Project Overview
It is a natural lagoon located North-East of Tunisia on the Mediterranean coast. It is the only remnant of the former Gulf of Utica. The direct impact of all this is the increase of the speed of the coastal erosion, as the main sources of sand to the coast are closed. The average coastal erosion rate is between 5 and 20 m per year, according to the different places. There is no more link between the Medjerda River and the lagoon. The catchment linked to the lagoon is very limited as it is surrounded by some hilly terrain. Thus only some very small tributaries are coming from the West, mainly filled by the waste waters of small agricultural areas and villages (Kalaat al Andalous, Bajou), with no measurable discharge. And the North side is very steep with no river, but the waste waters of the city of Ghar el Melh directly reach the lagoon, with no treatment.
Ecosystem Services
Provisioning
- Provisioning Services are ecosystem services that describe the material or energy outputs from ecosystems. They include food, water and other resources.
- Fresh water: Ecosystems play a vital role in the global hydrological cycle, as they regulate the flow and purification of water. Vegetation and forests influence the quantity of water available locally.
Regulating
- Regulating Services are the services that ecosystems provide by acting as regulators eg. regulating the quality of air and soil or by providing flood and disease control.
- Erosion prevention and maintenance of soil fertility: Soil erosion is a key factor in the process of land degradation and desertification. Vegetation cover provides a vital regulating service by preventing soil erosion. Soil fertility is essential for plant growth and agriculture and well functioning ecosystems supply the soil with nutrients required to support plant growth.
Habitat / Supporting
- Ecosystem services "that are necessary for the production of all other ecosystem services". These include services such as nutrient recycling, primary production and soil formation.
Cultural
- Cultural Services corresponds nonmaterial benefits people obtain from ecosystems through spiritual enrichment, cognitive development, reflection, recreation, and aesthetic experiences.
Major Issues
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No issues provided.
EH Engineering Solutions
As there are no significant surface water
As there are no significant surface water inputs to the GML, hydrological processes are mainly driven by the links between the sea and the lagoon waters, while little is known about the possible influence of groundwater in the nearby agricultural area to the West and Southwest, which are very flat areas (former Medjerda alluvial plain). The main source of pollution is the city of Ghar el Melh and few waste water small channels to the West, while agriculture activities bring some diffuse pollution along the northern and western shores of the lagoon.
* Quantification of the hydrological processes at
* Quantification of the hydrological processes at lagoon and watersheds scale, mapping the risk impacts and territorial solutions * Identification of potential areas for enhancement of ecosystem sustainability (dunes, waste waters and soil/water productivity) * Managing biota to control hydrological and biogeochemical processes (ecological engineering)
Two dedicated solutions : (1) Pilot site
Two dedicated solutions : (1) Pilot site for domestic waste water natural cleaning through constructed planted biofilters, with soil biodiversity enhancement, and REUSE for sustainable soil and water productivity (vegetable agriculture and fisheries). (2) Set-up of dune-fences on the sandy lagoon barrier to restore natural ecosystem services of the sand dunes, to stabilize and restore the foreshore, and the coastal aquifer and mitigate the sea level rise impact on coastal areas and human l.
Project Activities
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* Manage point sources of water pollution by constructed planted biofilters for agricultural production and the protection of soils and aquifers
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* Develop riverbeds to protect the lagoon from sedimentary pollution
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* Rehabilitation and stabilization of the coastal dunes by the Nature Based Solutions, the windbreakers, in order to stop the severe erosion and the lagoon ecosystems and to maintain and protect the socio-economic activities, tourism, fishery, agriculture.
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* Control the quality of the waters of the lagoon to maintain an effective natural biodiversity and keep high quality fishing
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* Maintain and enhance the “Ramli” agricultural practice through agroecological approach
Expected Outcomes
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