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Groundwater plays a critical water resources role in arid and semi-arid areas. Quantitative evaluation of groundwater recharge is crucial in hydrogeological investigations. Under the complex hydrogeological and climatic conditions in China's arid and semi-arid regions, groundwater recharge shows significant spatio-temporal heterogeneity. Although there has been much research, including hydrochemical analysis, isotope tracing, in-situ tests and numerical simulations, accurate quantitative groundwater recharge is still a great challenge. This paper reviews the progress in research on groundwater recharge in arid and semi-arid regions of China, focusing on the principles and current applications of the main techniques, as well as the achievements in nine typical arid and semi-arid regions (Tarim Basin, Junggar Basin, Shule River Basin, Heihe River Basin, Yinchuan Plain, Badain Jaran Desert, Loess Plateau, Ordos Plateau, North China Plain). The paper reveals that the chloride mass balance method is a popular method to estimate groundwater recharge rate, whereas stable isotopes and hydrochemistry analyses, as well as the joint use of both, have been widely used in the understanding of groundwater recharge processes and mechanisms in the arid and semi-arid regions of China. Numerical modeling and remote sensing technology will become important approaches to quantify large-scale groundwater recharge. It is also suggested that various estimation methods should be used in combination, in order to improve the reliability of recharge estimates. Furthermore, this review shows that the theoretical research so far still cannot meet the needs of regional development, and the paper highlights some scientific problems that need to be further explored. [ABSTRACT FROM AUTHOR]

Henan Province is the birthplace of Chinese civilization and one of the earliest human settlements, which means that the area has an important national cultural heritage. Traditional villages are an important facet of this cultural heritage, and studying their spatiotemporal characteristics in different periods has important theoretical and practical significance for the sustainable development and protection of cultural heritage in the region. This paper takes the traditional villages of the Yellow River basin in Henan Province that were formed before 1919 as the research object. Information on the ancient river was obtained through a literature search as well as via field research, and the important tributaries of the Yellow River in different periods were mapped using ArcGIS 10.0 software. The nearest neighbor index, kernel density estimation, standard deviation ellipse and other methods were adopted to analyze the spatiotemporal characteristics of the traditional villages. The factors that influenced the evolution of traditional villages were explored in depth by combining changes in the course of the river and water conservancy projects. The results show that the formation of traditional villages along the Yellow River in Henan Province has experienced a historical track of growth, contraction, growth and prosperity and stability. The traditional villages along the Yellow River in Henan Province generally show a clustered pattern, forming a dense concentration of traditional villages in the middle reaches of the Yellow River. The center of gravity shows a migration trend from southeast to northwest. In terms of influencing factors, the spatiotemporal evolution of the relationship between villages and their distance to water is closely related to climatic fluctuations, changes in channel, water conservancy projects and social and cultural factors. This paper deepens our understanding of the relationship between traditional village evolution and watersheds by improving the consistency between village spatial distribution and historical geography and provides a useful theoretical reference for the sustainable development of China's traditional villages. [ABSTRACT FROM AUTHOR]

This paper explores whether the sponge city construction implemented in China can restore the hydrological condition of the river basins through runoff depth. The annual runoff depth was calculated based on the volume capture ratio of annual rainfall (VCRAR) and compared with undeveloped and before sponge city construction. The results conclude as follows: the current rainwater source control standard benefits the hydrology recovery in China. But the difference between before sponge city construction and undeveloped is large in 12.9% of the regions. The adjustment recommendations of the VCRAR proposed in this paper are favourable to restoring the river basin hydrology. [ABSTRACT FROM AUTHOR]

For mankind's survival and development, water, energy, and food (WEF) are essential material guarantees. In China, however, the spatial distribution of WEF is seriously unbalanced and mismatched. Here, a collaborative governance mechanism that aims at nexus security needs to be urgently established. In this paper, the Yellow River Basin in China with a representative WEF system, was selected as a case. Firstly, a comprehensive framework for WEF coupling coordination was constructed, and the relationship and mechanism between them were analyzed theoretically. Then, we investigated the spatiotemporal characteristics and driving mechanisms of the coupling coordination degree (CCD) with a composite evaluation method, coupling coordination degree model, spatial statistical analysis, and multiscale geographic weighted regression. Finally, policy implications were discussed to promote the coordinated development of the WEF system. The results showed that: 1) WEF subsystems showed a significant imbalance of spatial pattern and diversity in temporal changes; 2) the CCD for the WEF system varied little and remained at moderate coordination. Areas with moderate coordination have increased, while areas with superior coordination and mild disorder have decreased. In addition, the spatial clustering phenomenon of the CCD was significant and showed obvious characteristics of polarization; and 3) the action of each factor is self-differentiated and regionally variable. For different factors, GDP per capita was of particular importance, which contributed most to the regional development's coupling coordination. For different regions, GDP per capita, average yearly precipitation, population density, and urbanization rate exhibited differences in geographical gradients in an east-west direction. The conclusion can provide references for regional resource allocation and sustainable development by enhancing WEF system utilization efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • The drought pattern in China is closely related to the basin distribution and multiple teleconnection factors. • The intensity and frequency of drought in China exhibited an increasing trend. • The ENSO-AO had important positive effects in the major basins in China. • Multiple wavelet coherence helps identify the processes controlling drought changes. Due to increasing global warming and the frequent occurrence of severe drought risk in recent decades, many studies have investigated drought in China. However, the spatiotemporal heterogeneities of droughts are complicated, and a comprehensive analysis of the driving forces has not been thoroughly explored. In this paper, we studied the temporal and spatial patterns of drought in China from 1960 to 2018 and disclosed its relationship with multiple teleconnection factors on different time scales. The results show that (1) Drought in China has exhibited a fluctuating increasing trend over the past 59 years, with a standardized precipitation–evapotranspiration index (SPEI) rate of change of –0.12/10 a, and the most severe droughts occurred during 2000–2010. (2) There was a significant abrupt change in China's meteorological droughts induced by climate change around 1997. (3) The trend in China was characterized by drought in spring and autumn and humidification in winter, while the trend in the Southwest River Basin was characterized by drought. (4) A combination of factors can best explain the drought variations from basin to basin, and the El Niño-Southern Oscillation (ENSO)-Arctic Oscillation (AO) was most commonly the best predictor. The use of multiple wavelet coherence helps to identify the dominant drought change processes. [ABSTRACT FROM AUTHOR]

