei. Results suggested that reducing the discharge of sewage could reduce EFw and reducing the water consumption per 10,000 yuan of GDP could reduce WRL. This study provides valuable support for the sustainable utilization of water resources and the protection of ecological security in the Beijing–Tianjin–Hebei region. [ABSTRACT FROM AUTHOR]

The Zhangcheng District is critically responsible for protecting water resources, preserving sand sources, and improving the ecological environment in Beijing. Quantitative evaluation and research on the ecosystem water supply services in this area are beneficial for developing conservation planning and establishing ecological compensation mechanisms in water conservation areas. In this paper, based on the land use, meteorological, soil, and field observation data of the research area, the InVEST water yield model is used to estimate the water supply of the ecosystem in the Zhangcheng District. The model quantitatively analyzes the spatiotemporal distribution characteristics of water supply services in the basin and the influence of different topographic factors. The results show that the average supply of ecosystem water in the Zhangcheng District is approximately 45 mm, and there is a degree of spatial heterogeneity. The total water supply in the Zhangcheng District is relatively small. The water resource supply in the southwest is relatively small, the rainfall in mountainous forest areas in the southeast is high, its water supply is higher, and the supply of forest land water is relatively high. The high-value areas are mainly distributed at 1500 to 3500 m and 15°~40°; the water supply on the sunny slope is greater than that on the shady slope. With the increase in altitude and slope, the water supply in the basin tends to increase first and then decrease. [ABSTRACT FROM AUTHOR]

High-resolution hydrological modeling is crucial for detecting extreme hydrological events and understanding fundamental terrestrial processes. However, spatial resolutions in current hydrological modeling studies have been mostly constrained to relatively coarse resolution (~10–100 km), and they therefore have a difficult time addressing flooding or drought issues with fine resolutions. In this study, a continental-scale high-resolution hydrological modeling framework (0.0625°, ~6 km) driven by remote sensing products was used to detect extreme hydrological event occurrences in China and evaluated based on the Variable Infiltration Capacity (VIC) model. The results showed that the developed model provided more detailed information than the coarser resolution models (a 0.25° and 1°), thereby capturing the timing, duration, and spatial extent of extreme hydrologic events regarding the 2012 Beijing flood and 2009/10 drought in Hai River Basin. Here, the total water storage changes were calculated based on the VIC model (−0.017 mm/year) and Gravity Recovery and Climate Experiment (GRACE) satellite (−0.203 mm/year) to reflect the water availability caused by climate change and anthropogenic factors. This study found that the 0.0625° dataset could capture detailed changes, thereby providing reliable information during occurrences of extreme hydrological events. The high-resolution model integrated with remote sensing products could be used for accurate evaluations of continental-scale extreme hydrological events and can be valuable in understanding its long-term occurrence and water resource security. [ABSTRACT FROM AUTHOR]

Based on LEAP and WEAP, this paper establishes the coupled model of energy and water in cities. With Beijing as a case, 26 scenarios are designed to explore the energy saving/water saving of different policies in Beijing in the future and its nexus effect, including the sensitivity analysis of the results. The results show that the total energy consumption in Beijing will grow slowly by year. Carbon emissions will peak in 2020, and fluctuate after 2035 it will slowly increase until 2050. Total water demand is stable between 3.6 and 4.1 billion cubic meters. According to the forecasted water supply capacity, there is no shortage of water supply and demand. The proportion of groundwater from the source of water supply fell to 27%, and the proportion of water in the South-to-North Water Transfer increased to 40%. The total energy saving of the "13th Five-Year Plan" water saving policy is 1.003 million tons of standard coal, which is equivalent to 8.165 billion kWh of electricity. The energy saving policy has reached 276 million cubic meters of water, equivalent to 140 Kunming Lakes. The energy demand of residents' lives, service industry, construction industry and traditional manufacturing industry has a good correlation with water demand value, which proved they are important water-coupled sectors. In terms of energy-saving/water-saving effects in different scenarios and recent/long range periods, the industrial structure optimization policy showed good energy-saving potential in the short-term, but the long-term energy-saving effect was not obvious, while it was accompanied by an increase in water consumption. The irrigation technology innovation and planting structure optimization scenarios in the agricultural sector have better energy saving and water saving effects in the short term. However, with the occurrence and further expansion of water shortage, the medium and long term the water saving effect is sill, while the energy saving effect is not significant. The sensitivity analysis shows that the parameters of the scenario such as economic slowdown, industrial structure optimization, development of public transportation, and planting structure optimization are more sensitive. For the synergistic effect of water and energy conservation, the synergy effect is more obvious in the energy saving scenarios of the service industry and the industrial sector. For the policies of the same department, the synergistic saving effect of the situation of improving energy intensity is obvious. From the perspective of the difficulty in policy implementation process and overview effects, the water saving and energy saving policies of the industrial sector face more difficulties while implementation. The external power regulation policy and the capital rising residents' wareness of water saving policy has good performance both in the difficulty of implementation and overview effects. • This paper establishes the LEAP-WEAP coupled model of energy and water in cities. • Beijing energy saving policy has reached 276 million m3 of water, equivalent to 140 Kunming Lakes. • Beijing water saving policy is 1 million tce, equivalent to 8 billion kWh of electricity. • Water and energy saving policies of industrial sector face implementation difficulties. [ABSTRACT FROM AUTHOR]

