南方红壤丘陵地区土地利用变化特征——以吉泰盆地为例

本文以南方红壤丘陵典型案例区吉泰盆地为例,运用RS和GIS技术,在对典型时段遥感影像进行解译的基础上,采用土地利用程度综合指数、土地利用类型动态度以及土地利用类型变化趋势和状态指数等模型,计算了1995-2006年吉泰盆地土地利用变化数量特征,揭示了南方红壤丘陵地区11年来土地利用变化的时空格局。研究结果表明:①1995-2006年吉泰盆地土地利用结构基本稳定,林地和耕地是该区主要土地利用类型;②11年来吉泰盆地水域和建设用地面积缓慢增长,水域增幅较多,其他地类面积有所下降,草地减幅最大;③林地转化为耕地,耕地转化为水域,以及草地转化为林地是吉泰盆地主要土地利用类型的转移模式,三种类型的转化面积依次为2887.91 hm2、2821.19 hm2和2326.97 hm2。从空间分布上看林地转为耕地模式分布最为广泛,耕地转化为水域分布较松散,草地转林地主要分布在吉泰盆地的北部地区;④动态度和状态指数研究发现,吉泰盆地未利用地的年变化率绝对值最大,林地年变化率最小。在未来的一段时间内,水域和建设用地规模呈增大的趋势,其余地类呈不同程度减少的态势。

Land Use Change over Red Soil Hilly Regions in Southern China:Taking Jitai Basin as an example

This paper analyzed the land use changes from 1995 to 2006 in Jiangxi's Jitai Basin, which is in the typical red soil hilly regions in southern China, using the ARCINFO format land use data in 1995 and 2000 with a scale of 1:10 000 and the high-resolution Landsat TM image in 2006. By interpreting the TM images with the reference to the above data, the 2006 land use data was obtained. Based on these three-period land use data,this paper did some analysis work using ArcGIS 9.2 and EXCEL, and investigated the characteristics of land use change in the Jitai Basin. The outcomes indicated that during the study period, the land use was steadily developed in Jitai Basin, in which forestland and farmland remained as the main types. Water area and buih-up land area were gently increased while the other four land use types were declined, but the proportion of every type is basically unchanged. The annual changing rate of unused land was the largest, and that of forestland was the smallest. Considering the transform of land uses in the Jitai Basin, forestland converted to farmland, farmland converted to water area, and grassland converted to forestland were the three main types from 1995 to 2006, any of which covered an area above 2300 hm~2. In view of the point of spatial distribution, forestland converted to farmland was the most widely distributed type, while the type of farmland converted to water area was scarcely distributed. Grassland converted to forestland was mainly distributed in the northern part of the Jitai Basin. In the future, built-up land area and water area will expand gradually, both of which have positive state index, and the others have negative state index values, thus they will slowly shrink.