No abstract

An analysis of the floating islands of Kuttanad-Vembanad Wetland Ecosystem (KVWE) was conducted as part of a major study on aquatic macrophyte vegetation of Kuttanad from November 2004 to November 2006. The study revealed that there are three types of floating islands in KVWE which vary considerably in their origin, development, species composition, community and physical structure and sustenance even though there are common vegetation elements. Among the three types the type-1 which formed in deep excavated portions of abandoned rice fields is found as the biotic climax in the ecological succession. Continuous abandoning of rice fields, stagnation, nutrient enrichment, proliferation of exotic invasive plants and less salinity and tidal flow are the major ecological factors which are found promoting this recent formation of floating islands here indicating the level of deterioration of the ecosystem. KVWE is one of the fast changing wetland sites of the world located in the State of Kerala, India with well developed and ancient culture, economy, art and rich biodiversity. Rice cultivation need to be promoted at all costs in order to save this wetland.

No abstract

ABSTRACT:Aquatic macrophytes (AM) can serve as useful indicators of water pollution along the littoral zones. The spectral signatures of various AM were investigated to determine whether species could be discriminated by remote sensing. In this study the spectral readings of different AM communities identified were done using the ASD Fieldspec® Hand Held spectro-radiometer in the wavelength range of 325 -1075nm. The collected specific reflectance spectra were applied to space borne multi-spectral remote sensing data from Worldview-2, acquired on 26 th March 2011. The dimensionality reduction of the spectro-radiometric data was done using the technique principal components analysis (PCA). Out of the different PCA axes generated, 93.472 % variance of the spectra was explained by the first axis. The spectral derivative analysis was done to identify the wavelength where the greatest difference in reflectance is shown. The identified wavelengths are 510, 690, 720, 756, 806, 885, 907 and 923 nm. The output of PCA and derivative analysis were applied to Worldview-2 satellite data for spectral subsetting. The unsupervised classification was used to effectively classify the AM species using the different spectral subsets. The accuracy assessment of the results of the unsupervised classification and their comparison were done. The overall accuracy of the result of unsupervised classification using the band combinations Red-Edge, Green, Coastal blue & Red-edge, Yellow, Blue is 100%. The band combinations NIR-1, Green, Coastal blue & NIR-1, Yellow, Blue yielded an accuracy of 82.35%. The existing vegetation indices and new hyper-spectral indices for the different type of AM communities were computed. Overall, results of this study suggest that high spectral and spatial resolution images provide useful information for natural resource managers especially with regard to the location identification and distribution mapping of macrophyte species and their communities.

Web geoservices is the obvious graduation of Geographic Information System in a distributed environment through a simple browser. It enables organizations to share domain-specific rich and dynamic spatial information over the web. The present study attempted to design and develop a web enabled GIS application for the School of Environmental Sciences, Mahatma Gandhi University, Kottayam, Kerala, India to publish various geographical databases to the public through its website. The development of this project is based upon the open source tools and techniques. The output portal site is platform independent. The premier webgis frame work 'Geomoose' is utilized. Apache server is used as the Web Server and the UMN Map Server is used as the map server for this project. It provides various customised tools to query the geographical database in different ways and search for various facilities in the geographical area like banks, attractive places, hospitals, hotels etc. The portal site was tested with the output geographical database of 2 projects of the School such as 1) the Tourism Information System for the Malabar region of Kerala State consisting of 5 northern districts 2) the geoenvironmental appraisal of the Athirappilly Hydroelectric Project covering the entire Chalakkudy river basin.