The long-term overexploitation of groundwater leads to serious land subsidence and threatens the safety of Beijing-Tianjin-Hebei (BTH). In this paper, an interferometric point target analysis (IPTA) with small baseline subset InSAR (SBAS-InSAR) technique was used to derive the land subsidence in a typical BTH area from 2012 to 2018 with 126 Radarsat-2 and 184 Sentinel-1 images. The analysis reveals that the average subsidence rate reached 118 mm/year from 2012 to 2018. Eleven subsidence features were identified: Shangzhuang, Beijing Airport, Jinzhan and Heizhuanghu in Beijing, Guangyang and Shengfang in Langfang, Wangqingtuo in Tianjin, Dongguang in Cangzhou, Jingxian and Zaoqiang in Hengshui and Julu in Xingtai. Comparing the different types of land use in subsidence feature areas, the results show that when the land-use type is relatively more complex and superimposed with residential, industrial and agricultural land, the land subsidence is relatively more significant. Moreover, the land subsidence development patterns are different in the BTH areas because of the different methods adopted for their water resource development and utilization, with an imbalance in their economic development levels. Finally, we found that the subsidence changes are consistent with groundwater level changes and there is a lag period between land subsidence and groundwater level changes of approximately two months in Beijing Airport, Jinzhan, Jingxian and Zaoqiang, of three months in Shangzhuang, Heizhuanghu, Guangyang, Wangqingtuo and Dongguang and of four months in Shengfang. [ABSTRACT FROM AUTHOR]

The Middle Route Project of South-to-North Water Diversion (MRPSNWD) is a major strategic project to alleviate the serious shortage of water resources in northern China, and it benefited 14 large- and medium-sized cities in Henan, Hebei, Beijing, and Tianjin. Most of the predecessors used qualitative analysis to study the impact of the MRPSNWD on the water-receiving cities (WRCs), and they only considered one aspect of economy, society, resources, and environment, which could not fully reflect the impact of the MRPSNWD on the water-receiving cities. Therefore, based on the data of economic and social resources and environment of the water-receiving cities in the MRPSNWD from 2010 to 2019, an evaluation model based on entropy weight–analytic hierarchy process (AHP) fuzzy comprehensive evaluation method was constructed to account for the impacts on the economy-society-resources-environment of the water-receiving cities after the operation of the MRPSNWD and scientifically evaluated the comprehensive benefits of the MRPSNWD. The evaluation results revealed that the economic and environmental impacts of the MRPSNWD on the water-receiving cities were more obvious than those on society and resources. As far as water-receiving cities were concerned, the impact of the Middle Route Project of South-to-North Water Diversion on Zhengzhou, Shijiazhuang, Tianjin, and Beijing was generally higher than that of other cities. As far as the Middle Route Project of South-to-North Water Diversion was concerned, its overall impact on water-receiving cities was relatively slow. [ABSTRACT FROM AUTHOR]

With the intensification of human activities, the natural water cycle has a significant nature-society dual feature, and identifying the mutual feedback mechanism between natural and social water cycles is an important basis for a more accurate simulation of the dualistic water cycle. In this study, two indexes of cumulative runoff change rate and social water cycle feedback rate are put forward, representing the degree of change in socio-hydrological unit runoff under the mutual feedback of the natural social water cycle in all upstream regions, and the degree influence of the water intake, consumption, and discharge process of the social water cycle on the natural water cycle in the socio-hydrological unit, respectively. Taking the Beijing–Tianjin–Hebei region, which is marked by strong human activities, as the study area, the 2035 natural-social dualistic water cycles were simulated by a water allocation and simulation (WAS) model. Different water supply types and use structures cause the social water cycle to increase or decrease local runoff in different areas. The social water cycle feedback rate is greater than 1 in Beijing and Tianjin, and less than 0.25 in the mountainous areas and the Hebei plain, indicating that the social water cycle of each unit in the Beijing–Tianjin–Hebei region increases or decreases local runoff due to different water supply types and use structures. The cumulative runoff change rate in this region was 0.66, indicating that the overall runoff was attenuated due to the social water cycle, and runoff attenuation was greater in the south than the north. [ABSTRACT FROM AUTHOR]

