Dottorato Di Ricerca Trial of Protocols and Techniques
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Università degli Studi di Cagliari DOTTORATO DI RICERCA Scienze e Tecnologie della Terra e dell’Ambiente Ciclo XXIX TRIAL OF PROTOCOLS AND TECHNIQUES FOR INTEGRATED GROUNDWATER MANAGEMENT IN ARID AND SEMI-ARID REGIONS TO COMBAT DROUGHT AND DESERTIFICATION Settore/i scientifico disciplinari di afferenza GEO/05 Presentata da: Alberto Carletti Coordinatore Dottorato Prof. Aldo Muntoni Tutor Prof. Giorgio Ghiglieri Esame finale anno accademico 2015 – 2016 Tesi discussa nella sessione d’esame marzo – aprile 2017 I Abstract In order to combat drought and desertification, it is essential a holistic approach such as that one represented by the paradigm of the Integrated Water Resources Management (IWRM). IWRM can be considered as a flexible conceptual framework based on the principles of equity, efficiency and sustainability that indicates general guidelines for a more efficient water management (Leidel et al., 2012). Within this framework, an effective solution consists, in particular in arid and semi-arid regions, in sustainable water management practices which include, in many cases, a combination of both water harvesting and managed aquifer recharge (MAR) techniques (Cosgrove and Rijsberman, 2000). This research was developed within the WADIS-MAR “Water harvesting and Agricultural techniques in Dry lands: an Integrated and Sustainable model in MAghreb Regions” demonstration Project (2011-2016) (www.wadismar.eu), funded by the EC under the Regional Programme “Sustainable Water Integrated Management” (SWIM) (www.swim-sm.eu). Among its objectives, the Project aimed at increasing groundwater availability through an integrated water harvesting and managed aquifer recharge system in two watersheds in Maghreb Region: Wadi Biskra in Algeria and Oum Zessar in Tunisia. Both areas are characterized by water scarcity, overexploitation of groundwater resources and high vulnerability to climate change risk. The overall objective of this research was to develop an interdisciplinary methodology to define guidelines for the design and implementation of integrated and innovative MAR systems that can be applied in arid and semi-arid environments. This methodology was tested in the two study areas in Algeria and Tunisia. As required by its application, with the support of the interdisciplinary research group of WADIS-MAR, the different components of the Water Resources System (WRS) at local level were defined: the water budget, the 3D hydrogeological model and the hydrogeochemical and isotopic characterization. Because of the lack of a sufficient number of quality data for hydrological modeling, a physiography-based indirect method for determining the runoff coefficient (Ghiglieri et al., 2014) was applied at sub-basin scale for three watersheds (Koutine, Megarine-Arniane and Hajar) in the Tunisian study area. The water budget was estimated on a daily time scale basis, over a 10-year period (2003-2012), through a simplified water balance model, modifying the model proposed by Allen et al. (2006) that considers effective infiltration as part of the surplus from water storage in the soil. An average Available Water Content (AWC) of soils and an average runoff coefficient were considered for each sub-basin. 3D hydrogeological models were implemented for II both study areas through the realization of several balanced geological cross-sections and data processing in a 3D environment by 3D MOVE software. A detailed hydrogeochemical characterization was carried out, including bulk chemistry and multi-isotopic analyses of water and solid samples. The estimated average annual groundwater recharge of the aquifers resulted consistent with the reference values in literature. 3D hydrogeological model reconstruction showed that the groundwater circulation and the geometry of aquifers is strongly influenced by several tectonic structures and this evidence is confirmed by hydrogeochemical and isotopic results. All these results allowed to design MAR systems which are innovative because they present some technical innovations to improve the efficiency of managed aquifer recharge: the recharge chambers and the Passive Treatment System. Finally, the estimated potential recharge rate (m3 year-1) for the targeted aquifers related to the designed MAR systems were about 1.7 hm3 year-1 and 1.2 hm3 year-1 in Algerian and Tunisian study area, respectively. III Acknowledgements First and foremost, I would like to express my sincere gratitude to my tutor Prof. Giorgio Ghiglieri for his valuable guidance and confidence not only during this three-year period of my PhD but also throughout the whole working time together since 2003. I’m greatly thankful to the Desertification Research Centre of the University of Sassari (NRD-UNISS) and the WADIS-MAR project for giving me the possibility of carrying out this PhD research. I would like to thank Prof. Pier Paolo Roggero, Prof. Luciano Gutierrez and Prof. Giuseppe Enne for the support and the opportunities to collaborate to this project. I’m also grateful to Dr. Matteo Funaro and Dr. Alessandra Paulotto, my colleagues of the WADIS-MAR staff, and to all the other colleagues at NRD (they are so many and I would not forget anyone) for their moral support and friendship. A special and affectionate memory goes to my colleague and friend Dr. Oumekheir Belkheiri (Mimì) who is no longer with us and with whom I shared so many years at NRD, especially on the WADIS-MAR project. I would like to express my appreciation to the researchers and professors of the Department of Chemical and Geological Sciences of the University of Cagliari for their collaboration and support among which Dr. Stefania Da Pelo and Dr. Maria Teresa Melis. Special thanks go to Dr. Cristina Buttau and Dr. Gabriela Afrasinei for their important support and expertise provided for the geological and land use issues, respectively, related to the study areas in Tunisia and Algeria. Sincere thanks go also to my PhD colleague Dr. Claudio Arras for sharing with me some aspects of this research and for his support and collaboration on the occasion of the mission in Tunisia during the MAR systems implementation. I’m grateful to the researchers of the Mineralogia Aplicada i Geoquímica de Fluids research group of the University of Barcelona (MAG-UB), in particular to Prof. Albert Soler and Dr. Manuela Barbieri, for sharing with me the research related to the hydrogeochemical characterization of the study areas and for the collaboration on the MAR systems design. I would also like to thank the Algerian and Tunisian partners of WADIS-MAR, Institut des Regions Arides (IRA) (Tunisia), Agence Nationale des Ressources Hydrauliques (ANRH) (Algeria) and Observatoire du Sahara et du Sahel (OSS) for the support and collaboration. Special thanks go to the IRA’s staff involving in WADIS-MAR, Dr. Mohamed Ouessar, Dr. Kamel Nagaz, Dr. Mongi Sghaier, Dr. Mongi Ben Zaied, Dr. Ammar Zerrim and Dr. Messaoud Guiad for the expertise and support during my research, especially during the MAR systems realization, as well as for their hospitality. Sincere thanks go to Dr. Toufik Mesrati, Dr. Elhadj Meftah and Dr. Mohamed Bennacer (ANRH) for their collaboration during my missions in Algeria. Many thanks go to Dr. Mouhamadou Ould Baba Sy (OSS) for his support, availability and friendship. I would also like to thank the technicians of the Commissariats Régionaux au Développement Agricole (CRDA) in Médenine (Tunisia), Dr. Samir Sahal, Dr. Khaled Ben Zaied and Dr. Ahlem Ettiss for their support and collaboration on the field regarding the supervision of the works related to the MAR systems implementation in Tunisian intervention sites. I would like to express my gratitude to Dr. Andrea Motroni and Dr. Simona Canu of the Hydro Meteorological and Climatic Department of the Regional Environmental Protection Agency of Sardinia (ARPAS) for their guidance and support on the research activity related to the water budget estimation of the study area in Tunisia. IV Special thanks go to Dr. Pierluigi Cau and Dr. Pier Andrea Marras of the Center for advanced studies, research and development in Sardinia (CRS4) for their support and advices for the attempt to implement the SWAT model in the Tunisian study area. I’m also thankful to Dr. Enrique Fernández Escalante for his training on MAR on the occasion of the training course organized within the WADIS-MAR capacity building activities and his valuable suggestions on MAR systems design. My deepest heartfelt gratitude goes to my mother and my brother (and his family) for all their support and affection throughout these years and not only during my PhD. My sincere and hearty gratitude to the Contini family for their support and encouragement and special thanks go to Valerio and Ella for their hospitality during my many stays in Cagliari. Last but not least, to my wife Eleonora and my sons Nicolò and Mattia. I would never be able to finish this work without their support, patience and understanding. I apologise for the time I could not spend with them promising that I will make up for lost time. Thank you for believing in me always. I love you so much. V Table of Contents 1. INTRODUCTION ................................................................................................................................ 1 1.1. Research background ................................................................................................................. 1 1.2. Research objectives ...................................................................................................................