Remote Sensing Assessment Of Land Cover/Land Use Changes And Its Relationship On Land Surface Temperature In Penang Island
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Date
2010-05
Authors
Tan, Kok Chooi
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Land surface temperature (LST) plays an important role in local, regional and global climate studies. LST controls the distribution of the budget for radiation heat between the atmosphere and the Earth’s surface. Therefore, it is important to evaluate abrupt changes in land use/land cover (LULC). Penang Island, Malaysia has been experiencing a rapid and drastic change in urban expansion over the past two decades due to growth in industrial and residential areas. The aim of this study was to investigate and evaluate the impact of LST with respect to land-use changes in Penang Island, Malaysia. Three supervised classification techniques known as Maximum Likelihood, Minimum Distance-to-Mean and Parallelepiped were applied to the images to extract thematic information from the acquired scene by using PCI Geomatica 10.1 image processing software. These remote sensing classification techniques help to examine LULC changes in Penang Island using multi-temporal Landsat data for the period of 1991–2007. Training sites were selected within each scene and seven land cover classes were assigned to each classifier. The relative performance of each technique was evaluated. The accuracy of each classification map was assessed using a reference data set consisting of a large number of samples collected per category. Four Landsat satellite images captured in 1991, 1999, 2002 and 2007 were chosen to classify the LULC types using the Maximum Likelihood classification method, determined from visible and near-infrared bands. The study revealed that the Maximum Likelihood classifier produced superior results and achieved a high degree of accuracy. The LST and Normalised Difference Vegetation
Index (NDVI) were computed based on changes in LULC. The results showed that LULC changes from 1991-2007 for the urban area (highly built-up area) has been increased drastically, from 10.89 km2 in 1991 to 65.28 km2, around 499.45 %. Besides that, the urban area (minimally built-up area) also increased moderately, about 57.11 %, from 30.52 km2 in 1991 to 47.95 km2 in 2007. On the contrary, forest area decreased significantly within nearly 16 years, from 126.20 km2 became 103.64 km2, nearly 17.88 %. Meanwhile, the area for grassland also decreased slightly within this period, approximately 84.80 km2 in 1991 to 83.68 km2 in 2007. But, for barren land, the area decreased dramatically from 1991 to 2007, about 79.77 %. These changes in LULC caused at significant difference in LST between urban and rural areas. Strong correlation were observed between LST and NDVI for all LULC classes. The remote sensing technique used in this study was found to be efficient; it reduced the time for the analysis of LULC changes, and it was found to be a useful tool.
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Keywords
Evaluate the impact of LST with respect to land-use , changes in Penang Island