M. MOKHTARI Elhadj

Etude de sensibilité de l’érosion hydrique et des zones à risques d’inondations aux pluies extrêmes dans les bassins versants (K’sob) Hodna/(Boussellam) Soummam

Elhadj Mokhtari, Belkacem Merzouk, Yasmine Haltali, Wafa Djeddi. Apport des SIG et de la télédétection dans le suivi et l’évaluation de la qualité physico-chimique des eaux de surface. Etude de cas : Barrage de Telesdit Wilaya de Bouira. 1er Séminaire National : Eau, Environnement et Energies renouvelables (SN3ER’24), 13 - 14 Octobre 2024, Université de M’Sila, Algérie.

Rainfall-Runoff relationship using HEC-HMS model for Boukerdane watersheds (North Algeria)

Modélisation et identification des zones vulnérables à l'érosion des sols dans le sous-bassin versant de l’oued Ksob en Algérie : Application du modèle EPM et du processus d'analyse hiérarchique AHP

Dans ce polycopié de cours, les étudiants seront initiés aux phénomènes hydrologiques et
leurs origines, ainsi qu'aux méthodes essentielles pour estimer et évaluer les paramètres
associés, tels que les précipitations, les débits des cours d'eau et les crues. À travers les
différents chapitres, nous explorerons les divers aspects de l'hydrologie.
Le premier chapitre traitera des bases de la probabilité et de la statistique, telles qu'elles
s'appliquent à l'hydrologie. Vous y découvrirez comment ces concepts sont utilisés pour
caractériser les événements hydrologiques et évaluer les risques associés.
Le deuxième chapitre se concentrera sur l'analyse statistique des précipitations. Vous
apprendrez à interpréter les données pluviométriques, à appréhender les distributions de
probabilité des précipitations, et à tirer des conclusions pour une meilleure compréhension
des phénomènes hydrologiques.
Le troisième chapitre explorera les différentes méthodes de mesure des débits des cours
d'eau. Vous découvrirez les principes fondamentaux du jaugeage, les techniques de mesure
sur le terrain, ainsi que l'utilisation d'instruments spécialisés pour évaluer les débits des cours
d'eau.
Enfin, le dernier chapitre examinera l'étude des débits des crues. Vous comprendrez les
mécanismes de formation des crues, les méthodes d'analyse des données hydrologiques en
période de crue.

This study aims to predict land use and land cover (LULC) changes for the years 2030 and 2050 using Markov models, and subsequently assess the impacts of these changes on water resources in the Wadi Soummam watershed, Algeria, employing the HEC–HMS model. The research compares five LULC maps (2005, 2015, 2020, 2030, and 2050) to identify variations over the years. The results indicate a notable increase in urbanization, accompanied by a reduction in agricultural and forested areas, leading to a decline in overall vegetation cover. Forests and grasslands experienced a consistent decrease between 2020 and 2050, while urban areas expanded. These LULC alterations have significant implications for the water resources in the study area. From 2030 to 2050, the average annual water yield witnessed an increase of 38.6 m3/s for the 10-year return period event and 70.8 m3/s for the 100-year return period event. Conversely, peak flows exhibited a decline for various return periods between 2005 and 2015, followed by an increase from 2015 to 2020 due to the impact of LULC changes. For instance, the peak flow for the 10-year return period in 2005 was 1651.1m3/s, which decreased to 1604.5 m3/s in 2015, but rose to 1632.8 m3/s in 2020.

Land degradation is a growing concern, exacerbated by recent climate change. Water erosion emerges as a crucial tool to address this issue. This study focuses on estimating soil loss from water erosion in the Boussellam valley watershed, a part of the ex-pansive Soummam basin in northeastern Algeria, characterized by a semi-humid to humid climate. Covering an expanse of 4,301 km2 with a perimeter of 420 Km, the basin's assessment incorporates often-overlooked factors such as temperature. Utilizing Geographic In-formation System (GIS) in conjunction with GAVRILOVIC's EPM (Erosion Potential Method) model, erosion projections for the year 2022 have been generated. The findings reveal that the entire Boussellam watershed experiences an average erosion rate of 8.50 tonnes per hectare annually. However, it is evident that the current protective measures implemented by decision-makers are suboptimal. To pinpoint the most vulnerable areas, GIS was employed to map and subsequently categorize them into five levels of erosion intensity: low, moderate, medium, high, and very high. These detailed maps will enable more precise and tailored interventions by decision-makers to effectively safeguard the regions most impacted by erosion.

