While numerous studies have examined pollution sources and seasonal effects on surface water quality independently, the complex interactions between these factors remain understudied. This research aimed to fractionate and quantify pollution sources and examine their interactive effects with seasonal variations on surface water quality in Khanh Hoa, Vietnam. The current study was based on 1080 surface water samples taken from three common water bodies - lakes, rivers, and canals across dry and rainy seasons and analyzed for 13 physiochemical properties. Findings revealed that surface water quality was influenced by four primary pollution sources: agricultural activities, residential areas, onsite erosion, and climatic factors. Agricultural sources dominated canal water quality (93.0-94.7%) but had less impact on lakes and rivers (12.8-23.8%). Residential sources significantly affected lakes and rivers (30.23-32.66%) but minimally influenced canals (2.6-5.6%). Onsite erosion sources had greater impacts on lakes and rivers typically during the rainy season and exhibited minimal impacts on canals. Lakes and rivers maintained consistent and higher water quality across seasons (water quality index (WQI) 9.1 to 9.3 out of 1.0 - excellent), while canals exhibited substantially lower quality in the dry season (WQI 0.75) compared to the rainy season (WQI 0.78). These interactive impacts were mitigated by self-purification, water residence time in lakes and rivers, dilution effects, and fast pollutant transport in canals. Our findings highlight the importance of effective management of these key pollution sources in interaction with seasonal variation for maintaining water quality and ensuring environmental sustainability.
来源平台：STOCHASTIC ENVIRONMENTAL RESEARCH AND RISK ASSESSMENT
