DIGITAL CHANGE DETECTION OF MANGROVE FOREST IN SELANGOR USING REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEM (GIS)

Abstract

Forest Research Institute Malaysia (FRIM), Kepong 52109 Selangor * Corresponding author: khali@frim.gov.my Abstract: Mangrove is one of the forest type found in Malaysia. The habitat of mangroves normally occurs along the west coast of Peninsular Malaysia, notably in the coasts of Perak, Selangor, Johor, and Kedah. This forest type plays an important role in protecting the coastlines from the wave actions and acts as a buffer for the surrounding communities as well as a source of income for the state. However, due to various human activities, the mangroves areas are rapidly depleting. Land development including for urban and settlement, establishment of shrimp farms, and expansion of agricultural lands have been identified as the main factors that contribute to the depletion of mangrove areas. In addition, natural phenomena such as tsunami, el-nino and la-nina and coastal erosion have also significantly deteriorating the prominence of mangroves in the region. This study is carried out to detect changes in terms of magnitude and extent that occurred on the mangrove areas along the coast of Selangor for the last two decades. Several sets of Landsat -TM, -ETM+ and SPOT -XS satellite images dated between February 1989 and March 2007 were utilised to identify distribution and areas of currently existing mangroves and changes that have undergone within that period. Digital post classification change detection technique has been applied to the images and analysis was performed in GIS platform. From the study, it was found that the mangrove in Selangor has decreased from 28,954.6ha in 1989 to 19,456.1ha in 2007, a reduction of about 9,498.5ha or 32.8% with the average loss of some 527.7ha per year. If this trend continues, the impacts will not only affect the mangrove itself but also to the environment and communities as a whole. Urban and settlement developments and establishment of shrimp ponds were identified respectively in Klang and Sabak Bernam areas as the major reason for the mangrove loss. Hence, necessary management actions should be undertaken to minimise the mangrove reduction area in the near future. Key words: Mangroves, remote sensing, GIS, Selangor