三江平原土地利用／覆被动态变化对洪河保护区湿地植被退化的影响

Effects of Sanjiang Plain Land Use/Cover Change on Wetland Vegetation Degradation of Honghe Nature Reserve

基于遥感与地理信息技术,分析近30年来高强度人为干扰下三江平原东北部土地利用/覆被动态变化过程及其对内部洪河保护区湿地生态系统的影响,探讨了保护区湿地植被的退化过程与机理。结果表明:1976-2005年,研究区湿地被大范围的开垦为农田,沼泽和草甸的面积分别减少了457075hm2和326511hm2,而旱地和水田的面积各自增加了362984hm2和246086hm2。区域高强度的农业开发对内部洪河保护区的湿地生态系统产生了间接影响。自1997年有地下水观测资料以来,地下水水位持续下降,区域平均地下水位下降了3.66m。保护区已有759hm2的草甸和沼泽被林地入侵,湿地植被退化趋势明显。

Based on the remote sensing and geographic information system, the land use/cover northeast of Sanjiang Plain and its effect analyzed. We also discussed the process on the wetland vegetation degradation of Honghe and mechanism of wetland degradation in Honghe change process of the Nature Reserve were Nature Reserve. Results showed that lots of wetlands in study area were reclaimed from 1976 to 2005. The area of marsh and meadow decreased respectively by 457 075hm^2 and 326 511hm^2 while the area of dry land and rice field separately increased by 362 984hm^2 and 246 086hm^2. The high strength exploitation of agriculture exerted an indirect influence on wetland ecosystems of Honghe Nature Reserve. Groundwater level around Honghe Nature Reserve descended continuously since its data were recorded from 1997. The average ground water level decreased by 3. 66m. In Honghe Nature Reserve, 759hm^2 of meadow and marsh were encroached by forestland, and the degradation tendency of wetland vegetation was significant.