Multitemporal Landsat Image Based Water Quality Analyses of Danjiangkou Reservoir

摘要

Danjiangkou Reservoir (DJKR) is one of the largest artificial freshwater lakes in Asia and a water source of the South: the North Water Transfer Project. However, few studies have analyzed the spatio-temporal water quality distribution or investigated the causative factors of the long-term water quality variation of DJKR. In this study, we used multi-temporal Landsat images combined with the multiple linear stepwise regression (MLSR) method to retrieve long-term distributions of the main water quality parameters in DJKR, i.e., total nitrogen (TN), total phosphorus (TP), permanganate index (CODMn), and five-day biochemical oxygen demand (BOD5). Results indicated the heavily polluted regions and an alarming water quality deterioration trend between May 2006 and May 2014. A combination of land use/land cover (LULC) maps and socioeconomic data was considered to investigate the causative factors of the water quality distribution, as well as the deterioration. This study could provide a valuable reference for the decision-making for water quality conservation in DJKR.