Comparison Of Two Hydrological Models (Lumped And Distributed) Over A Pilot Area Of The Issen Watershed In The Souss Basin, Morocco

The present study aims to develop a hydrological model of flood forecasting to arid environment in the Issen basin (sub-chatchement of Aguenza basin) through a comparison between two conceptual hydrological models (HEC HMS) and ATHYS which is a conceptual distributed model rarely used in the Moroccan context. The aim is to measure the degree of adaptability of these models to the study area in order to generalize the selected model to the entire watershed. The obtained results from the validation phase of the two models were satisfactory, the two models were able to reproduce the hydrological behavior of the Aguenza watershed during flooding periods. Besides, this study has shown that a good distributed model can provide improvements over a global model for flood forecasting and particularly in terms of volume as in the present study case

ESTIMATE OF THE METALLIC CONTAMINATION OF THE URBAN EFFLUENTS BY THE EFFLUENTS OF THE MOHAMED V HOSPITAL OF MEKNES

The Mohamed V hospital of Meknes is one of the most important establishments for public health in the entire region of Meknes-Tafilalet; it is also one of the biggest sanitary structures of Morocco. According to the classification of the American Hospital Association (American Hospital Association [AHA], 1986) based on the number of active beds, this hospital belongs to class 7, with a real bed capacity of 531 beds among which 416 are functional, hence this has led to the importance of the study of the impacts of its effluents on the environment. Wastewaters of this hospital contain pollutions of microbiological, chemical, organic, mineral and metallic nature. They are rejected in the sewer system of the city without any preliminary treatment and has a loosened open-air at the level of Aïn Choubbik district where they are reused by the local residents for the irrigation of truck farm, cereal and tree-dwelling farm. Moreover, the major part of these wastewaters is poured into Bourouh river, in particular during pluvial period. Consequently, we may note direct harmful impacts on the health of Man as well as on the environment with its diverse compartments, water (Surface Water and subsoil water), ground and air. Thus, we will try using this present study to evaluate the pollution rate by elements in state of trace, taking a case of heavy metals effluents of the Mohamed V hospital of Meknes and the consequences it could have on the environment and as well as the proposed solutions. So, we are also going to estimate the pollution rate by these elements at the levels of urban wastewaters of the Ain Choubbik district receptacles of the hospital effluents

ETUDE DU RÉGIME HYDROLOGIQUE DU FLEUVE INAOUÈNE, MAROC SEPTENTRIONAL

The analysis of the Inaouene river hydrologic behavior has shown a mediterranean typical regime, characterized by the abundance of rain with high winter flow rates, therefore, heavy flooding, and on the other hand, by a strong dry season, thus, low flow. The annual module, as well as the different coefficients, highlights the hydroclimatic fluctuations, in relationship with a semi-arid climate. The hydrological balance highlighted the importance of water volumes routed upstream and downstream, confirming the morphometric parameters of the basin and the lithologic nature which involves two major different units (formations essentially karstic carbonate in the Middle Atlas at the Southern part of the basin and, a marly impermeable substratum in the Prerif; northern part of the basin). The frequency study of extreme high flow rates showed that they are not governed by a specific law

Etude De La Contamination Par Les Métaux Lourds Des Eaux Et Des Sédiments Au Voisinage De La Mine De Tighza (Maroc Central Oriental)

The analyses performed on four stations upstream and eight downstream of the Tighzamine (Jebel Aouam) were carried out to assess the contamination degree from tailings discharges. From the standpoint of water and soil qualities, concentrations of trace and major elements (TME), including Cd, Mn, Pb and Zn which concentrations (µgL-1 ) reach respectively 82, 49918, 669, 36858 in water samples and 443, 161, 23607, 19459 in sediments, exceed greatly, in the vicinity of the mine, the international standards. Depending on the TME analyzes, all downstream stations shows different degrees of contamination, whereas it is less or absent at the upstream stations. Downstream stations thus require water and soil treatment, since the contents TME are quite large and clearly present a danger not only in the surrounding environment for population, fauna and flora, but also over long distances especially as the waters of Tighza river flow into the oued Bouregreg and thus reach the Sidi Mohammed ben Abdellah Dam (Rabat) which is used as drinking water for urban consumption. It is therefore imperative to treat these waters, so that they become drinkable and avoid bad impacts to the population

