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题名	坡地降雨侵蚀试验研究
作者	王勇强
学位类别	硕士
答辩日期	2007
授予单位	中国科学院水利部成都山地灾害与环境研究所
授予地点	成都
导师	王玉宽
关键词	紫色土 燥红土 坡耕地 降雨侵蚀
学位专业	土壤学
中文摘要	雨滴打击和径流冲刷是坡面侵蚀发生的主要原动力，雨滴打击地表不仅直接搬运土粒，而且还通过破坏土壤表面结构、堵塞土壤孔隙、减少入渗，来加剧径流冲刷侵蚀作用。降雨打击作用是降雨侵蚀发生的能量来源，在引起土粒直接飞溅的同时，也会改变土壤抗蚀强度，影响地面产流。本文通过不同雨强、不同坡度、不同土壤类型、不同土壤处理方式的人工降雨模拟试验，对降雨、径流、泥沙的过程展开全面的观测和土、水样品的采样分析，系统的研究了长江上游两种典型土壤降雨侵蚀的过程和机理，旨为以搞清两种不同侵蚀作用力的侵蚀机制与规律，为建立长江上游土壤侵蚀动力学模型服务。研究取得主要结论如下： 1、利用自行设计制作的微径流小区（0.35×0.35m2），通过室内人工模拟降雨比试验得出：0.35×0.35m2微小区在紫色土和燥红土两种土壤上消除雨滴打击作用后，地表径流侵蚀微弱，侵蚀作用可以忽略。表明试验设计的微小区可以用于研究降雨侵蚀（雨滴打击侵蚀）。 2、 紫色土坡面降雨侵蚀率和含沙量在降雨初期随着降雨历时的增加有很微小的变化，在产流开始3min后侵蚀率趋于稳定。侵蚀率与雨强基本呈线性关系，侵蚀率随地表坡度的变化趋势为：从5o到10o呈增加趋势, 10o后增加较平缓，15o附近到达峰值。 3、燥红土坡面侵蚀率和含沙量在降雨初期随着降雨历时的增加有很微小的变化，然后逐渐趋于稳定。中小坡度上侵蚀率随着雨强线性增加，而在坡度较大的情况下侵蚀率随雨强的变化表现出两个不同的过程。在雨强<53.4mm/h段直线的斜率小侵蚀率随雨强增加慢；雨强>53.4mm/h段直线斜率较前一过程直线斜率大一些侵蚀率增加快。侵蚀率从5o到25o随坡度的增大侵蚀率一直曾增加，4、 裸坡耕地降雨侵蚀模型：紫色土：St=45.32*(EI)1.294*S0.8570 ；燥红土：St=15.24*(EI)1.676*S0.7321 。 5、两种土壤降雨产流差异不大，降雨侵蚀差异明显。紫色土降雨侵蚀率大于燥红土，随着坡度的增大紫色土和燥红土的含沙量差别在逐渐减小。6. 过筛和未过筛土试验对比：过筛紫色土地表径流量要略小于未过筛紫色土，未过筛紫色土含沙量和侵蚀率大于过筛紫色土。
英文摘要	Raindrop splash and runoff scour are the main motive power in slope cropland soil erosion, Raindrop splash is used to increase runoff scouring effect by the following mode, including: transit soil particle; destroy soil surface structure; stuff soil porosity; decrease infiltration. The soil particle is transited by Raindrop splash, while change the soil anti-Erosibility and runoff rate.Many simulated rainfall experiment under different rainfall intensities, slope gradients, soil type and soil treatment have been used to observe the natural events, corresponding rainfall, runoff process, soil loss sequentially. And series water and sediment samples were collected from each rainfall events. Erosion process and mechanism in upper reaches of the Yangtze River on two typical soil Slope cropland were studied understand different erosive mechanism and disciplinarian. The objectives were to service for soil erosion dynamic model The following results were obtained: 1.simulation rainfall experiments with the mini runoff plot （0.35×0.35m2）were studied, the results showed that Lamina flow erosivity was too feeble to neglect without eliminated rainfall splash both in purple soil and dry red soil. It was feasible to study rainfall erosion with mini plot method2.A little variation of surface soil erosion rate and soil concentration in initial time with duration of rainfall could be described and the stable status was occurred at 3 minutes after rain began in purple soil. The erosion ratio is increasing by linear with the rainfall intensity, but Slope gradient influenced erosion ratio have a trend that it firstly increase till the critical slope degree, across the critical slope degree Stable erosion ratio begin to decrease, the critical slope gradient is about 15°.3.A little variation of surface soil erosion rate and soil concentration in initial time with duration of rainfall could be described in dry red soil. The erosion ratio is increasing by linear with the rainfall intensity in gentle slope, in steep slope two period of time were showed: below the turning point of 53.4mm/h erosion ratio is increasing less slowly than over turning point of 53.4mm/h. erosion ratio is all among increasing with the slope gradient from 5o to 25o.4.Dualistic experiential model had been established based on the mechanism of rainfall erosion on slope land : St=45.32*(EI)1.294*S0.8570(purple soil) and St=15.24*(EI)1.676*S0.7321(Dry red soil).5.The results of the two varied soil sort experiments showed that, the discrepancy of rainfall erosion was more obvious than runoff. The soil concentration and erosion rate of purple soil were higher than Dry red soil, however the discrepancy decreased with slope gradient.6. The runoff rate in sieving purple soil was little less than no-sieving purple soil under the two varied soil treatment, however the soil concentration and erosion rate of sieving purple soil were higher than no-sieving purple soil.
语种	中文
学科主题	土壤学
公开日期	2010-10-21
分类号	S15;U41
内容类型	学位论文
源URL	[http://ir.imde.ac.cn/handle/131551/2278]
专题	成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前）
推荐引用方式 GB/T 7714	王勇强. 坡地降雨侵蚀试验研究[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2007.

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