Hydrological modeling is a critical and decisive technique for estimating hydrological processes and the availability of water resources. In our research, we used Hydrologic Modeling System (HEC-HMS), a 4.4 version, to achieve the affected goals, and a watershed in the east of Algeria, known as Rhumel Smedou watershed, was chosen as a case study which covers an area of 1,083 km2. A Geographic Information System (GIS) was used to analyze and process the Digital Elevation Model 30-meter resolution data accompanied with Landsat of Land Use Land Cover 10-meter resolution with accuracy to extract and deduce the basic inputs of the simulation model, which are: curve number (%), lag time (mn), impermeability (%), and rainfall (Ia) (mm). The research purpose is to compute runoff depth and volume rate for four extreme events. Two events are chosen for model calibration and two for model validation. The results of the statistical tests [NSE (%) RMSE_PBIAS (%)] proved the success and ability of the model to achieve the research objectives, and their averages were as follows: [82%_0.45_32.55%] for calibration phase, and [77%_ 0.45_30.95%] for validation phase. After calibrating and validating the effectiveness of the model, the volume and flow were predicted for different return periods (2y, 10y, 50y, and 100y).

his study employs adaptive deep learning (utilizing DNN and CNN approaches) to accurately predict soil erosion, a crucial aspect of sustainable soil resource management. The goal is to develop fuzzy logic models for erosion forecasting in a large watershed with limited in-puts, comparing them to predictions from the Revised Universal Soil Loss Equation (RUSLE). Integration of GIS enables analysis of satellite data, providing crucial details like land use, slope, rainfall distribution, and flow direction. This synergistic approach enhances erosion prediction capabilities and yields spatial erosion distributions. Producing precise erosion risk maps within GIS is crucial for prioritizing high-risk areas and implementing effective conservation methods in the Wadi Sahel watershed, Algeria. The assessment in the Oued Sahel-Soummam watershed involved overlaying five RUSLE factor maps using Arc GIS spatial analysis, resulting in an aver-age annual soil loss of 4.22 tons per hectare. The DNN and CNN models were integrated with GIS for detailed calculation of annual average soil loss (tons per hectare per year) and mapping erosion risk areas in Wadi Sahel-Soummam watershed. Using the CNN model, estimated annual soil loss in Sahel-Soummam wadi was about 4.00 tons per hectare per year, while the DNN model estimated around 4.13 tons per hectare per year. This study employed two deep learning models for erosion prediction, with the DNN model featuring six hidden layers performing no-tably better than the compared CNN model.

The lack of soil erosion data and other information about watersheds continues to limit soil erosion modeling. To overcome these limitations, many researchers have turned to machine learning models to analyze and model the complex water erosion processes and integrate them with empirical models. The Beni Haroun dam watershed faces soil erosion due to specific geo-environmental settings and land practices. It poses serious threats to agricultural and natural resource development. For these reasons, this study attempts to identify soil erosion susceptible zones using the Revised Universal Soil Loss Equation (RUSLE) using five key factors (rainfall erosivity, soil erodibility, topography, cover management and conservation practice factor) in GIS environment. Furthermore, we integrated the five RUSLE parameters and the model outputs into two machine learning (ML) algorithms, namely Random Forest (RF) and Random Tree (RT). The proposed models underwent training on 70% of the dataset and were subsequently validated on the remaining 30%. Our results indicated that the most vulnerable to severe soil erosion was concentrated in northwest regions, in contrast to the southeastern regions, which most occupy low erosion and moderate erosion. RUSLE and RT-based RUSLE models yielded nearly identical results in classifying erosion severity, estimating the annual average soil erosion at 17.5 and 17.69 (t ha–1y–1), respectively. In contrast, the Random Forest RF-based RUSLE model presented slightly divergent findings 23.89 (t ha–1y–1). Overall, these findings contribute to the identification of the area’s most vulnerable to soil erosion, providing valuable insights to inform land management and conservation strategies.

