Faculty of Geography, Yunnan Normal University, Yunnan, 650500, China.
GIS Technology Research Center of Resource and Environment in Western China, Ministry of Education, Yunnan Normal University, Yunnan, 650500, China.
Environ Sci Pollut Res Int. 2021 Apr;28(13):16767-16780. doi: 10.1007/s11356-020-12093-0. Epub 2021 Jan 4.
Lake surface water temperature (LSWT) is an important factor affecting a lake's ecological environment. In recent decades, LSWT worldwide has shown an increasing trend in the context of global climate change. This rising trend has been more evident in urban lakes. With the rapid development of urbanization, urban lakes are affected not only by climate warming but also by human activities. Among these factors, due to the increase in impervious surface coverage (ISC), the impact of thermal runoff pollution caused by precipitation events on urban lakes cannot be ignored. Therefore, this study used the Dianchi Lake watershed as a study area, and the surface water temperature of Dianchi Lake, the precipitation data, and the land use data were collected and analyzed. Based on these data, the influence of precipitation events on the surface water temperature of Dianchi Lake was analyzed. The research results show that under the background of different ISC levels and different growth rates of impervious surface area (ISA), precipitation events have different effects on the LSWT. When ISC is low and the growth rate of ISA is slow, the annual precipitation is negatively correlated with the annual average surface water temperature of Dianchi Lake (r = - 0.183). When ISC is high and the growth rate of ISA is fast, the annual precipitation is positively correlated with the average annual surface water temperature of Dianchi Lake (r = 0.65). With the increase in ISC, the correlation between seasonal precipitation and the average surface water temperature in Dianchi Lake changed from negative to positive in spring and autumn. Under the action of impervious surfaces, precipitation events have a warming effect on the surface water temperature of the lake, and this effect will be intensified with the increase in ISC.
湖泊表层水温（LSWT）是影响湖泊生态环境的重要因素。在全球气候变化的背景下，近几十年来，全球 LSWT 呈上升趋势。这种上升趋势在城市湖泊中更为明显。随着城市化的快速发展，城市湖泊不仅受到气候变暖的影响，还受到人类活动的影响。在这些因素中，由于不透水面覆盖率（ISC）的增加，降水事件引起的热径流污染对城市湖泊的影响不容忽视。因此，本研究以滇池流域为研究区，收集和分析了滇池表层水温、降水数据和土地利用数据。基于这些数据，分析了降水事件对滇池表层水温的影响。研究结果表明，在不同 ISC 水平和不同不透水面面积增长率（ISA）的背景下，降水事件对 LSWT 的影响不同。当 ISC 较低且 ISA 增长率较慢时，年降水量与滇池年平均表层水温呈负相关（r = -0.183）。当 ISC 较高且 ISA 增长率较快时，年降水量与滇池年平均表层水温呈正相关（r = 0.65）。随着 ISC 的增加，春季和秋季季节性降水与滇池平均表层水温之间的相关性由负相关变为正相关。在不透水面的作用下，降水事件对湖泊表层水温具有变暖效应，这种效应会随着 ISC 的增加而加剧。
