昆明松华坝水源地降水特征及小波分析

对松花坝站1953～2011年降水特征分析表明,昆明市松华坝水源地降水量呈减少趋势,且降水高度集中在主汛期,后汛期降水偏少,不利于水库防洪调度与水库蓄水。小波分析结果表明,松华坝水源地年降水量、汛期、主汛期和后汛期降水量均存在2a短周期,但长周期各异。年降水量、汛期及主汛期降水量在较大时间尺度上分为1977年之前的偏丰期、1977～1993年的偏枯期、1994～2008年的偏丰期、2009～2011年的偏枯期,而后汛期降水量在较大时间尺度上分为1957年前的偏枯期、1957～1968年的偏丰期、1969～1982年的偏枯期、1983～1997年的偏丰期、1997～2011年的偏枯期。由小波分析和趋势来看,2009年之后的降水偏枯期还将延续11a左右的时间。

Wavelet Analysis of Precipitation Characteristics in Songhuaba Water Source Area of Kunming

The analysis of precipitation characteristics at the Songhuaba Station from 1953 to 2011 indicates that the precipitationin the Songhuaba water source area of Kunming has a decrease trend, the precipitation highly concentrated in main flood period,and precipitation is less than normal in post -freshet period, which is unfavorable for flood control and reservoir storage. Theresults of wavelet analysis show that the annual precipitation, the precipitation of flood period, main flood period and post-freshetperiod have short period of 2 years. The annual precipitation, the precipitation of flood period and main flood period in large timescale can be divided into the high-water period before 1977, low-water period from 1977 to 1993, high-water period from 1994 to2008, low-water period from 2009 to 2011. The precipitation of post-freshet period in the larger time scale can be divided intothe low-water period before 1957, high-water period from 1957 to 1968, low-water period from 1969 to 1982, high-water periodfrom 1983 to 1997, and low-water period from 1997 to 2011. The wavelet analysis shows that the low-water period after 2009will last about 11 years.