http://depot.umc.edu.dz/handle/123456789/7070 2026-10-28T18:33:43Z http://depot.umc.edu.dz/handle/123456789/14865 Les Ziban : durabilité des effets des aménagements hydrauliques et atténuation des risques d’inondation et de sècheresse. Maou, Zakarya; Bougherara, Ahmed The Ziban, located in the extreme North-east of the Sahara in an arid climate (rainfall below 150 mm/year), benefit from the waters of the Septentrional Sahara Aquifer System (SASS) and surface run-off from the southern flank of the Saharan Atlas (Oued Labiod, Abdi, El-Hai, Larab and Oued Djedi). This situation provides them with significant and diversified water resources (groundwater and surface water), which have given rise to a number of Oases that have shown unrivalled agricultural dynamism in recent decades. Today, however, surface water only accounts for 7 % (82 Hm3 /year) of mobilized water resources. Nevertheless, their inflow has ensured the recharging of aquifers, particularly groundwater tables, which has supplied and continues to supply the city of Biskra with drinking water. Groundwater resources account for 98 % (1124, 24 Hm3/year) of mobilized water resources. Today, the rate of abstraction imposed by the expansion of developed areas (1040 ha/year) has led to a significant reduction in water levels and a deterioration in the quality of the resource. In this context, the impact of man’s action can aggravate the imbalance or mitigate the contradictions and promote the resilience of a rapidly developing region. In addition, the Foum El Gherza dam, 80 % silted up, no longer ensures flood control, hence the reappearance, after decades, of the risk of flooding in its downstream section (towns and agriculture). However, the impoundment of the fountain of the Gazelles and Bouzina dams (2000 and 2021) has dried up the Oueds El-Hai and Abdi, which were responsible for recharging the groundwater downstream. However, the planned underground dam (Ouled Djellal) remains the most suitable for hydro-morphological conditions and is perfectly suited to the harsh conditions of arid zones. To support the current pace of development, it has become inevitable to connect the Ziban to other regional sources. To this end, two water transfer projects have been adopted, a supply from the Albien at Touggourt and a drinking water supply from the Beni Haroun transfer system (Koudiet Medaouar dam). This strategy can only guarantee the resilience of the Ziban region. 2024-11-18T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14854 المجال الشبه الحضري بين التمدد العمراني والاستغلال الزراعي في المناطق الجبلية عبدي, نضال; بولحواش, علاوة The present study focused on the analysis and then the measurement of some of the environmental impacts associated with the phenomenon of urban expansion to the detriment of semi-urban agricultural areas and mountainous areas near major Algerian cities. Because of the increasing migration of the population to the outskirts of cities and their settlement in them since the early eighties. This has further accelerated the change in the morphological shape of cities and the areas around them due to the phenomenon of urban expansion, which depends on the random (unplanned) model and affects the environmental and climatic level at the national and international levels. Historical, descriptive, analytical and quantitative methods have been used in the temporal and spatial monitoring of the population and land cover and land use patterns in these semiurban areas. Therefore, the wilaya of Constantine and its semi-urban area, composed of four subordinate municipalities (El Khroub, Hamma, Bouziane, Ain Smara and Didouche Mourad), were chosen as the geographical area for the application of this study, which covered the period between 1984 and 2020. A questionnaire was distributed to a sample of 50 farmers throughout the state, and field interviews were conducted with 25 representatives of local and state administrative authorities. The study has led to a series of results, the most important of which are the following: the first reason for the appearance of the negative environmental impact in the semi-urban area is temporary administrative practices that do not allow the environment to be affected by the environment. The study resulted in a series of results, the most important of which is that there is a notable change in the area of agricultural land occupation and use for semi-urban areas in mountainous areas of 29.70%. There is a significant difference in the distribution of values of the studied botanical indicators NDVI, MNDWI, NDBI and EVI from year to year, as most of them tend to change. An increase in the temperature of the earth's surface in the semi-urban area of Constantinople by 05°C in the last thirty-six years alone. Finally, the study recommends the need for a serious implementation of a policy of environmental awareness, the use of modern technologies and the activation of dissuasive laws to reduce the phenomenon of expansion to the detriment of semi-urban land, which will continue to intensify and affect the environment in the future (horizon 2040). 