摘要
Abstract
A key component of the urban ecological infrastructure , urban wetlands offer important ecological ser vices including water resource conservation , climate regulation and water purification .Yangzhou City is located in the intersection of Yangtze River basin and Huaihe River basin , with a complex river network and abundant wetland resources .The rich wetland resources support good wildlife habitat and support aquaculture , bringing ecological , e-conomic and social benefits to the people of Yangzhou .However , the rapid urbanization and population growth have caused excessive exploitation of urban wetland resources in Yangzhou , accompanied by loss of wetland area , wet-land landscape fragmentation and the degradation of wetland function .It is therefore important to document the changes and explore the driving forces to provide scientific evidence for the protection of wetland resources and the development of an ecological city .In this paper, remote sensing images for the years 2002, 2007 and 2013 were used as the primary data sources and the spatial distribution of wetlands in Yangzhou were determined by interpre -ting the images.The transition matrix method and landscape metrics were combined to quantify the dynamic chan-ges of wetland landscape pattern from 2002 to 2013 .Additionally , the primary driving factors for wetland landscape changes were diagnosed through principal component analysis .The results indicate that the area of the wetlands in Yangzhou decreased year by year from 2002-2013.The total area of wetlands decreased by 13.69 km2 (1.1%) from 2002 to 2007, and decreased by 43.23 km2 (3.3%) from 2007 to 2013.During the study period, the area of bottomlands increased by 73.2%and the area of artificial reservoirs and ponds increased by 6.2%, resulting in an increase in the percentage of total wetland area from 49 .84%in 2002 to 55 .37%in 2013 .Conversely , the river area decreased by 5.6%, and lake area decreased by 29.7%, resulting in a decline in proportion to the total wet-land area from 32.83%in 2002 to 24.14%in 2013.Artificial reservoirs and ponds occupied the largest proportion of wetland areas in Yangzhou as compared to lakes , rivers and bottomlands .Our analysis of landscape metrics shows that lakes , bottomlands and artificial reservoirs and ponds display different degrees of fragmentation , while rivers maintained a high connectivity and the patch shape was even and simple .In general , the wetland landscape pattern of Yangzhou is trending toward fragmentation and a more complicated shape .Landscape diversity increased as different wetland types became more equally distributed across the landscape .Driving force analysis indicates that economic development , increasing population , changes in the proportion of secondary industry and annual pre-cipitation were the main factors driving changes in the wetland landscape pattern of Yangzhou city .关键词
湿地/景观格局/驱动力/扬州市Key words
wetland/landscape pattern/driving force/Yangzhou city分类
资源环境
