HYDROGEOLOGICAL VARIATIONS OF GROUND WATER IN DIFFERENT GEOMARPHIC UNITS OF KRISHNA EASTERN DELTA, ANDHRA PRADESH

摘要

The Krishna Eastern delta is located South of Vijayawada City in Andhra Pradesh. The area of the Krishna Eastern delta enclosed between Latitude 15042N 16042 N and Longitude 80042 E 81036 E. The present study is done on Krishna Eastern delta separately because the physiographic and lithological configuration of this part of the delta varies widely with that of the Western part. Moreover, the aquifer of this region has unique hydrochemical characteristics. In recent years the ground water in this region has been subjected to intensive exploitation for both irrigation and domestic purposes and accordingly high seasonal hydrochemical modulations were noticed in this part of the delta region. Kulakarni KM et.al. (1998) have studied drinking water salinity problem in Coastal Orissa. In this context a detailed study has been made to update the hydrogeochemical information of the aquifer system of this region. In addition to the earlier works carried out by Nageswara Rao, K. et.al. in the year 1979 and 1985. The details viz., land form locations in the delta region were taken from the study. The seasonal variation of groundwater quality in different geological units in Krishna Eastern Delta has been subjected to study by collecting water samples in different open wells in the study area and subjecting them to detailed chemical analysis. This data has been utilized to draw contour diagrams of different water quality parameters for different seasons. The present study is an attempt to visualize the spatial water quality variations in different geomorphic units present in the deltaic environment. The chemical parameter of Electrical Conductivity was taken as the prime parameter to focus the seasonal spatial variations of different geomorphic forms and the data was used to draw contours for different seasons. The detailed studies of Ground Water Department, District Office were also studied in many unpublished reports for understanding the nature of the Krishna delta system. The Schematic representation of water quality parameters were studied from the book entitled Groundwater Hydrology John Wiley & Sons inc., New York (Todd-1959). Geochemical conceptual approaches for the study of different land forms and the important logistics of water quality parameters were drawn from the book entitled Groundwater Assessment Development and Management by K.R. Karanth, 1987. The inferences of the present study may help in identifying the response of different landforms for precipitation and for identifying the shallow fresh water aquifers to cater the domestic needs in the drinking water problematic areas of the Krishna Eastern delta region.