Skip to main content
Weiter zur Homepage der Europäischen Kommission (öffnet in neuem Fenster)
Deutsch de
CORDIS - Forschungsergebnisse der EU
CORDIS
Inhalt archiviert am 2022-12-23

Recharge characteristics and groundwater quality of the Grand Erg Orientale Basin

Ziel

- To define the limits of sustainable groundwater development in the continental intercalaire (CI) and Complexe Terminal (CT) aquifer in Algeria/Tunisia;
- To determine the extent of modern recharge and the recharge history over the past decades (relating to climate change) using geochemical techniques;
- To examine and evaluate the interface between recent recharge and palaeowaters for this aquifer system and the extent/risks of salinisation;
- To define the sustainable limits to development of the aquifer.
Expected Outcome

- The study will provide a synoptic overview and a concise synthesis of the limits to development of the aquifer system, which is a type-basin-basin for other parts of North Africa;
- ln combination with the existing knowledge of the area an up-to-date, bilingual report with Arabic summary on the overall conditions in the aquifer will be produced, providing to planning authorities the basis for appropriate management and conservation of the CI and CT aquifer systems.


Results

- The deep groundwaters of the Continental Intercalaire have been sampled (90 sites along four representative cross sections) in sites in Tunisia and Algeria between 2.20.00 E and 9.00.00 E and extending to 28.00.00 N. The principal east-west cross section spans some 350 km along a flow line (maximum depth 1800 m) which extends from M'Zab to the Gulf of Gabes. The isotopic evidence shows that these waters are palaeowaters many of which are beyond the range of radiocarbon dating. The average recharge temperatures of these waters however is around 17°C, indicating that they were derived from rainfall some 5°C cooler than the present day. Other information has been obtained on a wide range of chemical and isotopic indicators that are helping to solve the questions of residence times, source areas, heterogeneity and potability of these waters. For the overlying Complexe Terminal aquifer system, a similar number of samples have been obtained and clearly many of these have been recharged during the past 10000 years under climatic conditions similar to the present day.
- The extent of modern recharge across the region of the Grand Erg Orientale has been carried out by studies of the moisture profiles of the unsaturated zone. Three boreholes have been drilled at Tozeur into Miocene sands of the Complexe Terminal and further profiles are being obtained at Redjem Maatoug in southern Tunisia and also at El Baguel in the West of the studied area. The approach adopted for recharge calculation is to use chloride (concentrated by evapotranspiration) contained in the unsaturated zone as a conservative record of inputs of atmospherically derived solutes. Chemical analysis of rainfall has been carried out in both countries as part of the recharge studies. Using the geochemical investigation of the unsaturated zone it is also possible to investigate recharge history over the recent decades and to investigate the extent of falling water tables. Recharge studies have also been carried out in the vicinity of wadis and in the Atlas foothills in both countries.

Follow-up

- An end of project seminar will be held in Damascus, Syria in collaboration with ACSAD (Arab Centre for the Studies of Semi-arid Zones and Drylands) in November 1997 at which the implications for the exploitation of groundwater from other large basins in the Arab region will be explored in the light of the Avicenne geochemical studies. Several papers are currently being prepared on the results and these will be presented at international symposia and the scientific literature.
- Characterisation of the palaeowater system is being carried out through geochemical sampling for major and trace elements, stable isotopes, radioisotope, inert gas and in situ measurements of chemical parameters. Work is being carried out along several key traverses of each aquifer;
- Recharge studies are based on field sampling and analysis of historic hydrogeological data, i.e. water table variations in oasis. Estimation of recharge is being carried out using geochemical methods and to support this rainfall sampling and analysis is being carried out over two seasons;
- Recharge via wadi systems is being studied in two localities using the existing network of shallow wells;
- Recharge via the Atlas foothills is being studied using existing data and through new geochemical sampling;
- Salinisation is being studied at about 20 sites in two environments : near the Chotts and in the coastal zones to study the state of present day saline intrusion to confirm the source of salinity and establish the residence times of the saline pollution.

Wissenschaftliches Gebiet (EuroSciVoc)

CORDIS klassifiziert Projekte mit EuroSciVoc, einer mehrsprachigen Taxonomie der Wissenschaftsbereiche, durch einen halbautomatischen Prozess, der auf Verfahren der Verarbeitung natürlicher Sprache beruht. Siehe: Das European Science Vocabulary.

Dieses Projekt wurde noch nicht bei EuroSciVoc klassifiziert.
Schlagen Sie die Wissenschaftsbereiche vor, die Ihrer Einschätzung nach besonders relevant sind, und helfen Sie uns, unseren Klassifizierungsdienst zu verbessern.

Sie müssen sich anmelden oder registrieren, um diese Funktion zu nutzen

Programm/Programme

Mehrjährige Finanzierungsprogramme, in denen die Prioritäten der EU für Forschung und Innovation festgelegt sind.

Thema/Themen

Aufforderungen zur Einreichung von Vorschlägen sind nach Themen gegliedert. Ein Thema definiert einen bestimmten Bereich oder ein Gebiet, zu dem Vorschläge eingereicht werden können. Die Beschreibung eines Themas umfasst seinen spezifischen Umfang und die erwarteten Auswirkungen des finanzierten Projekts.

Daten nicht verfügbar

Aufforderung zur Vorschlagseinreichung

Verfahren zur Aufforderung zur Einreichung von Projektvorschlägen mit dem Ziel, eine EU-Finanzierung zu erhalten.

Daten nicht verfügbar

Finanzierungsplan

Finanzierungsregelung (oder „Art der Maßnahme“) innerhalb eines Programms mit gemeinsamen Merkmalen. Sieht folgendes vor: den Umfang der finanzierten Maßnahmen, den Erstattungssatz, spezifische Bewertungskriterien für die Finanzierung und die Verwendung vereinfachter Kostenformen wie Pauschalbeträge.

CSC - Cost-sharing contracts

Koordinator

NERC British Geological Survey
EU-Beitrag
Keine Daten
Adresse
Nicker Hill
NG12 5GG Keyworth
Vereinigtes Königreich

Auf der Karte ansehen

Gesamtkosten

Die Gesamtkosten, die dieser Organisation durch die Beteiligung am Projekt entstanden sind, einschließlich der direkten und indirekten Kosten. Dieser Betrag ist Teil des Gesamtbudgets des Projekts.

Keine Daten

Beteiligte (2)

Mein Booklet 0 0