昆明市极端降水事件演变特征及城市效应

为探究昆明市极端降水事件在城市化进程中的演变规律，基于百分位法、Mann-Kendall检验及R/S分析等方法，对1960—2017年昆明市极端降水事件时空演变特征、严重程度及城市效应进行了定量分析。结果表明:1960—2017年昆明市极端降水量呈不显著增加趋势，速率为 0.24 mm/a，且其发生率、贡献率及强度均呈增长变化，降水夜昼间分配不均，极端降水量在主城区以及城市下风区存在明显高值区；1960—2017年城市化对年极端降水的增雨系数为1.16，城市化增雨明显，并且呈加剧趋势；昆明市缓慢发展期城市效应不明显，而快速发展期极端降水量城、郊差异均值较缓慢发展期增长了57.04%，城市效应凸显；极端降水严重度指数及其城、郊差异均呈持续增加趋势，表明昆明市极端降水严重程度以及城市化对其影响效应均将不断加剧。

Evolution characteristics of extreme precipitation events and its urban effect in Kunming City

In order to explore the evolution law of extreme precipitation events during the process of urbanization in Kunming, the temporal and spatial evolution characteristics, severity and urban effect of extreme precipitation events in Kunming from 1960 to 2017 were quantitatively analyzed based on the percentile method, Mann-Kendall test, R/S analysis and other methods. The results show that from 1960 to 2017, the extreme precipitation in Kunming showed no significant increasing trend with a rate of 0. 24 mm/a, while its occurrence rate, contribution rate and intensity all showed increasing changes. The distribution of precipitation was uneven between night and day. The extreme precipitation in the main urban area and the downwind area of the city had obvious high value areas. From 1960 to 2017, the enhancement coefficient of urbanization to annual extreme precipitation was 1. 16, which indicated that the effect of urbanization on increase of precipitation was obvious, and the effect tended to intensify. The urban effect of Kunming was not obvious in the slow development period, while the mean value of extreme precipitation difference between urban and suburban areas increased by 57. 04% in the rapid development period with the urban effect being prominent. The extreme precipitation severity index and the index difference between urban and suburban areas showed continuous increasing trend, which indicated that the severity of extreme precipitation and the effect of urbanization on it will continue to intensify.