唐山近50年不同时间尺度降水变率及 降水量变化分析

以唐山11个观测站数据资料为基础，采用气候统计方法，分析了不同区县平均年降水量的变化特征。并从年、季、月等不同时间尺度分析了各区县近50年降水平均相对变率。结果显示：近30年平均年降水量较历年平均年降水量减少8.5%~22.4%，其中沿海地区减少最多，主要作物生长季降水量减少幅度没有超过10%。在年份尺度上，降水变率为20.1%~33.0%之间，降水相对变率从东部沿海向西北逐渐减少；在季节尺度上，春、夏、秋、冬季节降水变率范围分别为57%~68%、38%~48%、24%~31%、37%~42%，春季为降水变率最大的季节；在月份尺度上，1月、12月降水变率最大，超过100%，5~9月是降水变率最少的月份，范围为40%~60%，其中7~8月均在40%左右，其余月份为60%~90%。

The Analysis of Change Rate of Precipitation and Quantity Change of Precipitation in the Past 50a in multiple temporal Scales in Tangshan

Using climatic statistical methods, based on the data of 11 observation stations in Tangshan, the change characteristic of annual precipitation of different districts was analyzed. And from different angle of year, quarter and month, the rate of average relative precipitation of different districts was analyzed nearly 50 years. The results showed that: Over the past 30 years, the average annual precipitation reduces 8.5%~22.4% than the average annual rainfall. The reduction of coastal areas is most, but reduced extent of precipitation in the main crop growing season did not exceed 10%. At the year angle, the change rate of precipitation is 20.1%~3.0%, and the relative change rate of precipitation is gradually decreasing from the eastern coastal areas to the northwest. At the quarter angle, the change rate of precipitation of spring, summer, autumn and winter is 57%~8%、38%~8%、24%~1%、37%~2% respectively, the change rate of precipitation of spring is most. At the month angle, the change rate of precipitation in January and December is most, more than 100%. The change rate of precipitation May to September is least, the change range is 40%~60%, the change range of July-August is about 40%, and the other is 60%~90%.