摘要
研究降水的径流影响对干旱半干旱地区水资源管理具有重要指导意义,但目前对其空间尺度效应定量研究还不深入,限制了研究结果的跨尺度应用。以黄土高原泾河流域为例,利用13个子流域的多年降水和径流数据,定量评价了降水的径流影响随流域面积增大的尺度效应。研究表明:泾河流域降水和径流空间差异很大,13个子流域年降水量变化在311~563mm,年径流深变化在14.17~128.05 mm。在各子流域内,年径流深随年降水量呈显著线性增加(P<0.05);在子流域间,年径流深随年降水量呈显著的指数型增加(P<0.05)。降水能解释45%左右的径流变化。各子流域降水-径流线性关系参数(回归系数、截距)和径流系数的变异系数随流域面积增大呈非线性减少,证实了降水-径流影响存在空间尺度效应。其中,回归系数、截距常数项绝对值的变化符合对数函数,径流系数变异系数的变化符合幂函数,说明随空间尺度增大,流域降水形成径流的能力在减弱,但维持较稳定的降水-径流关系的能力在增强。基于降水径流关系及尺度效应量化分析,提出了考虑年降水量和流域面积的跨尺度年径流深计算关系:y=a·x_1·lgx_2+b·x_1+c·lgx_2+d,其中y为年径流深(mm),x_1为年降水量(mm),x_2为流域控制面积(km^2),a、b、c、d为拟合参数。利用13个子流域年均降水、径流数据和历年的降水、径流数据及流域面积分别对上式进行拟合,检验均达极显著水平(P<0.01),决定系数r^2(0.788,0.510)均大于仅考虑降水影响的降水-径流指数关系(0.469,0.443),证明考虑尺度效应的降水-径流关系优于单纯的降水-径流关系。未来还需考虑土地利用方式、流域地形等因素的影响,以更深入地认识和应用降水-径流影响的空间尺度效应,指导干旱半干旱地区的水土资源管理。
It is very important to study the influence of precipitation on runoff in a basin,especially in arid or semi-arid regions.However,there are still lacks of deep insights into the relationship between precipitation and runoff and its spatial scale effect.In this work,we quantified the annual runoff responses to annual precipitation in13sub-basins in Jinghe Basin,and their changes with increasing basin area.Results showed that huge difference existed in the spatial distribution of both annual precipitation(311?563mm)and anual runoff(14.17?128.05mm)in Jinghe basin.Within each sub-basin,the annual runoff increased with rising annual precipitation linearly(P<0.05);whereas among the basins,the relationship turned into an exponential one(P<0.05).The precipitation can only explain about45%of the runoff variance.With the enlargement of basin area,parameters of the relationship and coefficients of runoff variance decreased unlinearly,implying the existane of spatial scale effect and basin area increase lessened the water yield capacity of basins but enhanced its ability to keep a stable relationship between precipitation and runoff.Based on the above results,a combined relation was derived as:y=a.xi*lg:2+b+xi+c*lg\:2+d,in which,y is the annual runoff(mm),xi is the annual precipitation(mm),X2is the basin area(km2).This relation was fitted with the observed data of annual precipitation and runoff of all the13sub-basins,and it can be used to explain and predict the runoff variation with the consideration of both precipitation and basin area.The test on the regression with yearly and many-years-averaged data of annual precipitation and annual runoff and the basin area was well above the significant level(P<0.01).The adjust coefficient(0.788,0.510)was better than that only considering the precipitation effect(0.469,0.443),implying the annual precipitation-runoff relationship was better if considering the spatial scale effect.In the future studies,other factors such as landuse and landform should be considered for quantifing the spatial scale effect of precipitation-runoff relationship,for a better guiding of the soil-water resources management in the arid and semi-arid regions.
作者
贺亮亮
张淑兰
于澎涛
李振华
王彦辉
HE Liangliang;ZHANG Shulan;YU Pengtao;LI Zhenhua;WANG Yanhui(Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091,China;Jiamusi Uniesity, Jiamusi 154007, China;School of Life Science and Technology, Xinxiang Uniesity, Xinxiang 453000, China)
出处
《生态环境学报》
CSCD
北大核心
2017年第3期415-421,共7页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(41230852
41390461
41471029
41671025)
国家重点研发计划项目(2016YFC0501603)
国家林业局宁夏六盘山森林生态站资助
宁夏生态修复与多功能林业综合研究中心资助
关键词
子流域
面积
尺度扩大
径流系数
subbasin
area
scale enlargement
runoff ratio