The influence of surface water resource exploitation and utilization projects on groundwater has been widely studied. Surface water diversion projects lead to a reduction in river discharge, which changes the recharge of groundwater systems. In this study, the numerical simulation method is used to predict the variation in groundwater level under different diversion scale scenarios. The Zhangfang water diversion project in Beijing, China, was chosen for the case study. The downstream plain area of the Zhangfang water diversion project is modeled by MODFLOW to predict the influence of reducing water diversion on the dynamic change in the groundwater level in the downstream plain area. The model results show that the difference in groundwater recharge and discharge on the downstream plain of Zhangfang is 9,991,900 m3/a, which is in a negative water balance state, and the groundwater level continues to decrease. Reducing the amount of water diverted by the Zhangfang water diversion project to replenish groundwater is beneficial to the rise of the groundwater level in the downstream plain area. The results indicate that the groundwater flow model in the downstream plain area of Zhangfang performed well in the influence assessment of surface water resource exploitation and utilization projects on groundwater. This study also provides a good example of how to coordinate the relationship between surface water resources and groundwater resources. [ABSTRACT FROM AUTHOR]

Sediment deposition and intensified eutrophication of the Miyun Reservoir are directly affecting the water quality in Beijing, China, owing to water pollution issues in the Chaohe River Basin, which contains the main inflow river of the reservoir. This study analysed the runoff, sediment, total nitrogen and total phosphorus load simulation results from three observation stations using the Hydrological Simulation Program–FORTRAN model (Nash efficiency coefficient [NSE] = 0.65–0.8, R2 = 0.62–0.92) and a statistical regression model (R2 = 0.55–0.79). Results indicate that applying these models in combination to basins from which pollution source data are difficult to obtain can fully utilize the advantages of both models. The parameter uncertainty analysis of the model's runoff and pollution‐related parameters is discussed from the basis of the generalized likelihood uncertainty estimation analysis method. Further, using the Mann–Kendall test and the double cumulative curve method, an attribute analysis of climate change and human activities in the basin was carried out. Results show that in the context of global climate change, fundamental ways to achieve the goal of adaptive catchment management include adjusting the land use structure, optimizing the land use mode and carrying out comprehensive management of soil and water loss with vegetation restoration as the main body. [ABSTRACT FROM AUTHOR]

The problem of corrosion in water supply pipelines not only poses a considerable threat to the safety of drinking water but also causes a large amount of water wastage due to the leakage of the pipeline network, which can be a chronic problem for a municipal water supply system, as observed in Beijing and other cities in China. In this study, a new piezoelectric PVDF fiber membrane was prepared by electrospinning process, and a piezoelectric anticorrosive film was fabricated based on the internal environment of the pipeline. In the simulated water supply pipeline environment, based on the principle of the piezoelectric effect and the principle of cathodic protection, the electrochemical corrosion protection effect of piezoelectric materials in the water supply pipeline environment, under different water quality conditions, was investigated by a single factor experiment. The results show that piezoelectric anticorrosion tablets have an obvious inhibitory effect on pipeline corrosion under different pH values, ammonium nitrate concentrations, chloride ion concentrations, and sulfate ion concentrations. Furthermore, under the conditions of pH neutral, alkaline, and high ion concentration, the piezoelectric anti-corrosion sheet can protect the pipeline by 100%. Additionally, since the piezoelectric material can convert mechanical energy into electrical energy and does not cause pollution during the experiment, it has good environmental and economic benefits. The use of piezoelectric materials for preventing corrosion of pipelines is a frontier exploration. We believe that the improvement and development of material properties, and the combination of these new materials and traditional techniques, will provide new ideas and methods for pipeline anti-corrosion technology. [ABSTRACT FROM AUTHOR]

Groundwater serves as one of the crucial natural resources in the safety and sustainable development of Beijing economy. Due to the fact that Beijing is one of the megacities with groundwater as the main water source, it abstracts two-thirds of the city's water supply from groundwater. Meanwhile, the groundwater aquifer storage depletion has been larger than 1.04 × 1010 m3 during the past decades, which has brought serious eco-environmental problems to Beijing. The purpose of this study is to evaluate various abstraction schemes using a 3-D transient numerical groundwater flow model, to understand the present situation and future trend of groundwater resources in Beijing plain. The sustainable utilization of groundwater under these scenarios was comprehensively analyzed. The most reasonable scenario, which meets the appraisal restraint conditions, is the one that the groundwater extraction volumes of the three subsidence centers are reduced by 50%, 20%, and 100%, respectively, with the groundwater abstraction rate of 1.769 × 109 m3/year. Countermeasures that could be considered to improve sustainable groundwater management include: reducing groundwater abstraction directly; importing surface water from outside river basins; improving agricultural water use efficiency; and controlling the groundwater abstractions in the subsidence centers. The results of the modeling study could be used to inform policymakers and the government of Beijing. [ABSTRACT FROM AUTHOR]

