Experimental and Simulation Studies on the Impact of Sluice Regulation on Water Quantity and Quality Processes

Abstract

Research on the impact of sluice regulation on water quantity and quality (WQQ) processes in regulated rivers is a fundamental requirement in basin management at present but remains a research puzzle at the basin scale because of insufficient monitoring data, irregular order of sluice or dam regulation, and numerous influencing factors in real-world river basins. This paper presents a laboratory experiment in a single reach as an artificial case study and develops a dynamic numerical model. Through analysis of the observed data and modeling, the river WQQ processes under sluice regulation are investigated and the interaction of WQQ and its regulation capacity downstream of a sluice is explored. Furthermore, a sensitivity analysis of model parameters is carried out and the model validity is tested on a prototype (real-world) scale. Results show that the WQQ variation downstream of a sluice has complicated nonlinear relationships with upstream flow, pollutant load into a river, and sluice regulation. The impact of sluice regulation on water quantity and thus, water quality, is inversely proportional to the relative opening of sluice and upstream flow, respectively. The WQQ results simulated by the numerical model in a real-world-scale system are reasonable, and the patterns are similar to experimental observation. Thus, the experiment and the numerical model will provide a potential approach to mimicking real reaches in a river system with dense sluices where the reaches between adjacent sluices are short and the change in sluice regulation is a dominant factor, such as in the Huai River basin of China. This study provides the foundation and reference for exploration of the mechanism of WQQ changes in regulated river systems and the technical support for the joint WQQ regulation of dams and sluices in complicated real river basins.