【摘要】 利用1988,1999和2003年3个时段的TM,ETM+遥感数据,在GIS和FRAGSTAT景观分析软件的支持下,对二滩库区(盐边)的土地利用景观格局和水土流失动态特征进行了定量分析。结果表明,(1)耕地面积减少,所占百分比呈下降趋势,而有林地、灌木林地、草地所占百分比呈上升趋势。(2)耕地的斑块数目增加,平均斑块面积在减少,斑块密度上升;有林地的斑块数目减少,平均斑块面积增加,斑块密度下降;草地的斑块数目不断增加,平均斑块面积增加,斑块密度下降。说明耕地向不断破碎化发展而有林地、草地呈现持续扩张的空间集中化特征。(3)耕地、有林地、灌木林地、疏林地面积加权的平均斑块形状指数略有下降,斑块形状趋于简单化,而草地的该指数上升,斑块形状趋于复杂化。(4)从景观水平上看,景观格局变化总体特征是斑块数增加,拼块平均面积减少,斑块密度增加,最大斑块指数减少,说明景观破碎度增加。蔓延度降低,散布与并列指数增加,说明景观类型的相互关系变得复杂,镶嵌度增加。(5)景观多样性指数和土地利用相对合理指数增加,坡度较大的地区,耕地面积明显减少,相应地林地、草地面积明显增加,整体上土地利用结构趋于合理。(6)研究区强度以上水土流失面积15 a来减少了23.02km2,减少率为15.13%,水土流失强度向低层次转变。说明随着水库的修建蓄水,加上天然林保护工程、退耕还林工程的实施,二滩库区的水土流失明显好转,生态环境逐渐得到改善。更多还原

【Abstract】 Based on GIS and landscape pattern theory,dynamic landscape pattern of land use and soil and water loss in the Ertan Reservoir area of Yanbian County were analyzed using translated data from remote sensing images in 1988,1999,and 2003.Results showed that the area percentage of farmland decreased obviously,while the percentage of woodland,bush-land,and grassland increased.The patch number of farmland increased and its mean patch area and patch density decreased.The patch number of woodland decreased,its mean patch area increased,and its patch density decreased.The patch number of grassland and its mean patch area increased and its patch density decreased.The AWMSI of farmland,woodland,bush-land,and sparse forestland decreased slightly and its patch shape became simple.The AWMSI of grassland increased and its patch shape became complicated.In view of the land-level,the general characteristics of landscape pattern change were that the patch number and patch density increased,while the mean patch area and LPI decreased,indicating an increase in fragmentation degree.The CONTAG decreased,while IJI increased,implying an enhanced connectedness of landscape.Landscape diversity and relative land use rationality index increased,indicating that an improved land use structure.Soil and water loss status in the Ertan reservoir area of Yanbian county was improved greatly from 1988 to 2003.更多还原