2035年珠江三角洲核心区湿地退化风险评估研究

Risk Assessment ofWetland Degradation in the Core Area of the Pearl River Delta in 2035

以珠江三角洲核心区的广州市、深圳市、珠海市、佛山市、东莞市、中山市和香港特别行政区、澳门特别行政区所辖范围为研究区,利用Google Earth提供的1995年和2015年卫星遥感影像数据产品,采用人机交互方式,提取了研究区的湿地信息;利用耦合空间马尔科夫链和元胞自动机模型,模拟了研究区2035年城市群空间格局,评估了空间网格(5 km×5 km)尺度下的湿地退化风险。研究结果表明,与1995年相比,2015年,珠江三角洲核心区的天然湿地(河流和近海与海岸湿地)和人工湿地(养殖塘和水库)都发生了明显萎缩,湿地总面积从1995年的734 421.38 hm^2减少至2015年的637 726.51 hm^2,减少了96 694.87 hm^2;深圳市的近海与海岸湿地和佛山市的养殖塘、水库的面积减少幅度较大;到2035年,珠江三角洲核心区的湿地还可能发生进一步退化,高风险湿地退化区域面积占研究区面积的22%以上,其主要位于广州市中南部、东莞市西部、佛山市西南部和中山市东部等生态环境保护与城市开发矛盾较为激烈的区域。

This study took the core area of the Pearl River Delta, including Guangzhou city, Shenzhen city,Zhuhai city, Foshan city, Dongguan city, Zhongshan city, Hong Kong and Macao Special Administrative Regions, as study area, and the distribution and variation information of the wetlands in the study area was extracted from the satellite images in 1995 and 2005, which were collected from Google Earth platform, by human-computer interaction method. The results showed that the wetlands(river wetlands, offshore and coastal wetlands, breeding ponds and reservoirs) in the core area of the Pearl River Delta particularly in Shenzhen city and Foshan city have significantly shrunk from 1995 to 2015, and the total area of wetlands has decreased from 734 421.38 hm^2 in 1995 to 637726.51 hm^2 in 2015, a decrease of 96 694.87 hm^2 was detected.In order to discover the potential variation trend of the wetlands, the coupled spatial Markov chain and cellular automata models were further used to simulate the growth pattern of the urban agglomeration area in2035, and the degradation risk of the wetlands due to the urban sprawling was evaluated at the grid scale with the size of 5 km×5 km. The results reflected that the wetlands in the study area are inclined to be encroached with the high risk up to the year of 2035. The higher-risk region covers over 22% of the total area and are mainly located in the south-central part of Guangzhou, the west of Dongguan, the west of Foshan and the east of Zhongshan, where the conflict between urban development and ecological environment protection shows more obvious than other areas.