No abstract

Tuticorin corporation stretches geographically from 8°43 0-8°51 0 N latitude and 78°5 0-78°10 0 E longitude, positioned in the East-West International sea routes on the SouthEast coast of India. The rapid urban developments in the past two decades of Tuticorin have caused depletion of groundwater quantity, and deterioration of quality through excessive consumption and influx of pollutants from natural and anthropogenic activities. The water samples collected in the field were analyzed for electrical conductivity, pH, total dissolved solids, major cations like calcium, magnesium, sodium, potassium, and anions SUCH AS bicarbonate, carbonate, chloride, nitrate and sulfate, in the laboratory using the standard methods given by the American Public Health Association. In order to assess the groundwater quality, 36 groundwater samples had been collected in year 2011. The geographic information system-based spatial distribution map of different major elements has been prepared using ArcGIS 9.2. The Piper plot shows that most of the groundwater samples fall in the field of Ca 2?-Mg 2?-Cl-SO 4 2and Na ?-K ?-Cl-HCO 3 by projecting the position on the plots in the triangular field. The cation concentration indicate that 83, 39 and 22 % of the K ? , Na ? , Ca 2? concentrations exceed the WHO limit. As per Wilcox's diagram and US Salinity laboratory classification, most of the groundwater samples are not suitable for irrigation due to the presence of high salinity and medium sodium hazard. Irrigation waters classified based on sodium absorption ratio, have revealed that 52 % groundwater are in general safe for irrigation, which needs treatment before use. permeability index also indicates that the groundwater samples are suitable for irrigation purpose.

The present study was carried out to decipher the groundwater potential zones in the coastal terrain of Tuticorin using Indian remote sensing satellite IRS-1C, LlSS-III data on a 1:50,000 scale and Survey of India (SOI) toposheets. The thematic layers such as lithology, slope, land-use, lineament, drainage, soil and rainfall were generated and integrated to prepare the groundwater prospect and recharge map of the study area. These layers were transformed to raster data using feature to raster converter tool in Arc GIS 9.2 software. Subjective weights are assigned to the respective thematic layers and overlaid in GIS platform for the identification of potential groundwater zones within the area. These potential zones were categorized as ‘high’, ‘moderate’, and ‘low’ zones with respect to the assigned weightage of different thematic layers. The resultant map shows that 10% of the area has highest recharge potentials, this is due to the percolation of precipitated water into the sub-surface rocks, followed by 65% of the area with moderate groundwater recharge potentiality, and rest of the area has low recharge potential. The study highlights that the total average annual precipitated water (877 mm) is responsible for natural recharge of the aquifers in the Tuticorin area.

We formerly reported the existence of a hormone, derived from neurosecretory brain cells of fly larvae, which accelerates puparium formation (pnpariation) in

Geochemical signatures of groundwater in the coastal aquifers of Kadaladi block of Ramanathapuram District, Tamilnadu, India were used to identify the chemical processes that control hydrochemistry. The parameters such as pH, EC, TDS and major ion concentrations Na, K, Ca, Mg, Cl, HCO 3 , SO 4 , PO 4 and NO 3 of the groundwater were analyzed. Abundances of these ions are in the following order Na [ Ca [ Mg [ K and Cl [ HCO 3 [ SO 4 [ NO 3 [ PO 4 . Na-Cl is the dominant hydrochemical facies of the study area. Interpretation of the hydrochemical data suggests that hydrochemistry of the study area is controlled by mixing of fresh water with relict saline water, ion-exchange processes, silicate weathering and evaporation are responsible for the groundwater chemistry of the study area. Above statement is further supported by Gibbs plot where most of the samples fall within the evaporation zone. Good quality groundwater is restricted to coastal sand dunes running parallel to the coast and it is important to conserve these dunes.