This study investigates shared benefits through the cooperation between North Korea and China over transboundary water management in the Yalu River Basin. Primary attention has been placed on joint hydropower development since the 1950s, which has brought in developmental benefits for North Korea and security benefits for China. Data on the study have been collected from relevant papers, government publications, and media reports of China and South Korea. The information on North Korea, particularly about hydropower dams, is only accessible through secondary sources collected from South Korean government thinktanks due to the lack of publicly available data. The case study method is deployed for exploring specific issues and context and addressing problems. The significance of the study lies in the fact that this study is one of the first studies to examine transboundary river cooperation for development and security benefits between the countries. An array of bilateral agreements over the river basin has culminated in co‐building and jointly operating the four dams along the river. The construction of two additional dams, which is nearing completion, symbolizes shared benefits for both countries, hydroelectricity for North Korea, and regional security for China. Research Impact Statement: The study provides an in‐depth and unique analysis of joint hydropower development between North Korea and China in the Yalu River Basin. [ABSTRACT FROM AUTHOR]

Based on daily temperature observation dataset with high quality and spatial resolution, this paper revealed the dominant invading paths of the extreme cold surges (ECSs) within China by using the fifth percentile of temperature drops instead of the traditional unified threshold in the operation. The maximal probabilities of the ECSs from the upstream regions to the down‐stream regions along the invading paths are also provided. Results indicate the distribution of the fifth percentile is quite different in various regions, with the highest value centers of more than 8°C in northern China, and a secondary center of 6–7°C in southern China. While in the areas between the Yellow River basin and the Yangtze River basin, the two longest rivers in China, the values are below 5°C. This result explains the unreasonable frequency gap between the two rivers in previous unified threshold. Based on the distribution, the whole country is roughly divided into 18 regions at an approximate box of 5°N × 10°E to acquire clear and objective invading paths by the lead–lag correlation analysis and an objective identification of the paths. Results show the ECS invading path in northern China has a dominant west or northwest track. But in southern China, the invading paths are more complex, generally from north to south. In China, about 30–40% ECS cases in the upstream regions can lead to the ECSs in the down‐stream regions along the dominant paths. By the identification and the lead–lag correlation, northwestern China could be regarded as the source of ECSs invading other regions. [ABSTRACT FROM AUTHOR]

China consumes 0.15-0.2 million tons of antibiotics yearly, which takes up 50% of the world's consumption. In this paper, 7 watersheds in China were investigated in order to show a clear picture of the antibiotic distribution in the environment, seasonal variation, and sources. We find that the majority of the aquatic antibiotics come from livestock and aquaculture, followed by medical waste, wastewater treatment plants, and domestic sewage. The spatial distribution of antibiotics varies greatly. Antibiotic concentrations were the lowest in the Yangtze River while the highest was in the Liaohe River and the Pearl River. Songhua watershed and the Southwest River, influenced by the economy and population in the northwest region, displayed a lower quantity of antibiotics. Seasonal variance showed dry season concentrations that were higher than the wet season. Additionally, antibiotics exist not only in the water but also in the sediments. Overall, the distribution of antibiotics in China is uneven due to the economy and population levels. Public health risk and ecological impacts are big concerns regarding the great deal of antibiotic consumption and discharge. [ABSTRACT FROM AUTHOR]

The Badain Jaran Desert (BJD) in China is a desert with impressive sand dunes and a groundwater situation that has attracted numerous researchers. This paper gives an overview of the mysteries of groundwater in the BJD that are exhibited as five key problems identified in previous studies. These problems relate to the origin of the groundwater, the hydrological connection between the BJD and the Heihe River Basin (HRB), the infiltration recharge, the lake-groundwater interactions, and the features of stable isotope analyses. The existing controversial analyses and hypotheses have caused debate and have hindered effective water resources management in the region. In recent years, these problems have been partly addressed by additional surveys. It has been revealed that the Quaternary sandy sediments and Neogene-Cretaceous sandstones form a thick aquifer system in the BJD. Groundwater flow at the regional scale is dominated by a significant difference in water levels between the surrounding mountains and lowlands at the western and northern edges. Discharge of groundwater from the BJD to the downstream HRB occurs according to the regional flow. Seasonal fluctuations of the water level in lakes are less than 0.5 m due to the quasi-steady groundwater discharge. The magnitude of infiltration recharge is still highly uncertain because significant limitations existed in previous studies. The evaporation effect may be the key to interpreting the anomalous negative deuterium-excess in the BJD groundwater. Further investigations are expected to reveal the hydrogeological conditions in more detail. [ABSTRACT FROM AUTHOR]

A constrained total water-use policy has been implemented to maintain sustainable water supply in some water shortage areas. Managing a constrained water-use quota (T) in water allocation is a challenging goal. This paper proposes a new framework for water allocation under total water-use constraint by utilizing the concept of the Newsboy model, commonly used in operations management and applied economics, and applying it to the Dongjiang River Basin, South China. This framework considersTas a state variable of the objective function, rather than simply dealing with it as a constraint of multi-objective analysis. Using this framework, it is revealed how different schemes ofTplay out in water allocation, and water-use warning is provided for each sector and water governor in water resources management. [ABSTRACT FROM PUBLISHER]

