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Study Region: Upper to Middle Yellow River Basin (UMYRB). Study Focus: Climate, land use, and landscape engineering measures are the main drivers affecting watershed hydrology, yet disentangling their respective contributions over large and complex regions is a great challenge. We combine process modeling techniques and hydrological observations to investigate the temporal changes of streamflow and sediment in the UMYRB during 1971–2016 and the imprints of climate change and anthropogenic activities. New hydrological insights for the region: Long-term statistical analysis shows that streamflow and sediment decreased over time across the basin with an increasing magnitude of reduction from upstream to midstream. Streamflow of UMYRB and sediment in the upstream area have decreased by 37.59 % and 71.86 %, respectively, since their change-point years. Analytical modeling results in the UMYRB demonstrate that 77.30 % of the streamflow reduction was attributed to landscape engineering measures, 16 % to climate change and the remaining 6.70 % to land use change. For sediment reduction, landscape engineering measures appeared to be the sole decisive factor for the upstream (over 126 %), while climate and land use changes positively affected sediment yield. Our study highlights the importance of considering the impacts of multiple factors when evaluating hydrological changes in large basins, and the method we adopted can be valuable elsewhere. Developing process-based methods to quantify the hydrological effects of engineering measures is still a research priority moving forward.

Study region: Wales, United Kingdom. Study focus: Climate change is predicted to have a large impact on the hydrological regimes of Welsh rivers. However, its influence on the abstraction capability of key sectors, such as public water supply (PWS) and hydroelectric power (HEP), is not yet fully understood. We use the Soil and Water Assessment Tool (SWAT) to generate future (2021–2079) streamflows under a worst-case scenario of greenhouse gas emissions (Representative Concentration Pathway 8.5) at two catchments in Wales, the Conwy and Tywi. SWAT streamflow output is used to estimate total unmet demand for PWS and changes in generation characteristics for HEP. PWS unmet demand is assessed using the Water Evaluation And Planning (WEAP) system under increasing, static, and declining demand scenarios. Mann-Kendall analysis is performed to detect and characterise trends. New hydrological insights for the region: Under all future demand scenarios, there is increased occurrence of insufficient streamflow to satisfy PWS demand. For HEP, decrease in annual abstraction volume results in a loss of generation potential, despite an increasing number of days that maximum abstraction is reached. Changes in HEP generation and PWS availability are most pronounced in the medium-term (2021–2054), with rate of change slowing after 2060. We provide a novel perspective on future water resource availability in Wales, giving context to management planning to ensure future PWS sustainability and HEP generation efficiency.