This atlas is meant to be used by decision-makers, development partners and the general public.
The purpose of the atlas, containing some 30 maps and graphs derived from an OSS regional study on the Iullemeden, Taoudeni/Tanezrouft Aquifer System, is to provide information on the availability and use of water resources in this region of seven countries (Algeria, Benin, Burkina Faso, Mali, Mauritania, Niger and Nigeria).
The atlas also offers the reader illustrations concerning water and the strategic role it plays in transboundary cooperation, food security, health, and socio-economic development to help cope with global changes.
This atlas is meant to be used by decision-makers, development partners and the general public.
The major activities of the Database component have been to carry out the analysis of required entities and attributes for Database development, defining entity relationship model at Conceptual level and thereafter to carry out Database installation and testing, data conversion and semantic translation, data input into the database and data output generation.
Since this is the first sub-regional database for the IGAD member countries, a huge work have been done to come up with this useful tool for data management which cuts across several water resources (surface and groundwater) sub-disciplines. The Database built included both identification and variable data/information on borehole, shallow wells, Meteorological, hydrological and river gauging stations. In total, 83,064 (Eighty three thousand and sixty four) water points have been input the regional Database.
Data provided were quite heterogeneous, different formats and semantics. Efforts were made to harmonize them before their introduction into the Database. This operation can be improved by continuous treatment. The established GIS database enrichment will allow in the future updating the thematic maps produced by the project. This will also serve for national use and support for decision making.
The major shortcomings encountered during data compilation and analysis was as follows: lack of, or wrong coordinates; duplication; Lack of Identifier, etc.. There is a need to overcome the shortcomings and the lack of data by involving the national Coordinators from member countries. As Database construction is a continuous and dynamic process, this issue will be addressed in a further stage of the project
The Transboundary Diagnostic Analysis recommended by the Global Environment Fund has been applied to transboundary waters of the Iullemeden Aquifer System (IAS) shared by Mali, Niger and Nigeria. It allowed identifying three major transboundary risks namely (1) the reduction of resource availability, (2) degradation of water quality, and (3) the impact of variability / climate change.
Recognizing the need for a regional approach for shared groundwater management to face those transboundary risks for which efforts of one country cannot find a sustainable solution, the three countries committed themselves in a process of joint water resources management. Through this process, they plan to mitigate the negative impacts of these risks on their shared groundwater resources.
The policy and strategy elements to mitigate these risks have been designed to help countries in formulating their policies and strategies accompanied by an action plan in the medium and long term. These elements include the political, socio-economic and environmental dimension. They were developed by conducting the analysis of solutions for each risk examined according to (a) hydrogeological and environmental (b) socio-economic, and (c) legal and institutional dimensions.
To develop this policy at regional level, national legislation on water should be updated taking into account the achievements of the project in terms of the methods and management of transboundary groundwater regimes.
The Water Resources Modeling section conceptualized and developed of a hydrologic model for water resources assessment of the identified transboundary basins in the IGAD region. Despite the lack of data (meteorological data, daily stream flows, etc.) which limited the effective calibration of the model, several attempts were carried out to ensure effective estimation of the Water resources for the IGAD basins.
The evaluation of the hydrological performance of the SWAT model on a daily/monthly time resolution for the IGAD basins faced large deficiencies in the database, especially regarding daily observations - a number of observations are missing. Model calibration requires the availability of reliable flow data for major rivers within the basins in both temporal and spatial terms. These data were not available for the current study. Consequently, the study used the available data from other sources which are sparse and not free of errors. Furthermore, the model helped clearer understanding of the hydrological response of several IGAD catchments and the potential use. A simple sensitivity study helped reduce the dimensionality of the calibration challenge.
The Water Resources Modeling of the Six (6) identified transboundary river basins (Danakil, Gash-Baraka, Turkana-Omo, Ayesha, Juba-Shebelle and Ogaden) represent a first attempt to comprehensively model their water resources within the IGAD sub-region. For most of the basins, the estimated available annual water resources were in good agreement with results from other studies. As such the estimates for all basins need further investigations before they can be used as a basis for comprehensive decisions about the basins. There is need for collection of additional data from the member countries as soon as a mechanism for data sharing can be implemented.