• We assess the regional water resources carrying capacity (WRCC) scientifically. • Level of regional WRCC is assessed from three subsystems. • Change of WRCC can assess benefits of South-to-North Water Diversion Project (SWDP). • A new variable precondition S-type cloud algorithm is proposed to assess WRCC. • SWDP can increase carrying capacity of local water resources by 3.80% in Beijing. The purpose of water resources carrying capacity (WRCC) research is to meet the sustainable utilization of water resources and realize its sustainable development strategy. Scientifically evaluating the carrying capacity of regional water resources is extremely important. In this study, a variable precondition S-type cloud algorithm (VPSCA) is developed for assessment of regional WRCC based on social economic subsystem, water resources subsystem, ecological and environmental subsystem including thirteen indicators, which can overcome the shortcoming that the existing evaluation methods rarely consider fuzziness, randomness, and dynamic variability of parameters at the same time. First, forward S-type cloud generator algorithm (FSCGA) is developed based on segmented S-type membership function. On this basis, precondition S-type cloud generator algorithm (PSCGA) is proposed. Moreover, the VPSCA is developed by embedding PSCGA into variable fuzzy evaluation (VFE) method. Taking Beijing as a typical research area, this paper analyzes and forecasts the comprehensive benefits of water supply of the Middle Route of South-to-North Water Diversion Project (SWDP) in 2030 using VPSCA. The results show that SWDP can increase the carrying capacity of local water resources by 3.80%. In addition, feasibility and validity of VPSCA are further verified by comparison with other existing methods. This study aims to provide some suitable theoretical and practical implications of the evaluation of WRCC. [ABSTRACT FROM AUTHOR]

Comprehensive land surface models are very important for climate and weather forecasting and for improving our understanding of the relationships between humans and the Earth system. This work presents a land surface model of the Chinese Academy of Sciences (CAS‐LSM) that considers groundwater lateral flow, human water regulation, soil freeze‐thaw front dynamics, riverine dissolved inorganic nitrogen transport, anthropologic heat release, urban water usage, and urban planning based on the Community Land Model. Global simulations with the updated CAS‐LSM were conducted to evaluate its performance, and the results show its advantages in reproducing ecohydrological processes. Groundwater lateral flow can replenish the groundwater depletion cone caused by overexploitation, where the offset rate increases as the aquifer thickness increases. The maximum thaw depth increases by 3.62 mm yr−1 in permafrost areas, and the maximum frost depth decreases by 1.89 mm yr−1 in seasonally frozen areas. Nitrogen fertilizer use and point‐source pollution increase the riverine dissolved inorganic nitrogen flow rate in western Europe and eastern China. To further verify the model's ability to simulate the effects of urban planning implementation, simulations over Beijing were conducted using the Weather Research and Forecasting (WRF) model coupled with CAS‐LSM. The results show that anthropogenic heat release enhances the sensible heat flux and temperature in the city center. In terms of urban water planning, most of the total water supply in Beijing should be used for urban irrigation, and a small part should be used for road sprinkling to obtain a greater cooling effect. Plain Language Summary: This work presents a land surface model of the Chinese Academy of Sciences (CAS‐LSM) that considers groundwater lateral flow, human water regulation, soil freeze‐thaw front dynamics, riverine dissolved inorganic nitrogen transport, anthropologic heat release, urban water usage, and urban planning based on the Community Land Model. Global simulations with the updated CAS‐LSM were conducted to evaluate its performance, and the results show its advantages in reproducing ecohydrological processes. Simulations conducted using the Weather Research and Forecasting (WRF) model coupled with CAS‐LSM over Beijing show that the model can be used for urban water management. The results demonstrate that CAS‐LSM is a feasible tool for studying the effects of human activities on land surface processes. Key Points: The land surface model of the Chinese Academy of Sciences (CAS‐LSM) is developedThe model considers the effects of lateral flow, water use, nitrogen discharge and river transport, freeze‐thaw fronts, and urban planningEvaluation of the updated model shows its advances in simulations of ecohydrological responses to human activities [ABSTRACT FROM AUTHOR]

The impacts of climate change and human activities are challenging water sustainability in many cities around the world. Advanced understanding of the future long‐term coevolution of coupled urban human‐water systems is of considerable interest in this context. This study uses a previously developed sociohydrologic model to explore the coevolutionary trajectories of Beijing City's human‐water system over the 2015–2099 period under possible climate changes. The effects of multiple human adaptive actions under alternative climate scenarios are investigated in particular. Results show that there might be a recurrent competition for water between humans and the natural environment (e.g., groundwater aquifer) in the long‐term future, indicating that effective water management needs to ensure that this competition remains within a safe operating space. Three regimes of the human‐environment competition are revealed, including a sustainable development regime in which human society and groundwater aquifer are both safe throughout their coevolutionary trajectories, a regime that may lead to severe population loss due to overaggressive population control actions, and a regime that may cause aquifer depletion due to under‐perception of the drawdown of groundwater table. Results also show that relying too much on interbasin water diversion project might slacken human water conservation measures and eventually cause more severe aquifer depletion in the long run. Maintaining a high community sensitivity to drawdown of groundwater table and moderate measures to control population growth are keys to avoid unintended, negative consequences. Key Points: Three possible regimes of human‐environment competition for water depending on human adaptive actions are revealedActively transferring water from outside might unintendedly cause more severe aquifer depletion in the long runMaintaining a high community sensitivity to changes in groundwater depth is the key to avoid unintended negative consequences [ABSTRACT FROM AUTHOR]

