Trend analysis of water surface evaporation in central area of Shanghai City

To investigate the influence of local meteorological elements on evaporation, and effectively conduct evaporation trend forecasting, this study analyzed evaporation data of Dianpu East Sluice Station and Dazhi West Sluice Station in Minhang District from 2006 to 2025 by using descriptive statistics, linear regression, parametric and non-parametric significance tests, anomaly analysis, and Sen′s slope estimation combined with the Mann-Kendall trend test to examine monthly, seasonal, and annual evaporation fluctuations and trends.Results showed that evaporation at both stations increases from January to August and decreased from September to December, with an anomalous decline in June due to the plum rain climate in the middle and lower reaches of Yangtze River area.Seasonal evaporation variability at both stations follows the order as summer > winter > spring > autumn.The Dianpu East Sluice Station showed an insignificant upward trends in all seasons, and the Dazhi West Sluice Station showed insignificant downward trends in spring and summer, an insignificant upward trend in autumn, and a significant upward trend in winter.A paired t-test indicated non-significant difference in annual mean evaporation between the two stations, while monthly mean evaporation differed significantly only in October and November.The findings can provide a reference for regional water resource management and hydrometeorological research.