攀西地区土壤侵蚀空间特征及与影响因子的关系分析

发布时间：2018-06-06 12:20

本文选题：土壤侵蚀 + RUSLE　；参考：《南京信息工程大学》2017年硕士论文

【摘要】：土壤是人类发展及生存的基础,土壤侵蚀是引起土地退化、减少农业生产、产生不稳定斜坡、造成水污染及河道变化等一系列环境问题的重要因素,土壤侵蚀的发生制约了人类可持续发展及生态文明建设进程,因而,土壤侵蚀的监测与预报是必不可少,对土壤侵蚀的治理也是刻不容缓。GIS与遥感技术的飞速发展,为土壤侵蚀的实时监测与空间格局的直观观测提供了强大的技术支持。本文以地质构造复杂且多暴雨的四川省攀西地区为例,在GIS与遥感技术的支持下,基于RUSLE 土壤侵蚀定量评价模型,计算攀西地区2010年土壤侵蚀量与土壤侵蚀模数,分析攀西地区土壤侵蚀强度的空间分布特征,在此基础上,充分考虑流域地理背景条件,利用地理探测器中的因子探测器与交互探测器,添加与流域相关的因子,定量分析河流周围地区土壤侵蚀量与不同环境因子之间的相关关系。得出的主要结论如下:(1)研究区2010年年均侵蚀模数为26.96t·hm2t·a-1,大于水利部规定的西南地区允许土壤侵蚀模数5t.hm2.a-1。攀西地区的土壤侵蚀程度以微度侵蚀为主,占侵蚀总面积的37.37%,轻度侵蚀与中度侵蚀的面积比例分别是20.43%和20.39%,主要分布在安宁河、雅砻江以及金沙江流域的河谷地区以及河流中下游地区较为宽广的冲积平原。强度侵蚀、极强度侵蚀以及剧烈侵蚀的部分,面积百分比之和为21.81%,主要分布于攀西中部地区南北走向坡度较大且植被盖度较低的地区。(2) 土壤侵蚀强度在不同高程带上基本呈现由大变小的变化趋势。在不同坡度带上,土壤侵蚀强度基本呈现波状变化趋势,随着坡度变大,相同土壤侵蚀强度的面积也在不断增大,坡度越大,地表的土壤越不容易保存,侵蚀强度也会增加。但是随着植被覆盖度的增加,土壤侵蚀强度越大的地区其面积比重是在不断下降的。不同土地利用类型条件下,土壤侵蚀强度也不同,水田、居民点、建设用地、城镇用地、湖泊、河渠、水库、裸地、未利用地、滩地主要以轻度侵蚀为主;而旱地主要是微度侵蚀和轻度侵蚀为主;随着海拔与坡度的增加,人类活动越来越少,有林地、高覆盖度草地、灌木林地、疏林地、中覆盖度草地、低覆盖度草地、其他林地这些地区土壤的轻度侵蚀、中度侵蚀、强度侵蚀的比重也比其他土地利用类型的比重要大很多。(3)地理探测器的因子探测器揭示了不同地理图层代表的因子对土壤侵蚀量影响的相对大小及其解释力为:坡度(0.9578) 暴雨频率(0.9518) 植被覆盖度(0.7534) 汇水流域面积(0.4616) 土地利用类型(0.3127) 土壤类型(0.1499) 河网等级(0.013) 离河流距离(0.0066) 离汇水点距离(0.0025)。交互探测器得出各因子间的交互作用都大于单个因子对土壤侵蚀量的影响。
[Abstract]:Soil is the basis of human development and survival. Soil erosion is an important factor that causes land degradation, reduces agricultural production, produces unstable slopes, and causes water pollution and river channel changes. The occurrence of soil erosion restricts the sustainable development of human beings and the process of ecological civilization construction. Therefore, the monitoring and forecasting of soil erosion is essential, and it is also an urgent task to control soil erosion with the rapid development of GIS and remote sensing technology. It provides powerful technical support for real-time monitoring of soil erosion and visual observation of spatial pattern. Based on the quantitative evaluation model of soil erosion based on GIS and remote sensing technology, the soil erosion volume and soil erosion modulus in 2010 in Panxi area of Sichuan Province are calculated based on the quantitative evaluation model of RUSLE. On the basis of analyzing the spatial distribution characteristics of soil erosion intensity in Panxi area, and considering the geographical background of the basin, the factors related to the watershed are added by using the factor detector and the interactive detector in the geographical detector. Quantitative analysis of the correlation between soil erosion and different environmental factors around rivers. The main conclusions are as follows: (1) the average annual erosion modulus of the study area in 2010 is 26.96 t hm2t a-1, which is larger than the allowable soil erosion modulus of 5t.hm2.a-1 in southwest China as stipulated by the Ministry of Water Resources. The degree of soil erosion in Panxi area is mainly micro-erosion, which accounts for 37.37% of the total area of erosion. The proportion of mild erosion and moderate erosion is 20.43% and 20.39% respectively, mainly distributed in the Anning River. The Yalong River, the valley area of Jinsha River and the broad alluvial plain in the middle and lower reaches of the river. The part of intensity erosion, extreme intensity erosion, and intense erosion, The total area percentage was 21.81%, mainly distributed in the area with large north-south trend slope and low vegetation coverage in the central Panxi area.) the soil erosion intensity basically showed a trend of change from large to small in different elevation zones. In different slope zones, the soil erosion intensity basically presents a wave-like change trend. With the slope increasing, the area of the same soil erosion intensity is also increasing. The larger the slope, the less easy the soil is to preserve, and the more erosion intensity will increase. However, with the increase of vegetation coverage, the area proportion of soil erosion intensity is decreasing. Under different land use types, the intensity of soil erosion is different, paddy field, residential area, construction land, urban land, lake, canal, reservoir, bare land, unused land, beach land are mainly slightly eroded; With the increase of elevation and slope, the human activities are less and less, such as woodland, high coverage grassland, shrub land, open forest land, middle coverage grassland, low coverage grassland, etc. Other woodlands, these areas of the soil erosion, moderate erosion, The ratio of intensity erosion is also much larger than that of other land use types.) the factor detectors of geographical detectors reveal the relative magnitude of the factors represented by different geographic layers on soil erosion and their explanatory power. The slope is 0.9578) the frequency of heavy rain is 0.9518) the vegetation coverage is 0.7534) the area of catchment basin is 0.4616) the land use type is 0.3127) the soil type is 0.1499) the river network grade is 0.013) the distance from the river is 0.0066) and the distance from the catchment point is 0.0025. Interaction detector showed that the interaction of each factor was greater than that of single factor on soil erosion.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157.1

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