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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:

  162

  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.

• Water mining and landscape: study on north-western part of Bankura district, west Bengal, India

  48-64

  Namgyal Tshewang Bhutia

  Malavika Sinha

  Views:

  357

  Groundwater depletion occurs when the rate of groundwater extraction is higher than the rate of replenishment. It is unequivocal that the demand for fresh water is ever increasing.  The study area lies in the semi-arid climatic zone and it's a solely agrarian society. The water scarcity leads to an impact on soil moisture and soil becomes drier during the dry months. The study is based on the changes in the regional water table which exhibit a relatively rapid response to acute scarcity of water. To specify the soil dryness gravimetric method has been used to study the selected soil samples. The groundwater withdrawal without estimating the water requirement at the regional level leads to soil dryness, and water stress situation to the agrarian economy, and it leaves a direct impact on the land. The perception of the farm owner, that ownership of farmland is synonymous with water mining right from their land leads to stress on the water table. 

   

• A GIS-based study on the changing course of the River Jiadhal in the Dhemaji district, India

  14-27

  Pranamee Gogoi

  Views:

  248

  River bank-erosion, deposition and channel-shifting are considered most dynamic and significant geomorphological processes formed by complex geological, hydrological, and anthropogenic factors. In the present study, river Jiadhal is one of the main sub-tributary of the River Brahmaputra in the Dhemaji district of Assam that changes its channel course frequently due to bank-erosion and sediment-deposition in the intermediate part and lower course of the channel. A study on the changing course of the river Jiadhal was carried out using satellite imageries for the years 1987, 1997, 2007 and 2017. The study found that the changes in the river vary from time to time and the bank-erosion and sediment-deposition fluctuate from place to place.  The total area of bank-erosion is 13.34 km² from 1987 to 2017 and the total area of sediment-deposition is 14.59 km² from 1987 to 2017. This paper evaluates how the shape, size and position of the Jiadhal River have changed from the years 1987 to 2017 using remote sensing and GIS techniques. The study is also necessary for effective management along the side of the river Jiadhal to control bank erosion and to mitigate the adverse impact of erosion and channel-shifting. 

• Population an land cover dinamics of Sundarbans impact zone is Bangladesh

  1-13

  Md. Sanaul Haque Mondal

  Views:

  407

  Sundarbans is the largest mangrove forest of the world that lies in Bangladesh and India. This paper examined the correlation among population dynamics of Sundarbans impact zone (SIZ) from 1974 to 2011; impact of climate change on the forest; and changes in land cover of the forest from 1973 to 2010. Population size of SIZ was increased by 1.6 times between 1974 and 2011, whereas decreased by 2% during 2001 to 2011. During 1973 to 2010, water bodies, barren land and vegetated land reduced by 7.35%, 49.56% and 15.92% respectively; while grass land increased by 228.14% during the same period. But both population size and vegetated land declined during 2001 and 2011. This was due to the landfall of two severe cyclones in 2007 and 2009 through Sundarbans which resulted thousands of human casualties and out migration, and destruction of the forest. In addition, anthropogenic interventions like low flow from Ganges River and policy constraints also contributed to the demolition of Sundarbans. Thus, population growth, climate change and anthropogenic interventions are playing a decisive role to the depletion of forest resources from the Sundarbans mangrove forest.