近50年呼伦湖水系草地退化时空过程及成因分析  

The Spatial and Temporal Process in Grassland Degradation and Causes in Hulun-Lake Basin in the Past 50 Years

作　　者：杨久春[1,2] 张树文[1] 

机构地区：[1]中国科学院东北地理与农业生态研究所,吉林长春130012 [2]中国科学院研究生院,北京100049

出　　处：《中国草地学报》2009年第3期13-19,共7页Chinese Journal of Grassland

基　　金：国家自然基金(40771162);中国科学院知识创新工程重要方向项目(KZCX2-SW-320-1)

摘　　要：利用遥感影像和地形图提取得到呼伦湖水系20世纪50年代中期、80年代中期和2000年、2005年四期1∶10万土地利用/覆被数据,然后在各期土地利用/覆被类型转换的基础上,以覆盖度和退化程度作为对生态环境质量影响的主要指标,确定呼伦湖水系草地退化类型指标包括覆盖度降低、沙化、盐碱化和开垦,并获得了草地退化时空过程数据集。进一步采用GIS空间分析、地统计分析和相关分析方法对呼伦湖水系草地退化时空过程和成因进行分析,结果表明:近50年来,草地退化以覆盖度降低最严重,其次为盐碱化;以中度和重度退化为主;80年代中期以来,在气候条件较适宜牧草生长的情况下,人口的急剧增长是该时期草地开垦的主要原因,而牲畜数量的大规模增加对草地退化产生直接影响。Based on the land use/ cover change data in 1 ＂ 100 000 scale obtained by remote sensing images and relief maps from the mid-1950s to 2005 in Hulun-Lake Basin, according to the land use/ cover transformation, the indexes of grassland degradation types in Hulun-Lake Basin, including coverage reduction, desertification, alki- salification and reclamation, were determined. The datasets of grassland degradation were obtained synchronously. Based on the methods of GIS spatial analysis, geostatistics, and correlation analysis, the spatial-temporal charac- teristics and causes were further analyzed. The results showed that the reduction of coverage in grassland degradation was the most serious in the recent 50 years, then was the alki-salification. And the medium degradation and heavy degradation was dominant. Under the conditions of appropriate climate which is suitable for grass growing since the mid-1980s, the rapid increase of population was the main cause of grassland reclamation, and the sharp increase of livestock aggravated a direct and negative impact on grassland.

关 键 词：草地退化 遥感 时空过程 成因分析 呼伦湖水系 

分 类 号：S127[农业科学—农业基础科学]