20世纪70年代中期以来奈曼旗土地利用变化及生态环境效应研究

Study on Land Cover/Land Use Change and Eco-environment Effects of Naiman Banner Since 1976s

本文在遥感技术与GIS技术支持下,以内蒙古自治区奈曼旗近二十五年来的土地利用为例,对土地利用/覆盖的时空演变、景观格局变化及其生态环境效应进行了探讨。结果表明:1976—2000年间,奈曼旗发生土地利用变化的面积约占总面积的22.70%,发生变化的土地总面积为184015.51hm2。林地、未利用地面积明显增加,耕地面积明显减少,减少幅度约为21.86%。景观斑块的聚集程度变小,破碎程度加大,趋于离散分布。从生态效应上来看,土地利用变化引起的生态环境质量变化呈现出改善和恶化并存的趋势,主要表现在草地生态功能的退化以及土地的沙化、盐碱化,沙地有扩展蔓延趋势;林地面积的增加、耕地面积的减少对提高区域生态质量和生态功能起到了积极的作用。

Naiman Banner has become one of the most serious land desertification zones in Horqin desert owing to its fragile natural environment and intense utilization of mankind.Based on GIS and RS technology,Naiman Banner＇s land use chang from 1976a to 2000a in InnerMongolia was selected for research.The result showed that cultivated land,grassland and unused land are three main land utility types of Naiman Banner,the transformed area is 184015.51 hm^2,occupy 22.70 percent of the total area.The area of woodland land and unused land increased,while the area of cultivated land decreased significantly,decreased range is 21.86%.the main trends of Naiman Banner＇s 1and use change were cultivated land to grassland,grassland to unused land,and unused 1and to grassland.Because of fragile natural environment and intense utilization,the clustering of patch characteristics decreased and landscape fragmentation increased.The ecologic environment situation in Naiman Banner is very critical because of grassland degeneration,land desertification and land salinization.On the other hand,the increase of woodland area and decrease of cultivated land exert positive effects on the regional Eco-environment quality and function.