Authors : M.E. Toriman, Nor Rohaizah Binti Jamil, Mushrifah Idris, S.A. Sharifah Mastura, Habibah Ahmad, A.C. Er, Nor Azlina Abdul Aziz, Q.Y. Lee and Rahmah Elfithri
Abstract: Tasik Chini is the 2nd largest freshwater lake of Peninsular Malaysia lately experienced diminishing population of lotus. Therefore, this study aims at mapping the distribution of lotus in two different seasons, August, 2004 (dry season) and April, 2007 (normal season) in this freshwater lake. Two IKONOS images dated August 26, 2004 (dry season) and April 07, 2006 (normal season) were acquired. Computerized analysis was carried out in image processing until the supervised classification stage by using ERDAS Imagine 8.7 and ArcGIS 9.0 software. IKONOS multispectral image acquired on both dates was geometrically corrected and a water mask was used based on strong absorption of Near Infrared (NIR) wavelengths by calm, clear and deep water. The water mask was applied using band reflectance values for a specific pixel satisfying the conditions of band decreasing property (green>red>NIR) and NIR<NIR threshold. Unsupervised classification was applied to the wetland-only image to identify submerged plant vegetation classes. Spectral similarity among the isodata classes was used to decrease the number of the classes to the available species in the lake. Classification of IKONOS satellite data with an unsupervised classification technique provided high accuracy for identification and mapping of submerged plant coverage and of different lotus, other submerged plant species and water classes (0.4, 27.1 and 72.5%, respectively for IKONOS image dated August, 2004). Image dated April, 2006 showed; 1.45 lotus, 18.74 of other submerged aquatic plants species and water classes 79.81%. IKONOS sensor data were found to be very useful for classifying submerged plants in large and shallow lakes.
M.E. Toriman, Nor Rohaizah Binti Jamil, Mushrifah Idris, S.A. Sharifah Mastura, Habibah Ahmad, A.C. Er, Nor Azlina Abdul Aziz, Q.Y. Lee and Rahmah Elfithri, 2012. Identification and Mapping of Lotus (Nelumbo nucifera) Distribution in a Shallow Lake Using Satte; Ite Imagery and Geographical Information System (GIS). Journal of Engineering and Applied Sciences, 7: 300-305.