降雨-植被格局耦合作用对坡沟系统水沙特征影响  

Coupling Effect of Rainfall-vegetation Pattern on Runoff and Sediment Characteristics in Slope-gully System

作　　者：程圣东[1] 李鹏[1] 李聪 任宗萍[1] 王添[1] 唐辉[1] 赵宾华[1] 

机构地区：[1]西安理工大学西北旱区生态水利工程国家重点实验室培育基地,陕西西安710048 [2]河南黄河水文勘测设计院,河南郑州450004

出　　处：《应用基础与工程科学学报》2016年第2期230-241,共12页Journal of Basic Science and Engineering

基　　金：水利部黄土高原水土流失过程与控制重点实验室开放课题基金(2014003;2014004);国家自然科学基金重点项目(41330858);陕西省自然科学基础研究计划项目(2014JM2-4036)

摘　　要：不同植被格局的产流产沙特征是研究坡沟系统植被调控机理的重要基础.本研究以坡-沟系统物理模型为载体,通过间歇性模拟降雨试验对坡面5种覆草格局的产流产沙特征进行了分析.结果表明,植被格局对坡沟系统的产流产沙量均有显著性影响(p<0.05).坡下部的蓄水减沙效益总体优于坡上部,但在坡沟系统条件下,并非将草带种植得越靠近坡面最下端,其蓄水减沙效益最佳,不同植被格局的蓄水减沙效益依次为:坡面中下部>坡下部>坡面中上部>坡面上部,即将草带种植在距离坡面4m时其水土保持效果最佳,此处可减水7.35%,减沙62.93%.在不同格局条件下,第2、3次降雨径流量均值分别比第1次降雨增加5.39%~37.16%、1.83%~21.83%,产沙量均值分别比第1次减少42.05%~82.45%、72.34%~92.26%,即随着降雨场次的增加,径流量略有增加且趋于稳定的时间逐渐缩短,产沙量急剧下降.在不同植被格局条件下,随着模拟降雨历时的延长,径流量在0~10min内以约0.54L/min的速度快速增加至8~10L/min,之后处于水平稳定状态.产沙量的变异系数Cv在50%以上,产沙过程波动剧烈.草带削减径流量为5%左右,蓄流作用稍弱,相对来说对泥沙的拦截作用较好,能使产沙量下降33%左右.The characteristics of runoff and sediment yield of the different coverage patterns provided an important foundation for the regulation mechanism of vegetation in slope-gully system.According to the intermittent rainfall simulation experiment through the physical model of the slope-gully system,the characteristics of runoff and sediment yield under 5 vegetation patterns on the slope were analyzed. Results showed that the vegetation pattern had a significant influence on runoff and sediment yield of the slope-gully system( p < 0. 05). The benefits of runoff and sediment reduction at the bottom of the slope were superior to the upper slope as a whole,whereas,it was not the best that the grass was near to the bottom of the slope under the condition of slope gully system. The order of the benefit of runoff and sediment reduction of the different vegetation patterns was the middle and lower > the lower > the middle and upper > the upper of the slope on the slope-gully system. Then planting the grass on the slope away from the top 4m was would be the best pattern in this study,which would reduce the runoff by 7. 35% and the sediment by 62. 93%. Under different vegetation patterns,the average runoff of the 2nd and 3rd rainfall were more than the 1st,which were increased by 5. 39% ~ 37. 16% 、1. 83% ~21. 83% respectively. While the average sediment of the 2nd and 3rd rainfall were less than the 1 st,which were decreased by 42. 05% ~ 82. 45%,72. 34% ~ 92. 26% respectively.Consequently,with the increase of rainfall events,the runoff increased slightly,the time of achieving of stable state is sooner,while the sediment yield declined sharply. Under different vegetation patterns,as time went on the runoff fast increased to 8 ~ 10 L / min at a speed about 0. 54 L / min and remained stable within 10 minutes,while the sediment yield experienced severe fluctuations with the Cv above 50%. The runoff were decreased by 5% with a the weaker storage capacity. Correspond to the runoff,the sediment yield were decreased by 33% with a be

关 键 词：坡沟系统 植被格局 间歇降雨 侵蚀产沙 

分 类 号：S157.1[农业科学—土壤学]