Effective disaster management heavily relies on accurate flood susceptibility mapping. The fuzzy analytic hierarchy process (FAHP) is adept at considering the imprecise nature of decision-making criteria. This study assesses FAHP's effectiveness in flood susceptibility mapping, comparing it with the conventional analytic hierarchy process (AHP). By using Geographic Information System-analyzed remotely sensed data, the research systematically evaluates flood risk southeast of Algiers. Various datasets, including Digital Elevation Model, slope, precipitation, and land use maps, were collected via remote sensing. A linear fuzzy membership function transformed the data into fuzzy values. AHP determined the importance of each dataset, with calculated weights multiplied by corresponding fuzzy values. Fuzzy analysis combined these characteristics into a five-category flood risk map, verified with Google Earth and satellite images. Results indicate a high potential for flood hazard mapping, categorizing 30% of frequently flooded regions as high risk. Maps reveal north basin areas are more flood prone due to excessive precipitation, and urban areas in floodplains are vulnerable. Receiver operating characteristic (ROC) curves and area under the ROC curve (AUC) assessments demonstrate AHP and FAHP's effectiveness. AUC values of 88.40 and 92% indicate that both models accurately predict flood-prone areas. FAHP excels, reducing subjectivity and ambiguity in human judgments.

This article presents a study on the daily reliability analysis of a full-scale activated sludge wastewater treatment plant
located in Northern Jordan. The coefficient of reliability (COR) is calculated to assess the performance of the plant in regard
of wastewater concentrations of COD, BOD5, and TSS. The results indicate that the global effluent performances for COD,
BOD5, and TSS comply with Jordanian standards. However, the BOD5 performance is found to be below the quality level
due to issues in the ventilation basin and exceeding treatment capacity, while the TSS performance is affected by problems
in the grit chamber and variations in influent quality and quantity. The study fills a research gap by focusing on the reliability
of wastewater treatment plants using activated sludge technology and utilizes a probabilistic model proposed by Niku et al.,
(1979) to evaluate the reliability. The findings provide valuable insights into the daily variability of the treatment plant and
suggest measures for improving reliability and overall efficiency

Water erosion in general is considered a natural danger that worsens with passing of years, and this is in the absence of human awareness and taking the necessary preventive measures to manage areas exposed to erosion. Most studies on water erosion have been subject to one framework, which is the evaluation of water erosion. This research contributed to the identification of soil erosion-prone areas in the sub-watershed of Boussellam and K’sob, Algeria, through the use of the Analytical Hierarchy Process (AHP), Fuzzy Boolean Modeling and the Modified Global Soil Loss Equation (RUSLE). A group of factors that affect soil erosion were used (Curvature, Slope, Aspect, Elevation, Rainfall Erosivity, Land use land cover, Drainage Density, K factor/Soil, Lithology, NDWI, Factor Ls, NDVI, Factor P, C Factor). Water erosion conditioning factors were integrated and erosion risk maps were extracted using the Geographic Information System. The study results, after using the RUSLE, fuzzy and AHP models, indicate areas with very high erosion risks occupied 12.91%, 12.98% and 9.49%, respectively, of the study area, and with the help of Receiver Operating Characteristics curves the risk maps were validated. Water erosion under the curve (AUC) and the results revealed that the models showed good predictive capabilities in determining soil erosion susceptibility zones with AUC values of 0.783, 0.806, and 0.644 for the AHP, fuzzy logic and RUSLE models, respectively. This study contributed to identifying the area’s most vulnerable to water erosion to help decision-makers to intervene quickly and take the essential strategies to reduce this problem in the research area.

