Hydrogeochemical Characteristics and Evolution of Coastal Groundwater at Cuddalore Area, Tamilnadu, India

ABSTRACT- The hydrogeochemical data of groundwater’s of the different aquifers of the Cuddalore coastal area, Tamilnadu were examined to determine the main factors controlling the groundwater chemistry and salinity as well as its hydrogeochemical evolution. The geology of the area plays a significant role in the determination of the groundwater potential of the region. The area underline by the various geological formations ranging in age from the oldest Archaean rocks to recent sediments. Groundwater of the coastal alluvial aquifer has the highest conductivity values in the study area due to the impact of seawater and agricultural activities. Piper diagram showed that Cl and SO4 are the dominant anions, whereas Na is the most dominant cation, where it is sometimes replaced by Ca and/or Mg in the hydrochemical facies of the ground waters. The paper revealed that the groundwater has been evolved from Ca-HCO3 recharge water through mixing with the pre-existing groundwater to give mixed water of Mg- SO4 and Mg-Cl types that eventually reached a final stage of evolution represented by a Na-Cl water type. Different ionic ratios revealed the impact of seawater and marine aerosols on the hydrochemical composition of groundwater of the Quaternary aquifer. Dissolution of carbonate and sulfate minerals in the aquifer matrices and recharge areas as well as cation exchange are shown to modify the concentration of ions in groundwater. Groundwater-mineral equilibrium showed the prevailing dissolution-precipitation reactions in the groundwater

Variation of Snowline and Mass Balance of Glaciers of Warwan and Bhut Basins of Western Himalaya Using Remote Sensing Technique

Glaciers are natural reservoirs of fresh water in frozen state and sensitive indicators of climate change. Among all the mountainous glaciated regions, glaciers of Himalayas form one of the largest concentrations of ice outside the Polar Regions. Almost all the major rivers of northern India originate from these glaciers and sustain perennial flow. Therefore, in view of the importance and role of the glaciers in sustaining the life on the Earth, monitoring the health of glaciers is necessary. Glacier's health is monitored in two ways (i) by mapping the change in extent of glaciers (ii) by finding variation in the annual mass balance. This paper has been discussed the later approach for monitoring the health of glaciers of Warwan and Bhut basins. Mass balance of glaciers of these two basins was determined based on the extraction of snow line at the end of ablation season. A series of satellite images of AWiFS sensor were analysed for extraction of snowline on the glaciers for the period of 2005, 2006 and 2007. The snow line at the end of ablation season is used to compute accumulation area ratio (AAR = Accumulation area/Glacier area) for each glacier of basins. An approach based on relationship of AAR to specific mass balance (computed in field) for glaciers of Basapa basin was employed in the present study. Mean of specific mass balance of individual glacier for the year 2005, 2006 and 2007 of Warwan basin was found to be -ve 0.19 m, -ve 0.27 m and -ve 0.2 m respectively. It is 0.05 m, -ve 0.11 m and -ve 0.19 m for Bhut basin. The analysis suggests a loss of 4.3 and 0.83 kmA(3) of glacier in the monitoring period of 3 years for Warwan and Bhut basins respectively. The overall results suggest that the glaciers of Warwan basin and Bhut basins have suffered more loss of ice than gain in the monitoring period of 3 years

A comparative study of deglaciation in two neighbouring basins (Warwan and Bhut) of Western Himalaya

Glaciers of the Himalaya contribute significantly in the processes linking atmosphere, biosphere and hydrosphere, thus need to be monitored in view of the climatic variations. In this direction, many studies have been carried out during the last two decades and satellite-based multispectral data have been used extensively for this purpose throughout the world. The present study is aimed at mapping of glaciers in two adjacent basins (Warwan and Bhut) of the Western Himalaya with almost similar altitude and latitude and comparing the changes in the two time-frames with respect to three parameters, i.e. area, debris cover and area altitude distribution of glaciers. The two time-frames are topographical maps of 1962 and IRS LISS III images of 2001/02. Deglaciation was observed in both the basins with 19% and 9% loss in the glaciated area in Warwan and Bhut respectively. This difference may be due to: (i) the smaller size of the glaciers of the Warwan Basin (e.g. 164 glaciers having <1 sq. km area in comparison to 101 glaciers in the Bhut Basin), (ii) lower percentage of moraine cover in Warwan (18) than in the Bhut Basin (30) and (iii) higher percentage of glaciated area lying below 5100 m (80) in Warwan than in the Bhut Basin (70)