In this paper, the intensity, area and duration of future droughts in China are analyzed using the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). The SPI and SPEI are used to evaluate the simulation ability of drought characteristics with the regional climate model COSMO-CLM (CCLM). The projected intensity and duration of future drought events are analyzed for the period 2016-2050 under three different respective concentration pathways (RCPs). The simulated and projected drought events are analyzed by applying the intensity-area-duration method. The results show that CCLM has a robust capability to simulate the average drought characteristics, while some regional disparities are not well captured, mainly the simulation of more drought events of shorter duration in Northwest China. For the future period 2016-2050, more intense dryness conditions are projected for China. An increase in evapotranspiration is found all over China, while a reduction in precipitation is apparent in the southern river basins. The increase in evapotranspiration plays an important role in the changes of future droughts over the northern river basins and southern river basins. Under RCP2.6, drought events of longer duration and with higher frequency are projected for the southwest and southeast of China. Under RCP4.5 and RCP8.5, a continuing tendency to more dry conditions is projected along a dryness band stretching from the southwest to the northeast of China. More frequent drought events of longer duration are projected in the southwestern river basins. For all future droughts, larger extents are projected, especially for events with long-term duration. The projected long-term drought events will occur more often and more severe than during the baseline period, and their central locations will likely shift towards Southeast China. The results of this study can be used to initiate and strengthen drought adaptation measures at regional and local scale, especially in the south of China. [ABSTRACT FROM AUTHOR]

Acquiring freshwater resources is a necessary component of sustainable human settlement subject to increasing pressure from population and climate changes. This sometimes scarce resource primarily comes from rivers, and international river basins ( IRBs), where watersheds and watercourses cross political boundaries, are often spaces of great political tension and conflict worldwide. Such conflict potential has garnered interest from a wide range of research communities, and each emphasises public access to hydrologic data as integral to successful international management of IRBs. However; these hydrologic data, especially measurements of river flow rate, are often closely guarded state secrets. Satellites have been cited as a key technology set to challenge this data monopoly that have yet been unable to calculate river flow rate without some form of guarded ancillary data. Now, at-many-stations hydraulic geometry ( AMHG) offers a means of circumventing data limitations without any a priori information, and the forthcoming NASA/ CNES Surface Water and Ocean Topography ( SWOT) satellite also promises to estimate flow rates solely from its novel measurements following launch. In this paper, we explore how these newly available estimates of river flow rate could reconfigure water-management and interstate relations in IRBs, and demonstrate AMHG, for two cases: the Ganges- Brahmaputra and Mekong. For these basins we find that satellite flow rate retrievals will likely reinforce and favour state-level negotiations of water resource governance. Also, satellite flow retrievals can have the direct, concrete effect of improving hydrologic understanding of the upstream Ganges- Brahmaputra, a sorely needed advance that will positively benefit millions of Bangladeshis and affect state-level interactions between India, China, and Bangladesh. Finally, we avoid offering prescriptive water management solutions for each case, as local stakeholders will ultimately determine if and how such satellite retrievals will be used. [ABSTRACT FROM AUTHOR]

Soil sealing (loss of soil resources due to extensive land covering for the purpose of house building, road construction etc.) and subsequent soil landscape pattern changes constitute typical environmental problems in many places worldwide. Previous studies concentrated on soil sealing in urbanized regions, whereas rural areas have not been given sufficient attention. Accordingly, this paper studies soil landscape pattern dynamics (i.e., landscape pattern changes in response to rural anthropogenic activities) in the Tiaoxi watershed (Zhejiang province, eastern China), in which surface sealing is by far the predominant component of human forcing with respect to environmental change. A novel approach of quantifying the impacts of rural anthropogenic activities on soil resources is presented. Specifically, quantitative relationships were derived between five soil landscape pattern metrics (patch density, edge density, shape index, Shannon’s diversity index and aggregation index) and three rural anthropogenic activity indicators (anthropogenic activity intensity, distance to towns, and distance to roads) at two landscape block scales (3 and 5 km) between 1985 and 2010. The results showed that the Tiaoxi watershed experienced extensive rural settlement expansion and high rates of soil sealing. Soil landscapes became more fragmented, more irregular, more isolated, and less diverse. Relationships between soil landscape pattern changes and rural anthropogenic activities differed with the scale (spatial and temporal) and variable considered. In particular, the anthropogenic activity intensity was found to be the most important indicator explaining social development intensity, whereas the other two proximity indicators had a significant impact at certain temporal interval. In combination with scale effects, spatial dependency (correlation) was shown to play a key role that should be carefully taken into consideration in any relevant environmental study. Overall, the findings of this work suggest that soil sealing can be a critical human forcing issue with considerable consequences deserving serious attention by the experts, the public and the government alike. [ABSTRACT FROM AUTHOR]

Summary: In this paper, the trends of the annual streamflow and precipitation and cross correlations between them were analyzed in nine large river basins of China during 1956–2005. The results indicate that: (1) the annual mean streamflow decreases in arid and semi-arid regions of north China; however, increasing trends occur in south and Southwest China; (2) the annual streamflow and precipitation exhibit reasonable correlation in nine large river basins except those located in inland areas. The annual streamflow over most areas of China is fed by precipitation; however, the decline in streamflow is faster than the decreases of precipitation since 1970s in the arid and semi-arid regions of north China. The relationship between the annual precipitation and streamflow presents a non-stationary state in north China. This non-stationary relationship is strongly influenced by both human activities and precipitation changes; (3) a significant increase of water use might be the major factor responsible for the steeper decline in streamflow than in precipitation in Haihe River, Yellow River and Songliao River basins in north China. In inland river areas, increase of water use and actual evapotranspiration might result in decline in streamflow although precipitation has an increase tendency. This paper sheds light on the non-stationary relationship between annual precipitation and streamflow and possible underlying causes, which will be helpful for a better understanding of the changes of precipitation and streamflow in China at large scale and in other regions of the world. [Copyright &y& Elsevier]

