基于1961-2019年宁夏固原市隆德县降水数据,通过滑动平均法、M-K检验法、Sen's坡度法、R/S分析法、小波分析法以及多元线性回归法等方法,研究隆德县降水在不同时段的变化特性及影响时段内降水量变化的主要因素.结果表明:隆德县多年平均降水量为519.67mm,年降水量以8.94mm/(10a)的速率减少,降水整体呈现不显著下降趋势且该趋势具有持续性;各季降水中,夏、秋季降水量呈减少趋势,冬季降水量上升趋势显著;年内降水量主要集中在夏季,春、秋季次之,冬季最少;此研究时段内主要存在28a,22a和12a的周期变化,其中28a为第1主周期;年降水总量及夏季降水量年际间的变化主要受降水强度的影响,而春、秋、冬3季降水量年际间的变化则受降水频率和降水强度的共同影响.研究成果可为隆德县农业生产、自然灾害防御及水资源规划提供科学依据.
The variation characteristics of precipitation at different time periods in Longde County and the main factors affecting the precipitation changes during the time periods were studied by sliding average value method,M-K test method,Sen's method,R/S analysis method,wavelet analysis and multiple linear regression method,based on the precipitation data from 1961 to 2019 at Longde Station in Guyuan,Ningxia.The results show that the average annual precipitation is 519.67 mm,and the annual precipitation decreases at a rate of 8.94 mm/(10 a).The overall precipitation shows an insignificant decreasing trend and the trend is continuous.Among the precipitation in each season,the precipitation in summer and autumn shows a decreasing trend,while the precipitation in winter shows a significant increasing trend.The annual precipitation is mainly concentrated in summer,followed by spring and autumn,and the least in winter.There are mainly 28 a,22 a and 12 a cycle changes in this study period,where 28 a is the first main cycle.The inter-annual variation of total annual precipitation and summer precipitation is mainly influenced by precipitation intensity,while that of spring,autumn and winter is jointly influenced by precipitation frequency and precipitation intensity.The results of the study can provide scientific basis for agricultural production,natural disaster defense and water resources planning in Longde County.