基于RUSLE模型的四川省土壤侵蚀敏感性评价及时空演化分析

Sensitivity assessment of soil erosin and its spatio-temporal evolution analysisin Sichuan province based on RUSLE

把握四川省土壤侵蚀敏感性的空间分异规律和演变趋势,可以为四川省科学防治水土流失工作提供有力的理论支持与决策依据。本文以降雨数据、高程数据、土壤数据和遥感影像数据为数据源,应用地理信息技术和遥感技术,结合改进的土壤侵蚀RUSLE模型,选取降雨、土壤、地形、植被覆盖4个因子建立土壤侵蚀敏感性评价体系,对四川省2005—2018年土壤侵蚀敏感性进行评价。结果表明:四川省土壤侵蚀敏感性主要以不敏感和轻度敏感为主。空间分布上,不敏感、轻度敏感区域主要分布在川西北北部、成都平原大部分地区和川东北。时空变化上,2005—2018年期间四川省土壤侵蚀敏感性呈增强的趋势。不敏感区域面积减少26%,轻度敏感区域面积增加17.51%,增加面积主要来源于不敏感区域的转变,中度敏感区域面积增加8.08%,增加面积来源于轻度敏感区域的转变,高度敏感区域面积增加2.67%,主要来源于中度敏感区域的转变,转变区域主要分布在川西高原西北部、成都平原以及川西南山地的大部分区域,该变化主要由植被覆盖因子和降雨侵蚀力因子综合影响所致。在土壤侵蚀敏感性影响因子中,植被覆盖因子与土壤侵蚀敏感性具有最显著的正相关性。研究四川省土壤侵蚀敏感性的时空变化,可以为四川省水土流失治理工作的实施、生态环境治理与修复提供理论理论依据与价值参考。

It is helpful for the control of water and soil erosion to grasp the spatial differentiation characteristics and evolution trend of soil erosion sensitivity in Sichuan province,which can provide strong theoretical support and decision-making basis for the scientific prevention and control of soil erosion.Taking rainfall, DEM, soil type and remote sensingimage data as data sources, four factors including rainfall, soil, topography, vegetation coverage were selected to establish asoil erosion sensitivity evaluation system combined with GIS, RS and RUSLE. The results showed that the sensitivity of soilerosion in Sichuan province was mainly insensitively and mildly sensitive. In the spatial distribution, the insensitive andmildly sensitive areas were mainly distributed in the north of northwest Sichuan, most areas of Chengdu Plain and northeastSichuan. In terms of the spatial and temporal change, soil erosion sensitivity in Sichuan Province increased from 2005 to2018. The area of non-sensitive area decreased by 26 %, and the area of mild sensitive area increased by 17.51 %. Theincrease area mainly came from the change of non-sensitive area, the area of moderate sensitive area increased by 8.08 %, theincrease area came from the change of mild sensitive area, and the area of high sensitive area increased by 2.67 %, mainlyfrom the change of moderate sensitive area. The change area was mainly distributed in the northwest of the western SichuanPlateau, the Chengdu Plain and most of the mountainous areas in southwest Sichuan. The change was mainly caused by thecomprehensive influence of vegetation cover factor and rainfall erosion factor. Among the influencing factors of soil erosionsensitivity, vegetation coverage factor had the most significant positive correlation with soil erosion sensitivity. Thespatial-temporal changes of soil sensitivity in Sichuan province were studied, which contributed to the implementation of soilerosion control, ecological environment control and restoration in Sichuan Province.