城镇化背景下的南方红壤丘陵区土地覆盖演变——以衡阳盆地为例

土地利用与覆盖（LULC）变化是生态环境演变的主要驱动力。南方丘陵区人口密集,但生态环境脆弱,20世纪90年代快速的城镇化进程产生了急剧环境变化。以衡阳盆地为研究区,以1990年、2000年两个时期的TM遥感影像为主要数据源,采用面向对象分类技术提取植被和建设用地信息,通过反演植被覆盖度,对植被覆盖度进行分级处理,获得了研究区植被覆盖等级分布图,最后,通过对比1990年和2000年建设用地和植被覆盖等级图获得了研究区建设用地和植被覆盖演变信息。研究结果表明：10年内研究区建设用地发生了显著扩展,扩展区域主要集中在衡阳市区周边,扩展区总面积为237.34km2;植被恢复区主要位于研究区北部区域,植被退化区位于研究区西端以及衡南县、祁东县和常宁市等3县市交界的湘江河谷地带以及南部的山区;城镇扩展区内植被退化严重,植被退化面积达到166.84 km2,占城镇扩展面积的比例为70.30%。

LULC Chang in the Context of Urbanization in Hilly Areas of Southern China——A Case Study in Hengyang Basin

Land use and land cover（LULC） change is the main driving force.The population density in hilly areas of southern China is large,but its ecology is fragile.The rapid urbanization in 1990s has caused serious environment change.The Hengyang Basin is a typical area of hilly areas of southern China.It is significant to take it as a case to study LULC change.6 images including two periods（1990~2000） have been selected as data source,and a classification technology based on OOA has been applied to get vegetation cover and building land cover information.Additionally,the proportion of vegetation cover has been get from those images.Finally,vegetation cover and building land cover change have been get by comparing maps of two periods.The results shows：（1） The building land cover has expanded strongly and the expansion areas mostly locate in urban district,the area of expansion region is 237.34 km2.（2） The vegetation restoration areas locate in the north of study area and the vegetation degeneration area mostly locate 3 region,such as the west,the north west and the south area of study area.（3） The vegetation degeneration in building expansion area is very serious and the area has reached 166.84km2,and the proportion has reached 70.30 %.