Characterization of hydrogeochemical elements in determining the ground water quality for irrigation potential and its correlation with climatological parameters of chennai basin aquifer system, southern india.

ABSTRACT

An attempt has been made to comprehend the ground water quality and climate impacts of the Chennai River basin, which is aimed at its main socio-economic growth of the state of Tamil Nadu. The ground water samples collected from the study area were analyzed for its hydrogeochemical elements. The ground water quality and irrigation suitability were determined using several water quality assessment metrics. Ground water is extensively utilized for irrigation in the entire basin area for the past two decades, especially in the 38 over-exploited Firkas out of the 109 Firkas of the basin. It is inferred that the phreatic aquifer ground water quality is fresh in about 20%, as indicated by the EC value (< 750 µs/cm) at 25 °C. In about 63% of the ground water indicating the moderately fresh showing the EC varies between 751 and 2250 µs/cm at 25 °C, 11% of ground water exerted an EC ranging between 2251 and 3000 µs/cm at 25 °C indicating that the ground water is slightly mineralized, and in about 6% of groundwater, the EC is > 3000 µs/cm at 25 °C indicating that the ground water is highly mineralized. There were no water samples that exceeded the permissible limit of chloride either in phreatic aquifer or in fracture aquifer. The changes in rainfall frequency and atmospheric temperature affect the ground water movement and storage directly and indirectly. Similarly, the temperature data shows a positive relationship with the concentration of fluoride and nitrate ions in the water.