黑河中游分水前后林草变化动态监测

Dynamics of forest/grass areacs in middle reaches of Heihe River basin before and after water redistribution

为合理开发利用黑河流域的水资源、缓解中下游生态环境的持续恶化,国家从2000年在黑河流域实施分水政策。本文以黑河流域中游地区为对象,将该区域夏秋季的LandsatETM/TM数据作为信息源,采用人机交互方式目视解译获取了该地区1990、2000和2005年3期土地利用/覆盖数据;对3期数据进行动态编辑后,得到了全区的各土地利用/覆盖类型面积变化的状况;对比分析了分水前后林地和草地面积的变化。结果表明:林地面积从分水前的微弱增长转变为负增长,草地在持续退化,但在分水后退化速度有所减慢。该结果充分体现了分水这一政策的实施对研究区土地利用/覆被变化的影响。

Aimed to rationally exploit and utilize the water resources of Heihe River basin and to mitigate the continuous eco-environmental deterioration in the middle-lower reaches of the basin, Chinese government has implemented water redistribution policy since 2000. Taking the middle reaches of Heihe River basin as study area and based on the information from Landsat ETM/TM data, the land use and land cover data in 1990, 2000, and 2005 were obtained by human-computer interaction visual interpretation. Through editing these, data, the overall situation of land use/cover change in the area was understood, and the changes in the forestland and grassland ateas before and after water redistribution were analyzed. The forestland area changed from a slight increase before water redistribution to negative growth after water redistribution, while grassland had a continuous degradation but the degradation speed slowed down after water redistribution. These results fully reflected the effects of implementing water distribution policy on the land use/ cover change in this area.