Abstract: How to resolve the conflicting relationship between basin development and the protection of ecological environment, and to provide an objective assessment of the effects of dams and sluices on the environment, have become one of pressing scientific challenges and a new task of great significance. From the perspective of the natural characteristics of rivers, this paper explores the theories, key topics, and methodologies for the analysis of hydrological and environmental effects of dams and sluices, i.e., quantity and quality of waters, and proposes a quantitative framework to study and simulate water cycle at the river basin scale. As a case study in Huai river basin, one of the areas with most water projects and most polluted water, this paper presents a preliminary analysis of the effects of dams and sluices on the hydrological environment of the area. This study provides a theoretical basis for the management of water resources and control of water pollutions in the areas of dam-sluice regulated river basins, and contributes to the strategies for comprehensive management of river basins and for sustainable socio-economical development of the country.

Key words: dams and sluices, Huai river basin, hydrologic regimes, research framework, water environment