1984年以来8个时期杭州主城区西部湿地格局研究

Pattern of Wetlands in the West of Main City Zone of Hangzhou for 8 Periods Since 1984

以浙江省杭州市主城区西部低山丘陵区向杭嘉湖平原过渡地带为研究区,采用面向对象分类和人工目视解释相结合的方法,利用1984年、1995年、2000年、2005年、2007年、2009年、2013年和2018年的遥感影像数据,提取出8个时期研究区的土地利用信息;采用斑块密度、最大斑块指数、景观形状指数、蔓延度指数、聚集度指数和Shannon多样性指数,分析8个时期研究区湿地格局的变化。研究结果表明,1984年以来的8个时期,随着时间的推移,研究区的河流、沼泽和耕地面积在逐时期减小,建筑用地和道路面积在逐时期增大;2000年以来,湖泊/水库/坑塘面积也在逐时期减小;2005年以来,林地面积也在逐时期减小;1984年、1995年、2000年、2005年和2007年,湖泊/水库/坑塘在研究区分布最广泛,其次为林地;2013年和2018年,建筑用地的面积最大,其次为林地,再次为湖泊/水库/坑塘;1984年和1995年,研究区的湿地格局相对稳定;2000年和2005年,研究区的城市化进程加快,湿地明显萎缩、破碎化;2007年以后,在研究区中,除了西溪国家湿地公园中的湿地被保护的较好外,其它湿地大幅萎缩,局部甚至消失。

This study takes the transition zone from the western low mountain and hilly area to the Hangjiahu Plain in Hangzhou city,Zhejiang province as the study area.Based on the remote sensing images in 1984,1995,2000,2005,2007,2009,2013 and 2018,the land use information of the study area during 8 periods was extracted using the object-oriented classification combined with manual interpretation method.And the changes of wetland pattern in the study area during 8 periods were analyzed using patch density,maximum patch index,landscape shape index,spreading index,aggregation index and Shannon diversity index.The results showed that during 8 periods,with the passage of time,the area of rivers,marshes and arable land in the study area has decreased,while the area of buildings and roads has increased.Since 2000,the area of lakes,reservoirs and ponds has also decreased period by period,and the area of woodlands has also decreased period by period since 2005.In 1984,1995,2000,2005 and 2007,lakes,reservoirs and potholes were the most widely distributed in the study area,followed by the woodlands.In 2013 and 2018,the area of buildings was the largest,followed by woodlands,followed by lakes,reservoirs and ponds.In 1984 and 1995,the pattern of the wetlands in the study area was relatively stable.In 2000 and 2005,the urbanization process of the study area accelerated,and the wetlands shrunk and fragmented obviously.After 2007,in the study area,except for the wetlands in Xixi National Wetland Park,other wetlands have shrunk greatly and even disappeared.