Large dams represent a whole complex of social, economic and ecological processes, perhaps more than any other large infrastructure project. Today, countries with rapidly developing economies are constructing new dams to provide energy and flood control to growing populations in riparian and distant urban communities. If the system is lacking institutional capacity to absorb these physical and institutional changes there is potential for conflict, thereby threatening human security. In this paper, we propose analyzing sustainability (political, socioeconomic, and ecological) in terms of resilience versus vulnerability, framed within the spatial abstraction of a powershed. The powershed framework facilitates multi-scalar and transboundary analysis while remaining focused on the questions of resilience and vulnerability relating to hydropower dams. Focusing on examples from China, this paper describes the complex nature of dams using the sustainability and powershed frameworks. We then analyze the roles of institutions in China to understand the relationships between power, human security and the socio-ecological system. To inform the study of conflicts over dams China is a particularly useful case study because we can examine what happens at the international, national and local scales. The powershed perspective allows us to examine resilience and vulnerability across political boundaries from a dynamic, process-defined analytical scale while remaining focused on a host of questions relating to hydro-development that invoke drivers and impacts on national and sub-national scales. The ability to disaggregate the affects of hydropower dam construction from political boundaries allows for a deeper analysis of resilience and vulnerability. From our analysis we find that reforms in China's hydropower sector since 1996 have been motivated by the need to create stability at the national scale rather than resilient solutions to China's growing demand for energy and water resource control at the local and international scales. Some measures that improved economic development through the market economy and a combination of dam construction and institutional reform may indeed improve hydro-political resilience at a single scale. However, if China does address large-scale hydropower construction's potential to create multi-scale geopolitical tensions, they may be vulnerable to conflict – though not necessarily violent – in domestic and international political arenas. We conclude with a look toward a resilient basin institution for the Nu/Salween River, the site of a proposed large-scale hydropower development effort in China and Myanmar. [Copyright &y& Elsevier]

The assessment of the accessibility for medical resources is of great significance for understanding the distribution characteristics and optimizing the space allocation of medical resources. This paper incorporated the probability statistical data of actual medical treatment choice behavior of residents into the formulation of accessibility. We constructed a health facility accessibility index combined the travel time with waiting time and an improved three-step floating catchment area method to evaluate the accessibility of outpatient and inpatient treatment for residents. Results showed the accessibility of outpatient and inpatient treatment has significant geographical differentiation characteristics and presents a distribution pattern of high in the eastern and central China and low in the western. The outpatient medical service was available for residents, which there are more than 85% of the population having access to medical services within 30min.The accessibility of inpatient treatment presents a radiological distribution model with provincial capital city as the core, in which the spatial allocation of high-quality medical resources is not balanced and the regional difference is obvious. This study demonstrated the geographical differentiation characteristics of spatial distribution for the accessibility of medical resources in China, which can provide targeted proposals according to medical institutions level. • Evaluating the spatial accessibility from outpatient and inpatient medical treatment. • A health facility accessibility index and the improved three-step floating catchment area method were employed. • The policy-oriented matrix of medical services was constructed to provide policy recommendations for the provinces in China. [ABSTRACT FROM AUTHOR]

Responding to China's major environmental challenges, researchers are increasingly exploring dynamics between international non-governmental organisations, the nation-state, and local communities. Much less understood are domestic environmental non-governmental organisations (eNGOs) and their interactions with actors across scales. This paper responds by exploring domestic eNGOs and interactions with institutional actors, including international donors, and with levels of Chinese government. The practices of eNGOs in China are influenced by interactions at various scales. Rather than being directly influenced by international partners and simply constrained by state regulations, Chinese eNGOs are embedded in more complex power relations. These interrelationships are exemplified in the operations of Green Watershed, a domestic eNGO working in Yunnan Province. Green Watershed has extensive interactions with international donors and various levels of government as a result of its national campaign and long-term local projects. Relationships between eNGOs’ international donors and the Chinese government are significant in influencing eNGO practice. NGO–government relations in China are inconsistent and constantly changing owing to the diverse interests and priorities of the various levels of government. The impacts of the local practice of Chinese eNGOs are deeply informed by their relationships both at and beyond the local level. Complex interrelationships make it difficult to achieve bottom-up, participatory resource management in China. [ABSTRACT FROM PUBLISHER]

The paper analyses the range of lake management organizations (LMOs) established in China and proposes management recommendations for different lake types and contexts. Based on functions, regional coverage and sectoral focus, nine LMO patterns are identified, ranging from existing agency approaches in which there is no specific lake focus or institutional responsibility to comprehensive and powerful lake basin authorities. LMO development in China faces many challenges, including a preoccupation with organizational form rather than function and objectives, duplication with existing agency functions, and insufficient lake basin management and trans-jurisdictional coordination. We therefore propose that LMOs should be tailored to specific situations and problems, drawing distinctions between plateau, urban, plain, inland and wetland lakes as well as other contexts. [ABSTRACT FROM AUTHOR]

In this paper we use archaeometallurgical data from the Yunnanese Bronze Age sites of Hebosuo and Shangxihi, to examine the nature of early exchange networks within Yunnan, across southern China and into Mainland Southeast Asia (MSEA). Traditional perspectives on relations between China and MSEA were viewed from a Core-Periphery (C–P) perspective, derived from World Systems Theory (WST) but this area, though now divided by national borders, has shared ecological and cultural characteristics that allow its definition as the Southeast Asian Massif (SAM). The fourteen analysed samples were all unleaded copper or bronze, mostly as-cast and with some annealing. Their lead isotope signatures did not group at site level but showed broad consistency with the other, limited, signatures available from Yunnan, Sichuan and Guangxi. Critically, comparison with MSEA signatures revealed good isotopic consistency with key Bronze Age sites in Thailand, Myanmar and Vietnam, active within tight timeframes, and mostly lying on or near the path of major river systems that find their source in or via Yunnan. The picture we propose, based on current data, is one of a complex network of autochthonous SAM societies interacting at short (ca. 50 km), medium (ca. 300 km) and long (ca. 800–1600 km) ranges over mountainous and forested terrain. • Yunnan and Mainland Southeast Asia have recently aligned Bronze Age chronologies. • 14 copper-base artefacts from early 1st mill. BC Hebosuo and Shangxihi were analysed. • 8 were unleaded copper and 6 were unleaded copper.11 as-cast, 2 annealed & 1 corroded. • Lead isotope ratios did not cluster intrasite but were consistent with southern China. • Consistency with selected Mainland Southeast Asian signatures suggests radial network. [ABSTRACT FROM AUTHOR]

