1954—2015年三江平原沼泽湿地变化的区域分异及影响因素

Regional differentiation and factors influencing changes in swamps in the Sanjiang Plain from 1954 to 2015

以湿地变化较为剧烈的三江平原为研究区域,结合GIS和RS技术,利用动态度、景观指数和地理探测器模型,在流域尺度上对1954-2015年三江平原沼泽湿地变化的区域分异及影响因素进行定量分析。结果表明:1954-2015年,三江平原各流域沼泽湿地面积呈现减少趋势,其中挠力河流域和同抚流域沼泽湿地面积丧失最多,安邦河流域、萝北流域和倭肯河流域沼泽湿地丧失速率较快;三江平原各流域沼泽湿地格局变化特征具有一定的差异性,倭肯河流域沼泽湿地斑块的集中化程度逐渐增强且破碎化程度逐渐减少,其他流域沼泽湿地的集中化程度逐渐减弱且破碎化程度增加,各子流域沼泽湿地斑块之间的连接性和稳定性均呈下降趋势,其中安邦河流域下降幅度最大,最能表现三江平原各子流域沼泽湿地景观格局变化的指数是斑块密度;人为干扰是影响三江平原各子流域沼泽湿地变化的主要因素,自然因素中对沼泽湿地变化影响最大的是地形地貌,其次是气温和降水量。

We used the Sanjiang Plain where swamp changes have been more drastic as the research area.Regional differentiation and factors influencing the changes of in swamps in the Sanjiang Plain from 1954 to 2015 at the watershed scale were analyzed using the dynamic degree,landscape index,and Geodetector model,and by combining GIS and RS techniques.The results showed that from 1954 to 2015,the area of swamps in the Sanjiang Plain had a decreasing trend,in which,the loss of wetland area in the Naoli River and Tongfu Basins was the greatest,whereas in the Anbang River,Luobei River,and Weiken River Basins the loss was faster.The variation characteristics of the swamps pattern in each basin within the Sanjiang Plain had some differences.The concentration of patches in the swamps in the Weiken River Basin gradually increased and the degree of fragmentation gradually decreased,whereas the concentration of swamps in other basins gradually decreased and their degrees of fragmentation increased,and the connectivity and stability of swamp patches in all sub-basins showed a decreasing trend,in which,the Anbang River Basin showed the largest decline.The index that best demonstrated the change in the swamp landscape pattern in each sub-basin of the Sanjiang Plain was patch density.Human disturbance was the main factor affecting the changes in swamps in each sub-basin of the Sanjiang Plain.Among the natural factors,the most influence factors on the change of swamps were topography,followed by temperature and precipitation.