Erosion and runoff reduction potential of vetiver grass for hill slopes: A physical model study  

作　　者：Shamontee Aziz Mohammad Shariful Islam 

机构地区：[1]BUET-Japan Institute of Disaster Prevention and Urban Safety(BUET-JIDPUS),Bangladesh University of Engineering and Technology(BUET),Dhaka-1000,Bangladesh [2]Department of Civil Engineering,Bangladesh University of Engineering and Technology(BUET),Dhaka-1000,Bangladesh

出　　处：《International Journal of Sediment Research》2023年第1期49-65,共17页国际泥沙研究（英文版）

基　　金：financially supported by an Academic Research Grant of Bangladesh University of Engineering and Technology(BUET),Bangladesh.

摘　　要：Severe erosion is caused by intense rainfall in tropical regions. The erodible soil of steep hill slopes,accompanied by destruction of vegetation due to human interventions results in accelerated erosion. A sustainable and cost-effective solution such as vetiver grass(Chrysopogon zizanioides) is, thus, required to control the erosion process. In the current study, 6 small-scale glass models: 1 bare and 5 with vetiver grass, having a slope angle of 37°have been constructed. One year after planting, artificial rainfall of extremely high intensity was applied to all 6 small models and the role of vetiver canopy and roots in erosion and runoff control was observed. To see the effect of soil texture, one among these 5 models was made with silty sand and others contained sandy silt. The results demonstrated that, for sandy silt, the inclusion of vetiver reduced the soil loss by 94%-97%, and soil detachment rates were lowered by 95%.The average runoff also was reduced by 21%. The canopy cover showed a positive impact on reducing both quantities. An increase in average root diameter from 1.6 to 2.5 mm increases the soil loss due to its negative impact on added cohesion. The added cohesion showed a linearly negative correlation with soil loss. A composite system of vetiver and jute geotextile was most effective in erosion reduction among 4vegetated models with sandy silt. Under same vetiver planting layout, the grass covered model of silty sand yielded 84% lower erosion and 62.5% lower runoff than the grass covered one with sandy silt. Thus,vetiver was more effective in erosion and runoff reduction for soil with a greater percentage of sand, and soil type dominated the erosion process.

关 键 词：EROSION Small-scale model experiments Surface runoff Artificial rainfall Vetiver 

分 类 号：S157.1[农业科学—土壤学]