TC Maghreb: Regional Cooperation in the Water Sector

Report of the project:

Regional Project: Regional Cooperation for sustainable Water Resources Management - Maghreb

Fig. 1: Training on groundwater modelling Source: BGR

Background:
In the project "Coopération Régional pour une Géstion Durable des Ressources en Eau en Maghreb (CREM)", the Federal Institute for Geosciences and Natural Resources (BGR) is working together with the Sahara and Sahel Observatory (OSS) on various topics related to groundwater protection in Algeria, Morocco and Tunisia. Semi-arid to arid climate, climate change, intensive irrigation agriculture, population growth and urbanization cause a constant pressure on the water quality and lead to an overexploitation of the groundwater resources in the three partner countries. The aim of the CREM project is to provide measures for a sustainable water management in the pilot regions and to encourage the partner countries to exchange about the respective developed methods. As part of this project, BGR and OSS are assisting the authorities of the three partner countries in collecting and exchanging relevant hydrogeological information at regional level. Another important aspect is the training of the partner institutions (Figure 1) in these methods and applications in order to ensure the sustainability of the measures in groundwater management.

Fig. 2: Green houses in the Chtouka region Source: BGR

Fig. 3: Non-/irrigated areas in the Chtouka region Source: BGR

Remote sensing in the project area Constantine, Algeria:
In the project area Constantine in the northeast of Algeria, remote sensing is used to identify different agricultural areas. Due to the knowledge of the respective crops and their extent, evapotranspiration properties and volumes according to FAO 56 can be derived. On the one hand, water needs can be thus be quantified and, on the other hand, the additional amount of irrigated groundwater can be estimated for certain crops that cannot be covered by precipitation only. Groundwater abstraction for irrigation represents by far the largest component in the water balance of the aquifer. By a better estimation of the abstractions the long term water demand can be evaluated and sustainably managed.

Fig. 4: Seawater instrusion model Source: ANZAR Conseil

Monitoring of saltwater intrusion at Agadir, Morocco:
In Morocco the project region is located south of Agadir at the Atlantic coast. The local aquifer in the Chtouka region is facing problems of over-exploitation and sea water intrusion. Using various hydrogeological and geophysical methods, the project aims on better exploring the hydrogeology and, based on this, develop a conceptual model of the marine intrusion. The improvement of a numerical modeling (Figure 4) can better capture the current state of the intrusion and estimate the development in the future under different scenarios. The lack of reliable data represents a challenge, which can be counteracted e.g. by the expansion and rehabilitation of the groundwater monitoring network (Figure 5). Advanced hydraulic, chemical and geophysical measurements and improved process understanding are expected to develop methods for sustainable water use with the Moroccan partner Agence du Bassin Hydrogeologique Souss Massa (ABHSM) to protect this resource.

Fig. 5: Telemetric piezometers new/old (left/right) Source: BGR

Development of a Decision Support System for the project area Kairouan, Tunisia:
Similar to Algeria, remote sensing is used to estimate the volume of groundwater abstraction in the project region in northeastern Tunisia. Furthermore, groundwater information is collected and entered into a Decision Support System (DSS), which enables a more sustainable use of the water recources in different future scenarios. The core of the DSS is the water evaluation and planning software WEAP (Water Evaluation And Planning System), developed by the Stockholm Environment Institute (SEI) and the 3-d groundwater flow model MODFLOW, developed by the U. S. Geological Survey (USGS). An upstream located Soil Water Assessment Tool (SWAT) provides the input for surface runoff and the soil water balance model MABIA provides data on the water consumption of the plants. The DSS ultimately calculates the development of water demand dependent on different crop types and changing climatic conditions, eventually resulting in strategies. Additionally, radar interferometry is used to detect ground movement and cross-correlate data with groundwater abstractions for an extrapolation. By this method, groundwater abstractions may be quantified long term.

Partner: Observatoire du Sahara et du Sahel (OSS)

Information about "saltwater intrusion": Salt Water Intrusion Meeting (SWIM)

Literature:

Reports

Poster