Monitoring water quality from Landsat TM imagery in Penang, Malaysia

Rapid development of countries can cause many environmental problems. One of the problem is water pollution which is the result of urban runoff from industrial and resident area. It has become a major global problem as it can lead to many deaths and diseases among human being. One of the main sources of water pollution is the suspended or colloidal particles which commonly referred as total suspended solids (TSS). Before the launch of satellite imagery technology, the biological parameters of ocean is obtained by using traditional sampling method which is time consuming and expensive. With remote sensing technique, water quality monitoring can be carried out by using a large coverage of satellite images analysis for water quality mapping. It is proven to be effective as it has been widely used in many environmental studies such as environmental pollution monitoring and oceanography. The purpose of this study is to obtain the water quality over Penang Straits using remote sensing imagery data. By using four scenes of Landsat TM images and in-situ data sets of particular dates, the new algorithm for water quality mapping which is based on optical model of water is developed. First, the images were atmospherically corrected and filtered using PCI Geomatica software as it gave better results compared to raw data especially when performing multi-date analysis. The digital numbers of each images were extracted and regressed using Excel. The efficiency of the algorithm was determined based on the observations of correlation coefficient (R) and root-mean-square (RMS) deviations with in-situ data. The accuracy of the algorithm, in comparison of other algorithm was also investigated. Finally, the calibrated TSS algorithm was used to generate the water quality table of difference and this study shows that the research of water quality can be carried out using remote sensing technique.