Study On The Structure Of Aquatic Plant Distribution In Honghu Wetland Based On GIS

The wetland is an important part of the global ecological system, and plays an important role in many aspects. As an important part of wetland ecological system, the wetland aquatic plants have an irreplaceable role in sustaining health and stability of wetland ecosystem. Study on the structure and complexity of distribution of aquatic plants to carry out quantitative analysis can detect the dynamic changes of aquatic plants effectively. It can reflect the health level of lake ecosystem to provide reference for vegetation protection and restoration of the wetland. Hong hu is a typical representative of the lakes in Jiang han plain and it has the important reference significance to study the distribution of aquatic vegetation in Hong hu.The main contents of this paper and the conclusions include the following:(1) Based on the combination of theory and practice, this paper selects5indexes, namely the circle number, species number, total number of patches, shape index, the lake shoreline sinuosity. Using multiplication and normalization method, this paper established a pattern complexity of distribution of the wetland aquatic plants, And analyzed the applicable range of this model, the accuracy, the advantages and disadvantages and areas for improvement in the future.(2) Using GIS software, ARCGIS, this paper draw the distribution map of aquatic vegetation horizontal and vertical structure of the map of Hong hu in1982and2008. And combined with data of DEM, it is the use of ARCGIS in the3D analysis function is a profile of wetland in Hong hu. According to the profile, using the drawing tools Adobe Photoshop CS5, it draws the schematic diagram of the longitudinal profile, and join the distribution of aquatic plants in the graph. It analyzes the distribution characteristics and laws of Hong hu aquatic vegetation in1982and2008from the angle.(3) It analyzes their distribution characteristics in the patch shape, structure, vegetation species, dominant species, vertical stratification, etc.. This paper applied the model to the actual research in Hong hu wetland, and it found that:the complexity value of the distribution of aquatic plants in Hong hu in2008decreased from4.4994to4.4770, compared with1982. It shows that the complexity of the distribution of aquatic plants in Hong hu wetland in2008has reduced compared with1982. It shows that the reduction in the complexity and simplification of the distribution about aquatic plants in Hong hu wetland, but the changes were not severe. Especially in the past sixty years, it has a very important influence on the distribution of aquatic plants in Hong hu human disturbance degree and mode of development and utilization of Hong hu in three different historical stages. Conclusion:wetland aquatic vegetation in Hong hu has been restored to1982levels in large, but it has undergone some changes in the aspect of distribution and commmunity structure and hierarchy. This paper analyzed the reasons of its changes. And the paper shows that it is inseparable with the interference of human activities. According to the above conclusions and the existing problems, the paper put forward some feasible measures on macrophyte restoration and protection in Hong hu wetland in order to provide managers with some suggestions.