Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Application of geographical information system in decision making for sustainable water supplies in Abu Dhabi, UAE

Auteur : Al Mansoori, Mouza

Université de soutenance : Aberdeen University

Grade : Doctor of Philosophy (PhD) 2017

Résumé
Fresh groundwater is one of the most valuable of natural water resources - supporting human health, economic development and ecological diversity, particularly in the arid world. However, managing groundwater aquifer systems sustainabily is challenging. This thesis presents data through a Geographical Information System (GIS) to aid planners, managers and governments in the sustainable management of groundwater aquifer systems. In arid regions such as Abu Dhabi Emirate, managed recharge of groundwater aquifers offers a future for the retention of high quality and secure water resources. To embark upon such an undertaking requires considerable planning, surveying, data collection and interpretation. GIS can be used effectively as a tool to allow users to work strategically at a national and regional level. At a much higher resolution, it can be applied to monitor and measure changes within the selected zone before, during and after recharge and allow data to be reviewed and interpreted in a spatial context. The data interpreted in this thesis identified the Liwa Crescent as the most suitable area for such a project to be carried out after a general appraisal. The Liwa study area covers about 743.6 km². After establishing the suitability of this area for aquifer recharge, two large scale trials were conducted to monitor changes in water quality associated with recharging. The first one was over one experimental year and the second trial was performed over a duration of two years and had four temporal sampling events, once every six months. The GIS data presentation approach complements traditional figures and statistical output by placing the findings in a spatial context in the landscape. Users were able to relate measurements to causal effects and devise mitigation steps to resolve changes better. The GIS approach superimposed hydrogeological data across the measured analyses, and the results were inferred spatially enabling site-based analysis at a suitable resolution. A multivariate regression analysis was applied by using GIS to calculate the suitability index to define the optimal ASR location based on selected criteria. The results indicated that GIS could be successfully used to evaluate and rank a set of technical and economically suitable solutions and alternative scenarios for Aquifer Storage and Recovery (ASR) projects. GIS is the primary tool used in this study for selecting the optimal location for injection and recovery. Also, the results of this study can help the decision maker in driving suitable policy and strategy for groundwater aquifer recharge. The results of injecting almost 32,000 m³ daily of desalinated water into the shallow groundwater aquifer system through three recharge basins at Liwa area for 27 months indicated that the groundwater quality did not deteriorate. The value of this project will be 90 days of freshwater with the daily pumping of around 182,000 m³. The recovered groundwater quality complies with Abu Dhabi potable water quality standards. A GIS-based groundwater quality index that integrates relevant groundwater quality data, further confirmed compliance with Abu Dhabi standards and WHO guidelines. The application of GIS is not an alternative to traditional data analysis styles but is a valuable complement and offers ease of strategic management.

Présentation (EThOS)

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