Articles

• Integrated approach for lineament extraction in assessing groundwater potential: a case study in the highlands of Eritrea

  1-14

  Kabral Mogos Asghede

  János Vágó

  Péter Pecsmány

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  12

  Groundwater exploration is crucial for sustaining ecosystems and human activities, particularly in semi-arid regions like the highlands of Eritrea. This study evaluates the effectiveness of manual and automated lineament extraction methods for identifying geological structures indicative of groundwater potential. Using a 30-meter resolution SRTM digital elevation model (DEM), we generated hillshade images and extracted lineaments manually by ESRI ArcGIS and automatically with MATLAB's edge detection algorithms, including Canny, Sobel, Prewitt, Roberts, Approximate Canny, and Laplacian of Gaussian (LoG). Our findings reveal significant differences between the manual and automated methods. Directional analysis showed that manually identified lineaments primarily followed NE-SW and NW-SE directions. Among the automated methods, Canny, Approxcanny, and Prewitt exhibited similar directional trends. Lineament density maps indicated high-density areas in the western and northern parts of the study area for both manual and automated methods. The LoG algorithm showed the highest correlation (0.8561) with the manual method, suggesting it as a reliable alternative for lineament mapping, contributing to more efficient groundwater exploration in semi-arid regions.

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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

  15-28

  Imthiaz Ahammed

  Jayapal G

  Prasad T.K

  Suresh S

  Views:

  5

  The 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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• Satellite derived bathymetry (sbd) of inaccessible water: an application of log-transformed band ratio model

  29-40

  Kamal Nag

  Views:

  5

  The present study applied log transformed Band Ratio Model (BRM) on Sentinel-2A image of Copernicus programme of European Space Agency (ESA) to derive shallow water bathymetric map in a part of Indian eastern coast. The “empirical bathymetry processor” in SNAP software of ESA has been used for this purpose. General Bathymetric Chart of the Ocean (GEBCO)_2020 of Nippon Foundation has been taken as a reference image for point data input. Log transformed ratio of band-2 and ban-3 of Sentinel-2A at 10 m spatial resolution enables bathymetric mapping of nearshore water. Before applying BRM, image processing involves land mask, sun glint correction and dark object subtraction (DOS). This approach can be used as an alternative to conventional hydrographic survey for bathymetric mapping in inaccessible water with great savings of cost and time. 

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• Human induced conservation in the natural islets. Status of vertebrate diversity in the selected sacred forests of Kerala India

  41-47

  Krishnanand Pazhedath Vasudevan

  Dr. K S Anoop Das Karumampoyil Sakthidas

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  5

  Sacred 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.

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