A Study On The Recent 20 Years' Change Of Zizania Latifolia Community In Liangzi Lake By Using Remote Sensed Images

Wetlands, as a unique ecological system with highest productive forces on earth, are one of the most important environmental resources, which are named "kidney of the earth" and "super market of the living things". The wetland vegetation is the most important primary generator of the wetland biogeocenose ecosystem.At present, conservation and rational use of wetlands vegetation has become an international trend. The key of wetland research is to obtain and analyze quantitatively wetland information. RS,GIS and GPS technology provide a new method for wetland research. Wetland vegetation identification and dynamic monitoring is an important application for remote sensing technology due to the increasing relevance of environmental considerations.The Liangzi Lake ,as one of the Asia importance wetland catalog in China, is the second largest lake in Hubei province. Firstly, In this paper ,basing on the multi-temporal images of landsat 5 TM satellite imagery of 1987 and 2004, along with field investigate, it sets up interpretation symbol to draw the distribution map of Zizania latifolia community. According to this map , The recent 17 years' change of Zizania latifolia community in area and distribution was studied. Moreover, the relation model between the vegetation index of remote sensing and the Zizania latifolia community biomass were constructed, the Zizania latifolia community biomass in 1987 and 2004 were worked out,and the recent 17 years' change of Zizania latifolia community in biomass in Iiangzi Lake were compared.The main research result of this dissertation are the following:1. In 1987 ,the area of the Zizania latifolia community was approximately 31.62 km~2 and Mainly distribute to shallow water district in the east Liangzi Lake's shore zone within 30 meters and water depth does not surpass 2m in west Liangzi Lake's shore zone.In 2004, the area of the Zizania latifolia community became approximately 14. 04 km~2. In the east Liangzi Lake, the south of Xiajiazui village ,the Zizania latifolia community distribution the entire lake, also has certain area distribution near the Xingang village and the Yueshan village, and other waterfronts only fragmentarily distribute. However,The main body part of west Liangzi Lake already did not have Zizania latifolia community 's distribution, only had the fragmentary distribution in the...