A Study On The Analysis Of Dynamic Change Landscape Structure And Driving Forces Of Lake And River Wetland Of Wuhan

With the accelerated process of urbanization,wetland is having a serious threat. Wetland is a natural body existing between water and land as a transitional conformation, which has the richest biology diversity in nature,and is one of the most important surviving environment of human being.It is not only called as "kidney of earth",because it has tremendous function of water and element cycle,but also named as "biology supermarket" because of its big food meshwork and offering living environment for most biology in nature.But with expanding of the affection of global environment changing especially the change of land utilization and human activity,the area of wetland is reducing,the biology diversity is decreasing,and the wetland function is retrogressing.So it is great signification on wetland protection and restoration to research on the dynamic change of wetland and its function.The paper discussed the method and results of the research by RS(Remote Sensing) and GIS(Geographic Information System),and studied on the wetland function and landscape structure as well as its dynamic change in Wuhan city based on the theory and method of wetland landscape ecology.Using 1978,1987,1991,1996,2002,2007 six remote sensing data as basic information resource and with the support GIS,a spatial information dataset is built up.Through selecting the indices such as patch size,fractal dimension,fragmentation,diversity and dominance index,etc,the dynamic development of wetland landscape pattern is analyzed.Through the above work we attempt to search after reasonable method of protecting and restoration of wetland in Wuhan.The status of wetland resources,the wetland landscape structure and its dynamic change tendency have been got by the following step.At first interpreting the wetland type of the same area but different periods on the image from RS,And then analyzing and processing the results of the interpretation with the help of GIS software,and thus getting the surveying outcome about wetland landscape,at last comparing and analyzing the above results timely and accurately.Our results indicated that:(1) The area of lakes and rivers wetland in Wuhan City are 183673.57hm~2,183673.57 hm~2,178610.45hm~2,168110.10 hm~2,145004.34 hm~2,138982.68 hm~2 during the six periods of 1978,1987,1991,1996,2002 and 2007,which have a declining trend.(2) The patches Numbers are 558,638,720,755,794 and 809 during the six Period, and patches density are 0.0039,0.0046,0.0052,0.0059,0.0080 and 0.0088 per 100 ha. The patches Number and patches density of lakes and rivers wetland in Wuhan City are increasing which expose that the Porosity is increasing and wetlands have decentralized distribution increasingly.(3) The patches fractal dimension are 1.550,1.548,1.543,1.532,1.495 and 1.492 during the six Periods which all have a decrease in Varying degrees.Especially the value of patche fractal dimension had the most obvious changes and significant reduce from 1991 to 2002,and the shape of the landscape tend to make simplistic Due to human activities,and wetland landscape enhance the self-similarity.The dimension of other periods are more stable,and that human activities interfere more small relatively.(4)Landscape fragmentation index of lakes and rivers wetland in Wuhan City are 0.0015,0.0018,0.0021,0.0035,0.0075 and 0.0077 during the six Periods,Landscape Fragmentation index and heterogeneity are increasing and connectivity is reducing.(5)Dynamic change index of lake and fiver wetland of Wuhan are -0.0020,-0.0069,-0.00207,-0.0157 and -0.0083 in six periods from 1978 to 2007 for 30 years recently. This shows that,the dynamic change index from 1991 to 1996 is smallest,the wetland area change largest which reduces fast,the greatest human interferences it did;yet the dynamic changes index from 1978 to 1987 is biggest which reduces slowly,the greater human interferences it did;and the dynamic change rate for 5 years recently(2002-2007) has a certain control.(6)The driving force of Wuhan wetland landscape change is social factors,it suggested that Wuhan wetland area showed an obverse linear relationship with the Wuhan GDP(R~2=0.8381,P=0.0104),wetland area showed an significant linear relationship with the Wuhan GDP(R~2=0.8579,P=0.008).