祁连山典型小流域降水特征及其对径流的影响  

The Characteristics of Precipitation and Its Effects on Runoff in a Small Typical Catchment of Qilian Mountains

作　　者：张立杰[1] 赵文智[1] 何志斌[1] 胡广录[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所临泽内陆河流域综合研究站,寒旱区流域水文及应用生态实验室,甘肃兰州730000

出　　处：《冰川冻土》2008年第5期776-782,共7页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目“祁连山森林斑块形成机理研究”(40601007);西部之光项目“祁连山植被斑块水文过程观测研究”(0628221001)资助

摘　　要：研究了祁连山排露沟流域降水特征及对径流的影响．结果表明：降水的季节性强且分配不均匀，存在明显的干季（11月至翌年4月）和雨季（5-10月）之分；排露沟雨季降水占全年降水量的88％，占全年降水频数的70％；干季降水仅占全年的降水量12％，占全年降水频数的30％．降水事件主要以0～5mm的降水为主，占全年降水事件的78．8％，占全年降水量的30％；0～10d的降水间隔期出现的频率高达86．1％，占全年无降水期的55．5％．降水受海拔高度的影响明显，沿海拔梯度呈先增后减的趋势，降水的峰值出现在海拔3400m的区域．径流受降水的影响，主要集中在雨季，占全年的95．6％，干季径流仅占4．4％．径流与日降水、旬降水及其雨季月降水显著相关，其复相关系数均〈0．7．径流主要受降水量和前期降水的影响，对于前期无降水基础、雨量〈20mm降水过程，径流变化迟缓，而对于前期有一定降水基础，雨量〉25mm的降水过程，径流变化大．Precipitation is one of the key factors for hydrology and influences the runoff producing of a mountain ecosystem in arid and semiarid areas. Analyzing the characteristics of precipitation and its effects on runoff in the recent years in Pailugou catchment of Qilian Mountains reveals： 1）Precipitation exhibits a high seasonality, with an irregular distribution, There are two distinct seasons, a rainy season （from May to October） and a dry season （from November to April of the next year）. The percentage of precipitation and its frequency are 88% and 70% in the rain season and 12% and 30% in the dry season, respectively. 2） On average, 78.8% of all the precipitation events and 30% of the annual precipitation are ≤5mm, and 55.5% of annual dry period and 86.1% of dry day＇s frequency of different length are 410 days. 3） Under the effects of altitude, the precipitation from 2600 m to 3 400 m increases, and then decreases with altitude, with a maximum at the altitude of 3 400 mm. 4） Runoff is mainly controlled by precipitation and concentrated in the rainy season. The percentage of runoff is 95.6% in the rain season and 4.4% in the dry season. 5） The relationships between runoff and daily precipitation, ten-day precipitation and monthly precipitation in the rain season are evident （R^2=0.272, 0.642, 0.569）. 6） Runoff is mainly dependent on precipitation size and preceding precipitation process, and the runoff has a gently variance with precipitation below 20 mm without preceding precipitation; There is a high variance with a preceding precipitation over 25 mm.

关 键 词：祁连山排露沟 小流域 降水特征 径流 

分 类 号：P339[天文地球—水文科学]