两个时期的贵州草海国家级自然保护区土壤侵蚀动态变化遥感评估

Remote Sensing Assessment of Dynamic Changes of Soil Erosion in Guizhou Caohai National Nature Reserve in Two Stages

为促进贵州威宁草海湿地国家级自然保护区生境及区域社会、经济的可持续发展,结合遥感影像、植被覆盖度、土地覆盖因子以及DEM数据确定了保护区2010—2015年土壤侵蚀发生区域,对保护区土壤侵蚀时空变化特征进行分析,并探讨了不同土地利用类型与土壤侵蚀状况的关系。结果表明:(1)两个时期保护区土壤侵蚀均以轻度侵蚀为主,侵蚀总面积由2010年3187.33 hm2下降为2015年2904.84 hm2,总体上保护区侵蚀面积随等级增大而逐渐减小,其轻度、中度土壤侵蚀面积为下降趋势;而强度、极强度土壤侵蚀面积呈轻微增加趋势。(2)2010—2015年土壤侵蚀在轻度、中度、强度侵蚀上转化明显,其中轻度侵蚀有129.58 hm2转化为中度侵蚀,中度侵蚀有122.54 hm2转化为轻度侵蚀,强度侵蚀有19.37 hm2转化为中度侵蚀;表明保护区土壤侵蚀状况整体在改善,局部地区存在加剧现象;(3)土壤侵蚀中除湿地、建设用地无侵蚀面积外,耕地、草地、林地均在各等级土壤侵蚀中皆有不同分布,分别占保护区总面积的27.35%、19.4%、8.57%。表明以上区域(耕地、草地、林地)都是该地区土壤侵蚀防治的重要地带。

To promote the sustainable development of the habitat and regional social and economic development in the Weining Caohai Wetland National Nature Reserve in Guizhou,this study,combined remote sensing images,vegetation coverage,land cover factors and DEM data to determine the areas of soil erosion in protected areas from 2010 to 2015,analyzed the temporal and spatial characteristics of soil erosion in protected areas,and discussed different types of land use and soil erosion. The results showed that：（ 1） In the two periods,the soil erosion in the protected areas was mainly mild erosion.The total erosion area decreased from 3,183. 33 hm2 in 2010 to 2,904. 84 hm2 in 2015. Generally,the erosion area in the protected area gradually decreased with slightly increasing grades. The area of mild and moderate soil erosion showed a downward trend,while the area of intensity and extreme intensity of soil erosion showed a slight increase.（ 2） Soil erosion in 2010—2015 is obviously transformed on mild,moderate and intensity erosion. Among them,there is 129. 58 hm2 of mild erosion has converted to moderate erosion,122. 54 hm2 of moderate erosion has converted to mild erosion,and 237 hm2 of intensity erosion has converted into moderate erosion; it indicates that the soil erosion status of the protected area is improving as a whole,but there is aggravation in some areas;（ 3） In the soil erosion of each land use,except for the dehumidified land and the non-erosion area of the construction land,the cultivated land,grassland and forest land all have different distributions in all grades of soil erosion,accounting for 27. 35%,19. 4% and 8. 57% of the total area of the protected area,respectively. It shows that the above areas（ cultivated land,grassland,woodland） are important areas for soil erosion control in this area.