Impact of Temporal Variability of Rainfall on Groundwater Quality of Dindigul District, India

The present study aims to provide information regarding the temporal distribution of important physical-chemical parameters that affect water chemistry. Graphical representation is recorded for important physiochemical variables to understand groundwater quality and ecological status of the groundwater systems over a period of time in Dindigul district, Tamil Nadu. The Dindigul District monthly rainfall data were collected from the Public Works Department (PWD), Surface and Groundwater Division, Govt. of Tamil Nadu. After 1995, that there was a gradual increase in the rainfall pattern and the excess rainfall was recorded as 1018.59 mm, 1052.82 mm, 1073.73mm during the years 1996, 2008, 2010 respectively. The lowest rainfall of 588.51mm was recorded in 2012. Apart from excess rainfall years, all the other cases recorded the minimum rainfall and showed the decreasing trend from1995 to 2012. After 1990s, release of untreated waste water from Tannery industry in to the water ways and lands - contaminated the groundwater. The change in the rainfall pattern and quantity played important role in the salinity of the groundwater. After 1995s, the NO3value of 16.8mg L-1 was recorded during 2010. Accordingly, it had the highest excess rainfall of 1073.73 mm, during 2010. Deficit rainfall in 2000 ranges from 337.67mm, the NO3 value of 68.8 mg L-1 was recorded. The chemical characteristics of ground water are determined by the level of contribution from the geological sources and infiltration water from the surface sources. Monitoring of pollution patterns and its trends with respect to urbanization is an important task for achieving sustainable management of groundwater.