松嫩平原西部沙漠化空间格局及其变化的图形信息特征分析

Study on Graphic Information Characteristics of Desertification Land Spatial Pattern and Its Change in West of Songnei Plain

基于RS和GIS技术,利用1986年、1990年和2003年松嫩平原Landsat TM遥感影像,对遥感数据进行人机交互式解译,研究土地沙漠化现状与动态变化,借助于地学信息图谱理论、空间分析和转移矩阵方法分析土地沙漠化的演变过程和时空特征。结果表明:1986-2003年松嫩平原沙漠化土地以潜在及非沙漠化、中度和轻度沙漠化土地为主,1986年、1990年和2003年分别占土地总面积的88.13%、90.06%和85.63%;1986-1990年土地沙漠化发展速度为1 810.69 km2/a,逆转速度为1 857.45 km2/a,沙漠化扩展速率降低,沙漠化程度减缓,1990-2003年沙漠化土地发展速度为688.37 km2/a,逆转速度为539.57 km2/a,沙漠化土地快速蔓延,沙漠化程度加重;1986-2003年土地沙漠化过程中存在渐变与跃变两种方式,因此要遵循土地适宜性原则,慎重开发和利用区域土地资源。

Based on the RS and GIS technology, human-computer interaction interpretation was used to study the current situation and dynamic changes of desertification land in study region with the Landsat TM image in 1986,1990 and 2003. According to the geography graphic information theory and the ways of spatial analysis and conversion matrix, the change processes and spatio-temporal characteristics of desertification land were analyzed. The results showed that： the desertification land of nonedesertification,light and mild desertification of study region was major portion, the proportion were 88.13% in 1986,90.06 % in 1990 and 85.63% in 2003. From 1986 to 1990,the developed and reversed speed of desertifieation was 1 810. 69 km^2/a and 1 857.45 km^2/a ,it was very clear that the reversed speed was greater than developed speed,which mean the increasing rate of desertification land was lower and desertification intensity decreased. From 1990 to 2003, the reversed and developed speed of desertifieation was 539.57 km^2/a and 688.37 km^2/a, the developed speed was greater than reversed speed, which mean desertification land increased quickly and desertification intensity was serious. From 1986 to 2003 ,there existed gradually change and abruptly change in the expansion and reversion processes of sandy desertification in this region. According to the suitable theory of land use, it must be careful in land use development of study region.