In this article, we have highlighted the role of the gallery to improve the flow rate of foggara. The study based on observations and use of the latest inventory data (census 1998). The gallery of foggara can be divided into two parts: drainage and transport. The “drainage” part which is located inside the aquifer occupies 2/3 of the gallery of the foggara. The “transport” part of a length equal to 1/3 of the gallery of the foggara. Knowing the operating principle of the foggara, old methods of improving the flow of foggara were proposed. These included extension of the drainage part of the gallery, strengthening the base of the sealing of the transport part of the gallery, the realization of a small foggara and digging wells downstream of the main foggara.
Can we abandon traditional irrigation to the detriment of modern irrigation in the oasis of Ouakda? This is the question we pose in this study. Indeed, based on three missions carried out in the oasis of Ouakda during the years 2013, 2015 and 2016, we made visits and investigations to ancestral works as well as surveys of the local population. The results indicate that the Ksourian population irrigated the gardens and the palm grove by surface and underground water. Two ancestral dams made on the Bechar River for irrigation the gardens of the lower part. On the other hand, the foggaras irrigated the upper part of the palm grove. Today, new land has been built on the upper part of the palm grove. Thanks to new hydraulic techniques such as drilling and motor pumps, modern agriculture has developed on the other side of the palm grove to the detriment of oasis agriculture.
Boualem Remini, Djllali Bensafia and Tahar Nasroun
In this article, we discussed the effect of sediment transport in the Chellif catchment on the silting of Boughezoul reservoir. Since 1934, when the impoundment of the dam, nine bathymetric surveys were carried out by hydraulic services. Based on the last two bathymetric surveys (1986 and 2005), we assessed the average annual rate of silting 0.67 million m3·year−1. Is a filling rate of 70% of the total capacity of the reservoir in 2011. Storage capacity has decreased from 55 million m3 in 1934 to 15 million m3 in 2011. Concentrations exceeding 300 g·l−1, recorded in the river upstream of Boughezoul reservoir, caused formation of density currents.
In this article, we studied, for the first time, the foggaras of Saoura. Five missions were carried out in the oases of Kerzaz, Lahmar, Boukais, Beni Ounif, Ouakda, and Beni Abbes during the years 2009, 2010, 2011, 2012 and 2013. The first results showed that there was a difference between the foggaras of Touat and those of Saoura. The galleries of Saoura are much shorter than those of Touat and Gourara. On the contrary, the distribution of water from the Touat and Gourara foggaras is carried out per unit volume, whereas from the Saoura foggaras per unit time. The foggaras we visited are practically in a degraded condition. The contribution of modern technology (pumps and wells) in the oases of Saoura is the principal cause of the decline of the hydraulic system millennium.
The M’zab valley is a hyper arid region of average rainfall not exceeding 100 mm per year. However, the rare floods that occur in M’zab River drain large volumes of surface water. Thanks to the genius of the local population, traditional dams were made for artificial recharge of groundwater. Grace of traditional wells drilled in the valley, farmers irrigate their palm groves and gardens. However, since more than half a century, the contribution of deep drilling for the exploitation of the aquifer of the Continental Intercalary posed environmental problems. On the basis of investigations and surveys of the local population during the years 2010, 2011, 2012 and 2013, it appears that these modern techniques in water catchment caused harmful consequences to the region like the rising of water consumption, pollution of groundwater and soil salinity. Solutions and recommendations are outlined in this article.
Abdelkader Hadidi, Boualem Remini and Mohamed Habi
This article discusses the various water harvesting techniques used in the oases of Boussemghoun, Moghrar and Tiout for more than nine centuries. Several hydrological assessments have been conducted in the three oases since 2002 including surveys and investigations with the local communities. The results obtained showed that after the decrease in discharge of the sources, the population had resources to various ancestral hydraulic infrastructures such as: well, foggara, and small dams (Essad). The water harvesting technique is specific to the region and depends on the hydrogeology and the topography. Traditional low-flow water-saving technologies preserve the environment, modern hydraulic techniques give more water but have a negative impact on the environment. The drying up of springs and lowering of water tables are the result of the population growing and the socio-economic development. They require more and more water. A compromise between traditional and modern techniques (or types of management) can solve this problem.
Hamid Bouchelkia, Fadila Belarbi and Boualem Remini
The sediment transport in rivers in Algeria is very high. However, it is poorly quantified in some wadis because of the absence and the shortage of data especially the concentration of fine particles and also the unavailability of gauging stations. To fill this gap, a technique for estimating sediment yield, based on data recorded at the gauging station has been developed. The estimation of suspended sediment yield was conducted by a statistical analysis with double correlation on average daily flow and solid concentrations. The results obtained by applying this model to the watershed Chellif are very encouraging because the correlation coefficients of the found models are between 61% and 91% for the first correlation and between 86% and 97% for the second correlation. The estimated quantity of suspended sediment load is between 2.35 and 4.12 million tonnes per year, it appears important; This is due to the vulnerability of the Chellif basin facing erosion, the importance of its area and the importance of fluid flows in wadi Cheliff and its torrential regime. Mention here some of the results and their significance to the study.
This article deals with the subject of the Ghouts; an old hydro agricultural system of origin of the valley of Souf which, today is in distress. Hundreds of Ghouts were flooded by the waters of the lift and backfilled. Work missions were carried out in the oases of Souf during the period 2007-2017 to try to understand the decline of this heritage. Unfortunately, it is the waters from the Albian aquifer of the Continental Intercalary and the sanitation that is the main cause of the decline of the Souf Ghouts.
This article discusses the traditional irrigation system in the oases of Touat, Gourara and Tidikelt. Since centuries, farmers use the system of foggaras for irrigation of palm groves and gardens.
The results obtained following the inquiries and investigations carried out on the sites of foggaras, showed that since the eighties, drilling works multiplied in the oases of Touat, Gourara and Tidikelt. However, despite the application of these new techniques of water catchment, farmers still irrigate their gardens by traditional methods. For social, economic and environmental problems, foggaras degrade more and more; 50% of the foggaras decayed. Currently, the discharge of foggaras in service greatly diminished. The adoption of modern catchment techniques entails to the lowering of the water table.
Remini Boualem, Bensafia Djillali and Missoum Mohamed
The Foum El Gherza Reservoir fails to satisfy the irrigation of 300,000 palms of Sidi Okba and Seriana due to advanced siltation. Based on data from bathymetric surveys conducted by the National Agency for Dams, the siltation rate was estimated at 0.9 million m3/year. With a total capacity of 47 million of m3, the Foum El Gherza dam is silted up with more than 65 million m3. In this case, the life of the dam will not exceed 11 years of operation. The total silting of the reservoir will occur in 2023. Desilting the dam proves an emergency to save the palms of Seriana and Sidi Okba.