IdentificaionofVegetation Change ofMuthurajawelaWetland inSri Lanka from 1992 to 2015 by Using GIS-Remote Sensing

Abstract

Muthurajawela wetland is a coastal wetland system of high biodiversity and ecological significance. At present, this Muthurajawela wetland is being rapidly degraded by inadequately planned development activities and other detrimental activities related to growing human population pressure. As over a time, there will be change in vegetation area. Therefore, an effective method should be used to re-evaluate the change in area. Remote sensing technology is the most effective method and is used in this study. Three Landsat (TM) satellite images (1992, 2001 and 2015) were taken for comparison. The results showed that Multi-temporal Landsat images with the average resolution have the ability to assess the vegetation coverage changes with guaranteed results as, we have established a six-vegetation cover layer classification map with an overall accuracy of 84.66% and a kappa coefficient of 0.81. The total natural land area of Muthurajawela wetland was 6,232 ha in 2015. Of which, 492.95 ha was marsh, 232.94 ha was grass, 281.62 ha was water and 5,225.27 ha was of forest land; The area of mangroves forest in 1992 increased by 317.66 ha compared to in 2001 and decreased by 300.42 ha in 2001 compared with in 2015, increasing only 17.24ha in 1992 compared with in 2015.