甘肃陇中安家沟小流域日降水格局  

Daily rainfall pattern of Anjiagou catchment in Gansu province

作　　者：方书敏[1,2] 赵传燕[2] 吴东平 王小平 

机构地区：[1]甘肃农业大学资源与环境学院,兰州730070 [2]兰州大学干旱与草地农业生态教育部重点实验室,兰州730000 [3]甘肃省定西市水土保持科学研究所,甘肃定西743000

出　　处：《兰州大学学报（自然科学版）》2012年第3期14-17,共4页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(30770387);国家环境保护公益性基金项目(NEPCP200809098)

摘　　要：利用1981-2009年生长季日降水资料,对陇中黄土高原安家沟小流域日降水格局及脉动特征进行研究.结果表明:生长季年均降水量为271.56 mm,年际变异系数为29.14%.降水事件以≤5 mm的降水为主,占全年降水事件的44.55%;≥10 mm的降水频率很低,但对年降水的贡献大,占降水总量的64.87%.0～10d降水间隔期(无降水日)所占比例最大,为年无降水期的87.03%;>10d降水间隔期呈增加趋势.近30年来,≤5 mm/d的降水呈下降趋势,而≥10 mm/d的降水略有上升,年内总降水日数与降水量均呈下降趋势.With daily rainfall data in the growing season from 1981 to 20Q9, the rainfall patterns and pulse characteristics of Anjiagou catchment in the western Loess Plateau were analysed. The results showed that the mean annual rainfall in the growing season was 271.56 mm and the inter-annual coefficient of variation was 29.14%. The rainfall events of 65 mm were the majority of the annual rainfall events, which accounted for 44.55%. The rainfall events of 〉10 mm were infrequent but contributed more to the total annual precipitation, which accounted for 64.87%. Inter-rainfall period （no precipitation） of 〈10 d accounted for the largest proportion of the total annual no-precipitation days which were 87.03%, and inter-rainfall period （no precipitation） of 〈10 d was increasing. The conclusions can be drawn that the rainfall events of 65 mm/d had been reduced while those of 〉10 mm/d had increased, and both the annual precipitation and rainy days showed a decreasing trend in Anjiagou catchment of the western Loess Plateau over the past 30 years.

关 键 词：日降水格局 降水脉动 安家沟小流域 黄土高原 

分 类 号：P933[天文地球—自然地理学]