An Open Source GIS-Based Application for the Assessment of Groundwater Vulnerability to Pollution

Lia Duarte,Ana Cláudia Teodoro,Jorge Espinha Marques

doi:10.3390/environments6070086

Lia Duarte, Ana Cláudia Teodoro + Show 1 more

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https://doi.org/10.3390/environments6070086

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Journal: Environments	Publication Date: Jul 21, 2019
Citations: 24	License type: CC BY 4.0

Affiliation: University of Porto

Abstract

Groundwater is a crucial natural resource for regular socio-economic function. Groundwater vulnerability to pollution can be assessed through Geographical Information System (GIS)-based qualitative methods. GIS-based tools, dedicated to the assessment of groundwater vulnerability, usually present several limitations, such as high cost, unavailable code, and a lack of functionality concerning the flexible application of vulnerability indices and vulnerability map comparison. The objective of this work was to create a new GIS-based open source application for groundwater vulnerability assessment, GVTool, developed using QGIS software, with the capability of creating and comparing groundwater vulnerability maps considering four different methods: DRASTIC, GOD, SINTACS, and Susceptibility Index (SI). This application incorporates features from a previous tool, DRASTIC Model, and new functionalities were included, namely three additional vulnerability assessment methods, map comparative analysis, map statistics, and index interval reclassification and symbology definition. The GVTool functionalities and capabilities are illustrated through a groundwater vulnerability assessment in Serra da Estrela mountain (Central Portugal). GVTool is mostly useful in integrated assessments, helping to verify if the groundwater vulnerability maps are accurate and to decide which is the most suitable method or the combination of methods to express groundwater vulnerability to pollution in a specific area.

Highlights

Groundwater is a crucial natural resource for regular socio-economic function
Groundwater vulnerability maps are fundamental for spatial planning, since these instruments may be used to identify, and if necessary, to protect the most sensitive areas, for instance, by removing or preventing the installation of potentially pollutant economic activities
Groundwater Vulnerability Tool (GVTool) is a new Geographical Information System (GIS)-based groundwater vulnerability assessment tool developed under QGIS, a free and open source application, with the purpose of providing a friendly and accurate application for creating and comparing groundwater vulnerability maps using four well-established methods: DRASTIC, GOD, SINTACS, and Susceptibility Index (SI)

Summary

Introduction

Groundwater is a crucial natural resource for regular socio-economic function. The occurrence of potable groundwater is widespread, and, for that reason, it is an essential source of water supply worldwide. Groundwater provides more than 40% of the world’s irrigation water and around 50% of municipal water extractions [1]. The estimated worldwide groundwater abstraction is around 982 km3 /year, corresponding to around a quarter of the total water abstraction. Of this groundwater volume, 70% is for irrigation, 21% is for domestic use, and the remainder is mostly for industrial use [2]. The deficient access of populations to appropriate water supplies causes severe socio-economic vulnerability, and poverty. It is possible to promote water poverty to water prosperity through the sustainable exploitation of groundwater from high-quality, relatively low-cost, drought-resilient aquifers [3]

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