Identification of artificial groundwater recharge zones in Vavuniya district using remote sensing and GIS

R Ramya,I P Senanayake,A Nanthakumaran

doi:10.4038/agrieast.v13i1.63

R Ramya, I P Senanayake + Show 1 more

Open Access

https://doi.org/10.4038/agrieast.v13i1.63

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Abstract

Ground water is a major source for domestic and irrigation purposes in Sri Lanka and plays a crucial role to human life and economic activity. With rapid growth of population and urbanization water requirements for drinking and other purposes are dramatically increasing. The over extraction and unplanned development of ground water resources have led to considerable depletion of water resources. Artificial recharge is the practice of increasing the amount of water that enters groundwater reservoir by artificial means of planned human activity. The distribution and recharge of groundwater in the country varies significantly depending on geology, rainfall and geomorphology. The objective of this study was to identify artificial recharge potential. This study was conducted in Vavuniya district since the water shortage was observed over the years. Geomorphology, geology, soil, land use and stream data along with Landsat 7 ETM+ and DEM images were utilized to develop the relevant thematic layers such as geology, geomorphology, soil, slope, lineament density, land use and stream density by integrating GIS (Geographic Information System) and image processing techniques. The resultant thematic layers were utilized to prepare the groundwater recharge maps of the area through a weighted overlay method in a GIS platform. The results revealed that the artificial recharge was high in Southern part of the study area. Further the area has significant groundwater recharge zones which can be utilized for a sustainable ground water management system.

Highlights

The world's total water resources were estimated as 1.3*108 million ha-m
The resulted combined image of automatically extracted lineaments and major lineament showed the total lineaments of study area
The geomorphic units identified in the study area mainly composed of ‘low plantation surface with inselbergs and thin soil’ and the rest includes ‘Lower levels of intermediate Plantation surfaces’, ‘Upwarped pleistocene coastal plain’ and ‘River plain and adjacent coastal lowlands’

Summary

Introduction

The world's total water resources were estimated as 1.3*108 million ha-m. Out of this about 97.2 % is salt water, in oceans and only 2.8 % is available as fresh water at any time on the earth. About 2.2% of fresh water is available as surface water whereas 0.6 % as groundwater. Out of this surface water, 2.15 % is fresh water in the form of glaciers and icecaps. Sri Lanka is enriched with surface water and ground water resources. Surface water bodies includes the radial drainage pattern that carries surface water down from the high watersheds includes 103 distinct natural river basins while groundwater resources are replenished by surface water and rainfall

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