辽河中下游流域土地利用变化及其生态环境效应

辽河中下游地区地处东北老工业基地区,是我国重要的重工业、能源和商品粮生产基地。基于TM卫星遥感数据及调查资料,对辽河中下游流域1986—2000年土地利用时空变化特征及其生态效应进行了研究。结果表明,随着人口的增加和经济的发展,流域耕地面积持续扩大,林地、草地、水域面积趋于减少,居民地、工矿、交通等建设用地增加。整个景观斑块数量呈现减少趋势,景观的空间结构趋于简单化。农业用地是平原地区土地利用变化的主体和媒介,主要土地利用转变类型大多与耕地有关。土地利用/覆被变化导致了诸多环境问题如水土流失加剧,水资源短缺、水质恶化,湿地生态功能下降等,使流域生态环境更加趋于脆弱。

Land Use Changes and Its Effects on Eco-environment in Middle and Lower Reaches of the Liaohe River

The middle and lower reaches of the Liaohe River are located in the old industrial region of northeastern China and are important for food production and stockbreeding. Based on multi-temporal remotely sensed data from Thematic Mapper, this research attempted to reveal the spatial-temporal trends in land use and its impact on the eco-environment in middle and lower reaches of the Liaohe River. The results suggest that, in the last 15 years, the area of cultivated land increased and aggregated rapidly, while the area of woodland, grassland and water decreased considerably. The dominant land use change types were the conversion of woodland, grassland and wetland into cultivated land. The dynamic change of land use has had many effects on the local environment, including intensive soil erosion, increasing nitrogen content in the river and biodiversity loss in the region.