For close to a decade China has been implementing ‘eco-compensation’ mechanisms to address water-related ecosystem issues. This paper examines China’s approach to eco-compensation through experience in the Lake Tai watershed. Four typologies of eco-compensation schemes are identified and analysed, primarily through a legal lens. It is concluded that while progress has been made, there is need for improved legal approaches to this complex topic. [ABSTRACT FROM AUTHOR]

Abstract: Freshwater is the essential resource element to support and ensure human life and regional sustainable development. On the basis of the concept of ecosystem service footprint proposed by Burkhard, in this paper, we introduce a new methodological approach that addresses the sustainability and capability of regional freshwater provision and consumption, which we have coined freshwater ecosystem service footprint model (FESF model). The FESF model enhances the accuracy of water provision and consumption calculations and reveals a spatial-pattern of freshwater ecosystem service footprint at the watershed scale, overcoming the shortcomings of the traditional water footprint model, which was first introduced by Rees and Wackernagel in 1992. The proposed model is tested in the Beijing–Tianjin–Hebei (BTH) freshwater supply area in China, where water use restrictions are regularly imposed on the population and economic activities. The results of the physical process and theoretical analysis reveal that FESF model is a reliable and helpful model for researchers to understand the regional freshwater situation. The average FESF is 0.94hectare per capita in BTH, with a maximum of 2.52hectare per capita and a minimum of 0.36hectare per capita. Approximately 16.8% of the considered region, primarily parts of the mid-northern region and the surrounding eastern and southern low-lying regions, is under high freshwater resource pressure. In conclusion, this model can be used by researchers and policymakers for promoting sustainable human–ecology interactions. [Copyright &y& Elsevier]

Abstract: China''s floating population is one of the largest migrations in the world. In recent years, great efforts have been made to identify their socio-demographic characteristics. However, the extent of their concern about the local environment has had less attention in the research. In the major migration cities of China, large numbers of migrants have a serious environmental impact on the ecological environment. Their environmental concerns could influence local environment policy design and environment protection implementation. The role that the temporary nature of the floating population plays in their environmental perception is now attracting the attention of local administrations. Based on an investigation conducted in the Shawan River Basin of Shenzhen City, China, this paper studies the floating population''s environmental concerns and possible movement choices, as well as some socio-demographic features. The results show that the percentage of migrants intending to settle in Shenzhen is much larger than previous studies indicated. As concerns local pollution problems, most respondents seem unconcerned and show indifferent attitudes. In particular, migrants ignore the heavy water pollution, which is the most serious pollution in the Basin. People who intend to settle down have more positive opinions on the local environment. The results also indicate that the migrants do not have enough knowledge or environmental awareness and they lack a sense of belonging, which should concern local supervisors and administration. Better education and social activities should be conducted to improve the situation. [Copyright &y& Elsevier]

Available water resources are decreasing in river basins around the world. Some reseachers have suggested various indicators and methods that should be used to allocate water resources. This paper attempts an integrated approach to water allocation that accounts for a wide range of factors at the river basin level. Using the Hai, Huai, and Yellow River Basins of Shandong Province in China, 19 indicators were assimilated into a water scarcity index and weighted based on surveys collected from 82 multidisciplinary experts. Fuzzy set probability was then used to quantify water scarcity for each river basin. A water allocation method was also calculated using 13 indicators and objectively weighted using the analytical hierarchy process. Results show that all river basins in Shandong Province have severe water scarcity and highlight that economic factors play the most critical role in water scarcity, followed by water supply factors then water demand. Water allocation indicators were prioritized according to water resource pressure and utilization proportionality among districts in the Huai River Basin. The results should provide direction for future research. [ABSTRACT FROM AUTHOR]

Climate change, over abstraction, pollution and questionable engineering-based paradigms are contributing to a state of crisis in water governance. This paper reports on preliminary research in Lake Baiyangdian catchment, China, which has the potential to realise more systemic and adaptive forms of water governance through development and use of a method that reframes water catchment management in the form of social learning. A cross-disciplinary research group worked together with multiple-department managers and stakeholder representatives within a purposefully designed ‘learning system’ to create an insipient social learning platform. The results demonstrate the potential to reframe water catchment management in Lake Baiyangdian so as to better address the questions: who should manage the water catchment and what in the catchment should be the focus of managing? [ABSTRACT FROM AUTHOR]

Abstract: Evapotranspiration is an important flux term in the water cycle that integrates atmospheric demands and surface conditions. Thus, analysis of the temporal variation of reference evapotranspiration (ET0) will help us to understand climate change and its effect on hydrology. In this paper, we present an analysis of the monthly ET0 at 15 stations during 1961–2005 in the Taoer River basin in China, calculated by the FAO Penman–Monteith method. We derived the growing season and annual total ET0 time series and using the Mann–Kendall method, moving t test and Morlet wavelet conducted comprehensive time series analysis to characterize significance test, abrupt change and period in the ET0 data sets. The results present that: (i) in terms of the seasonal cycle, monthly ET0 reaches its peak in May and growing season ET0 accounts for 60.7% of annual total. Long term growing season ET0 fluctuates in accordance with annual ET0, both having turning points in 1982 and 1993; (ii) with respect to the long term persistence, the trends for growing season and annual ET0 show the same spatial patterns: high positive values in the west study area in the upper reach and negative values in the Southeast study area in the lower reach. The spatial distribution of annual tendencies suggests an influence from the altitude and latitude; (iii) for individual station, abrupt changes in annual ET0 are more pronounced than those in growing season ET0. The timings for the abrupt changes in ET0 series at individual stations are consistent with those in regional ET0. Abrupt changes detected in the early 1980s are all increasing changes, while those in earlier 1990 are all decreasing changes; and (iv) based on the Morlet wavelet analysis, there exist significant periods of 1, 3 and 7.3 years in annual ET0 series and significant 1 year period and 7.3 years period in growing season ET0 series. Maximum air temperature, mean air temperature, relative humidity and bright sunshine hours are main climate variables responsible for the periodicity in ET0. [Copyright &y& Elsevier]

