模拟降雨下草被坡面水沙调控效应及水分转化研究  

Effects of Grasses on Runoff and Sediment Reduction and Water Transformation on the Slope Under Simulated Rainfall

作　　者：宋亚倩 赵西宁[1,2] 潘岱立[3] 高晓东[2] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100 [3]西北农林科技大学水土保持研究所,陕西杨凌712100

出　　处：《水土保持研究》2016年第5期35-41,共7页Research of Soil and Water Conservation

基　　金：中国科学院重点部署项目(KFZD-SW-306);陕西省科技统筹创新工程计划项目(2015KTCL02-25);中央高校基础科研业务费(2452015056)

摘　　要：以黄土丘陵区四种多年生牧草(鸡脚草、白三叶、小冠花、百脉根)为研究对象,采用人工模拟降雨试验方法,定量研究不同草被措施不同生长阶段(5月上旬、6月上旬、7月中旬和8月下旬)的坡面水沙调控效应及土壤水分转化特征。结果表明:在整个生长周期内,四种草被措施坡面产沙率和含沙量均表现为鸡脚草坡面<白三叶坡面<小冠花坡面<百脉根坡面<裸地坡面。随着生长时间延长,四种草被措施坡面减流效益、减沙效益、土壤稳定入渗速率和土壤平均含水量增量均呈现先增大后减小的趋势。其中,鸡脚草坡面和白三叶坡面在结实期达到最大,小冠花坡面和百脉根坡面在孕蕾期达到最大。在不同生长阶段,鸡脚草坡面和白三叶坡面减流效益、减沙效益、土壤稳定入渗速率和土壤平均含水量增量均大于小冠花坡面和百脉根坡面,其中以鸡脚草坡面最为显著。四种草被措施在不同生长阶段坡面减沙效益都远大于减流效益。黄土丘陵区坡面水土流失主要来自7—9月份频率较高的降雨所产生的坡面径流,鸡脚草和白三叶生长旺盛期与水土流失频发阶段吻合,使其调控坡面水沙能力得以充分体现。Four kinds of perennial grasses（Dactylis glomerata L.,Trifolium repens L.,Coronilla varia L.,Lotus corniculatus L.）growing in the hilly region of Loess Plateau were studied under the simulated rainfall.The runoff and sediment trapping effects and soil water transformation on sloping lands covered by grasses were detected at various growth periods.It was turned out that in the whole growth stages,the sediment ratio and sediment concentration all followed the order：Dactylis glomerata L.Trifolium repens L.Coronilla varia L.Lotus corniculatus L.bare land.As the growth duration extended,runoff and sediment reduction,soil water content increment and soil stable infiltration all showed a trend of first increase and then decrease.The slope with Dactylis glomerata L.and Trifolium repens L.reached their best performance in the fruited phase,Coronilla varia L.and Lotus corniculatus L.in the stage of pregnancy reached their best performance,At different growth stages,the slope covered by Dactylis glomerata L.and Trifolium repens L.kept higher runoff and sediment reduction benefits,the soil stability infiltration rate and the average soil water content increment than that covered by Coronilla varia L.and Lotus corniculatus L.especially Dactylis glomerata L..All treatments obtained greater sediment reduction rate than runoff.The soil and water losses in loess hilly-gully region occur mainly from July to September due to the erosive rainfall events.The dynamics of annual runoff and sediment control in sloping lands covered by Dactylis glomerata L.and Trifolium repens L.matched well with that of soil and water losses,which may lead a better performance of Dactylis glomerata L.and Trifolium repens L.in the practice.

关 键 词：模拟降雨 草被措施 生长阶段 水沙调控 土壤含水量增量 

分 类 号：S157.2[农业科学—土壤学]