SPATIAL AND TEMPORAL PATTERN OF GROUNDWATER QUALITY IN KEECHERI-PUZHAKKAL RIVER BASINS, CENTRAL KERALA, INDIA

C.P.Priju, V.V.Prasad, K.R. Athira, S. Chinchumol, K.Madhavan, E.Abdul Hameed, N.B.Narasimha Prasad

Abstract: Spatial and temporal pattern of groundwater quality in shallow and deep aquifers of Keecheri-Puzhakkal river basin, central Kerala has been studied. 63 dug well and 7 bore well water samples from the basin area was collected and analyzed for the hydrochemical parameters during post-monsoon, monsoon and pre-monsoon season (2014-15). Chemical quality of water samples indicates that dominant cations are Na+ and Ca2+ and the anions are HCO3 - and Cl- . Spatial distribution plots indicate higher pH, EC, Cl- , total hardness, salinity and TDS in the western part of the basin adjoining the sea inlet (Chettuva). The EC in the dug well water samples ranged from 49-2600 µmho/cm in the pre monsoon and 64-1971 µmho/cm in the post monsoon season. The TDS content ranged from 28-1890 mg/L in the pre monsoon and 40-1399 mg/L in the post monsoon season. In the deep wells (bore well), the EC values ranged from 160-1491 µmho/cm in the pre monsoon and 344-804 µmho/cm in the post monsoon season. Hill-Piper plots shows that Na-Cl is the dominant water type followed by Ca-HCO3 and Na-HCO3 type in the shallow wells in pre and post monsoon seasons. Bacteriological analysis of the dug well water samples indicated Total coliforms are higher in density during pre monsoon season. E. coli is present in 28% of the dug well samples in post monsoon, 33% in pre monsoon and 42% samples in monsoon season. Total coliforms are seen in most of the bore wells whereas E. coli is absent.

Keywords: Groundwater quality, Keecheri-Puzhakkal River basins, Central Kerala

DOI: https://doi.org/10.15623/ijret.2016.0530001