澜沧县土地利用变化和土壤侵蚀特征分析

为了研究云南省澜沧县的土地利用和土壤侵蚀的变化特征,以"通用土壤流失方程"为模型,运用ENVI遥感影像解译软件和Arc GIS软件,综合分析了澜沧县2000、2010、2014年3个时期的土地利用变化和土壤侵蚀的特征。结果表明:1)2000—2010年10 a间,土地利用类型表现为草地向林地、桉树林转化,耕地向草地、林地、桉树林转化,林地向桉树林转化,园地向林地转化。2010—2014年,水域、桉树林面积增加明显,草地、耕地、林地面积小幅下降;2)15 a间澜沧县土壤侵蚀总面积变化不大,土壤侵蚀状况呈现先趋向好转之后又趋向严重的变化趋势;3)草地和耕地的侵蚀面积减少,土壤侵蚀量下降;2000—2010年,草地和耕地大量转变为林地和桉树人工林,植被覆盖恢复,土壤侵蚀减缓;2014年由于桉树人工林的轮伐、大型水电站和公路的兴修以及人口增长和城市化进程的加快等方面的原因,多数地区植被覆盖度下降,直接导致了林地、桉树林地的土壤侵蚀加重。

Analysis of land use change and characteristics of soil erosion in Lancang County

To study the land use and the characteristics of the changes of soil erosion in Lancang County,Yunnan province,this study,taking "Universal Soil Loss Equation" (USLE) as the model to acquire soil erosion data,utilizes ENVI Software and ArcGIS Software to analyze comprehensively the land use changes and soil erosion properties before and after the three periods,2000,2010 and 2014.The results show that,firstly,from 2000 to 2010,land use pattern manifested as the transformation from grassland to forest land and eucalyptus forest,the transformation from cultivated land to grassland,forest land and eucalyptus forest,the transformation from forest land to eucalyptus,and the transformation from garden plot to forest land.From 2010 to 2014,the area of waters and eucalyptus forest obviously increased,and the area of grassland,cultivated land and forest land slightly decreased.Secondly,the total area of soil erosion had little change for the past 15 years in Lancang County and the situation of soil erosion show the changing trend from improvement to severity.Lastly the areas of grasslands and farmlands decreased,while the amount of the soil erosion is constantly went down;From 2000 to 2010,a large amount of grassland and farmland were changed to forest land and eucalyptus plantations,and vegetational cover recovered and soil erosion slowed down.In 2014,due to the rotation of eucalyptus plantations,construction of large hydropower station and highways,population growth and speeding up of urbanization,vegetation coverage in most areas declined,which directly led to the serious soil erosion of forest land and eucalyptus plantations.