• Offers a specific method for a reasonable control strategy for TABS in Beijing. • Outside temperature compensated water supply temperature as the basic control was evaluated. • Pre-cooling on weekend nights and reducing the water supply temperature as part of the control strategy. • The accuracy of the software EnergyPlus was validated. • The demand of the peak load is reduced. In recent years, research on control strategies for thermally activated building systems (TABS) has gained momentum. Nevertheless, problems still exist regarding how to choose reasonable control methods for TABS. The purpose of this work was to propose the control methods applicable to the operation of TABS in Beijing so as to reduce the unit capacity on the premise of realizing comfort. In this paper, three different control strategies were proposed: (1) the basic control of the outside temperature compensated water supply temperature, (2) optimal precooling during the weekend night hours and (3) optimal control of the supply water temperature; The effects of each control strategy were evaluated and compared using the metrics of thermal comfort and the total energy consumption. The results show that the discomfort rate of the basic control is so high. Then we adopted pre-cooling on a weekend night and optimized the water supply temperature as part of the control strategy for unsatisfactory areas. The results indicate that in Beijing, adopting pre-cooling on weekend nights and reducing the water supply temperature can not only improve the thermal comfort, but also reduce the capacity of the unit by up to 35%. This study offers a specific method for a reasonable control strategy for TABS in Beijing. [ABSTRACT FROM AUTHOR]

Beijing, the capital of China, has a fast-growing economy but is known for water scarcity. Therefore, relieving plans such as wastewater utilization and South-to-North-Transfer are implemented. Therefore, relationships are complicated among components in Beijing's water supply-and-demand system. Maintaining the water balance in Beijing is crucial both economically and politically. However, few have directly addressed the problem systematically recently. Therefore, the system dynamics (SD) approach is applied for modeling of the water supply-and-demand system. The objective is to investigate and forecast water balance, and to identify and propose solutions for potential challenges. The SD approach is a popular computer-aided systematic method for investigating intricate behaviors of complicated systems. A serious water shortage in Beijing in a few years is forecast because current relieving plans will reach their limits. Restricting certain water demands and improving water reclamation is recommended. There is an urgent need to develop and implement sustainable methods for Beijing. [ABSTRACT FROM AUTHOR]

China is facing great challenges to balance its natural water resource use and eco-environment protection, especially in the north semi-arid region with large water consumption due to the rapid economic growth. This highlights the urgency to use water resource carrying capacity (WRCC) as a measure to maintain the sustainable development of the human and natural water system. Here, we used a coupled model based on the system dynamics and cellular automaton models to assess the WRCC under the critical value of water resource withdrawal ratio (40%) and its sustainability in the Yongding River watershed in Beijing-Tianjin-Hebei region, where the water use highly depends on river flow and nonrenewable groundwater resources. The analytical results showed that the current regional WRCC is severely overloaded due to strong human activities. The predicted results based on four scenarios, i.e., existing development, water saving, industrial restructuring, and integrated development schemes, showed that although the improvement of water saving and water use efficiency has mitigated the regional water shortage, evidenced by the increased WRCC, the water shortage would continue due to the increased water demand. Under the integrated development scenario, it will need at least additional 7.1 × 108 m3 water per year (Beijing: 2.5 × 108 m3, Tianjin: 0.8 × 108 m3, Hebei: 3.8 × 108 m3) via the water transfer project to maintain the sustainability in the next decades. Our research provides recommendations for reasonable water utilization and supplementation under the severe water crisis. [ABSTRACT FROM AUTHOR]

Since its implementation in 2015, the Middle Route of the South‐to‐North Water Diversion Project (MR‐SNWDP) has transferred an average of 45 billion cubic meters of surface water per year from the Yangtze River in southern China to the Yellow River and Hai River Basin in northern China, but how that supply is able to cope with droughts under different scenarios has not been explored. In this study, using the water demand for 2020 as the guaranteed water target, a Water Evaluation and Planning system was used to simulate available water supplies in Beijing under different drought scenarios. In the case of a single‐year drought, without the MR‐SNWDP, Beijing's water shortage ratio was 16.7%; with the MR‐SNWDP, this ratio reduced to 7.3%. In the case of a multi‐year drought, without the MR‐SNWDP, Beijing's water shortage ratio was 25.3%; with the MR‐SNWDP, this ratio reduced to 7.4% and domestic water supply was improved. Our research suggests that to prepare for multi‐year drought in the Beijing area, the SNWDP supports increased supplies to the region that would mitigate drought effects. This study is, however, mostly focused on water supply provision to Beijing and does not comprehensively evaluate other potential impacts. Multiple additional avenues could be pursued that include replenishing groundwater, increasing reservoir storage, and water conservation methods. Further research is needed to explore the relative costs and benefits of these approaches. Research Impact Statement: Importance of the MR‐SNWDP (middle route of the South‐to‐North Water Diversion Project) for ensuring available water supplies in Beijing. [ABSTRACT FROM AUTHOR]

