浑善达克沙地以北地区沙漠化动态初探

在收集大量前人研究成果和野外调查的基础上,运用RS和GIS技术,以2000年和2005年具有相同时相(秋季)的landsat TM4,3,2波段(分别赋予红、绿、蓝3种颜色)、分辨率为30 m×30 m的标准假彩色合成卫星影像的两期TM影像为信息源,利用Erdas8.7遥感图像处理软件、Arcinfo9.0和Arcview3.3等GIS软件,对浑善达克沙地以北地区的沙漠化土地进行了动态监测研究和分析。结果表明:土地沙漠化总体呈上升扩展的趋势,5 a多来沙漠化土地面积增加了1 366.057 km2,具体表现为轻度、中度、重度沙漠化土地面积分别增加;239.806,1 025.393,850.396 km2,严重沙漠化面积减少了749.539 km2;从全区各旗、县的角度来看,其中苏尼特右旗、苏尼特左旗、西乌珠穆沁旗、锡林浩特的沙漠化发展比较快,增加的面积分别为:1 038.377,185.487,69.431,51.554 km2,克什克腾旗、阿巴嘎旗的发展速度比较慢,增加的面积分别为:5.492,15.715 km2,林西的沙漠化面积基本没有变化。

Dynamic Changes of Sandy Desertification Land in North of Otindag Sandy Land

Through conducting field investigations and using digital methods of remote sensing and geographical information system techniques,we analyzed the dynamic changes of sandy desertification land of the north of Otindag sandy land based on the TM images of 2000 and 2005.The data adopted in this study were composed of two types,namely,census data of 2000 and 2005 and remote sensing(data).The datum source of sandy land and the(data) in 2005 came from the interpretation of composite Landsat 5 images of bands 4,3 and 2(R,G,B) according to the local conditions and land use status of sandy desertification.In order to minimize possible interpretation errors,a set of interpretation indicators was established based on field investigations.The area measurements of these types were made using the statistics function of GIS.Results indicated that the development and reversion of sandy desertification co-exited in the study area,and the area of sandy desertification land increased by 1 366.057 from 2000 to 2005.In terms of the extent of sandy desertification,the area of the light sandy desertification increased 239.806 km~2,the area of the moderate,1025.393 km~2,and the area of the severe,850.396 km~2.However the very severe sandy desertification decreased 749.539 km~2.In terms of the administrative region,the areas of sandy desertification land in Sonid Youqi,Sonid Zuoqi,Abga Qi,Xilinhot,Hexigten Qi,Xiujimqin Qi were 1 038.377 km~2,185.487 km~2,15.715 km~2,51.554 km~2,(5.492) km~2,69.431 km~2,respectively and area of sandy desertification land in Linxi had not clearly changed.In general,the status of sandy desertification in the North Otindag sandy land is still serious.