Landscape Changes And Driving Mechanism Of Nansihu Wetland From 2003 To 2013

Wetland is not only an important part of global ecosystem, also one of the most critical living environment for human beings. Nansihu is a key hub of China’s south to North Water Diversion project.The ecological system of the Nansihu wetland have been badly threatened due to the influence of natural factors and human activities. Also, its normal function has been destroyed. So, the study of wetland landscape changes is significant for the development of the Nansihu wetland. The research which aims at the Nansihu wetland is based on the statistical data of 4 periods of remote sensing data, and other auxiliary materials. Besides, a combined method of wetlandlandscape pattern index and transfer matrix is used in this study, and many kinds of software have been applied, such as ArcGIS,ERDAS,Fragstats and SPSS.The main conclusions are as flows:(1)The changes of the Nansihu wetland are. the artificial wetland include pond and paddy field are expanding, the waters,beaches and other natural wetland are decreasing,and transferring between all internal kinds from 2003 to 2013.(2) Take 2009 as the sector, landscape fragmentation of Nansihu wetland was increasing, the patch shape tended to be simplified,and dominance declined from 2003 to 2009.But during 2009 to 2013,the fragmentation improved and the diversity index decreased.(3) By the prediction and dynamic modeling of the Nansihu wetland from2003 to 2013, it can be concluded that a cubic polynomial y=a+bt+ct2+dt3 can be used to the quantify expression for dynamic changes of the wetland. And by the first, second and the third derivative of the polynomial, we can obtain velocity, acceleration and jerk of various types of wetland in order to analyze the trends of it.(4)The changes of landscape are closely related to the changes of temperature, precipitation, humidity, sunshine time, and the national ecological water supplement project and the south to north water diversion project development. Besides, the changes have an obvious relation to the population growth. Human factors have played an important role in the change of the landscape pattern, and will have a deeper influence towards it. The socio-economic factors can be grouped into inputs and outputs of them and the population changes. And the R2 of y=36387.303+655.18Yi-1960.302Y2 is 0.945,so the equation can express the relationship between wetland changes and the driving factors.