牧草调控绵沙土坡面侵蚀机理

ISWC OpenIR > 水保所知识产出(1956---)

	牧草调控绵沙土坡面侵蚀机理
其他题名	Mechanisms of grass in slope erosion control in loess sandy soil region of Northwest China．
	赵春红; 高建恩; 徐震
	2013
发表期刊	应用生态学报
卷号	24 期号:01 页码:113-121
摘要	采用人工模拟降雨方法,从坡面水动力学角度,结合土壤抗冲性分析,对不同坡度和雨强组合下牧草调控黄土高原风蚀水蚀交错区绵沙土坡面侵蚀机理进行了定量研究,为揭示植被调控土壤侵蚀机理及黄土高原水土保持植被选择提供科学参考.结果表明:覆盖度约为40%的牧草沙打旺能够有效控制坡面土壤侵蚀,减沙效益达70%以上,而且根系减沙效益大于草冠.裸坡、只有根系作用的坡面和整株牧草作用的坡面水流流速与雨强、坡度均呈V=DJ0.33i0.5的函数关系,其中,J为坡度比降,i为雨强(mm·min-1),下垫面不同,综合系数D取值不同.牧草根系和冠层能够显著减小流速,增加阻力,根系的减速作用大于草冠,而增阻作用小于草冠.根系调控坡面阻力主要通过增加坡面泥沙颗粒阻力实现,而草冠通过增加坡面形态阻力和波阻力来实现.利用薄层水流坡面产沙概念模型对土壤抗冲性进行评价,得到试验条件下裸坡、只有根系作用的坡面和整株牧草作用的坡面的临界径流切应力分别为0.533、0.925和1.672Pa.
其他摘要	By adopting the method of simulated precipitation and from the viewpoint of slope hydrodynamics， in combining with the analysis of soil resistance to erosion，a quantitative study was made on the mechanisms of grass in controlling the slope erosion in the cross area of wind-water erosion in Loess Plateau of Northwest China under different combinations of rainfall intensity and slope gradient，aimed to provide basis to reveal the mechanisms of vegetation in controlling soil erosion and to select appropriate vegetation for the soil and water conservation in Loess Plateau． The grass Astragalus adsurgens with the coverage about 40% could effectively control the slope erosion． This grass had an efficiency of more than 70% in reducing sediment，and the grass root had a greater effect than grass canopy． On bare slope and on the slopes with the grass plant or only the grass root playing effect，there existed a functional relation between the flow velocity on the slopes and the rainfall intensity and slope gradient ( V =DJ0． 33 i0． 5，where V is flow velocity，D is the comprehensive coefficient which varies with different underlying surfaces，i is rainfall intensity，and J is slope gradient) ． Both the grass root and the grass canopy could markedly decrease the flow velocity on the slopes，and increase the slope resistance，but the effect of grass root in decreasing flow velocity was greater while the effect in increasing resistance was smaller than that of grass canopy． The effect of grass root in increasing slope resistance was mainly achieved by increasing the sediment grain resistance， while the effect of canopy was mainly achieved by increasing the slope form resistance and wave resistance． The evaluation of the soil resistance to erosion by using a conceptual model of sedi-ment generation by overland flow indicated that the critical shear stress value of bare slope and of the slopes with the grass plant or only the grass root playing effect was 0． 533，1． 672 and 0． 925 Pa，respectively．
关键词	绵沙土 Loess Sandy Soil 根系 Root 冠层 Canopy Layer 水动力学机理 Hydrodynamics Mechanism 土壤抗冲性 Soil Resistance To
语种	中文
文献类型	期刊论文
条目标识符	sbir.nwafu.edu.cn/handle/361005/5538
专题	水保所知识产出(1956---)
推荐引用方式 GB/T 7714	赵春红,高建恩,徐震. 牧草调控绵沙土坡面侵蚀机理[J]. 应用生态学报,2013,24(01):113-121.
APA	赵春红,高建恩,&徐震.(2013).牧草调控绵沙土坡面侵蚀机理.应用生态学报,24(01),113-121.
MLA	赵春红,et al."牧草调控绵沙土坡面侵蚀机理".应用生态学报 24.01(2013):113-121.

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