基于WEPP模型的生产建设项目堆土水土流失预测与堆土形式优选

发布时间：2018-05-29 14:42

本文选题：土壤侵蚀 + WEPP模型　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：我国黄土区地形复杂,水土流失严重,土壤侵蚀问题成为限制该区经济发展的重要因素之一。水土流失预测是黄土区生态环境持续发展的重要内容,也是该区生产建设项目中水土保持措施布设和规划重要依据。怎样快速、准确的预测生产建设项目造成水土流失是水土保持方案编制过程中迫切需要解决的问题,也是水土流失防治措施设计需解决的核心问题。堆土场土壤侵蚀是生产建设项目水土流失的重要组成,在同样堆土数量和同一占地面积条件下,论文基于WEPP模型,模拟黄土区生产建设项目实施过程中不同堆土形式下的水土流失,探索不同堆土形式堆土场的土壤侵蚀规律,寻求最佳堆土形式。主要研究结果如下:(1)直线型坡面堆土条件下,堆土坡面角度越大,堆土场土壤侵蚀量越小,当坡面角度大于26°后,堆土场土壤侵蚀减小幅度几乎为零。在达到堆土场安全要求且减少压占土地条件下,建设项目区土壤休止角即为即为直线型堆土形式下土壤侵蚀最轻的角度。当坡面角度α=42°,堆土高度h=8.64m时,堆土场单宽土壤流失量最小,为110.9 kg/m。(2)当采用折线型坡面堆土时,堆土场土壤侵蚀受到两个坡面角度α1、α2的共同影响,当下半部坡面角度α1不变,随着上半部坡面角度α2的增加,堆土场土壤侵蚀先减小后增加;当α2不变,随着α1的增加,堆土场土壤侵蚀逐渐减少。(3)采用台阶式堆土形式,堆土场土壤侵蚀与堆土场的两个坡面角度有关,堆土场下半部堆土坡度α1保持不变的条件下,随着α2的增大,堆土场土壤侵蚀量呈现先减小后增加的趋势;堆土场上半部堆土坡度α2不变时,随着α1的增大,土壤侵蚀强度随之增加。马道宽度d的取值和堆土场土壤侵蚀成正相关,可据实际需要确定。(4)综合分析折线型和台阶型两种堆土方式,通过分析可以得出,堆土场土壤侵蚀最小的堆土坡度组合为α1=40°,α2=26°。(5)基于WEPP模型,分别模拟直线型堆土场坡面布设种草和密目网苫盖两种水土保持措施后堆土场的土壤侵蚀,模拟结果显示,种草和密目网苫盖能较好的防治堆土场的水土流失。
[Abstract]:The soil erosion is one of the most important factors that restrict the economic development of the loess area in China because of its complex topography and serious soil erosion. The prediction of soil and water loss is an important content of sustainable development of ecological environment in loess area, and it is also an important basis for the arrangement and planning of soil and water conservation measures in production and construction projects in this area. How to predict soil and water loss caused by production and construction projects quickly and accurately is an urgent problem to be solved in the process of formulating soil and water conservation scheme, and it is also the core problem to be solved in the design of soil and water loss prevention and control measures. Soil erosion is an important component of soil erosion in production and construction projects. Under the condition of the same amount of piling soil and the same area of land, the paper is based on WEPP model. In order to explore the law of soil erosion in different soil stacks and seek the best soil form, the soil erosion was simulated during the implementation of the production and construction project in loess area. The main results are as follows: (1) the larger the slope angle is, the smaller the soil erosion is. When the slope angle is more than 26 掳, the soil erosion decreases almost zero. The angle of soil repose in the construction project area is the lightest angle of soil erosion in the form of linear pile under the condition of meeting the safety requirement of the site and reducing the pressure of the land. When the slope angle is 42 掳and the height of pile is 8.64m, the soil loss of single width is minimum (110.9 kg 路m 路m ~ (-2). When the slope is broken, the soil erosion is affected by the two slope angles 伪 _ 1 and 伪 _ 2, and the slope angle 伪 _ 1 is not changed in the lower half of the slope, and the soil erosion is affected by two slope angles (伪 _ 1 and 伪 _ 2). With the increase of slope angle 伪 2 in the upper half of the slope, the soil erosion decreases first and then increases, and when 伪 2 does not change, with the increase of 伪 1, the soil erosion decreases gradually with the increase of 伪 1. The soil erosion is related to the two slope angles of the pile field. With the increase of 伪 2, the soil erosion volume decreases first and then increases under the condition that the slope 伪 1 of the lower half of the pile field remains unchanged. The soil erosion intensity increases with the increase of 伪 1 when the slope 伪 2 of the half part of the pile field is constant. The value of the width d is positively related to the soil erosion of the pile yard, and can be determined according to the actual needs. (4) the two types of soil heap, broken line type and step type, can be comprehensively analyzed, and the results can be obtained by the analysis. Based on WEPP model, the soil erosion in the slope field of linear pile site was simulated after two kinds of soil conservation measures, recommended by soil conservation measures and covered by dense mesh, respectively. The simulation results showed that the soil erosion of the slope site was improved. It is recommended that the mulch cover can prevent soil and water loss from heaps.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157

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