雅安地区降雨时空变化特征研究

Study on Spatial-Temporal Variation Characteristics of Precipitation in Ya'an Area

根据雅安地区有代表性的8个台站,1951~2016年历年逐月累计降水资料分析:(1)雅安地区中部累计降雨值较为偏大,存在三个高值中心,一是泥巴山以北龙苍沟附近,二是石棉县以西草科乡附近,三是位于天全县境内思经附近;(2)60年来雅安地区累计降水主要以减少趋势为主,并且峰值逐渐降低;汉源县整体略微有所增加,但在1990年以后累计降雨量峰值不断下降,整体呈减少趋势;(3)雅安地区累计降水以交替变化为主,三个地区都出现了准15~20年的年际变化,震荡明显并在不断从低频转为高频,震荡周期不断缩短,雨城区、荥经、天全在20世纪80年代末期以前出现了准5年左右周期,宝兴和石棉地区则在20世纪80年代末期以后表现为准5年周期。

according to the analysis of monthly accumulated precipitation data of 8 representative stations in Ya an area from 1951 to 2016,some conclusions was draw as the following:(1)the accumulated precipitation in the central part of Y aan area is larger,and there are three high value centers,one is near Longcanggou,north of Niba mountain.The second is near Caoke township to the west of Shimian County.The third is near Si Jing,Tianquan County.(2)In the past 60 years,the accumulated precipitation in Y aan area is mainly decreasing,and the peak value is gradually decreasing;that in Hanyuan county has slightly increased overall.But the peak value of accumulated precipitation has been declining since 1990,showing a decreasing trend in general.(3)The changing period of accumulated precipitation in Yaan area is alternated,and the accumulated precipitation in all three regions showed an interannual variation of quasi 15〜20 years.The oscillation is obvious and constantly changing from low-frequency to high-frequency,and the period of oscillation is getting shorter and shorter.Yucheng District,Yingjing county and Tianquan county had a quasi-5-year cycle before the late 1980s,while Baoxing county and Shimian county showed a quasi-5-year cycle after the late 1980s.