克拉玛依市1959—2008年降水变化的特征分析

Analysis on the Change Characteristics of Precipitation in the Last 50 Years in Kelamayi City

以1959—2008年克拉玛依市逐日降水资料为基础,采用线性趋势法、累积距平法、曼—肯德尔法、最大熵谱分析法等统计方法分析了克拉玛依近50 a的降水变化特征。结果表明:克拉玛依春、秋、冬三季及年降水量呈增加趋势,夏季降水量呈减少趋势;四季及年降水日数均呈减少趋势;从降水量级来看,R=0.0 mm的降水日数呈减少趋势,0.1 mm≤R≤4.9 mm、5.0 mm≤R≤9.9 mm、10.0 mm≤R≤24.9 mm、R≥25 mm的降水日数呈增加趋势(注:R为日降水量)。年降水量以12.9 a、8.3 a、2.9 a为主要周期,1987年为突变点,极端降水事件有增加的趋势。

Based on the data of daily rainfall from 1959 to 2008 in Kelamayi,several methods such as linear tendency,cumulative distance,Mann-kendall method and maximum entropy spectral analysis etc.were adopted to analyze the climate change characteristics of precipitation.The results show as follows： the rainfall in spring,autumn,winter and whole year are increasing in the last 50 years in Kelamayi,but decreasing in summer;the precipitation days are decreasing in each season and whole year;seen from the level of precipitation,the precipitation days of 0.1 mm≤R≤4.9 mm,5.0 mm≤R≤9.9 mm,10.0 mm≤R≤24.9 mm and R≥25 mm are decreasing except R=0.0 mm（R： daily rainfall）.The main cycles of annual rainfall in Kelamayi are 12.9 a,8.3 a,2.9 a,and 1987 is the abrupt point.The extreme precipitation events in Kelamayi seem to be increasing.