An extreme rainfall event that occurred in Beijing city during 19–21 July 2016 was investigated. The analysis indicated that the main pattern at 500 hPa was a "two-ridges-one-trough" pattern; meanwhile, the cyclonic circulation at 850 hPa controlled the Beijing area and the southerly wind brought wet air to Beijing, causing abundant water vapor during this event. Hindcast experiments were carried out using the NCAR's Weather Research and Forecasting model with the NCEP's Global Forecast System datasets as the initial and boundary conditions. We found that the model ensemble could reproduce the spatial distribution of the rainfall, and different model physical parameterization scheme combinations led to differing simulation skill. Furthermore, the analysis indicated that the model performed differently in different periods of the rainfall event. The water vapor supply, divergence, rain mixing ratio, and cloud mixing ratio were the main factors that influenced the model's performance. [ABSTRACT FROM AUTHOR]

The shortage of water resources is a key factor limiting the sustainable development of the economy and society in Beijing. This study analysed the spatiotemporal patterns of Beijing's water conservation services (WCS) based on the water balance equation at multiple scales, including city, main functional areas and key districts and counties, determined the differences in the water conservation amount among different land cover types and investigated the reasons for the spatiotemporal differences in the water conservation amount. The results indicated that: (1) compared to 2005, water conservation amount increased substantially in 2010. However, the overall water conservation capacity was low. (2) Among the various land cover types in Beijing, the average water conservation capacity decreased in the following order: wetland, forest, grassland, cropland, bare land and artificial surface. (3) The average water conservation amount in the main functional areas of Beijing varied substantially and was positive only in the ecological conservation area (ECA). (4) The water conservation capacity of each district and county varied substantially within ECA, among which the contribution of the forest in Miyun District, Huairou District and Pinggu District was the highest. The changes in the spatiotemporal patterns of Beijing's WCS were the synthetic effects of changes in the land covers and meteorological conditions. This study is helpful in achieving the sustainable utilization of water resources in Beijing. [ABSTRACT FROM AUTHOR]

The mismatch between water demand and water availability in many megacities poses vexing water management challenges. Managers are forced to take remedial efforts to address these challenges, often with a heavy focus on infrastructure solutions such as building reservoirs or interbasin transfers to meet demand, which may in fact exacerbate the problem through unintended consequences that arise from neglect of social, economic, and environmental factors. Such a situation awaits Beijing, China, which faces major water management challenges in spite of the addition of a large interbasin transfer to meet increasing demand. In this study, a sociohydrologic model is developed for investigating Beijing's future water sustainability from a holistic and dynamic perspective. Using the model, we first explore the sociohydrologic mechanisms that contributed to Beijing's worsening water situation during 1988–2014. We then use the model to assess possible future impacts of the South to North Water Diversion Project on Beijing's water supply prospects for the 2015–2035 period. Alternative futures are explored by combining three different sustainable management strategies. The model results show that the source of Beijing's dominant water pressure experienced a transformation from productive to domestic water use over the last 30 years. They also indicate that the transfer water via South to North Water Diversion Project cannot fundamentally reverse Beijing's water shortage in the long term and that demand‐oriented management measures will be required for alleviating the city's water stress. These findings provide guidance not only for Beijing's water management but also for other less developed cities around the world. Key Points: A dynamic urban sociohydrologic model is developed for understanding Beijing's water sustainability issuesPossibility space of alternative water futures is explored to guide future water management effortsConstraining domestic water demand remains a top concern for alleviating Beijing's future water stress [ABSTRACT FROM AUTHOR]

Karst water is an important element of underground water in Beijing and is characterized by abundance of supply and high quality. Karst water is an ideal water source for alleviating the supply and demand discrepancy of water resources and providing water for the city. The water environment of karst landforms is relatively fragile and requires additional attention. So the rational use of karst water requires the establishment of scientific and effective models of water quality evaluation. Taking several karst water distribution areas as examples, this study established an index and standard of estimation according to set pair analysis (SPA). The study subsequently built the corresponding connection and determined the weighting factor according to the degree of association. Basic indicators of water quality were processed and analyzed through comprehensive evaluation principles to provide a foundation for the actual management and the rational use of karst water distribution areas in Beijing. [ABSTRACT FROM AUTHOR]

