Dynamic Change Analysis Of The Minjiang River Estuary Wetland Based On Remote Sensing And GIS

Minjiang River Estuary is one of nine biggest coastal wetlands in Fujian Province. The wetlands in this drainage basin possess the specific features in terms of types and quantity of the waterfowls, and are important habitats for the migratory birds that migrate seasonally from the south to the north. The dynamic change of the wetlands is studied based on the remotely sensed data and "3S" techniques in order to protect the wetlands.The classification and dynamics monitoring of wetlands using the remotely sensed data is a complicated, work-loaded and time-consuming process with high cost required, and the accuracy varies depending on techniques used for image process and analysis, times and costs required for training, etc. This paper presents an optimization-based layered classification method for the classification and dynamics monitoring of wetlands based on a decision procedure of multiple objectives. Four driven factors including techniques to be used, classification accuracy, time and cost needed for the classification, were selected as the indicators of criteria in optimization of the layered classification. This method was applied to TM image classification of the wetlands in Minjiang River Estuary and led to the overall correct percentages of 85.13 % for seven categories of the wetlands.The dynamic change measurement, transferring matrix of the dynamic change, and its spatial distribution indication of the landscape in Minjiang River Estuary wetland are critical issues for study on the dynamic change pattern of the wetland in different periods of time. Classification and information extraction of the wetlands in the research are resulted from the remote sensed TM imagery in time of imaging year 1986, 1994, and 2000 respectively. In this paper, dynamic change for each classified type of wetlands is measured in terms of area; transferring matrix of the dynamic changes is formulated and model of transferring probability based on it is established; and applying the fragmentation index, mean landscape fractal dimension, and landscape diversity index, spatial distribution structure of the wetlands is figured out. Combining these issues above, the dynamic change processof Minjiang River Estuary wetland has been analyzed for the periods of year 1986 to 1994 and 1994 to 2000. The results indicate that the dynamic change pattern of the wetland in two periods are different due to the human activities imposed on it, which is highly associated with the local economic development level from time to time. It comes to conclusion that the wetland conservation plan in Minjiang River Estuary should take into consideration of the human activities affected on it in the progress of urbanization.The component-based GIS system has enormous advantages in seamless integration and the flexibility of the system. It stands for the development trend of GIS. Applying the COM technology, a specific GIS system for monitoring and management of the Minjiang River Estuary wetland has been developed in this research. The spatial visualization analysis of the wetlands' dynamic change, in turn, can be implemented.