Hydrology Research (Jan 2022)
Hydro-environmental response to the inter-basin water resource development in the middle and lower Han River, China
Abstract
As one of the most important influencing factors, inter-basin water resource development has been exerting an increasingly evident impact on the hydro-environment of river basins. The Han River was selected as a case study to reveal the hydro-environmental response to China's inter-basin water resource development. The hydrological changes and water-quality variations resulted from the middle route of the South-to-North Water Transfer Project (SNWTP) and the Three Gorges Reservoir (TGR) operation were examined based on a hydro-environmental model. The results indicated that the runoff reduction is obvious after the SNWTP operation, and the low-flow duration significantly increased by 4–5 months. Consequently, the flow decrease significantly contributed to the water quality deterioration in the middle and lower Han River, while the Yangtze-Han Water Diversion Project (YHWDP) can not alleviate the situation completely. Moreover, the nutrient assimilative capacity decreased after water diversion, which agrees with the hydrological changes along the middle and lower Han River. The quantitative analysis performed in this study distinguishes the spatiotemporal variation in water quality variables using the integrated model. It provides insights into water quality management under the influences of inter-basin water resource development. HIGHLIGHTS A coupled hydro-environmental model was set up to evaluate the river health.; Long low-flow duration was examined along the lower Han River.; Water quality of the middle and lower Han River deteriorated after the TGR and SNWTP operation.; SNWTP significantly contributed to the water environment deterioration.; YHWDP can not completely offset the adverse environmental influences resulted from the SNWTP operation.;
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