Author(s): Jia Yangwen; Niu Cunwen; Wang Hao; Gao Hui; Shen Suhui
Keywords: WEP-L; Distributed hydrological model; Water quantity; Water quality; Integrated assessment; USLE; The Yellow River
Abstract: There exist problems of both water shortage and water quality deterioration in the Yellow River Basin, which has become an important constraint of the social-economic development in the basin. To help in realizing the integrated water resources and water environment management, this study at first establishes an integrated model to simulate both hydrological processes and accompanied pollutant transfer processes in the Yellow River Basin. The model couples distributed hydrological model WEP-L and a newly added water quality module which includes simulation functions of soil erosion and sediment transport, and non-point and point sources transfer to and in rivers. Secondly, to overcome the defects of traditional water quality assessment, two aspects of improvement are conducted: one is the improvement of the traditional characteristic channel length approach, i. e., the product of multiplying channel length by lateral section area is selected as new assessment criterion to reflect the different contributions of small channels and big ones, thus making the assessment results more objective; another is the suggestion of integrated assessment approach for both water at channel lateral sections and water generated in sub-basins. The assessment results in the Yellow River Basin illustrate: 1) the improved characteristic channel length approach shows rivers of water quality worse than Level III account for 58% whilst the traditional approach give a result of 45% , implying that the actual status of water quality is worse than the traditional understanding; 2) the quality of water generated in sub-basins is better than that of at channel lateral sections. The assessment results describe the status of water resources quantity and quality from different points of view and thus provide valuable information for the water resources development and management in the basin.