关键词: 降水特性, 杭州市, 降水量, 水文统计方法, 变化特征, 趋势分析

Abstract: Analyzing the characteristics of precipitation in Hangzhou, an important city in the Yangtze River Delta, is of vital scientific and practical significance. According to daily precipitation data of Hangzhou Station from 1951 to 2014, the characteristics of precipitation variation was investigated by using M-K test, linear trend analysis and hydrological statistical method. Results revealed that: (1) The change trend of annual precipitation in Hangzhou in the past 64 years was insignificant; but the number of days of precipitation has been decreasing, indicating an increasing trend of single precipitation intensity. (2) In winter and summer, precipitation has been increasing, yet the number of precipitation days has decreased or remained unchanged; while in spring and autumn, precipitation and number of precipitation days both declined significantly. Flooding in summer and drought in autumn has exacerbated. (3) Precipitation was unevenly distributed in one year and mainly concentrated in March-September, accounting for 75% of yearly precipitation; the number of precipitation days in March-September accounted for about 65% of the annual precipitation days. (4) Maximum daily precipitation mainly concentrated in June; daily precipitation reached the maximum in June for 15 times over 64 years, accounting for 23.4%. The results offer scientific reference for forecasting short-term and mid-term precipitation trend, water resources development and utilization, and disaster prevention and reduction.

Key words: precipitation characteristics, Hangzhou City, precipitation, hydrological statistical methods, change characteristics, trend analysis