松嫩平原西部土地利用变化及其盐渍化效应研究——以大安市为例

Studies on Land Use Change and the Land Salinization of the Western Songnen Plain — A Case Study on Da’an City

利用1986年、1996年和2000年的遥感图像数据,对松嫩平原西部典型盐渍化区大安市的土地利用变化转换矩阵和空间格局指数进行计算,分析探讨了监测期间土地利用变化和分布特征及它们对盐渍化的影响。结果表明:大安市耕地、草地和碱斑地相互转化发生剧烈的地区主要分布在中部和南部地区,其中中覆盖草地变化最为剧烈;碱斑地分离度、分维数逐渐减小,面积不断扩大,占大安市总面积比由原来的23. 3%上升到32. 4%。耕地和草地是其面积变化的主要贡献者,其中草地对于碱斑地面积净增加和净减少的贡献分别达到48%和70%,其贡献远大于耕地。草地退化的主要原因是农业人口数和草原载畜量的不断增加,因此,合理的开发利用和保护草地资源将有助于盐碱化土地的防治。

Based on the remote sensing data of 1986、1996 and 2000,the convertion matrixof land use change and the landscape pattern indexes of land use were calculated, then the change and distribution characters of land use were analyzed, the effect of land use change on the salinization was discussed. The results indicated that the violenttransformamong farmland、grassland and alkaline spot were occurred in thecentral and the southern da’an city, and the middle-covered grassland changed mostly; Compared to 1986,the landscape isolation and the fractal dimension of alkaline spot were decreasing, and the ratio of alkaline land was increasing from 23.3% to 32.4%. From 1986 to 2000, the change of alkaline land area was attributed from farmland and grassland, especially the latter one which contributed to the net increaseand decrease of alkaline spot 48% and 70% respectively. The main reason of grassland degradation was the agricultural populationand the livestock increase. So the reduction of alkaline land depends on whether theexploitation and utility of grassland is reasonable or not.