退耕背景下北洛河上游水沙变化分析  

Change in runoff and sediment in the upper catchment of Beiluo River under the vegetation restoration

作　　者：刘二佳[1,2] 张晓萍[1,2] 谢名礼[3] 陈妮[3] 

机构地区：[1]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]中国科学院研究生院,北京100049 [3]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《中国水土保持科学》2013年第1期39-45,共7页Science of Soil and Water Conservation

基　　金：国家自然科学基金"北洛河水沙动态过程及对退耕还林(草)响应机理"(41101265);国家自然科学基金重点项目"气候变化背景下黄土高原土地利用影响径流的空间尺度效应"(41230852)

摘　　要：为探明黄土丘陵沟壑区退耕还林(草)政策的水沙响应问题,以1980—2009年期间植被重建规模较大的北洛河上游为研究区域,采用双累积曲线法和Pettit突变检验法,探讨径流输沙的变化趋势和跃变时间,同时结合气候和水土保持措施的资料,对不同时段的水沙过程进行对比分析。结果表明:1)径流量和输沙量变化可以分为2段(1980—2002年和2003—2009年),年时间尺度上,后段较前段径流量减少0.32亿m3、输沙量减少0.29亿t,并且后段波动较前段小;2)在月时间尺度上,2个时段的月降水量与月均流量过程基本相同,月均流量和输沙率关系基本呈现8字形,但是变幅及变率不同;3)相对于1980—2002年,2003—2009年年均降雨量、降雨侵蚀力分别减少10.06%和10.28%,降水具有减少径流和输沙的潜在条件。剔除降雨的影响,林草措施的减水和减沙效应分别为41%和81%。Grain for Green program since 1999 resulted in a great land use/cover changes in the Loess Plateau, China, which fundamentally influenced hydrological cycle and sediment transportation. It is important to understand the impacts of soil and ＇water conservation measures on the streamflow and sediment load in the catchment. The double accumulative curve and Pettit Test method were employed to identify trend and change point in the runoff and sediment in the upper catchment of Beiluo River from 1980 to 2009. Combined with the data of climate change and measures of soil and water conservation, the runoff and sediment process at monthly and yearly scales were analyzed. The result showed that ： 1 ） the change points in 2002 was detected for both runoff and sediment. Compared to period 1 （1980--2002） , the volume of runoff and the sediment discharge in period 2 （2003--2009）decreased by 0.32 × 10^8 m^3 , 0.29 × 10^8t respectively, and with less fluctuation. 2） At monthly scales, the patterns of monthly rainfall amount and monthly mean volume of runoff in both periods were similar. The relationship between monthly mean volume of runoff and sediment delivery was showed as clockwise 8, but the varying ratio was different. 3） Compared to period 1, the annual average rainfall amount and the annual average rainfall erosivity increased by 10.06% and 10.28%. The rainfall has the potential capability of reducing the runoff and the sediment . Regardless of the effect of rainfall, the effect of reducing runoff and sediment by forest and grass measures were about 41% and 81% , respectively.

关 键 词：退耕还林 水沙变化 时间动态 北洛河 

分 类 号：S161.6[农业科学—农业气象学]