The WAO Project

The WAO project aims to improve understanding of the hydrological functioning of the Saq aquifer in the Al Ula region (Saudi Arabia) in order to move towards sustainable management of this essential resource for the socio-economic and agricultural development of this oasis.

The WAO project is part of the OASIS programme funded by the AFALULA agency (Agence Française de Développement d'Al-Ula) through its cooperation with Saudi Arabia and the Royal Commission for Al-Ula (RCU). The aim of this research and development programme is to study the Al-Ula oasis, which is home to the archaeological site of Madâin Sâlih, better known by its ancient name of Hégra, a major site of Nabataean civilisation in north-west Saudi Arabia, and the first Saudi site to be listed as a UNESCO World Heritage Site.

This multi-disciplinary programme brings together archaeologists, geo-archaeologists, palaeoclimatologists, soil scientists, botanists, agronomists, ethnobotanists and ethnologists, and aims to improve our understanding of the Al-Ula oasis ecosystem and provide a knowledge base capable of building a sustainable development, economic and tourism model that respects this exceptional environment.

The 4-year project led by CEREGE focuses on studying the current and past functioning of the aquifer system that feeds the Al-Ula oasis ecosystem. The aim is to assess the current resource and the impact of withdrawals on it, and to reconstruct the functioning of this hydrosystem in the climatic and environmental context of recent millennia in order to clarify the conditions that enabled human occupation of this arid zone and the development of protohistoric societies.

To this end, the project proposes to :
. characterise the aquifer system by combining hydrogeological approaches (piezometric monitoring, setting up a network of sensors, modelling, etc.), geophysical approaches (satellite gravity data, etc.) and hydrogeochemical approaches (sampling, groundwater monitoring, elemental and isotopic analyses).
. to study different types of sedimentary archive in order to reconstruct climatic and environmental variability in the region.

The central questions that the WAO project aims to answer are

• How much water is currently withdrawn from the aquifer in the Al Ula region to support the oasis economy?
• What is the sustainability of the aquifer resource that can be mobilised on a local and regional scale?
• Is there current active recharge of the aquifer?
• What is the average groundwater quality in the Al Ula region?
• Is there a risk of contamination and salinisation in connection with the overexploitation of water resources?
• Where does the water come from and how old is it?
• What were the past environmental and climatic conditions that allowed human settlement in the Al Ula region?