基于RUSLE的黄土高原河龙区间西岸土壤侵蚀研究

发布时间：2018-05-13 04:09

本文选题：河龙区 + RUSLE　；参考：《西华师范大学》2017年硕士论文

【摘要】：河龙区间地处黄土高原中游的重点水土流失区,地形破碎,沟壑纵横,是黄土高原土壤侵蚀最为严重的地区,本文基于RUSLE模型和GIS等软件,利用DEM、降雨、遥感影像、土壤、土地利用数据,分析研究了黄土高原河龙区间西岸近五十多年来的土壤侵蚀情况,主要结论如下:1、从1956年到1989年,河龙区西岸土壤侵蚀呈现出下降的趋势,由1956-1969年的93.73 t·hm~(-2)·a~(-1)下降到1971-989年的79 t·hm~(-2)·a~(-1),研究区两个时段均为微度侵蚀所占面积最大,分别为44.10%和44.25%,其次为剧烈侵蚀,微度侵蚀、轻度侵蚀和中度侵蚀呈上升趋势,而强度侵蚀、极强度侵蚀和剧烈侵蚀相反;空间分布上总体西北风蚀区低,东南水蚀区高,并且水蚀区北高南低。同时在进行模型计算时,要注意短时强降雨对计算结果的影响。2、研究区不同坡度、不同土地利用类型、不同地貌发育阶段的土壤侵蚀差异明显。坡度较低的地方以微度侵蚀为主,而坡度大的地方以剧烈侵蚀为主且侵蚀量变化幅度大。旱地和草地在整个区域所占面积比例大,土壤侵蚀严重,成为土壤侵蚀的主要来源,其次为林地和未利用地,建设用地和水田所占面积最小。HI值在0.35-0.5、0.5-0.6的壮年期地貌发育阶段所占面积比例最大,达到92%,壮年偏幼和壮年偏老阶段所占比例分别为5.05%和2.37%,说明研究区主要处于地貌发育的壮年阶段,地形复杂,以微度侵蚀和剧烈侵蚀为主。3、研究区在无植被覆盖和水土保持措施的影响下,1971-1989年的土壤侵蚀模数和侵蚀量分级达到205.7679 t·hm~(-2)·a~(-1)和15.30亿吨,相较于实际侵蚀量增加了将近三倍,具体分析不同的土地利用类型可知,其中旱地和草地的潜在土壤侵蚀量最大,分别达到了约6.55亿吨和6.96亿吨,土壤保持能力最强的为水田。研究表明植被覆盖和水土保持措施对土壤侵蚀的抑制作用显著,在土壤侵蚀的治理中应以旱地和草地为治理重点。
[Abstract]:The He-long section is located in the key soil and water loss area in the middle reaches of the Loess Plateau. The terrain is broken and the gully is horizontal and vertical. It is the most serious area of soil erosion on the Loess Plateau. Based on the RUSLE model and GIS software, this paper uses DEM, rainfall, remote sensing image, soil, etc. Land use data were used to analyze and study the soil erosion in the West Bank of the Loess Plateau during the past 50 years. The main conclusions are as follows: 1. From 1956 to 1989, the soil erosion in the West Bank of the Loess Plateau showed a downward trend. It decreased from 93.73 t / hm ~ (-1) in 1956-1969 to 79 t / h ~ (-1) in 1971-989. In the study area, the area of micro-erosion was 44.10% and 44.25% respectively, followed by severe erosion, slight erosion, mild erosion and moderate erosion, while intensity erosion, in the two periods of the study area, was the largest in the study area, which was 44.10% and 44.25% respectively, followed by severe erosion, slight erosion, mild erosion and moderate erosion. The polar intensity erosion is opposite to the severe erosion, and the spatial distribution is generally low in the northwest wind erosion area, high in the southeast water erosion area, and low in the north and south of the water erosion area. At the same time, we should pay attention to the influence of short and strong rainfall on the results of the model calculation. The difference of soil erosion in different slope, different land use type and different geomorphologic development stage in the study area is obvious. Where the slope is low, the erosion is mainly micro-degree, while the area with high slope is dominated by intense erosion, and the amount of erosion varies greatly. Drylands and grasslands account for a large proportion of the total area of the region, with serious soil erosion, which is the main source of soil erosion, followed by woodlands and unused land. The area of construction land and paddy field is the smallest. Hi value is 0.35-0.5 ~ 0.5-0.6, and the proportion of the area is the largest in the stage of geomorphologic development in the period of 0.35-0.5 ~ 0.5-0.6. Reaching 92%, the proportion of young adults and young adults were 5.05% and 2.37% respectively, which indicated that the study area was mainly in the mature stage of geomorphology development, and the topography was complex. Under the influence of no vegetation cover and soil and water conservation measures, the soil erosion modulus and erosion classification reached 205.7679 t / h ~ (-2) a ~ (-1) and 1.53 billion tons in 1971-1989 in the study area, which increased by nearly three times compared with the actual erosion. According to the analysis of different land use types, the potential soil erosion of dryland and grassland was the largest, reaching about 655 million tons and 696 million tons respectively, and the paddy field had the strongest soil conservation capacity. The results showed that vegetation cover and soil and water conservation measures had significant inhibitory effect on soil erosion, and dryland and grassland should be the key in soil erosion control.
【学位授予单位】：西华师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157

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