Beijing's local water resources have been overexploited and the ecological and environmental pressures exceed the carrying capacity of this densely populated megacity. This article examines the current status of Beijing's water resources with respect to its industrial, residential, and eco-environmental water usage and the challenges it may face in the near future. The article describes the context of water uses, the steps taken by Beijing to alleviate the water shortage problems, and challenges to Beijing's abilities to meet its urgent and future water needs. A multipronged strategy is proposed that aims at both the present problems and the anticipated future challenges. In particular, engineering and institutional approaches for Beijing's successful transition from overexploitation to sustainable utilization of water resources are explained. Actions include reasonable water utilization, water conservation, reclaimed wastewater, and importing water from neighboring areas. We conclude that Beijing must take additional steps in water resource management to ensure its sustainable development that involves continued urbanization sprawls and population growth. Future water resource management strategies should focus on strengthening water demand management through water conservation, efficient interbasin water transfers, use of nontraditional water resources, strategically reserving water supply, and promoting rehabilitation of the eco-environments. [ABSTRACT FROM AUTHOR]

Water shortages in the Beijing-Tianjin-Hebei (BTH) region in China have constrained the region's coordinated development. A feasible solution is introducing water rights transactions through the middle route of the South-to-North Water Diversion Project (SNWDP). However, there are few methods available for systematically simulating and evaluating the impact of inter-regional water rights transactions. In this study, an improved computable general equilibrium (CGE) model was developed to simulate the water rights transactions. Different water resources were integrated as intermediate inputs, and the model includes a substitution mechanism between different water resources. The water stress index (WSI) was used to evaluate the impact on the economy and water resources simulated by the model. The study proposes and evaluates different scenarios with different water-saving levels and transaction volumes. Water rights transactions have a positive effect on the overall economic growth of the BTH region, reducing the local water resource stress in Beijing and Tianjin; the transactions have a limited impact on the economy and water usage of Hebei Province. Compared with the general water-saving intensity scenario without water rights transactions, the recommended scenario adopts ultra water-saving intensity, along with the transfer of 100 hm3 of water rights from Hebei to Beijing and Tianjin. This leads to an increase in the overall gross domestic product (GDP) of the BTH region by CNY 0.587 trillion (USD 99.6 billion); a decrease in local water usage in Beijing and Tianjin of 197 hm3; and a relief in the regional imbalance of water resources stress. This study provides a quantitative analysis tool for evaluating the impact of water rights transactions and optimizing water resources allocations in the BTH region, providing a reference for simulating and evaluating water rights transactions in other regions. [ABSTRACT FROM AUTHOR]

The water footprint (WF) vividly links water resources with virtual water of food, providing a novel perspective on food demand and water resources management. This study estimates the per capita WF of food consumption for six provinces in North China. Then, the study applies the logarithmic mean Divisia index method to decompose the driving forces of their WF changes. Results show that the per capita WF of food consumption in Beijing, Tianjin, and Inner Mongolia increases significantly in 2005–2017, whereas that in the other three provinces in North China varies slightly. All provinces have shown the same trend of food structure changes: the grain decreased, whereas the meat increased. In general, the urban effect was positive, and the rural effect was negative for all regions. The urban effects in Beijing and Tianjin played a leading role, whereas the rural effects in the other four provinces played a leading role from 2005–2009. However, the urban effects in all provinces played a leading role in 2010–2017. The WF efficiency increased in each province, and the effect in urban areas is stronger due to the higher water use efficiency. For most provinces, the consumption structure was positive because the diet shifted toward more meat consumption. The food consumption per capita effect was the major driving force in Beijing and Tianjin due to the increased consumption level, whereas the population proportion effect exerted a weak effect. To alleviate the pressure on water resources, further improving water use efficiency in food production and changing the planting structure should be emphasized for all regions in North China. [ABSTRACT FROM AUTHOR]

The human activities and urbanization process have changed the underlying surface of urban areas, which would affect the recharge of groundwater through rainfall infiltration and may further influence the groundwater environment. Accordingly, it is imperative to investigate the variation of hydrological cycle under the condition of underlying surface change. Based on the high-precision remote sensing data of 2000, 2005, 2010 and 2015, and Soil and Water Assessment Tool (SWAT) model, this work firstly studied the land use change and the corresponding changes in runoff generation mechanism and rainfall infiltration coefficient in Su-Mi-Huai area, Beijing, China. Meanwhile, SWAT-MODFLOW semi-loose coupling model was applied to analyze the water balance in the study area in typical hydrological years. The results showed that the area of the construction land (urban and rural residential land) increased by 1.04 times from 2000 to 2015, which is mainly attributed to the conversion of cultivated land to construction land in the plain area. This change caused the runoff in the area to increase by 7 × 106 m3, the runoff coefficient increased by 17.9%, and the precipitation infiltration coefficient was less than the empirical value determined by lithology. Compared with 2000, the average annual precipitation infiltration coefficient in 2018 decreased by 6.5%. Under the influence of urbanization process, the maximum reduction rate of precipitation infiltration recharge is up to 38%. The study investigated the response of surface runoff and precipitation infiltration recharge to land use change, which can provide helps for water resources managers to coordinate the relationship between land use change and rational water resources planning. [ABSTRACT FROM AUTHOR]

