城市湿地损失和内涝灾害响应的遥感分析——以武汉市南湖为例

随着快速的城市化，城市湿地不断转化成建设用地，这打破了城市水量循环的均衡，城市内涝灾害的敏感性和危害性随之提高。选取城市快速扩张的武汉市南湖地区，基于1988～2015年近30 a南湖湿地多时相遥感影像，以武汉市南湖2016年7月内涝灾害为对象，运用遥感和GIS手段，分析南湖湿地损失过程、驱动因素以及城市涝灾害的响应情况。结果表明：（1）1988~2015年间南湖湿地持续损失，累计消减1 563 hm2；南湖湿地损失经历了快速损失（1988~1996）急剧损失（1996~2004）缓慢损失（1996~2010）相对静止（2010~2015）的4个阶段，每个阶段南湖湿地转化为建设用地量分别为35.3、135、30、5.4 hm2；损失过程从南湖湿地北部开始，逐渐向南部蔓延；（2）环湖地区房地产发展是湖泊湿地损失的主要原因,52%的损失湿地转换为住宅用地；（3）85.7%的内涝灾害区域位于原湖泊湿地内；南湖地区海拔较低，随着住宅用地以及其他建设用地对湖泊湿地的侵占，南湖地区不透水面面积增加，湿地蓄水排水能力下降，在降雨量较多的时段，原湖泊湿地区域更容易受到内涝侵袭。 关键词： 城市湿地; 湿地损失; 内涝灾害; 武汉市南湖

Remote Sensing Analysis of Urban Wetland Loss and Waterlogging

Urban wetlands are decreasing and the wetlands are converted to construction land with the rapid development of urbanization. The possibility of urban waterlogging is increasing with the risk increasing across the process. South Lake wetlands in Wuhan is selected to analysis the process and drivers of urban wetland loss and the relationship between the loss and the waterlogging with RS and GIS technology, based on multi temporal satellite remote sensing data between 1988 and 2015. Research results show that: (1) the area of South Lake wetlands had fallen off from 1988 to 2015 and the total of the wetland reduced 1 563 ha. The rate of the loss was decreased obviously with certain fluctuation in the region, which could be divided into four phases: the processes of slow decrease (1988-1996), sharp decrease (1996-2004), slow decrease (2004-2010) and static (2010-2015), at the average loss amount of 35.3 ha, 135 ha, 30 ha and 5.4 ha each phase respectively. The loss started from the north of South Lake and the south of the area was to an end. (2) Residence was always responsible for the loss wetlands and about 52% loss areas were converted to residence land which had a total area about 803 ha. (3) By combining datasets wetland loss and waterlogging from authoritative and reliable media data, it was found that 85.7% of the identified occurred waterlogging disaster points were located in the area used to be wetlands. The ability of wetlands to store water declines because of the low elevation and the increasing amount of impervious surface in the area used to be wetlands. And the loss area of wetland is more vulnerable to waterlogging and floods in higher rainfall days. Key words：urban wetland; the loss of lake; waterlogging; South Lake