Multi temporal Landsat TM for monitoring mangrove changes in Pulau Indah, Malaysia

This paper presents a change detection analysis of land use/cover in Pulau Indah, Selangor, Malaysia using a time series of Landsat Thematic Mapper (TM) imagery for the years of 1995, 1999 and 2005. The work aims at mapping the extent of mangrove resources, to detect the changes of mangrove area and to study the driving forces that have led to the changes of mangroves in Pulau Indah. Using Maximum Likelihood algorithm, the supervised classification procedure was used to classify the images which produced seven land/use class viz water, urban, grasslands, oil palm, mixed crop, mangroves and cleared area. The area of mangroves for the years 1995, 1999 and 2005 were estimated to be 7,738.4 ha, 6,648.1 ha and 6,524.1 ha, respectively. The decreased in mangrove areas for the first and second intervals were at the rate of 2.73% and 0.24% per annum, respectively. The accuracy of classified maps were evaluated using classification error matrices. From an individual classification, the overall accuracies of the 1995, 1999 and 2005 thematic maps were 98.0%, 97.1% and 95.8%, respectively. The decrease in mangroves in Pulau Indah for both intervals was mostly attributed to their conversion to urban areas driven by the government policies to transform part of the island into industrial park.