近60年无为县降水变化趋势研究

Study on Change Trend of Precipitation in Wuwei County in Recent 60 Years

为了揭示无为县降水的变化趋势和规律,服务于水资源管理、生态建设等方面,采用线性倾向性估计、MannKendall突变检测、小波分析等方法,对无为县1957—2016年降水资料进行了分析。结果表明:无为县年、夏季和冬季的降水量呈上升趋势,春季和秋季的降水量呈下降趋势;年降水日数呈下降趋势,四季降水日数与其降水量保持相同的变化趋势;年和四季的平均降水强度均呈上升趋势;年平均降水强度的上升主导了年降水量的上升趋势,春季和秋季的降水日数的下降主导了春、秋两季降水量的下降趋势,夏季和冬季的降水日数和平均降水强度的上升共同主导了夏、冬两季降水量的上升趋势;年降水量没有发生突变,春季、夏季、秋季和冬季的降水量分别在1993年、1979年、1985年、1987年发生突变;年和四季降水量存在丰枯交替的多周期变化规律,目前均处于偏多阶段并将持续较长时间;年、春季、夏季和秋季的降水量与相应时段的平均气温存在一定的负相关关系,而冬季的降水量与其平均气温则存在一定的正相关关系。

To reveal the trend and pattern of the precipitation in Wuwei County for the purpose of resource management and ecological construction,we utilized linear tendency estimation,Mann-Kendall mutation detection,and wavelet analysis and other methods to analyze the precipitation information in Wuwei County from 1957 to 2016.The results demonstrated that:based on precipitation in Wuwei County,there was an uptrend in summer and winter,and a downtrend in spring and autumn;for annual precipitation,there was an uptrend.The annual precipitation days showed a downward trend,and the precipitation days in the four seasons were the same as precipitation amounts in the four seasons.The annual and seasonal average precipitation intensities showed the upward trend.The annual and seasonal precipitation intensities increased year by year.The declining number of precipitation days in spring and autumn dominated the downtrend of precipitation in these two seasons.The growing number of precipitation days as well as the average precipitation intensity resulted in the uptrend of precipitation in summer and winter.There was no significant change in annual precipitation,while major changes in precipitation happened in spring in 1993,in summer in 1979,in autumn 1985,and in winter in 1987.The annual precipitation and each season precipitation had the cyclical variation pattern of abundant and dry alternation.At present,annual and seasonal rainfall amounts are all in the rich stages and will last for a long time.There is a negative correlation between annual precipitation,spring,summer,and autumn precipitation,and the corresponding average temperatures.There is a positive correlation between winter precipitation and average temperature.