The emerging water crisis in China shows that the current institutional frameworks and policies with regard to water resources management are incapable of achieving an effective and satisfactory situation that includes Integrated River Basin Management (IRBM). This paper analyses this framework and related policies, examines their deficiencies in relation to all water stress problems and explores alternatives focusing on river basins. Water resources management reforms in modern China are reviewed and the main problems involved in transforming the current river management system into an IRBM-based system are analysed. The Huai River basin is used as an example of current river basin management, with quantitative data serving to show the scale and scope of the problems in the country as a whole. The institutional reforms required are discussed and a conceptual institutional framework is proposed to facilitate the implementation of IRBM in China. In particular, the roles, power and responsibilities of River Basin Commissions (RBCs) should be legally strengthened; the functions of supervising, decision-making and execution should be separated; and cross-sectoral legislation, institutional coordination and public participation at all levels should be promoted. [ABSTRACT FROM AUTHOR]

China's rivers face major challenges arising from social and economic development, particularly associated with pollution and over-abstraction. Although these issues vary significantly across the country, China has adopted a national, unified approach to manage water resources in a river basin context. This paper assesses the legal and institutional arrangements for river basin management in terms of decentralization and centralization. It considers the appropriate roles for the different levels of government, including providing for participation and integration across these levels. It proposes strengthening institutional development and capacity building in the future. [ABSTRACT FROM AUTHOR]

The formation and geomorphic evolution of the Jiuduansha Shoal are investigated over the past 50 years in this paper. The sedimentary processes, formation, and geomorphic evolution of the Jiuduansha Shoal in the Yangtze River Estuary, eastern China, are analyzed based on digitized sea maps from 1945 to 2001, satellite images from 1975 to 2001, and field survey data in the spring-neap tidal cycle in the dry and flood seasons in 2003. The suspended sediment concentration and hydrodynamics of the North Passage and South Passage during the dry and flood seasons in the spring-neap tidal cycle in 2003 were investigated, and relations between the North Passage and South Passage of the Jiuduansha Shoal are analyzed. Results show that seasonal and spring-neap tidal cycle variations in sediment and water discharge from the drainage basin correspond to erosion and deposition on the Jiuduansha Shoal. The results and data can provide useful information for the management of the Yangtze River Estuary and restoration of the estuarine tidal flat ecology. [ABSTRACT FROM AUTHOR]

[Display omitted] • Accurate assessment of China's ecological environment changes in the past 20 years is important. • We used time-series NDVI data (1998–2018) to evaluate China's ecological environment change. • In one-third of China the ecological environment has improved, and in 10%, the ecological environment has deteriorated. • The Yellow River Basin is an area where the ecological environment has significantly improved. • The main reason for the deterioration in the ecological environment of the eastern coastal areas is urban expansion. The ecological environment is the foundation of human survival and development. China's ecological environment has undergone a historic transition from partial improvement to overall improvement. In this paper, long time series NDVI data (1998–2018) are used to evaluate the ecological environment change and spatiotemporal change that has taken place in China over the last 20 years, at different scales (regional, provincial, county, and grid scales). Combined with typical areas, the causes of ecological environment change are revealed. The results show that in about one-third of China, the ecological environment improved, and in 10%, the ecological environment deteriorated. Ningxia, Shaanxi, Shanxi, Guizhou, and Guangxi are the provinces in which the improvement of the ecological environment is most pronounced. However, the ecological environments with vegetation as the core in Shanghai and Jiangsu Province have deteriorated significantly. The areas with the fastest improvement in their ecological environment are those with precipitation of 200–600 mm. The Yellow River Basin is an area where the ecological environment has significantly improved. Forestry projects and the development of oasis agriculture effectively promote the improvement of the ecological environment. In the past 20 years, the main reason for the degradation of the ecological environment in eastern coastal areas is urban expansion. China should continue to strengthen its overall layout of forestry projects and improve its ecological environment. When planning its ecological construction, China should fully consider the associated physical and geographical conditions, and adjust measures to local conditions accordingly. China should coordinate the relationship between development and protection and avoid the "pie spread" expansion witnessed in eastern coastal areas. [ABSTRACT FROM AUTHOR]

The relationship between forests and streamflows has long been an important research interest in China. The purpose of this paper is to summarize progress and lessons learned from the forest-streamflow studies over the past four decades in China. To better measure the research gaps between China and other parts of the world, a brief global review on the findings from paired watershed studies over the past 100 years was also provided. In China, forest management shifted in the later 1990s from timber harvesting to forest restoration. Forest-streamflow research was accordingly changed from assessing harvesting impacts to evaluating both harvesting and forestation effects. Over the past four decades, Chinese forest hydrology research has grown substantially. Significant progress has been made on measuring individual processes, but little solid, long-term data were available to assess the relationship between forest changes and streamflows because of an absence of standard paired watersheds. In addition, misuse of statistical analyses was often found in the literature. A unique opportunity exists in China to study the forestation effects on streamflow as several large-scale forestation programs are being implemented. Such an opportunity should include a robust paired watershed design under an integrated watershed ecosystem framework to avoid repeating the lessons already learned. Recommendations on future forest-streamflow research directions in China are provided. [ABSTRACT FROM AUTHOR]

