Integration of remote sensing-GIS Techniques for mapping Seagrass and Ocean Colour off Malaysian Coasts

This paper describes seagrass and ocean colour mapping off Peninsular Malaysia. The seagrass were extracted form visible bands of Landsat TM using the depth invariant index of the seabottom type. The ocean colour which is much referred to micro-plankton concentration is derived by regressing samples form known site collected at time of satellite overpass. Both these information were then input into GIS database which were also being established to assist the Marine Fisheries Management and Development Center in managing and monitoring coastal areas

Penggunaan teknik remote sensing dalam perolehan maklumat marin

Marine areas cover a large part of the earth's surface and consist of resources of economic value. Management of such vast areas required suitable marine information that can be acquired in a short duration of time. The conventional methods of obtaining marine information is by making ground measurements and sampling representative of the whole area. Such techniques are time consuming and costly and are usually limited to accessible areas. Remote sensing techniques can assits in overcoming the problems in conventional techniques. In this theses, four, studies were carried out on the use of the Landsat - 5 Thematic Mapper satellite data for deriving four types of information in marine areas. The first study involved water depth determination from satellite data based on limited depth measurements in the study area of Pulau Tioman. An algorithm was used to calculate depths which were then compared with ground check points. However, the results obtained were less satisfactory with a root-mean-square error of 4.59 metres. This accuracy is not suitable for navigation purposes. The second study was related to the determination of sea surface temperature (SST) values from satellite data over the same area. A computer program for correction of atmospheric effects and computation of SST was developed. Although ground truth values of SST were not available, the values derived from satellite data were within the range of SST values given in the "Monthly Summary of Marine Meteorological Observations" published by the Malaysian Meteorological Service. The temperatures that were derived from satellite dat

Extracting Ocean Colour and Sea-grass Information from Remote Sensing Data: Opportunities and Limitations

The opportunities and limitations of extracting ocean colour and sea-grass information based on studies carried out at UTM Centre for Remote Sensing were identified in this study. The Landsat-5 Thematic Mapper ™ data were used in two selected test sites: (i) off Kuala Terengganu including all island gazetted as Marine Park, and (ii) off Kuala Kedah including Pulau Langkawi and nearby small islands. Phytoplankton information were extracted based on regressing samples of phytoplankton density collected at the time of satellite over-pass of the corresponding test areas with the reflectance values recorded by the satellite’s sensor while information on sea-grass were determined using substrate indices computed from the measured reflectance of the sea area