Abstract

Contribution of remote sensing and GIS in the study of the evolution of the vegetation cover in the Soummam catchment in Northeast Algeria

In order to better manage and mitigate the effects of natural disasters, accurate flood susceptibility mapping is essential. In order to account for ambiguity and uncertainty in decision making, the Fuzzy Analytic Hierarchy Process (FAHP) and the Frequency Ratio (FR) model may be used in flood susceptibility mapping. The purpose of this research was to examine FAHP's usefulness in flood susceptibility mapping and to contrast it with the FR technique. This research presents a simple way to determine the likelihood of flooding in a section of Algiers's southwestern quadrant. Geograph-ic information systems (GIS) and remote sensing data are used in this methodology. A number of geospatial and remote sensing datasets were initially compiled for this study. These included a DEM, slope, precipitation, distance to major rivers, topographic moisture index (TWI), land use and land cover (LULC) maps, normalized difference vegetation index (NDVI), modified normalized water index (MNDWI), and drainage density. Finally, a flood risk map with five classes representing varying degrees of vulnerability to flooding was generated by integrating all the processed factors using the FAHP approach and the FR model. The final flood risk map's precision was calculated using both free Google Earth data and satellite images. Approximately 35% of the regions that experienced floods were found to have a very high or high risk of flooding based on the evaluation results. This study demonstrates the great promise of this method for producing reliable flood risk maps. The produced maps show areas of flood susceptibility, with high and very high susceptibility most prevalent in metropolitan areas along drainage networks and in the northern portions of the basin, which get more rainfall. After running both models and comparing the output maps to a map of recorded flood events, we calculated the area under the curve (AUC) and receiver operating characteristic (ROC) curves to assess the accuracy of each. With AUC values of 82.40% and 77.70%, respectively, the assessment findings showed that both the FAHP and FR models accurately identified flood-prone locations in the Cheliff-Ghrib basin. The FAHP model, on the other hand, is favored because of its efficacy in reducing the fuzziness and ambiguity of human assessments.

Modélisation et cartographie des risques d'érosion hydrique par l'utilisation de télédétection, SIG et le modèle EPM dans le sous bassin versant de l'K'sob (Algérie)

Evaluation et cartographie de l'érosion des sols dans le bassin versant de Oued Boussellam (Algérie) à l'aide du modèle erosion model potentiel méthode (EPM) et le SIG

Evaluation de l'érosion des sols à l'aide de SIG dans le bassin versant de l'oued Boussellam (ALGERIE)

Abstract

This study aimed to estimate the annual soil loss in the Boussellam watershed in the northeast of Algeria, using the Revised Universal Soil Loss Equation (RUSLE), geographic information system (GIS), and remote sensing. RUSLE model has been used for modeling the main factors involved in erosive phenomena. This basin is characterized by an altitude ranging from 189 m to 1757 m, with an average of 931 m and a slope ranging between 0 and 266 % with an average of 18 %. Results showed that the average erosivity factor R is 68 (MJ.mm/ha.h.an) with a maximum value of 140 (MJ.mm/ha.h.an). The soil erodibility factor K ranges from 0.04 to 0.21 with an average of 0.11 (t.h.ha)/(MJ.ha.mm). The LS topographic factor ranges from 0 to 216 with an average of 16. The mean P factor is estimated to be 0.77, and the average C factor is 0.076. The combination of the different maps of these parameters made it possible to deduce the erosion map from which, it appears that the phenomenon of erosion mainly affects the northern part of the basin with an average of 258 (t/ha/year) for July 2015.