2025-07-02T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14826 Le gisement de fer de Boukhadra (confins-Algérotunisiens) Ait Abdelouahab, Djaouza; Bouzenoune, Azzedine The Boukhadra massif belongs to the north-eastern part of the Saharan Atlas and to the mining district of the diapirs zone. It is a NE-SW orientated anticline characterised by formations of Lower Cretaceous age, cut in its SW part by a NW-SE orientated collapse trough in which Triassic evaporitic formations appear. These played an important role in the structuring of the region and in the emplacement of the Pb-Zn-Fe-Ba mineralisation found there. This work focuses on the carbonated (siderite) and oxidised iron mineralisation at Boukhadra, with the aim of describing and interpreting this type of mineralisation hosted in the Clansayesian limestones. Sedimentologically, the Boukhadra region resembles a barrier platform represented by a standard sequence of 9 microfacies indicating the passage from a frank marine environment (MF1) to a pre-barrier environment (MF2, MF3 and MF4), a barrier (MF5), a back barrier (MF6), then a lagoonal area (MF7) and finally a supratidal zone (MF8) capped by a pre-evaporitic sebkha-type environment (MF9), over an area limited in time and space. Most of the iron mineralisation occurs in the lagoonal facies with miliolae and rudists and in contact with Triassic evaporites, while small quantities of Pb-Zn mineralisation occur after the iron mineralisation and are found in the N-S fractures. The stable isotope geochemistry (C-O-S) carried out on the surrounding limestones, siderites and Triassic sulphates, as well as on a few sulphides, enabled us to define the conditions of deposition, namely that the carbon in the siderites is of mineral origin and that the sulphur originated in the evaporite formations of the Triassic by bacterial or thermochemical reduction. The results obtained at Jebel Boukhadras are comparable with those of the deposits in the diapir zone, both mineralogically and geochemically. These mineralizations are attributed to hydrothermal solutions that may have circulated through faults that acted as drains and favoured locations for Triassic extrusions. These diapiric formations and the Jurassic and Cretaceous cover could also be the source of the iron and lead-zinc elements that gave rise to the deposition of siderite by metasomatosis and the polymetallic veins. The post-Cretaceous periods saw the alteration of both the iron carbonates and the polymetallic veins, thus creating the oxidised mineralisation of the Pliocene period. 2023-11-28T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14822 L’hydrosytème du haut Rhumel à Hammam Grouz dans son cadre régional (hautes plaines du SW Constantinois) Mihoubi, Naouel; Mebarki, Azzedine This research focuses on the Upper Rhumel basin (1130 km2), controlled by the Hammam Grouz dam at Oued Athménia (Constantinois region in eastern Algeria). This basin of the semi-arid High Plains contains three main hydrogeological formations whose lithological and hydrodynamic conditions are varied: the surface layer of the mio-plio-quaternary, the aquifer of the Eocene and the aquifer of the Cretaceous. The cartography from the piezometric measurement campaigns showed a general drainage of the underground system towards the Oued Rhumel and two main directions of flow South West-North East and North East-South West respectively characterizing a convergent layer in the centre and divergent in the extreme West. Chemistry, the study of quality and the ACP have made it possible to highlight a high probability of mixing water and therefore a relationship between the surface aquifer and the deep aquifère (karstic). The Djebel Grouz massif, the site of the dam dyke, contains karst formations that cause remarkable leakage flows to the springs, partly thermal (Hammam Grouz springs), which emerge immediately downstream from the dam. The hydrological functioning of the dam (capacity: 45 hm3), is studied through the monthly and daily regulation balance data of the period 1987-2015, provided by the ANBT (National Agency of Dams and Transfers). These sets of information have made it possible to assess the significant water supply deficit of the basin, resulting in a low rate of annual regulation (30% on average). The variability of the rains and reserves of the Hammam Grouz dam was assessed using the wavelet consistency analysis which showed a correlation between the two signals exceeding 50% (and below 70%) on all modes of variability. Two major events linked to the exceptional rainy inputs of the hydrological years 2002/2003 and 2014/2015 marked the functioning of the system resulting in large volumes of water leakage, hence the appearance of large sinkholes (vortex) within the reservoir. The leakage volumes are estimated on the basis of measurements of the flows from the sources on the one hand, and the abnormal removal of water reserves from the dam on the other hand. The results of the three consecutive years of comparative analysis (2002/2003, 2003/2004 and 2004/2005) of the inputs (or ""tributary"") to the dam with those measured at the gauging station, located upstream, updated the leakage volumes to 7.04 hm3, 32.2 hm3 and 26.2 hm3 respectively. These results show that the leakage rates are much higher than those measured by the ANRH (National Agency for Hydraulic Resources) at the sources of the Hammam, emerging at the bottom of the dyke. Complementary tools and approaches have been implemented for the understanding of the phenomenon of leaks affecting Hammam Grouz: electrical imaging (geoelectric tomography, seismic reflection and seismic refraction), the log of reconnaissance drilling carried out in the dam site, the interpretation of fracturing maps and multivariate analysis of the degree of fracturing of RQD rock. They have made it possible to identify the fracturing-karstification-leakage link of the dam (sources) following the discovery of a fairly dense and complex fracturing network (large faults, corridors, beams, tectonic nodes, etc.), Despite the solutions recommended to preserve the tightness of the basin (injection veil, clogging of vortex), the problem of destocking the Hammam Grouz dam is far from being mastered. It reflects the complexity of setting up hydraulic developments in Constantine karst context. 2023-12-03T00:00:00Z