Beneficiaries: 10 regional offices, 500 professionals
We held several seminars to train on hydraulic problems of the region, saline intrusion phenomenon and critical hydraulic existing constructions.The programme addressed main technical and institutional subjects in the field, to let them be aware of actual problems as well as potentials of hydraulic structures.
Last ones stand as a main feature in development of the region for food and environmental protection reasons. Due to this rare phenomenon of saline intrusion, thousands of hectares of rice fields disappeared indeed, resulting in serious problems for communities based on agriculture, falling in poverty as an effect of the absence of cultivars and forced to buy imported rice.
We discussed and analyzed different works before to find right acting strategies .
Hereby you have an extract from the seminar aimed to better understand the problem. “Projects above detailed, even though their different years of realization, gather their features in an all-incuding one, passing through several changings along time and due to direct local experiencies, in order to loglast and finally becoming as most as efficient as possible. Most of times those buildings are no higher than few metres, according to tide abundance, levels and morphology of the valley. Some cases have been realized avoiding the complete closure of water flow, in order not to alterate the hydrological equilibrium, even if this process, such as for the Tanaf-Baghere bridge, showed an unappropriate quality on solving matters such as soil salinity and water contamination. Implementation of a Dam, interrupted from a free passage that allows the hydraulic exchange, is no longer the right answer, seen the lack of existing permant rivers all along the building area. Those areas consist, most of times, in stretches with superficial points below sea level and affected by several floods. In other cases the absence of incline and the altitude makes the area unable to contain increasing tides. Building real dams and close the valley, preventing tides from pouring salt, is the most efficient plan. Saline intrusion problem’s then fixed, even if the valley still needs to be cleaned form collected salt over years, more, to prevent also from unpredictable floods, it is necessary to build a draining mechanism. This consists in a manual working structure, except for bigger ones financially held from the country, managed by population and thanks to its experience on agriculture.
A pond is created upriver, collecting water and melting acids and salt deposits stored during rainy season. At the end of it, starting with farming one, clean water will wash the valley by simply and manually opening proper breaches. Exeperience often gave the right evaluation to succeed in such a work, as well as many changings have been apported to those breaches, in order to have a bigger or a minor washing efficiency of the valley operated by the hydraulic downflow. It naturally must have place depending on low tides level, easily determined by lunar cycle.”