山东省降水量与不同强度降水日数变化对干旱的影响

Impact of Annual Precipitation and Rainy Days with Different Grades Variation on Drought Disaster in Shandong Province

采用山东省82个地面气象站1961～2004年日降水量,统计了历年的降水量、不同强度降水日数;利用累积距平及t检验法分析了干旱受灾面积、降水量和不同强度降水日数的长期变化趋势并进行了突变检验,相关分析方法研究了干旱气象灾害对降水量和不同强度降水日数变化的响应。结果表明:干旱受灾面积、年降水量及中等强度以上降水日数的转折年大都出现在1976年,微量降水日数、0.1～4.9 mm/d降水日数及总雨日数的转折年出现在1988年全球气候变暖背景下,转折年后年降水量及不同强度的雨日数异常偏少年份频繁出现;干旱受灾面积与降水量和不同强度降水日数呈显著的负相关,降水量或不同强度的降水日数异常偏少都将导致干旱的发生。20世纪70年代中期以后随着全球气候变暖,降水量和5.0～99.9 mm/d以上降水日数异常偏少年份增多是极端干旱气候事件频繁发生、干旱面积扩大的最主要原因。

Based on daily precipitation data from 82 meteorological stations in Shandong Province from 1961 to 2004, the annual precipitation and rainy days with different grades were calculated. The long - term variation and abrupt change characteristic of annual precipitation and rainy days with different grades were analyzed by using accumulative anomaly and T - test, and the response of drought disaster to variation of precipitation and rainy days were analyzed also. The results are as follows ： The abrupt change of annual precipitation, rainy days with moderate and above rainfall and drought disaster area occurred in the middle 1970s, but rainy days with little and small rainfall as well as total rainy days appeared in 1988 under the global warming background. After the abrupt change, the years appeared frequently with anomaly decrease of annual rainfall and rainy days, while the strong rainy days increased obviously. Precipitation and rainy days with different grades have a much closer negative correlation with drought disaster area. Abnormal decreases of annual precipitation and rainy days enlarged the drought area in Shandong Province.