China, an upstream state and a regional hegemon in the Mekong River Basin, is commonly viewed as unilaterally exploiting water resources, irrespective of downstream states (Myanmar, Thailand, Laos, Vietnam, and Cambodia). This view is derived mainly from China's unilateral exploitation of the upper watershed for hydroelectricity and navigation, raising concerns about negative socio-ecological impacts on the downstream states. However, recent empirical evidence shows that China is gradually getting involved in negotiations and processes with the downstream states, compromising with them little by little. Indications of this policy shift include: (a) its signing agreements for hydrological data exchange, (b) confidence-building with co-riparans in the Dialogue Meeting of the Mekong River Commission, and (c) multinational negotiation with co-riparians in framework of regional institutions. In light of this shift, this article argues that China is not fully enjoying its superior resources or its superior riparian position, contrary to the common view. The aim of this paper is to (1) explain and provide updated information on these negotiation mechanisms, which are attempting to resolve the upstream-downstream dispute in the Mekong River Basin, and (2) produce counterevidence against the Theory of Hegemonic Cooperation. [ABSTRACT FROM AUTHOR]

In 1999, the Chinese government initiated a massive conservation programme, the 'Grain-for-Green' programme, to reduce soil erosion and to improve the eco-environmental status in western China through the set-aside of sloping agricultural lands and their conversion to forest and pasture. The attitudes and perceptions of farmers towards Grain-for-Green are little known, but will eventually dictate the direction and, ultimately, the success of the project. This paper interprets surveys concerning attitudes towards environmental protection, in general, and the Grain-for-Green programme, in particular, in two small catchments in the Loess hilly area. Participatory Rural Assessment techniques are used as survey instruments mad logistic regression analysis is used to analyze farmers' attitudes towards environmental conservation and Grain-for-Green. Most respondents are positive about environmental protection and Grain-for-Green in general. However, marked differences are evident between the two small catchments: the level of farmers' environmental protection consciousness in Anjiapo catchment is higher than that in Danangou catchment. Respondents in Azajiapo catchment expressed more support for the programme than respondents in Danangou catchment. Environmental care by farmers may not be sustainable should the programme come to an end. The results provide a useful insight into the interests and concerns of farmers, which might lead to a more positive attitude in officials in the future. [ABSTRACT FROM AUTHOR]

Transjurisdictional water pollution problems are increasing in number and are becoming a significant governance problem in China. A large number of transjurisdictional water pollution disputes that have far-reaching social effects are occurring between provinces and are also frequent between municipalities, counties, towns, and villages. In this paper, several transjurisdictional water pollution cases in China, particularly in the Yellow River Basin, are discussed. The problems and causes for transjurisdictional water pollution are addressed. There are many causes for transjurisdictional water pollution problems although the key reasons are the rapid economic development, the failure of local authorities to enforce the existing laws and to implement administrative decisions, as well as inadequacies in the legal framework. Other factors include poor technology, shortage of funds, the institutional division of jurisdiction and management over water quantity and quality both administratively and legally, the lack of transparency in the decision-making process, insufficient public participation and information disclosure, poor communication, and lack of involvement of stakeholders in basin or sub-basin organizations. [ABSTRACT FROM AUTHOR]

In this paper, future drought characteristics (frequency, duration and intensity) over China are analysed by using four climate models from CMIP6 under the seven SSP-RCP (shared socioeconomic pathway-representative concentration pathway) scenarios (SSP119, SSP126, SSP434, SSP245, SSP460, SSP370, and SSP585) for three defined periods of 2021–2040 (near-term), 2041–2060 (mid-term) and 2081–2100 (long-term). The corresponding four climate models output from CMIP5 are also used to conduct a comparison analysis between CMIP5 and CMIP6 to address the improvements added to CMIP6 in terms of drought identification. The drought characteristics are identified by applying the standardized precipitation-evapotranspiration index (SPEI) at a 12-month timescale and run theory. The results show that CMIP6 has a robust capability to capture historical (1986–2005) drought characteristics. For the future period of 2021–2040, the decrease in precipitation and increase in potential evapotranspiration will lead to continuous dry conditions in the upper and middle Yangtze River basin and eastern Pearl River basin. Relative to the reference period, drought events will be more frequent and severe with longer durations in the Northwest River basins and middle Yangtze River basin. Furthermore, higher emissions signify a greater increase in drought frequency and intensity in the long-term period. Except for the SSP585 scenario, the lower emission scenario corresponds to the higher drought duration soon and in the mid-21st century (2021–2060). This finding is regarded as a "strange phenomenon", which cannot be detected by the previous CMIP5-based emission scenarios (RCP2.6, RCP4.5 and the unlikely pathway RCP8.5). Therefore, additional "possible future"-based scenarios (SSP119, SSP126, SSP434, SSP245, SSP460, and SSP370) should be included in extreme climate studies, especially for the near future and mid-21st century. Notably, compared with CMIP5, the reduced biases in drought characteristics are more likely associated with improvements in the representation of physical processes in climate models from CMIP6. The results of this study could provide a basis for the development of drought adaptation measures over China. • Latest CMIP6 climate models and seven SSP-RCP scenarios are used to analyze the possible changes in droughts over China. • More robust projections will be presented by CMIP6 than CMIP5, due to the better representations in physical processes. • The higher emission signifies shorter drought duration, lower precipitation and PET in mid-21st century over China. [ABSTRACT FROM AUTHOR]