The model assessed the available water resources for the IGAD transboundary basins to 182.8 km3 (111.3 km3 for Surface water and 71.5 km3 for Groundwater). Additional data especially daily stream flows at several locations in the basin, are required to improve the water resources simulations.
The Transboundary Diagnostic Analysis recommended by the Global Environment Fund has been applied to the transboundary groundwater of the Iullemeden Aquifer System shared by Mali, Niger and Nigeria. The Transboundary Diagnostic Analysis is a scientific and technical fact-finding analysis based on technical and scientific information available and verified, to examine the state of the environment and the causes of its degradation, focusing on transboundary problems without ignoring national concerns and priorities.
Three major transboundary risks were identified: (1) reducing the availability of the water resource, (2) degradation of water quality, and (3) the impacts of climate variability/change. This required the development of a database with more than 17000 water points, a Geographic Information System and a mathematical model. This model has among other things, highlighted the overexploitation of the resource since 1995 and the interconnection between the Niger River and the aquifers. The immediate, root and underlying causes (including the governance of water) of these risks were analyzed.
The Transboundary Diagnostic Analysis is a participatory approach involving all stakeholders concerned with the issue. To this end, it contributes to strengthen solidarity and confidence between them.
Several transboundary river basins and aquifer systems have been identified in the IGAD sub-region. The basis of Integrated Water resources Management (IWRM) is that different uses of water are interdependent. These uses tend to have cross-border implications. Then implementing IWRM in transboundary basins provides a viable mechanism for addressing the challenges. The problem for most countries is the long history of unisectoral development. Water development and management should be based on a participatory approach, involving users, planners and policymakers at all levels.
It appears that modeling water resources management in the IGAD sub-region is challenging. Water resources are sparsely distributed in space and highly variable in time. Additionally, data on water demand and usage are scarce and can be unreliable in areas where they exist. Thus, the need for Water Evaluation and Planning were obvious.
The WEAP model was used for modeling water resources management in the IGAD sub-region. It allows to analyse the effect of polices interventions (both structural and non-structural) on water resources availability and demand in a region. The demand and supply data were collected at national and international level and used. The model was then successfully developed for six transboundary river basins in the IGAD sub-region. Alternative water management scenarios were simulated. The results have shown very optimistic results, ensuring that the IGAD sub-region has considerable water resources which, if well managed, can serve the needs of the basin inhabitants.
The implementation of IWRM is complicated by lack of political will, lack of institutional and legal tools and also lack of human resources capacity. An overall plan is required to envisage how the transformation can be achieved and this is likely to begin with a new water policy to reflect the principles of sustainable management of water resources. To put the policy into practice is likely to require the reform of water law and water institutions. This can be a long process and needs to involve extensive consultations with affected agencies and the public.
Training of model users will help in ensuring that the use of the model is integrated in their daily work and a critical mass of professionals can be built to implement the model at Transboundary basin level. The IWRM models were built from the data available at the time of analysis. The main idea behind the development of the models was the models will evolve over time as more information about water resources, demand and other policy issues becomes available.
This publication presents the main obtained results from the implementation ofthe different components of the project: hydrogeological data collection, analysis, and synthesis; elaboration of a common database and an informationsystem; development and exploitation of the NWSAS mathematical model andthe regional sub-models; establishment of a consultation mechanism for thebasin joint management; socio-economic study; and environmental study.
Since 1992, the OSS has shown a special interest in thedevelopment of a platform for dialogue among countries sharing nonrenewable water resources.An attempt is made to promote a ‘basin awareness’ by working to increase and exchangeknowledge on these units (geological and hydrogeological definition as well as improvement of models,etc.), creation of effective joint structures in the face of still poorly mastered resource management, anda harmonization of legislation.The OSS and UNESCO have established a fruitful cooperation on this theme and work together todistribute this reflection on the challenges which the OSS region faces for the future as concerns theselimited resources. This reflection was done with the participation of Jean Margat. Today, it takes on aparticular importance in light of the recent International Agreement to Combat Desertification, alreadysigned by more than 187 countries.
The present document sets out the principal results obtained through the implementation of the various components of the NWSAS project: Acquisition, Analysis and Synthesis of Hydrogeological Data; Elaboration of the Shared Database and of the Information System; Development and Exploitation of the NWSAS Mathematical Model; and Installation of the Dialogue Mechanism concerning the basin's shared management.