Abstract：
The river-connected Dongting Lake (DT) and Poyang Lake (PY), and the gate-controlled Taihu Lake (TH) and Chaohu Lake (CH) are the four important lakes in the Yangtze River Basin. The comprehensive Water Quality Index (WQI), the Eutrophication Integrated Index (TLI(Σ)), and the Positive Matrix Factorization (PMF) model were employed to evaluate water quality and the contribution of pollution sources for these lakes. The results show that WQI for all lakes indicated generally good water quality, with DT scoring 73.52-86.18, the highest among them. During the wet season, the eutrophication degree of river-connected lake was medium, and that of gate-controlled lakes was high. The surface runoff and agricultural non-point sources are the main pollution sources for both types of lakes, but their impact is more pronounced in gate-controlled lakes during the wet season. The study provides evidence support for scientific understanding of water quality problems and management strategies in these areas.
摘要：
与洞庭湖（DT）和鄱阳湖（PY）相连的河流，闸门控制的太湖（TH）和巢湖（CH）是长江流域的四个重要湖泊。综合水质指数(WQI)，富营养化综合指数(TLI(Σ))，并采用正矩阵分解（PMF）模型来评估这些湖泊的水质和污染源的贡献。结果表明，所有湖泊的WQI总体水质良好，DT得分为73.52-86.18，是其中最高的。在雨季，河流连通湖泊的富营养化程度中等，门控湖泊的比例很高。地表径流和农业非点源是两类湖泊的主要污染源,但是在雨季，它们的影响在闸门控制的湖泊中更为明显。该研究为科学理解这些地区的水质问题和管理策略提供了证据支持。