The China Geochemical Baseline (CGB) project (2008–2013) obtained harmonious geochemical baseline data covering all of China, and provided reliable data for 76 elements including F from 3382 top and 3380 deep soil samples. This paper described the statistical and spatial distribution of fluorine (F) throughout China. F concentration ranged from 63 to 9364 μg/g in top soil and ˂ 52 to 9346 μg/g in deep soil. The median concentration of F, which is deemed to be the geochemical baseline in top and deep samples are 488 μg/g and 456 μg/g respectively. The mean concentration of F in top and deep soil samples are 506 μg/g and 482 μg/g respectively. Low F concentrations areas are linearly distributed from northeastern to southwestern China, and high F concentrations areas are distributed in northwestern, northern China and karst area. The anomalous centres of F are exactly correlated with F mineralization. This distribution pattern of F in pedosphere is influenced by minealizations, lithology background, geomorphic landscapes, drainage basins and soil types. Generally, fluorine-bearing rocks provide a reliable source of F in pedosphere, and the geochemical behavior of F determines its ability to migrate in different media. • Low F concentrations areas are linearly distributed from northeastern to southwestern China, and high F concentrations areas are distributed in northwestern, northern China and karst area. • This distribution of F in China's pedosphere is influenced by lithology background mainly. Geomorphic landscapes, drainage basins and soil types played regional-scale roles. [ABSTRACT FROM AUTHOR]

• A physically-based, national-scale hydrological model in China was developed with 19,406 sub-watersheds and 81,687 contour belts. • The research incorporated new mechanisms on soil moisture movement in special vadose zone and strengthened the elevation effect of meteorological and vegetation variables. • The results can achieve a detailed description of the spatio-temporal variation of hydrological variables in large-scale region with diverse climate, topography and underlying surface conditions. Expansion of a detailed hydrological modelling from catchment- to national- or continental-scale is of important theoretical and practical significance, yet faces many challenges. We developed a high-resolution, physically-based hydrological model named WEP-CN (Water and Energy transfer Processes in China) for China. Different climatic and hydrological conditions and geological structures as well as their impact on infiltration and runoff were examined and incorporated in WEP-CN. The study area (9.6 million km2) was divided into 19,406 sub-watersheds and 81,687 contour belts. The computation units, model input, and model structure and parameters in WEP-CN were improved to obtain a well-defined simulation area, a more reliable input as well as a detailed description of soil moisture movement in several special vadose zones such as karst development, swelling and frozen soil. Continuous simulations of various natural hydrological processes were conducted for 62 years from 1956 to 2017. We demonstrated the efficacy of our model by comparing simulated and statistical monthly streamflow at 203 hydrological stations across the country. For the validation period of 1981–2000, the Nash-Sutcliff Efficiency (NSE) was found to be larger than 0.7 at 80% of the stations, and the absolute value of relative error (RE) was less than 10% at 95% of the stations. Our result highlights the benefit of incorporating new mechanisms on the special vadose zone water movement and accounts for the impact of elevation change on meteorological and vegetation variables. This paper can serve as a reference for large-scale hydrological simulation with diverse climate, topography and underlying surface conditions. [ABSTRACT FROM AUTHOR]

• The seasonal cycles of simulated runoff show good agreement with the UNH/GRDC composite runoff. • VIC-CN05.1 generally reproduces the monthly time series of latent heat fluxes well at flux tower sites in China. • The monthly modeled 0–10 cm soil moisture anomalies are highly correlated to in situ measurements. • The spatial patterns of simulated snow variables are generally similar to observations in northeastern and northwestern China. • Except for the northwest basin, the simulated monthly TWSC match well with that from the GRACE. This paper describes a daily 0.25° × 0.25° terrestrial hydrological dataset (VIC-CN05.1) for China during 1961–2017. The dataset is simulated by the latest variable infiltration capacity (VIC) model and driven by pure station-based atmospheric forcings and high-resolution soil parameters based on field surveys. Multiple observational (in situ and remote sensing) products and five statistical metrics, including biases, relative error (RE), root mean square error (RMSE), Nash-Sutcliffe efficiency coefficient (NSE), and correlation coefficient (R), are used to validate the model outputs. The results indicate that the seasonal cycles of simulated total runoff and composite runoff from the University of New Hampshire and Global Runoff Data Centre (UNH/GRDC) show good agreement in the Yangtze, southeast, and Pearl River basins, with positive REs ≤ 7% and NSEs ≥ 0.87. At the Changbaishan, Haibei Shrubland, and Qianyanzhou flux towers, VIC-CN05.1 reproduces the monthly latent heat fluxes well during 2003–2005. The monthly modeled 0–10 cm soil moisture anomalies are highly correlated to in situ measurements (438 stations) during 2003–2016, with mean R = 0.80. The spatial patterns of simulated and observed snow depth, snow water equivalent (SWE), and snow cover in winter are generally consistent in the northeastern and northwestern China. Except for the northwest basin, the simulated monthly terrestrial water storage changes in most river basins (particularly the Yangtze, Huai, and Yellow River basins) match well with observations based on the Gravity Recovery and Climate Experiment (GRACE) during 2003–2016, with positive NSEs and mean R = 0.41. This terrestrial hydrology dataset is valuable for hydroclimatic research in China, such as model evaluations and long-term trend analyses. [ABSTRACT FROM AUTHOR]

Urban land-use planning is becoming increasingly complex in China because it requires estimating the future urban extent and balancing its various aspects, e.g., provision of enough housing and employment opportunities and preservation of the environment. This paper presents an integrative approach to the problem of sustainable land-use planning. Specifically, an urban growth simulation tool, a cellular automata model, was used to determine the extent of the urban area, and a neural network approach was used to quantitatively predict the land-use structure in the projected year. A multiobjective optimization genetic algorithm was then developed to search for Pareto-optimal urban land-use plans within the urban extent determined by the urban growth model. To search for a sustainable urban land-use plan, social, economic, and environmental objectives were defined that reflect the multiple objectives of the urban system. In addition to these nonspatial goals, objectives concerning the spatial distribution of land usages were proposed. These are classified as local and global spatial objectives. A case study of the Donghu Lake watershed was conducted. Donghu Lake is one of the largest downtown lakes in central China, and the watershed area is undergoing rapid urbanization and suffering from nonpoint source water pollution. The study was carried out to validate the proposed method, and it demonstrated that the models are appropriate for areas undergoing urban expansion. [ABSTRACT FROM AUTHOR]