2013年三江平原北部洪水对沼泽湿地景观的影响

Impacts of Summer Flood Occurred in North of Sanjiang Plain in 2013 on Landscape of Marshes

基于Landsat 8 OLI和HJ-1 CCD影像,利用面向对象方法,对2013年8月发生在三江平原北部的洪水进行遥感监测,获取洪水浸淹范围,评估洪水造成的损失,分析洪水对沼泽湿地景观的影响。结果显示,在洪水淹没范围内,土地覆盖遥感分类的总体精度为93%,Kappa系数为0.92;洪水发生后,研究区内4个国家级自然保护区内的沼泽面积增加了30 654 hm2,沼泽斑块面积增加,斑块间水力联系加强,景观破碎度降低。2013年夏季洪水对研究区沼泽的恢复和重塑有促进作用。

In this paper, remote sensing images(Landsat 8 OLI and HJ-1 CCD) were used to monitor the floods occurred in north of Sanjiang Plain, Heilongjiang Province, in August 2013. Based on object-oriented method, flood losses were assessed and analyzed the impacts on landscape of marshes after getting the floods inundation range and former land cover types of flood areas. Accuracy assessment showed that the overall accuracy of the land cover classification was 93% with Kappa coefficient of 0.92. The results showed that the floods inundated area was about 224 308 hm2, mainly including farmlands and built-up areas. There are four national wetland reserves in the study area. The area of marshes increased by 30 653.9 hm2. The patch area,rate of patch area to landscape area and largest patch index of the marshes raised greatly, simultaneously number of patches and patch density declined sharply. This phenomenon showed that the hydraulic connection between marsh patches strengthened and the landscape fragmentation declined. The floods had an important role in promoting recovery and reshape of landscape of marshes.