The objective of this work is to study the evolution of soil erosion in the Boussellam watershed in the northeast of Algeria, using the Revised Universal Soil Loss Equation (RUSLE), geographic information system (GIS), and remote sensing. RUSLE model has been used for modeling the main factors involved in erosive phenomena. This basin covers an area of 4151 km² of elongated shape and low relief. It is characterized by an altitude ranging from 189 m to 1757 m, with an average of 931 m and a slope ranging between 0 and 266 % with an average of 18 %. Results showed that the average erosivity factor R is 68 (MJ.mm/ha.h.an) with a maximum value of 140 (MJ.mm/ha.h.an). The soil erodibility factor K ranges from 0.04 to 0.21 with an average of 0.11 (t.h.ha)/(MJ.ha.mm). The LS topographic factor ranges from 0 to 216 with an average of 16. The mean P factor is estimated to be 0.77, and the average C factor is 0.076. The combination of the different maps of these parameters made it possible to deduce the erosion map from which, it appears that the phenomenon of erosion mainly affects the northern part of the basin with an average of 258 (t/ha/year) for July 2015. These maps can be particularly useful in pinpointing potential areas of increased erosion risk underpinning targeted investigation and management action to support soil conservation for improved food and water security in this important watershed.

The current research examines the runoff response in the Bouhamdane watershed in Algeria using the soil and water assessment tool (SWAT). The SWAT model is applied for the Bouhamane watershed, which includes three sub-watersheds and 45 Hydraulic Response Units (HRUs). To assess the ability and effectiveness of the model, one-gauge
station in the basin (sabat) was chosen. Monthly discharge flow data are sourced from Algeria's National Water Resources Agency (NWRA). The soil and water assessment tool calibration uncertainty programs (SWAT-CUPs) with the sequential uncertainty fitting (SUFI
2) algorithm were used to calibrate and validate the model. The model was run from 1985
to 2004, with a calibration period between 1985 and 1994 and a validation period between
1995 and 2005. The model's runoff simulation efficiency has been improved by adjusting
watershed input parameters. The SWAT model's performance was assessed statistically
(coefficient of determination [R2], Nash-Sutcliffe Efficiency Coefficient [NSE], and Percent
BIAS [PBIAS]). The monthly calibration R2, NSE, and PBIAS were 0.89, 0.68, and 43, respectively, and the monthly validation R2, NSE, and PBIAS were 0.78, 0.76, and 10.4, respectively. These results support that the SWAT model is an effective tool for simulating
the surface runoff of the Bouhamdane watershed.

Potential soil loss estimation using RUSLE, GIS, and Remote Sensing in Boussellam basin in
Northeast Algeria

Soil Erosion Rate Prediction using Deep Learning Model (DNN vs CNN) and Geographic
Information System (GIS) of Wadi Sahel-Soummam Watershed (Algeria)

7th International Symposium on Flash Floods in Wadi Systems 5-7 June 2023

Flooding is one of the most devastating natural disasters brought on by climate change in North Africa. The occurrence of flood risk is due to
a combination of natural and man-made variables, necessitating a better knowledge of its spatial scope. The goal of this study is to locate and
map flood-prone regions in the Cheliff-Ghrib watershed. Within the ArcGIS interface, this study is based on the integration of multi-criteria
data such as slope, drainage density, type of soil, rainfall, population density, land use and sewer system density. For flood risk assessment
and mapping, the Analytic Hierarchy Process (AHP) technique was employed as a multi-criteria analysis, allowing the integration of numerous
factors under two criteria namely, hazards and vulnerability. The AHP flood risk map reveals that areas at high and extremely high risk of
flooding cover 22.5% of the study area. According to the findings, the Cheliff-Ghrib watershed is extremely vulnerable to flooding. Eight of
the Chelliff-Ghrib watershed’s 15 municipalities (8/15) are at high risk of flooding, necessitating the development of efficient flood mitigation
solutions for future flood events.

