CS(AR)-22/97-98 : Seasonal changes in groundwater hydrochemistry of Kakinada town, Andhra Pradesh during the year 1997

Abstract

The Deltaic Regional Centre of NIH has been monitoring shallow groundwater levels and its quality in and around Kakinada town since 1994. In continuation of this program the detailed hydrochemistry of Kakinada town during the year 1997 is presented in the report.

Total 164 groundwater samples were collected from 29 dug wells and 16 filter points during different seasons and analysed for its physical and chemical parameters. Further, the monthly groundwater levels were also measured in dug wells. The groundwater table contours (with reference to MSL) were plotted for pre monsoon (April 97) and post monsoon (Oct. 97) periods. The detailed hydrochemistry of dug wells and filter points are assessed through various classifications (Stiff, Piper and U. S. Salinity etc.) and the seasonal changes were analysed. The hydrochemistry of the study area shows that filter points are better than the dug wells for drinking water purposes. Further, the landuse/cover map of the study area was prepared on 1:50,000 scale using IRS 1B, LISS II FCC imageries. The impact of fertiliser/land use on groundwater quality was assessed through SO4/Cl ratio and it was found that the quality of groundwater is being influenced by fertiliser use.

The seasonal changes in water quality parameters are more in dug wells than in filter points. Much variation of TDS values observed between dug wells and filter points located in same place. More studies are necessary to find the groundwater quality at different depths in the study area rather than spatial distribution.