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Morphometric characteristics of a tropical river basin, central Kerala, India using geospatial techniques
1-14Views:315The Thutapuzha watershed (TW) is one among the major tributaries of Bharathapuzha – the largest west flowing river in Kerala, India. Morphometric analysis was carried out to determine the spatial variations in the drainage characteristics and to understand the prevailing geologic variation, topographic information and structural setup of TW using Survey of India topographic maps and ASTER-DEM. Geoprocessing techniques has been used for the delineation and calculation of the morphometric parameters of the watershed. The TW sprawled over 1107Km2 and the study revealed that the watershed includes a sixth order stream and lower order streams mostly dominate the basin with a drianage density of 1.36 m/Km2 exhibiting highly resistant subsoil, dense vegetation, and low relief of surface nature . The study indicate that rainfall has a significant role in the drainage development whereas the drainage pattern is controlled by structure and relief. The watershed of TW is moderate to well-drained and exhibited a geomorphic maturity in its physiographic development. The shape parameters revealed the elongated nature of TW having less prone to flood, lower erosion and sediment transport capacities and drainage network development in the watershed. This study strongly brings to light that the drainage morphometric parameters have the enormou spotentiality to unveil the hydro-morphologicalcharacteristics of the river basins. Integrating hydro-morphological characteristics with conventional watershed assessment methods would have a beneficial effect on judicious watershed management, which helped to formulate a comprehensive watershed management plan.
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Landslide Susceptibility mapping using the Analytical Hierarchy Process and GIS for Idukki District, Kerala, India
11-32Views:356This study demonstrates the application of the analytical hierarchy process (AHP) technique for landslide susceptibility mapping of Udumbanchola and Devikulam taluk of Idukki district (Kerala, India). The landslide conditioning factors, such as lithology, geomorphology, slope angle, slope aspect, relative relief, drainage properties, land use/ land cover, and lineament characteristics,are derived using remote sensing data and GIS. The landslide susceptibility of the region is estimated using the weights derived by the AHP method. The analysis indicates the controls exerted by the structural and fluvial process and relief characteristics on the landslide activity of the region. The landslide susceptibility map of the region suggests that the high and severe susceptible zones cover about 10.68% of the area, and another 9.40% falls under the moderate susceptibility zone. The results highlight the significance of implementing various structural and non-structural measures in the moderate to severe susceptibility zones to mitigate the impacts of landslides.
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Geographical Information System and Multi-Influencing Factor techniques for the assessment of groundwater potential zones of tropical watersheds: A case study
15-28Views:129The groundwater of a region is predisposed much by terrain factors along with climatic factors. Being a subsurface phenomenon groundwater cannot be observed directly, it had to be done indirectly based on the analysis of data of observable features collected through field observation and various geophysical techniques. Groundwater occurrence is a phenomenon which is heavily dependent on multiple parameters viz., Geomorphology, geology, land use, slope, soil texture, drainage density, lineament density, relief, and vegetation. The present study intends to examine the need and prospect of assessing the groundwater potential of a tropical watershed on Geographical Information System (GIS) platform using the Multi-Influencing Factor (MIF) technique. A multi-influencing factor approach is used, where weights were assigned to each factor based on their level of influence and finally conducted weighted overlay platform to generate groundwater potential zones of the Perumba watershed, in the Kannur District of Kerala, India. Various parameters of groundwater have been analyzed from a geomorphological standpoint and potential zones were identified and categorized. The study signifies the application of MIF and GIS techniques in hydrological studies, as they qualify for comprehensive assessment and spatial analysis of various factors that affect the dynamics of groundwater. The results were verified through a field survey.
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Human induced conservation in the natural islets. Status of vertebrate diversity in the selected sacred forests of Kerala India
41-47Views:101Sacred forests are conserved based on religious aspects. Regional differences are visible among sacred groves in their management policies, temple construction, landscapes, and religious beliefs. This study analyzed whether there is any relationship between vertebrate species diversity and the management policies adopted by respective owners. To examine this, twenty sacred groves were selected. The vertebrates, such as birds, reptiles, amphibians, and mammals were surveyed, which lasted up to 2 years. Specific methodologies, such as point count for bird survey and visual encounter surveys for other vertebrates, were followed. To analyze the management policies adopted by the respective owners, nine parameters were considered, and each parameter was given a score for all the study sites. 135 species of vertebrates were recorded, and their species diversity is estimated by using the Shannon Wiener Index. To estimate the association between the management policies and species diversity, the scores of each parameter for all the sacred groves were summed and correlated with the Shannon‒Wiener index. A positive correlation between these factors obtained indicated that the management policies taken by the owners influenced the species conservation.