Determination of Chlorophyll-a concentrations in the coastal waters of Kuala Terengganu using OCM (Ocean Color Monitor) satellite data

Abstract

The field of remote sensing can be used to determine the distribution of different types of constituents in seawater such as chlorophyll-a, Colored Dissolved Organic Matter (CDOM) and Total Suspended Solids (TSS). In this research, IRS-P4, OCM satellite data was used to determine the chlorophyll-a concentration in the coastal waters of Kuala Terengganu. Twenty-two sampling stations were setup and data collections were conducted on the 141h of September 2006 and 1 ?1h of September 2006 concurrently with satellite overpass. The data from the satellite image were extracted to derive the empirical model of chlorophyll-a. The highest R2 value was used to estimate surface water variables in the study area. Using the model maker, map of chlorophyll-a distribution were derived from the algorithm and the concentration of chlorophyll-a at the study area were determined and compared with actual data. The highest R2 was found at band 4 (510 nm) with R2=0.7739, (y = 7.7352x1 .8296 ) and the second highest R2 was found at band 5 (555 nm) with R2=0.7026, (y = 4.3484x1 .om). Algorithm from band 4 indicates station 12 as the highest concentration while band 5 indicates station 21. These two stations were located near to the coastal area, and might be contain high concentration of phytoplankton. Band 4 and 5 algorithms were also indicated that station 17 has the lowest chlorophyll-a which located quite far from the coastal area. It can be concluded that the distance from coastal area and water turbidity have a great influence on the concentration of chlorophyll-a at the study area.