Response of urban lake water quality to monthly hydro-meteorological drivers at the catchment scale

Urban storm-water runoff transports nutrients into water bodies, where high temperature and wind accelerate pollution risks. Understanding the impact of hydro-meteorological and urban development factors, specifically gross domestic product (GDP), population density, and green cover rate, on water quality under climate change is essential for integrated urban water management. Focusing on East Lake in Wuhan (2012–2023), this study analyzes interannual and seasonal variations in precipitation, temperature, wind, and total phosphorus (TP) concentration, evaluates their statistical relationships, and uses multiple linear regression method (MLR) to identify primary drivers of TP. The results show that: (1) No significant long-term trends were detected, but a TP breakpoint occurred in May 2021; (2) TP and temperature exhibit ~ 27-month cycles, while precipitation and wind show shorter seasonal cycles; (3) TP concentration correlates positively with temperature (r = 0.391, p < 0.01); (4) MLR identified 1-month lagged precipitation (score = 0.916), temperature (0.496), and population density (0.225) as primary drivers of TP variation. These findings show a significant association between pollution, meteorology and urban indicators in an urban lake basin, though a lack of internal nutrient data limits mechanistic insight. Thus, future studies require higher-resolution time-series and vertical profile data.