Search

Groundwater exploitations in semi‐arid regions result in significant declines of groundwater levels and streamflow and even trigger seasonal streamflow drying up, which may bring adverse impacts on riparian ecosystems. It is critical to explore future streamflow changes caused by variable climate scenarios and groundwater exploitation intensities; however, a comprehensive assessment of the streamflow drying up frequency remains lacking. Furthermore, the thresholds of controlling factors beyond which streamflow drying up occurs have rarely been explored. Here we develop an integrated surface water‐groundwater model for the Taoer River Basin (TRB), a typical semi‐arid watershed in northeast China. We apply the model to multiple future scenarios to reveal the frequency of potential streamflow drying up and explore the thresholds of controlling factors of streamflow drying up based on a decision tree method. We find that the groundwater level in the lower region of the TRB (LTRB) is hard to recover to the riverbed elevation and the streamflow drying up frequency is still high unless the groundwater exploitation is reduced by 50%. However, this leads to a competition between the ecological and economic objectives. Our results also show that the streamflow drying up frequency in the LTRB is very sensitive to the upstream water inflow that can be regulated through the reservoir operation or inter‐basin water diversion, indicating the importance of a basin scale strategic management. The findings of this paper can help policy makers sustainably exploit water resources in semi‐arid regions. [ABSTRACT FROM AUTHOR]

With the development of rapid industrialization, urbanization, and modernization, water resources have been facing a series of increasingly severe problems in China, especially in urban areas. However, the absence of an effective, scientific evaluation method may lead to a lack of awareness of sustainable water usage. Thus, this paper focuses on performance analysis for regional sustainable water use in China. First, the sustainable water management (SWM) efficiency is defined, and then, six indicators are selected to construct an evaluation index system. Given that experts are usually not completely rational in practice, we need to take the effect of the experts' nonrationality into consideration when evaluating the SWM efficiency. In view of the indicators' uncertainty and fuzziness, and the experts' nonrationality, the hesitant fuzzy TODIM (HF‐TODIM; TODIM is an acronym in Portuguese for interactive multicriteria decision making) method, which can capture the influence of the experts' psychological factors on the evaluation results, is used to evaluate the SWM efficiency. Furthermore, the assessment method is applied to some sample regions in Tuojiang River Basin. Based on the calculated results, some findings and implications for the SWM efficiency in the sample regions are analyzed. Finally, the applied results using the proposed method are compared with the results derived using the HF‐TOPSIS (hesitant fuzzy technique for order preference by similarity to an ideal solution in hesitant fuzzy environment) method. Through the comparative analysis, we conclude that the HF‐TOPSIS method does not take the experts' psychological factors into consideration, but the HF‐TODIM method can avoid this issue and is very useful for the evaluation of the regional SWM efficiency. [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]