Assessment of groundwater quality and its suitability for the inhabitants of Andrott Island, Lakshadweep

摘要

Groundwater serves as the main sources of drinking water for the Islanders. Now a days, the groundwater is contaminated due to sea water intusion and continuous anthropogenic activities. A proper understanding of the groundwater quality is important to meet the increasing demand and also for the future planning and development of the water resources. Andrott island is the largest Island in Lakshadweep having an area of 4.90 km~2 with a population density of 2312 person/km~2 (2011 Census). It lies in the east-west direction, between 10° 48' and 10° 50' N latitude and 73° 39' and 73° 42' E longitude. It is 293 km (158 nautical miles) away from Kochi (mainland). This paper aims to appraise the spatial distribution of groundwater quality of Andrott Island using geospatial approach. Detailed physico-chemical studies had been carried out to identify potential fresh groundwater resources and quantifying vulnerable parts of Andrott Island. BIS standard has been adopted to assess the quality of ground water at each sampling locations. 50 Samples were collected from water quality lab Andrott Island and GPS has been used to collect the sampling point locations. The statistical analysis has been performed using standard methods, by calculating correlation coefficients between different pairs of parameters. Spatial interpolation technique inverse distance weighted (IDW) has been used to estimate the spatial distribution of the groundwater parameters. The final integrated WQI map shows three priority classes such as good, poor and very poor groundwater quality zones of the study area and provides a guideline for the suitability of groundwater for domestic purposes. The result of the study estimated that 82% of pre Monsoon and 64% of post Monsoon samples fall under poor water category and the rest is categorized under good and very poor as per the WQI classification. The present study is helpful in proper planning and management of available water resources for drinking purposes.