EFFET DE L’ÉPURATION PAR ÉLECTROCOAGULATION SUR LA POLLUTION DES EFFLUENTS DE L’HÔPITAL MOHAMED V DE MEKNÈS

The effluents of the Mohamed V hospital of Meknes include strong polluting factors harmful to environment and to human health, notably important bacterial load. This hospital has not a pretreatment station so it rejects its effluents in the urban sewer system without any preliminary treatment. The urban effluents are cleared open air at the level of the Aïn Choubbik district and poured into Bourouh river notably during pluvial period; consequently they cause a physicochemical and biological deterioration of the aquatic ecosystem. To reduce their negative impacts, several treatment techniques are operated. The chemical coagulation and the biological treatments are techniques used particularly for the treatment of various types of effluents. Their inconveniences it is because they cause an acidification of treated water and a production of important quantities of muck. The electrocoagulation is a very interesting alternative to these techniques. The present job registers as part of research works which have as objective to study the effects of this technique on wastewaters of the Mohamed V hospital of Meknes. This is the way how we studied experimentally the treatment of the hospital effluents by the means of the electrocoagulation by using iron electrodes. To determine the optimal conditions of treatment of these effluents, we made several experiments by varying every time the intensity of current and time of retention. The obtained rates of reduction are very important, they reached 79,21 % for COD, 93,76 for suspended matter and 97,33 % for the fecal coliformes

INTEGRATION OF GIS AND HEC-RAS IN FLOODS MODELING OF THE OUERGHA RIVER, NORTHERN MOROCCO

In recent years, hydrological hazards continue to worsen due to climate changes affecting the whole world. In Morocco, after a long period of severe drought that has ravaged the country since the eighties, the last years were exceptionally rainy. Records have been exceeded in terms of rainfall and flooding that affected many parts of the country. The Ouergha River, contributing with 50% of total water yield of the Sebou basin which is one of the most important watersheds in Northern Morocco, broke all records in 2009/2010 providing an exceptional amount of water of 7,4 109 m3. In this study, one-dimensional hydraulic modeling with HEC-RAS®, allowed to calculate the water flow profiles for some flood events that occurred downstream of Al Wahda dam. The exploitation of obtained results led to establish flood extension maps for each calculated profile, which made it possible to evaluate the management of the dam by the Sebou hydraulic Basin Agency. This type of results acquired from the hydraulic simulation and geographic information system, can significantly contribute in flood management interventions against overflows that persist despite the existence of a large dam (Al Wahda), because of extreme climatic and hydrologic events observed in recent years

Hydrological and hydroclimatic regimes in the Ouergha watershed

This work consists in studying the hydrological and hydroclimatic regime of the Ouergha watershed and frequency analysis of extreme flows and extreme rainfall for peak estimation and return periods, in order to prevention and forecasting against risks (flood...). Hydrological regime analysis showed a regime of the rain type, characterized by rainfed abundance with very high winter flows, so strong floods. The annual module and the different coefficients show hydroclimatic fluctuations in relation to a semihumid climate. The water balance has highlighted the importance of the volumes of water conveyed upstream than downstream, thus confirming the morphometric parameters of watershed and the lithological nature. Frequency study of flows and extreme rainfall showed that these flows governed by dissymmetrical laws based on methods Gumbel, GEV, Gamma and Log Pearson III

Impacts of natural conditions and anthropogenic activities on groundwater quality in Tebessa plain, Algeria

