Climate change is having short- and long-term impacts on surface and groundwater in the northern part of the African continent. This has led to a wide range of consequences that have added pressure on the groundwater systems in this part of the world. Among such pressures, we can cite the mal-distribution and the irregularity of precipitation and ice, flooding, evaporitic sediments input by the drainage net, water degradation, mud stagnation in dams, dead tranche, drought, decreasing of the natural recharge and increasing of the groundwater abstraction, conflict between trans-boundary waters, desertification, imbalance between the regions, migration, revolution, socio-economic imbalance, etc. Actually, water-monitoring networks indicate noticeable hydrogeologic variations and a rise of the groundwater salinity. It was confirmed by the geochemical analysis of water resources that showed scattered data between the northern part characterized by low mineralized groundwater (TDS ranging 0.4–3 g/l) and the southern area where the salinity ranges from 2.5 to 90 g/l. The obtained values are far above the permissible limits for both human consumption, agricultural and tourist activities. These effects, when compounded, are anticipated to worsen the situation and to constitute veritable threats for social and economic development in these regions of North Africa (Morocco, Algeria, Tunisia, Libya, Egypt, etc.). The potential solutions consist of taking urgent to utilize the intelligent technology (bio and nano-technology), policies relevant policies to manage water resources, and the engagement of private, civil, and international sectors if a major crisis is to be averted (collective effort).

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Climate impact on surface and groundwater in North Africa: a global synthesis of findings and recommendations

Climate Change and Tourism

Future projections of temperature and precipitation climatology for CORDEX-MENA domain using RegCM4.4

Water, land and carbon footprints of sheep and chicken meat produced in Tunisia under different farming systems

The Middle East and North Africa (MENA) region is the world’s most water-stressed region, with its countries constituting 12 of the 15 most water-stressed countries globally. Because of data paucity, comprehensive regional-scale assessments of groundwater resources in the MENA region have been lacking. The presented study addresses this issue by using a distributed ArcGIS model, parametrized with gridded data sets, to estimate groundwater storage reserves in the region based on generated aquifer saturated thickness and effective porosity estimates. Furthermore, monthly gravimetric datasets (GRACE) and land surface parameters (GLDAS) were used to quantify changes in groundwater storage between 2003 and 2014. Total groundwater reserves in the region were estimated at 1.28 × 106 cubic kilometers (km3) with an uncertainty range between 816,000 and 1.93 × 106 km3. Most of the reserves are located within large sedimentary basins in North Africa and the Arabian Peninsula, with Algeria, Libya, Egypt, and Saudi Arabia accounting for approximately 75% of the region’s total freshwater reserves. Alternatively, small groundwater reserves were found in fractured Precambrian basement exposures. As for groundwater changes between 2003 and 2014, all MENA countries except for Morocco exhibited declines in groundwater storage. However, given the region’s large groundwater reserves, groundwater changes between 2003 and 2014 are minimal and represent no immediate short-term threat to the MENA region, with some exceptions. Notwithstanding this, the study recommends the development of sustainable and efficient groundwater management policies to optimally utilize the region’s groundwater resources, especially in the face of climate change, demographic expansion, and socio-economic development.

A quantitative assessment of groundwater resources in the Middle East and North Africa region

Global temperature is increasing and that the main cause is the accumulation of carbon dioxide and other greenhouse gases in the atmosphere as a result of human activities. The economic costs alone will be very large: as extreme weather events such as droughts and floods become more destructive and frequent; communities, cities, and island nations are damaged or inundated as sea level rises; and agricultural output is disrupted. Impacts on ecosystems and biodiversity are also likely to be devastating. But what about Climate change impacts on water resources and agriculture in North African regions and especially on Tunisia country? North Africa is vulnerable to climate change impacts. Scenarios predict an average rise in annual temperatures, higher than the average expected for the planet. Heat waves would then be more numerous, longer and more intense. North Africa would be particularly affected by droughts that would be more frequent, more intense and longer-lasting. The projections also announce a drop of 4 to 27% in annual rainfall. The water deficit will be worsened by increased evaporation and coastal aquifers will become more salty. The sea level could rise by 23-47 cm. by the end of the 21st century. Many Mediterranean regions would then run a major risk of being submerged and eroded. In North Africa, rising temperatures associated with climate change are expected to decrease the land areas suitable for agriculture, shorten the length of growing seasons and reduce crop yields. In these countries, we estimate that a 1°C rise in temperature in a given year reduces economic growth in that year by about 1.1 points. The decrease in annual precipitation that is predicted for Northern Africa in the 21 st century will exacerbate these effects, particularly in semiarid and arid regions that rely on irrigation for crop growth. These effects of climate change are more dramatic for Tunisia country especially for water resources and arable cropland. The African countries face numerous environmental challenges and have to reconcile many conflicting priorities, from promoting economic diversification, ensuring water supply and food security, and furthering environmental protection and conservation to adapting to the impacts of global warming.

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Climate change impacts on North African countries and on some Tunisian economic sectors

La surexploitation et le gaspillage de nos ressources en eau, en particulier dans le domaine agricole, privent d’eau d’autres zones entrainant ainsi la baisse de la production agricole.
L’amelioration de l’efficience de l’irrigation – soit l’augmentation de la production pour chaque metre cube d’eau investi – est un objectif crucial pour l’avenir et doit donc devenir l’une des premieres priorites. Que ce soit l’irrigation deficitaire ou l’usage d’eaux saumâtres, l’utilisation de ces eaux peut s’accompagner de transformations morphologiques, physiologiques et biochimiques dont l’intensite depend de la plante.
L’influence de contraintes hydriques et salines a ete etudiee sur la photosynthese de 3 ecotypes locaux de mil soumis a 3 doses de sel et a 3 niveaux d’irrigation.
Les resultats ont montre que l’efficience photosynthetique du mil est meilleure en presence d’un leger manque d’eau ou en presence d’une salinite moderee et que seule une secheresse
severe ou un exces d’eau sont contraignants pour la photosynthese de cette plante.
Egalement, la photosynthese a presente une variabilite selon les ecotypes utilises.

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Leila Radhouane

Papers

Climate change impacts on North African countries and on some Tunisian economic sectors

La photosynthèse du mil ( Pennisetum glaucum (L.) R.Br.) en présence de contrainte hydrique et saline