Distribution et collecte des eaux urbaines

Soil erosion is an important factor that should be considered when planning renewable natural resource
projects, effects of which can be measured by modelling techniques. Therefore, disintegration models determine soil
loss intensity and support soil conservation practices. This study estimates soil loss rates by water erosion using the
Erosion Potential Method (EPM) in the Kebir Rhumel Watershed located in Northeast Algeria. The area is north to
south sub-humid to semi-arid, receives irregular rainfall, and has steep slopes and low vegetation cover which makes it
very vulnerable to erosion. The main factors in the EPM (soil erodibility, soil protection, slope, temperature, and
rainfall) were evaluated using the Geographical Information System (GIS) and data provided by remote sensing
technologies. The erosion intensity coefficient Z was 0.60, which indicates medium erosion intensity. While the results
showed the average annual soil erosion of 17.92 Mg∙ha–1∙y–1, maximum and minimum losses are 190.50 Mg∙ha–1∙y–1
and 0.21 Mg∙ha–1∙y–1, respectively. The EPM model shows satisfactory results compared to some studies done in the
basin, where the obtained results can be used for more appropriate management of land and water resources,
sustainable planning, and environmental protection.

Apport de la télédétection et de SIG pour le suivi de la qualité physicochimique des eaux du barrage de Beni Haroun W de Mila

Assessement of drought in the soummam watershed

Determination of physiographic parameters of Soummam Watershed

Evaluation and mapping of erosion risk by RUSLE model in the Boussellam catchment in Northeast Algeria

In recent decades, Algeria has experienced rapid and irregular demographic growth, and this irregular change has inevitably led to periodic floods threatening human life. Urbanization, an anthropogenic cause, is rapidly evolving and has been considered as a non-negligible part in altering land use and land cover (LULC), despite the fact that precipitation characteristics are related to the climate of the region and may change over time. It is therefore essential to assess the changes in runoff as a result of LULC changes. Awareness of the relationship of rainfall and runoff is necessary for urban drainage network modeling and design. The implementation of Low-Impact Development (LID) is a popular strategy to minimize stormwater runoff and pollutant loads. In developed countries, software to estimate impacts of certain LID controls has expanded in recent years; however, readily available modeling approaches are still in high demand in developing countries, such as Algeria. In this article, we seek methods that can decrease runoff peaks and volume for the Guelma watershed located in northeast Algeria by integrating the Personal Computer Storm Water Management Model (PCSWMM) and a geographic information system (GIS). PCSWMM calibration is conducted by using the sensitivity-based radio tuning calibration tool. The Nash–Sutcliffe efficiency (NSE) (0.70–0.88), coefficient of determination (R2) (0.76–0.96), and relative error (RE) (0.018–0.23) indicated good model performance in this urban watershed. The implementation of five LID practices, including permeable pavements, bioretentions, rain gardens, infiltration trenches, and rainwater harvesting systems, in scenarios explored could reduce peak runoff by 54.7% and reduce total runoff volume by 75.2%. The current research will assist decision-makers in improving and choosing the most appropriate LID designs that are effective in view of future climate changes and changes in LULC. This study can contribute to further applications of rainfall–runoff models in Algeria.

Assessment of surface runoff in urban watershed using GIS and PCSWMM Case study: Guelma town, Algeria

Participation à l'organisation de concours de doctorat LMD Hydraulique

The First International Conference on Water and Climate

Accurate prediction of soil erosion rate is a quite important issue for a wise and sustainable use of soil resources. In this study, an adaptive neuro-fuzzy inference system (ANFIS) approach is used to construct a prediction model. The objectives of this study is to develop fuzzy logic models that predict soil erosion in a relatively large watershed using a limited number of input variables, compare the predictions of soil erosion using ANFIS model with those of the Revised Universal Soil Loss Equation RUSLE. With the incorporation of Geographical Information System (GIS), it is possible to analyse satellite data, which gives required information like land use and cover, slope, distribution of rainfall, flow direction etc. of study watershed. The capabilities of these technologies increase when they are integrated with ANFIS model for erosion prediction. ANFIS model and GIS integrated erosion prediction models do not only estimate soil loss but also provide the spatial distributions of the erosion. Generating accurate erosion risk maps in GIS environment is very important to locate the areas with high erosion risks for prioritization and to develop adequate conservation techniques for a better sustainable management of Wadi Sahel watershed (Algeria).