The “Merdja” is the shallow aquifer of Tebessa plain, located in the northeast of Algeria. The climate is typical of semi-arid steppes, where extensive agro-pastoral activities are dominating. It is still the main water resource used by major sectors. Due to its proximity to the City, it is vulnerable to pollution. According to earlier studies, this aquifer undergoes seasonal water quality fluctuations (between wet and dry seasons), induced mainly through anthropogenic activities. The study is utmost important, as it tracks the groundwater quality and aims to gain an understanding of how the local and natural conditions influence this resource at temporal (interannual) and spatial scales, by following up the evolution trend of hydrochemical parameters of the “Merdja” aquifer. Seventy-one groundwater samples were collected and analyzed from drinking/irrigation wells, through four field measurement campaigns (2001, 2006, 2009, and 2010). The results obtained confirm the fact of water pollution. Point-sources of pollution with nitrate and salinity are revealed on the respective maps of these parameters, especially downstream at the nearby areas of Tebessa City. Non-point sources of groundwater pollution are also manifested. The Piper diagram reveals a relative stability of water type and that rainfall plays a role in the natural remediation, by taking part in the aquifer recharge. The ionic ratios and the principal components analysis highlight that the temporal change of groundwater quality results respectively from: (i) ionic exchange process and the dissolution of evaporites; (ii) the sources of nitrate in groundwater remain the excess application of inorganic nitrogenous fertilizers, organic manures, and wastewater effluents. Keywords: Tebessa plain, Hydrochemistry, Groundwater pollution, Natural remediation, Salinit

Assessment and mapping of water erosion by the integration of the Gavrilovic “EPM” model in the Inaouene watershed, Morocco

Water erosion is one of the main causes of soil degradation around the world. In M orocco, In M orocco, the watersheds have very significant soil wastes, related to various physical and anthropic factors. The Oued Inaouene watershed is concerned because of its location in the eastern part of the Saïss basin, between the Middle Atlas and the Pre-Rif, where water erosion is more accentuated. This basin covers a total area of 3597.13 Km2 and it is marked by a semi-arid climate with relatively abundant (989.68 mm), irregular rainfall and strong anthropic pressure. This will have an impact of overexploiting natural resources in general and soils in particular. The excessive use of agricultural land has led to their fragility and aggravation of their susceptibility to erosion. These conditions, both natural and anthropic, have induced a rather intense erosive dynamic, which can be visible in its various forms, including gullying and landslides. The erosive dynamics leads progressively and certainly to impoverish the soils of the watershed and the silting of the dam Idris 1st located downstream of the Oued Inaouene, hence the interest of this study. The use of the “EPM” model for the estimation of soil losses approaches the severity of the erosive phenomenon. The average soil loss due to water erosion according to the model used is estimated at 53.34 t/ha/year. The maximum losses are about 597.642 t/ha/yr per plot. Total annual losses for the watershed are approximately 211084195 t/yr. Furthermore, the analysis of these results allowed, with the help of GIS, to determine the factors that control water erosion and which are, in order of importance: rainfall, slope, and soil sensitivity Soil protection. If anti-erosion measures aren’t adopted in the threatened parts of the watershed, this will have serious consequences for the dam and water quality

Assessment of Inaouene River Pollution for Potable Water Supply, Northern Morocco

Under hydrological uncertainty and to secure the potable water supply for the Fez city with more than one million and a half inhabitants, the competent authority intends to bring water from the Idriss 1 st reservoir 30 km away, downstream the Inaouene watershed. The pollution risks as well as the contamination degree of surface water and sediments were assessed by monitoring the physicochemical characteristics of the water and sediment samples. The results revealed high values of chemical oxygen demand and chloride mainly linked to the uncontrolled liquid discharges. Calcium and magnesium showed also high concentrations that are due to the watershed geology, where carbonate rocks are dominant. The contents of some heavy metals remain relatively low and within the Moroccan standards. The metal contents in sediments show a low degree of the anthropogenic pollution. This led to conclude that the waters and sediments in the study area show relatively degraded quality and then could be used for water supply under continuous control