Dynamic Changes Of Coastal Beach Based On RS And GIS

Coastal beach is a transition zone between land and sea, which is the habitat and breeding ground of wildlife, and also provides human beings with abundant means of subsistence and production. However, Coastal beach has been suffered more and more serious disturbance and destruction from humanity because of economical development, population growth and city expansion in the recent 30 years. How to prevent coastal beach from degrading and disappearing became a major concerned issue.This article takes the coastal beach in Panjin city as the research object, extracted information and class images of the study area in the year of 1979, 1988, 2001 and 2008 by using RS and GIS technology, findings accorded with the field research in typical area. In addition, predicted the trend of development of study area by using the land-use transfer matrix, land-use dynamic degree, land-use trends model, fractal theory and the Markov model and evaluate the tendency of environmental quality change by environmental index.Through analyzing, some results of this paper were concluded as follows:(1) It made clear that reflecting the beach landscape information better through combining band5, band2, band1of TM images by calculating Optimum Index Factor (OIF) the optimal band combination index. And then extracted its distribution information by supervised classification, the classification accuracy kappa coefficients were 0.817, 0.816, 0.816 and 0.840.Gernerally, the results accorded with the field research in typical area.(2) The area of reed wetlands, natural water and mudflat has been reducing continually in the study area. From 1979 to 2008, the area of reed wetlands, natural water and mudflat reduced separately 2184.14hm~2, 1277.07hm~2 and 630.56hm~2. The area of aquaculture, paddy field and construction land has been increasing continually. From 1979 to 2008, the area of aquaculture, paddy field and construction land increased 1262.23hm~2, 478.48hm~2 and 278.01hm~2 respectively. The tendency of the beach landscape from 2010 to 2030 predicted according to the Markov model.(3)Conclusion was drawn by the fractal analysis: In the four periods, the stable index SK of tidal creeks were 0.217,0.208,0.160 and 0.267, the index SK of radial sand ridges were 0.388,0.341,0.328 and 0.306,which indicated that these two types of landscape less affected by human activities. The index SK of natural water were 0.056,0.014,0.083 and 0.076, the index SK of reed wetlands were 0.150,0.135,0.062 and 0.035, indicating that these two types of landscape more affected by human activities.The SK index of aquaculture surface, paddy field and construction land fluctuated, indicating that these three man-made landscapes changed constantly under the influence of human activities.(4)Ecological environment quality of coastal beach in Panjin City presented the declining trend. The relationship between Eco-environmental quality and coastal beach with radial sand ridges, natural water, reed wetlands presented a positive correlation, and the correlation coefficients were 0.923,0.953,0.873;The relationship between Eco-environmental quality and construction land, paddy field ,aquaculture surface presented a negative correlation, the correlation coefficients were 0.937, 0.995and 0.912, which indicated that kinds of economic activity resulted to the quality of the coastal beach ecological environment dropping.