No abstract

The reuse of treated wastewater can reduce the water deficit in Saharan areas, especially in Ghardaia. The M'Zab wastewater treatment plant (WWTP) is designed to treat wastewater by the natural lagoon system, and to reuse the treated water for irrigation of agricultural perimeters in order to contribute to sustainable development efforts in the region. Indeed the present work aims to search for the study of the possibility of reusing treated wastewater of M 'Zab in irrigation, to do this, we established and followed the evolution of the various physical-chemical and bacteriological analysis for two years (2013-2015), to study the effectiveness of biological treatment in the reduction of wastewater pollution, and then compare the results of treated water with national and international standards in the field of 'irrigation. The results showed that the treated water is considered as poor quality water is not usable only for some salt-tolerant species and on well-drained soil and leached, require additional treatments for ensured the quality of this precious resource.

This modest chapter deals more particularly with the reliability and the problems of the different processes used at the level of several treatment plants installed in the Algerian Sahara with the aim of eliminating the nuisances and the risks of contamination in the urbanized areas, protecting the receiving environment and water resources, the possibility of reusing treated effluents for irrigation. Through an evaluation of the performance of these stations after years of operation which confronted with climates such as the high temperature and evaporation and the impact of the sand winds on the efficiency of the basin, technical and anthropic problems such as the salinity and mismanagement of the waters on the other hand.

Natural risks, particularly flood risk, are a topical subject in Algeria and throughout the world, particularly given the last major catastrophic floods in Sudan (2020) and North Africa. With the development of the climate change phenomenon in the world, risk management is becoming increasingly necessary for all the actors concerned (decision-makers, technicians, and the population) to identify protection issues. In 2018, in the extreme south of Algeria, In-Guezzam City suffered a devastating flood that caused significant damage and loss of human and material resources. More than 100 homes collapsed, and approximately 345 families were displaced. Currently, there is no research work to assess the hydrological situation and the risk of flooding in this region. Therefore, the main purpose of this study is to shed light on the risk of flash floods in the extreme south of Algeria with more specific attention to the August 2018 floods as well as the climate trends over the past 30 years using Mann–Kendall test and Sen’s Slope Estimator. The chosen approach involves a hydrological study and hydrodynamic modeling using HEC-RAS software. This latter allows for simulating floods using statistical methods and creating several regional flood hazard maps.

Many populations of isolated and rural areas around the world are facing major problems of water deficit in domestic needs, irrigation and grazing and remains the daily concern of the inhabitants and which are particularly accentuated in the arid and desert areas. In this context, several researchers have recently oriented their research to the solar system. This energy is clean and nonpolluting and its use provides an inexhaustible source of energy. Photovoltaic pumping is one of the applications of solar energy in remote sites where conventional electricity is absent, such as the Algerian Sahara, which has one of the highest solar deposits in the world which can exceed yearly 2263 kWh/m2. This solution represents the ideal technical method for supplying water from wells of groundwater. The main purpose of this work is to evaluate the reliability of solar pumping systems compared to a conventional power system applied to two experimental wells installed in an isolated pastoral region in the Algerian Sahara and precisely in the Ouargla region.The results showed that the generator pumping technique appears to be the least expensive at the beginning of the operation. The balance becomes clearly in favor of the solar pumping solution after a few years of operation (about 5 years), with a 50% benefit in the cost per cubic meter of water.