摘要
选取丹江口水库河南部分的最大入库河流老鹳河的支流蒿坪河小流域为研究对象,依托径流场等野外设施,系统开展了不同坡度和土地利用类型降雨径流特征的研究,研究结果表明:蒿坪河小流域降雨年度分布不均,暴雨集中型降雨产流量大,是产生非点源污染主要降雨类型。0°～5°耕地、5°～10°耕地、10°～15°耕地、栎林和果园平均径流系数分别为2.01%,2.98%,5.44%,16.47%和2.42%。陡坡地带栎林在降雨侵蚀力大于0.5的时候开始产流,以超渗方式为主;果园在降雨侵蚀力大于2.5的时候开始产流,以蓄满产流为主;耕地产流受人为影响显著,产流界限不容易确定,在暴雨集中型降雨条件下其产流以超渗方式为主。栎林和果园产流量与降雨侵蚀力均存在一定的线性相关性,R2分别为0.939和0.912。耕地由于受人为影响比较大,其产流与降雨侵蚀力关系波动较大。在暴雨集中型降雨条件下,坡度是影响产流的主要因素,10°～15°耕地产流和0°～5°,5°～10°差异性显著(P<0.05)。在小雨集中型降雨条件下,土壤结皮成为影响产流的主要因素。对大于10°的耕地,实施坡改梯工程,根据气象条件适时的锄地,有利于雨水的下渗,对于保持土壤水分、减少径流和农业非点源污染都有很重要的现实意义。
The characteristics of rainfall and runoff in different slopes and land uses were studied in Haoping river watershed,which is a tributary of Laoguan river-the largest tributary of Danjiangkou Reservoir in Henan.The results showed that the distribution of annual precipitation in Haoping watershed was variable,and the centralized storm rainfall was the main type generating non-point source pollution.The average runoff coefficients of 0°～5°,5°～10°,10°～15° cropland,oak forest and garden were 2.01%,2.98%,5.44%,16.47% and 2.42% respectively.When rainfall erosivity （R） was greater than 0.5,oak forest in the steep slope began to generate runoff,and the main type was infliration excess runoff.When R was greater than 2.5,garden started to generate runoff,and the main type was saturation excess runoff.Cropland was dramatically affected by human,so it was not easy to determine the runoff boudary,and the main type was saturation excess runoff in centralized storm rainfall.The product of runoff and R showed a linear correlation in the oak forest（R^2=0.939） and the garden（R^2=0.912）.The runoff and rainfall erosivity had no significant correlation in cropland,because it was significantly affected by human.In the condition of centralized storm rainfall,runoff was mainly affected by slope.The product of runoff in the cropland had significant difference between 0°～5°,5°～10° and 10°-15° cropland（P〈0.05）.In the condition of centralizd light rain,soil crust was the main factor affecting runoff.It has a very important practical significance for implementing of terraced fields construction,and timely hoeing according to weather conditions in the impaction of soil and water conservation,reducing runoff and agricultural non-point source pollution.
出处
《水土保持学报》
CSCD
北大核心
2010年第2期40-43,共4页
Journal of Soil and Water Conservation
基金
河南省高校科技创新人才支持计划项目(2008HASTIT004)
国家自然科学基金项目(40701160)
关键词
南水北调
小流域
降雨径流
降雨侵蚀力
South-North Water diversion
small watershed
runoff
rainfall erosivity
