基于GIS和RS的称钩河流域土壤侵蚀及其影响因素研究

发布时间：2019-06-11 21:52

【摘要】：本文以陇中黄土高原称钩河流域为研究对象,运用GIS和RS技术,在DEM、遥感影像、降雨径流泥沙等观测数据的基础上,利用RUSLE模型对称钩河流域土壤侵蚀进行了模拟,并基于降雨观测资料、地形数据以及淤地坝集水单元,分别分析了流域降雨、地形及土地利用对土壤侵蚀的影响,为该流域及同等类型区域的土壤侵蚀研究提供借鉴和参考。取得了以下主要结论:(1)称钩河流域土壤侵蚀以微度和轻度侵蚀为主,年土壤侵蚀模数为618.31t/(km2·a),年土壤流失量为9.93万t/a。治理后流域绝大部分区域土壤侵蚀得到了有效控制,但还有部分区域如阳坡荒坡侵蚀仍然严重,部分沟道边坡时有滑坡、崩塌等重力侵蚀现象发生。(2)近10年称钩河流域年降雨量为399.23 mm、年汛期降雨量为280.85 mm,年侵蚀性降雨量为172.30 mm,占年降雨量的43.16%。该流域侵蚀性降雨年际变化显著影响土壤侵蚀的变化,而年降雨量、年汛期降雨量对土壤侵蚀的影响相对较小。该流域年内影响土壤侵蚀大小的主要降雨指标为高强度降雨发生的次数,土壤侵蚀主要是由一次或者几次高强度降雨所造成的。(3)称钩河流域地形因子与土壤侵蚀关系非常显著。在高程方面,流域土壤侵蚀与高程变化呈负相关,随着高程的增加,土壤侵蚀模数、土壤侵蚀程度显著降低;在坡度方面,流域土壤侵蚀与坡度变化呈正相关,随着坡度的增加,土壤侵蚀模数、土壤侵蚀程度增强;在坡向方面,流域土壤侵蚀模数、土壤侵蚀程度为阳坡半阳坡半阴坡阴坡。(4)称钩河流域土地利用方式以梯田、草地及林地为主,共占流域总面积的86.08%。从不同土地利用类型的土壤侵蚀模数来看,梯田人工草地灌木林地有林地旱平地天然草地建设用地坡耕地裸地。梯田、人工草地为主要减沙土地利用类型,天然草地、裸地为主要产沙土地利用类型。
[Abstract]:Based on the observation data of DEM, remote sensing image and rainfall runoff, the soil erosion of the river basin is simulated with the RUSLE model based on the observation data of DEM, remote sensing image, rainfall runoff and sediment, and based on the data of rainfall observation, this paper uses GIS and RS technology. The effects of rainfall, topography and land use on soil erosion in the basin are analyzed, and the soil erosion in the basin and the same type of area can be used for reference and reference. The following main conclusions have been obtained: (1) The soil erosion in the Hoi River basin is dominated by microdegree and slight erosion, the annual soil erosion modulus is 618.31t/ (km2 路 a), and the annual soil loss is 9.93 million t/ a. The soil erosion in most areas of the post-treatment basin has been effectively controlled, but there are some areas, such as the waste slope of the sunny slope, which is still serious, and the phenomenon of gravity erosion such as landslide, collapse and so on in the part of the channel slope. (2) In the last 10 years, the annual rainfall of the Hoi River basin is 399.23 mm, the annual rainfall in the flood season is 280.85 mm, and the annual erosion rainfall is 172.30 mm, accounting for 43.16% of the annual rainfall. The interannual variation of the erosion in the river basin has a significant effect on the change of soil erosion, and the annual rainfall and the annual rainfall in the flood season have a relatively small effect on the soil erosion. The main rainfall index that affected the size of soil erosion during the year is the number of high-intensity rainfall, and the soil erosion is mainly caused by one or several high-intensity rainfall. (3) The relationship between the terrain factor and the soil erosion is very significant. In the aspect of elevation, the soil erosion of the river basin is negatively correlated with the change of the elevation, with the increase of the elevation, the soil erosion modulus and the degree of soil erosion are significantly reduced; in the aspect of the slope, the soil erosion of the river basin is positively related to the change of the slope, and the soil erosion modulus increases with the increase of the slope, The soil erosion degree is enhanced; in the aspect of the slope, the soil erosion modulus of the basin and the degree of soil erosion are the semi-negative slope of the semi-yin slope of the semi-positive slope of the sunny slope. (4) The land use method of the Hoi River basin is dominated by terraced fields, grassland and forest land, accounting for 86.08% of the total area of the basin. On the basis of the soil erosion modulus of different land use types, the land of the natural grassland construction land of the land-land dry land in the artificial grassland of the terraced field is bare land. Terraces and artificial grass are mainly of the type of land use, natural grassland, and bare land are the main types of land use.
【学位授予单位】：甘肃农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157.1;S127

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