鲁中地区近35a不同历时降水变化特征

Variation of Precipitation with Different Duration in Recent 35 Years in the Middle Area of Shandong Province

利用鲁中地区8个气象站1980—2014年逐日降水资料,分析不同持续时间不同强度降水的时空变化规律。结果表明:鲁中地区近35 a无特大暴雨发生,降水发生频率随降水强度和持续时间的增加而减少,降水频率与降水强度的变化规律基本一致。1 d降水除小雨外,其他强度降水发生次数均呈增加趋势,最多发生在7月,大暴雨的降水强度除沂源外,其他地区呈增加趋势,暴雨降水强度在中部平原和南部山区呈增加趋势;除大暴雨外,其他不同强度降水年均发生次数主要空间变化规律一致,但在第二特征向量上存在差异;持续2 d降水除暴雨年均发生次数随时间呈增加趋势外,其他强度降水均呈减少趋势,暴雨的降水强度除中西部平原外,其他地区呈增加趋势,大雨和小雨最多出现在8月,暴雨和中雨出现在7月,暴雨中北部平原最多,大雨东部平原最多,中雨、小雨山区最多;持续3 d中雨和小雨年均发生次数随时间呈增加趋势,降水强度在多数地区呈增加趋势,最多出现在8月,山区最多;持续4、5 d小雨年均发生次数随时间呈减少趋势,降水强度在多数地区呈减少趋势,最多分别出现在8月、9月,空间分布均匀。

Based on the daily precipitation data from 1980 to 2014 of eight weather stations in the middle area of Shandong Province, spatial and temporal variations of precipitation with different durations and different intensity were analyzed. The results showed that no extraordinary rainstorm happened in recent 35 years, and occurrence frequency of other precipitation decreased with the increasing intensity and durations of precipitation, the variations of occurrence frequency and intensity of precipitation were the same. Annual precipitation occurrence lasted for one day increased except light rain, and mostly happened in July, the intensity of heavy rain had an increased trend except Yiyuan, and the intensity of rainstorm increased in the middle part of the plain area and the southern mountain area. In addition to large rainstorm, the main spatial changes of the other precipitation with different intensity were the same, but there had different spatial changes in the second feature vectors. Precipitation lasted for two days with different intensity decreased except the rainstorm with increasing trend, the intensity of rainstorm increased except the mid-western plain, most of the heavy rain and light rain happened in August, and moderate rain and rainstorm happened in July, most of rainstorm happened in the mid-northern plain, and heavy rain happened in the east plain, and moderate rain and light rain happened in the mountain areas mostly. The annual moderate rain and light rain lasted for three days had an increase trend with time, and the intensity of them also had an increased trend, which mostly happened in August in the mountain areas. The annual light rain lasted for four days and five days decreased with time, and the intensity of it also had a decreased trend, which mostly happened in August and September, and the spatial distribution was uniform.