1974～2010年洪湖湿地景观类型特征变化的分析

Analysis on Honghu wetland landscape type traits change from 1974 to 2010

湿地是自然界最富生物多样性的生态景观,湿地景观类型变化对生物多样性的保护和利用是极为重要。本研究以洪湖湿地为研究对象,以MSS、TM、ETM、CBERS等卫星数据为数据源,将洪湖湿地分为永久性河流、洪泛平原湿地、淡水湖、草本沼泽、淡水养殖池塘、农用池塘/小型水池、灌溉用沟渠、稻田/冬水田8种类型,开展1974～2010年洪湖湿地的景观类型特征变化研究。结果表明:从1974～2010年间湿地景观斑块数量增加明显,湿地破碎化程度增大,斑块面积的变异系数减少,斑块数量变化起伏较大的地类为旱地、农用池塘和稻田/冬水田;面积增长最快的属淡水养殖池塘;边缘总长度指数分布曲线基本一致,且景观类型边缘长度的排序和景观类型斑块面积一致,排列前3位为稻田/冬水田、旱地和淡水养殖池塘;周长面积分维数(PFRAC)曲线变化趋势基本一致,周长面积分维数(PFRAC)曲线变化最大属灌溉用沟渠。

Wetland is one of nature’s most rich biological diversity of ecological landscape and wetland landscape type change is very important to biodiversity protection and utilization.By taking Honghu wetland as the research object,and using MSS,TM,ETM satellite data as the data sources,Honghu wetland were divided into 8 wetland types,such as permanent rivers,flooding plain wetland,freshwater lake,marsh,fresh water aquaculture ponds,agricultural pond/small pool of water,irrigation ditches,rice fields/winter paddy field.With the aid of RS and GIS technology,the type traits changes of Honghu wetland landscape during 1974~2010 were studied.The results show that from 1974 to 2010,the number of wetland landscape patches was significantly increased,the wetland fragmentation degree was increased,the variation coefficient of plaque area was reduced,the wetland types that had more ups and downs were dry land,farm ponds and rice fields/winter paddy field;the wetland type that had fastest area growth was freshwater aquaculture pond,the exponential curves of total edge length of the wetland types were basically the same,the edge length sort and plaque area of the landscape types were also basically the same,the top three were turn/winter for rice paddy field,dry land and freshwater aquaculture ponds;the circumference surface integral dimension（PFRAC） curves of all landscape types were almost the same changing trends,the biggest changing value of circumference surface integral dimension（PFRAC） curve was that of irrigation ditches.