三江平原湿地动态变化及驱动力分析

以1993年和2003年2个时期的TM和ETM图像作为基本的信息源,在实地考察和资料分析的基础上,利用Erdas软件对三江平原地区湿地数据进行提取。结果表明:(1)从土地变化结构上来看,2003年较1993年,三江平原的湿地、林地、草地面积呈减少趋势,其中湿地减少的最多,达到75.05%;耕地、水域、居民点面积增加,其中耕地的面积增加最大,为23.32%。(2)通过三江平原湿地空间变化分析可知,10 a间耕地增加了924 513.33 hm2,湿地变为耕地414 125.33 hm2,占湿地减少面积的70.46%,湿地转化为耕地的贡献率为44.79%;但是耕地转换为其它土地利用类型的面积很少。从得到的结果分析,影响三江平原湿地面积变化有3个原因:气温升高、年降水量减少使湿地面积退缩;人口增加加快了人类开垦湿地的步伐;空间区位因子的变化对于湿地的减少具有很大的影响。基于上述原因,提出了合理利用三江平原湿地和相应的保护对策的建议。

Dynamic Change of Wetland and Driving Force Analysis of Sanjiang Plain

Using the 1993 and 2003 TM and ETM images as the basic source of information,based on the on-the-spot investigation and material analysis,the data of the Sanjiang Plain wetlands were extracted by Erdas software.The results showed that：（1） from the land change structure point of view,compared with 1993,the wetland,woodland and grassland in Sanjiang Plain tended to decrease in 2003,which wetlands decreased the most,up to 75.05%;cultivated land,water,residential area increased,of which the largest increase was cultivated land area,up to 23.32%.（2）Through the spatial variation of the Sanjiang Plain wetlands analysis,farmland increased 924 513.3 hm2,wetlands turned to arable land was 414 125.3 hm2,accounting for 70.46% of reducing wetlands area,wetlands turned into arable land contribution rate of 44.79%;but the farmland converted to other land use types was very little.The reasons that affected the change of wetland in the Sanjiang Plain were：increasing temperature and decreasing rainfall reduced the wetland area;Human population growth accelerated the pace of reclamation of wetlands;Spatial location factor had great impact on the reduction of wetlands.For these reasons,some protection policies of reasonable using the Sanjiang Plain wetlands were proposed.