Mediterranean Karst Aquifer Map

Background:
Karst aquifers constitute important freshwater resources, but are challenging to manage and to protect, because of their unique structure and behaviour, representing continuous challenges for research and development. Karstified carbonate rocks occur on 15.2 % of the global land surface (Goldscheider et al. 2020) and are widespread in the Mediterranean region, where groundwater from karst contributes to the freshwater supply of most countries and many big cities, such as Rome, Montpellier, and Beirut.

Groundwater resources in karst aquifers are often hydraulically connected over large areas and particularly vulnerable to contamination. Rapid and turbulent groundwater flow in a network of conduits and caves often results in variable spring discharge and water quality.

Mediterranean Karst Aquifer Map

Map methodology:
The preparation of the Mediterranean Karst Aquifer Map (MEDKAM) generally followed the workflow used for the World Karst Aquifer Map (WOKAM) (Chen et al. 2017). The topographic basis for MEDKAM is the International Hydrogeological Map of Europe 1 : 1,500,000 (IHME1500) (BGR & UNESCO 2019) and its recently digitised extension to North Africa.

To complete missing parts in the North African countries and the Arabian Peninsula, the digital versions of the Quantitative maps of groundwater resources in Africa from the British Geological Survey (MacDonald et al. 2012) and the Bedrock geology of the Arabian Peninsula from the United States Geological Survey (Pollastro 1998) were used.

IHME is a series of general hydrogeological maps with 30 map sheets compiled by hydrogeologists and national experts in related sciences under the auspices of the International Association of Hydrogeologists (IAH). A new lithological classification has been developed for MEDKAM, similar to that of WOKAM, which groups the geological units into four meaningful hydrogeological units:

• Karst aquifers in sedimentary and metamorphic carbonate rocks
• Karst aquifers in evaporite rocks
• Various hydrogeological settings in other sedimentary and volcanic formations (karst aquifers are possibly present at depth)
• Local, poor and shallow aquifers in other metamorphic rocks and igneous rocks (no karst aquifers present at depth)

Additional karst aquifer information:
MEDKAM also presents a selection of karst water sources, caves and karst groundwater dependent ecosystems (PDF, 844 KB). Karst water sources include conventional karst springs, thermal springs, submarine springs, wells and other water abstraction structures. Water sources were primarily selected on the basis of their discharge during low-flow conditions, which is more relevant in terms of water supply than the maximum discharge. The regional importance was also considered. For example, a spring in an arid region that is used for water supply has a higher regional importance than an unused spring in a humid region. There are several examples of large karst springs that ran dry due to overexploitation.

Caves were selected based on a combination of their dimensions and their regional importance. Caves associated with important freshwater resources and caves that are the longest or deepest in a large karst region, were assigned a high regional importance. The selection of water sources and caves is to some degree subjective and also reflects the regional differences in data availability. In regions with high spatial density of large karst springs and caves, many important features cannot be displayed.

Funding:
MEDKAM, realised within the framework of the KARMA project, has received funding from the Partnership on Research and Innovation in the Mediterranean Area (PRIMA). PRIMA develops urgently needed solutions for a more sustainable management of water and agri-food systems in the Mediterranean region. It is a ten-year initiative (2018-2028), partly funded by the EU's Horizon 2020 research and innovation programme.

The Karlsruhe Institute of Technology (KIT), the American University of Beirut (AUB), the University of Malaga (UMA), the National Engineering School of Tunis (ENIT), the Sapienza University of Rome (URO), the University of Montpellier (UM), and the Federal Institute for Geosciences and Natural Resources (BGR) contributed to the development of the Mediterranean Karst Aquifer Map (MEDKAM)

Recommended citation:
XANKE J, GOLDSCHEIDER N, BAKALOWICZ M, BARBERÁ JA, BRODA S, CHEN Z, GHANMI M, GÜNTHER A, HARTMANN A, JOURDE H, LIESCH T, MUDARRA M, PETITTA M, RAVBAR N & STEPANOVIC Z (2022): Mediterranean Karst Aquifer Map (MEDKAM), 1 : 5,000,000. Berlin, Karlsruhe, Paris. doi: 10.25928/MEDKAM.1

References:

• BGR & UNESCO (2019): International Hydrogeological Map of Europe 1 : 1,500,000 (IHME1500). Digital map data v1.2. Hannover/Paris.
• CHEN Z, AULER AS, BAKALOWICZ M, DREW D, GRIGER F, HARTMANN J, JIANG G, MOOSDORF N, RICHTS A, STEVANOVIC Z, VENI G, GOLDSCHEIDER N (2017): The World Karst Aquifer Mapping project: concept, mapping procedure and map of Europe. Hydrogeol. J. 25, 771–785. doi: 10.1007/s10040-016-1519-3
• GOLDSCHEIDER N, CHEN Z, AULER AS, BAKALOWICZ M, BRODA S, DREW D, HARTMANN J, JIANG G, MOOSDORF N, STEVANOVIC Z, VENI G (2020): Global distribution of carbonate rocks and karst water resource. Hydrogeol. J. 28, 1661–1677.
• HARTMANN A, LIU Y, OLARINOYE T, BERTHELIN R, MARX V (2020): Integrating field work and large-scale modeling to improve assessment of karst water resources. Hydrogeol. J. 29, 315–329.
• MACDONALD AM, BONSOR HC, Ó DOCHARTAIGH BÉ, TAYLOR RG (2012): Quantitative maps of groundwater resources in Africa. Environ. Res. Lett., 7(2):024009.
• MARTENS B, MIRALLES DG, LIEVENS H, VAN DER SCHALIE R, DE JEU RAM, FERNANDEZ-PRIETO D, BECK HE, DORIGO WA, VERHOEST NEC (2017): GLEAM v3: Satellite-based land evaporation and root-zone soil moisture. Geosci. Model Dev., 10(5), 1903–1925.
• Ó DOCHARTAIGH BÉ, DOCE DD, RUTTER HK, MACDONALD AM (2011): User Guide: Aquifer Productivity (Scotland) GIS datasets, Version 2. British Geological Survey Open Report, OR/11/065. 17pp.
• POLLASTRO RM (1998): Bedrock geology of the Arabian Peninsula and selected adjacent areas (geo2bg): U.S. Geological Survey data release.
• RODELL BYM, HOUSER PR, JAMBOR U, GOTTSCHALCK J, MITCHELL K, MENG C, ARSENAULT K, COSGROVE B, RADAKOVICH J, BOSILOVICH M, ENTIN JK, WALKER JP, LOHMANN D, TOLL D (2004): The Global Land Data Assimilation System. Bull. Amer. Meteor. Soc., 85(3), 381–394.
• XANKE J, LIESCH T (2022): Quantification and possible causes of declining groundwater resources in the Euro-Mediterranean region from 2003 to 2020. Hydrogeol. J. 30, 379–400.

Printed maps:

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