近40年粤港澳大湾区湿地景观及其受损程度时空变化

Wetland landscape pattern change and its damage degree in Guangdong-Hong Kong-Macao Bay Area in recent 40 years

湿地具有丰富的生物多样性、极高的生产力和生态价值。粤港澳大湾区湿地资源丰富,但随着社会经济的快速发展,湿地遭到城镇化、围垦和水环境污染等多种外界因素的干扰。利用1980—2019年5期粤港澳大湾区生态遥感解译数据,综合运用GIS空间分析和景观格局指数等方法分析粤港澳大湾区近40年来湿地景观时空变化及其受损程度。研究结果表明:1)1980—2019年,粤港澳大湾区湿地面积呈现增加的变化趋势,主要由人工湿地造成,人工湿地共增加1752.55 km^(2),而天然湿地共减少688.98 km^(2),近10年天然湿地减少量明显变缓;2)粤港澳大湾区浅海水域、河流湿地和养殖塘湿地是优势景观类型,红树林、沿海滩涂、内陆滩涂、养殖塘和水库坑塘空间破碎度有所增加;3)湿地严重受损区域主要分布在广州、深圳和珠海,主要由建设用地、农田侵占湿地引起,40年间湿地转为城镇和农田的面积分别是762.73和178.71 km^(2)。

Wetland ecosystem has rich biodiversity,high productivity and ecological value.The Guangdong-Hong Kong-Macao Greater Bay Area(GBA)is rich in wetland resources.However,with the rapid development of society and economy,the wetlands in the GBA are disturbed by urbanization,reclamation and environmental pollution.Based on the land use data of five periods during 1980—2019,we analyzed the changes in the wetland landscape and examined the degree of wetland damage in the GBA by using GIS and landscape metrics.The results are as follows:(1)From 1980 to 2019,the wetland area showed an increasing trend,which was mainly caused by constructed wetlands.Constructed wetlands increased by 1752.55 km^(2),while natural wetlands decreased by 688.98 km^(2) in the study period.In recent ten years,the reduction of natural wetlands slowed down significantly.(2)Shallow waters,river and aquaculture ponds were the dominant landscape types in the GBA.Fragmentation increased in mangroves,tidal flats,beaches,aquaculture ponds and reservoirs during 1980—2019.(3)The severely damaged wetlands were mainly distributed in Guangzhou,Shenzhen and Zhuhai,mainly caused by construction land and farmland encroach wetland.In the past 40 years,the transformation area of wetland to construction land and farmland was 762.73 km^(2) and 178.71 km^(2),respectively.