湘西北地区石漠化遥感调查的技术方法

REMOTE SENSING INVESTIGATING ON TECHNOLOGYMETHOD OF ROCKY DESERTIFICATION IN WESTNORTHERN

应用20世纪70年代末和90年代末TM卫星数据,综合运用ENVI、PHOTOSHOP、MAPGIS、ARC/INFOGIS等遥感图像处理与应用软件,通过石漠化训练样区的选择、监督分类、矢量化和数据转换等步骤,实现了石漠化的自动分类与专题图件制作。将分类石漠化图按2 mm×的网格进行网格化,依据石漠不关心化所占网格总面积的比例进行归并、筛选,面积>2mm以上的网格单元合并为石漠化区;面积～的网格单元合并为轻度石漠化区;面积<70%70%50%的网格单元合并为非石漠化区。调查表明:湘西北地区近内,石漠化区总面积增加了约50%20a300km2平均每年增加约,15km2,即所占比例由增加到约。0.54%1.60%

Applying Mss satellite date of 1970s' end and TM satellite date of 1990s' end,the paper uses remote sensing image processing and GIS applying Microsoft,according to ENVI,PHOTOSHOP,MAPGIS,ARC/INFO,selects train region of rocky desertification,then puts into supervised classification,×vector and date transforming.On the basis of 22 mm grid,which the proportion of desertification is up to 70 percent is the region of desertification,which between 70 and 50 is weak,the rest is nondesertification.Investigating indicates that total area of rocky desertification extends approximate 300 km2,that extnds approximate 15 km2 every year,in other words,proportion is from 0.54 percent to 1.60 percent,in westnorthern hunan near twenty years.