Function Evolution And Its Driving Force Analysis Of The Structure Of Inland Wetland

The functions of wetland include adjust water storage capacity, regulate climate, material production, protect biodiversity, etc. Lake Hong wetland is a typical inland subtropical wetland and rich in the functions. In recent years, with the higher intensity interference of human activities, the way and the level of land use has undergoing great changes, which will affect the evolution of wetland functions and structures.This research is based on the applying of RS/GIS technology and land use change, together with relative theory of landscape ecological patterns. We will construct the dynamic model of land use and the index system of landscape patterns to analyze the evolution of wetlands functions and structures and the driving force.Take Honghu wetland as the object of the study, the remote sensing image in the four stages between1990and2010is processed. According to the results, we use dynamic model of land use, land use change model and land-use transition matrices to analyze the change of land use structure. Characteristics of different landscape types are analyzed through the index of landscape pattern. What’s more, the evolution of Lake Hong wetland function and its driving forces are analyzed.The main conclusion of this paper is:In terms of the structure evolution of Lake Hong wetland, lakes area is shrinking while ponds area is increasing. The area of reed/tidal flats is phase down during1990-2003. From2003to2007, the area has been recovered. However, from2007to2010, the area is decline due to the increasingly interference of human activities.Judging from the transition of land use, lakes mainly transferred to the lotus ponds/fish ponds and reed/tidal flats. The area of paddy field is decreasing and mainly shifted to lotus ponds/fish ponds and residential area. Moreover, the rise of residential area is result from the transfer of paddy fields and lotus ponds/fish ponds.The evolution of wetland functions shows that for the reduction of lakes, the control function is wakening. Besides, the reduction of vegetation makes the function of climate regulation become weakened. And the production structure has transferred from the crop production to the aquaculture. That is, under the influence of the change in material production structure, the function of species production is changed, either. Besides, the function of protecting biodiversity is also reduced.Finally, from the part of driving forces, the changes of wetland structure result in the evolution of the wetland function, which is driving by climate change,population and urbanization, market mechanism, policies and other factors.