Increasing water scarcity has made it difficult to meet global water demands, so the sustainable use of water resources is an important issue. In this study, the sustainable water resource system (SWRS) operating mechanism is discussed, considering three components: dynamics, resistance and coordination. According to the SWRS operating mechanism, a universal indicator system with three layers, including goal, criterion, and index layers, is constructed for SWRS evaluation. Additionally, considering the fuzziness of threshold values for grading standards, an SWRS evaluation model is constructed based on the set pair analysis (SPA), analytic hierarchy process (AHP) and attribute interval recognition methods. This model is conceptually simple and convenient. An evaluation indicator system is constructed for the SWRS in Beijing, and evaluation standards with five grades are established. The dynamics of the sustainability of the Beijing SWRS and corresponding operating mechanism are analyzed using the SPA evaluation model. The results suggest that the three components of the operating mechanism all have positive effects on the Beijing SWRS state, but the SWRS state has not yet been fundamentally changed. Therefore, considerable improvements can be achieved regarding the sustainability of the Beijing SWRS. [ABSTRACT FROM AUTHOR]

A sustainability assessment of water resources is essential for maintaining regional sustainable development. In this study, a comprehensive assessment of changes in the sustainability of the water resource system in Beijing from 2008 to 2018 was conducted on the basis of the driver-pressure-state-impact-response (DPSIR) model. To reflect the impacts of humans on the water consumption and pollution of water resources, the water footprint was considered. In addition, key factors that affect the sustainability of water resources were filtered by the modified entropy method. The results indicated that all drivers, pressures, states, impacts, and responses demonstrated increasing tendencies. As a result, a remarkable improvement in the sustainability of the water system, which was mitigated from an alert state to a good state, was achieved due to the comprehensive effect of the indexes. From these results, we inferred that the sustainability of regional water resources could only be achieved through a comprehensive consideration of regional social, economic, and environmental water systems and climate change. Therefore, formulating medium- and long-term urban, economic, and water development plans and adjusting medium- and short-term water utilization programs could contribute to the sustainable utilization of regional water resources. [ABSTRACT FROM AUTHOR]

Streamflow is likely affected by climate change and human activities. In this study, hydro-meteorological data from six rivers upstream of Beijing, namely, the Yongdinghe, Baihe, Heihe, Chaohe, Juhe, and Jumahe Rivers, were analyzed to quantify the spatial and temporal variability of streamflow and their responses to climate change and human activities over the period of 1956–2016. The Mann–Kendall test and moving t-test were used to detect trends and changing points of the annual streamflow. Results showed that the streamflow into Beijing experienced a statistically significant downward trend (p < 0.05), abruptly changing after the early 1980s, owing to climate and human effects. The climate elasticities of the streamflow showed that a 10% decrease in precipitation would result in a 24.5% decrease in total streamflow, whereas a 10% decrease in potential evapotranspiration would induce a 37.7% increase in total streamflow. Human activities accounted for 87% of the reduction in total streamflow, whereas 13% was attributed to climate change. Lastly, recommendations are provided for adaptive management of water resources at different spatial scales. [ABSTRACT FROM AUTHOR]

With increased attention paid to the changes of global climate, the impacts on hydrological processes remain poorly understood in specific basins. In this study, we selected Luanhe River Basin, which is an important source of water supply to Beijing and Hebei, as a case study for the analysis of the combined impact of precipitation and temperature change to hydrological components in a semi-arid river basin. This study investigated the change of the blue water flow (BWF), green water flow (GWF), and green water storage (GWS) by employing the SWAT (Soil and Water Assessment Tool) model and stochastic methods in different time scales during 1960 to 2017. The contribution of climate changes to hydrological change were quantified by 16 hypothetical scenarios by recombining climatic data. The results show that the annual daily maximum and minimum temperature (Tmax, Tmin) increased while their differences (DTR) decreased. However, there was no significant trend in annual precipitation and hydrological components. The trend of precipitation has a positive impact to the change of all three hydrological components. Although precipitation contributes more to changes in hydrological components, more attention also needs to be given to the change of DTR, which has positive impact of GWF that contrasts with that of BWF and GWS. Seasonal scale studies of these changes suggested that more attention should be paid to the climate change in spring and winter when the hydrological components were more sensitive to climate change. Our results summarized hydrological components variability under the impact of climate change and demonstrated the importance of analyses at different time scales, which was expected to provide a reference for water resources management in other semi-arid river basins. [ABSTRACT FROM AUTHOR]