In order to take measures to control soil erosion, it is necessary to estimate soil losses over the area of interest. Soil loss due to soil erosion can be estimated using predictive models such as the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE). The accuracy of these models depends on the parameters used in the equations. One of the most important parameters in the equations used in both models is the C-factor which represents the effects of vegetation and other land cover types. Land cover estimation by remote sensing image interpretation uses the Standard Difference Vegetation Index (NDVI), an indicator showing vegetation cover. The purpose of this study is to estimate the C-factor values for the Boussellam watershed using satellite images. The final C-factor map was generated using the regression equation in the Spatial Analyst tool of the Arcgis 10.3 software. It is found that most of the basin is characterized by C-factor values between 0.6 and 0.8 (45.29% of the total catchment area).
Keywords: Erosion, RUSLE, USLE, Factor C, Landsat, NDVI

The present study aims to estimate theannual soil loss in the Soummam watershed in the of Algeria, using the Revised Universal Soil Loss Equation (RUSLE), geographic information
system (GIS), and remote sensing (RS). RUSLE model has been used for modelling the main factors involved in erosive phenomena. The Soummam watershed covers a surface area of 9108.45 km2 of irregular shape, northeast –southwest towards southeast. It is characterized by an altitude varying between 2 m in the northeast and 2308 m in the northwest. Results showed that the average erosivity factor (R) is 70.64 (MJ·mm)/(ha·h·year) and the maximum value reaches 140 (MJ·mm)/(ha·h·year), the average soil erodibility factor (K) is 0.016 (t·h·ha)/(MJ·ha·mm) and maximum values reach 0.0204 (t·h·ha)/(MJ·ha·mm) in the southeast regions of the watershed, the average slope length and steepness factor (LS) is 9.79 and the mean C factor is estimated to be 0.62. Thematic maps integration of different factors of RUSLE in GIS with their database, allowed with a rapid and efficient manner to highlight complexity and factors interdependence in the erosion risk analyses. The resulting map for soils losses, with an average erosion rate of 6.81 t/(ha·year) shows a low erosion (<7.41 t/(ha·year)) which covers 73.46% of the total area of the basin, and a medium erosion (7.42 to 19.77 t/(ha·year)), which represents 17.66% of the area. Areas with extreme erosion risk exceeding 32.18 t/(ha·year) cover more than 3.54% of the basin area. The results can certainly aid in implementation of soil management and conservation practices to reduce the soil erosion in the Soummam watershed.

Keywords: Soummam watershed; Soil erosion; Revised Universal Soil Loss Equation; Remote

L’intégration des cartes thématiques des différents facteurs de l’Equation universelle de pertes en sol USEL dans le système d’information géographique (ARC GIS) avec leurs bases de données, a permis d’une manière rapide et efficace d’éclaircir la complexité et l’interdépendance des facteurs dans l’analyse des risques d’érosion. Les techniques de SIG et les données provenant de la télédétection ont été utilisées avec succès pour déterminer les facteurs d'érosion des sols.

Le présent document consiste à donner un aperçu sur les différents ouvrages des aménagements hydrauliques. Il s’agit d’un support de cours de la matière " Aménagements Hydrauliques " destiné aux étudiants de la 3ème année de Licence, Filière Hydraulique du domaine des Sciences et Technologies (ST). Le cours est structuré selon le programme des enseignements de la 3ème année de Licence Hydraulique, 6ème semestre. Le contenu de ce document est inspiré des documents et sources cités dans la liste des références bibliographiques. Dans cette matière l'étudiant(e) apprend les connaissances nécessaires à la conception, à la réalisation des ouvrages hydrauliques dont la fonction est l’aménagement des cours d’eau.

The problem of natural hazards in general and, in particular, floods are among the most common among the peoples of the world in general and Algeria in particular, especially through recent flood incidents. The weather-related floods in the Soummam Valley are the most feared natural hazard for the people living on its shores, the latter becoming increasingly intolerable on the human and material levels. For this reason, the management of these dangers has become an imperative, including the use of all available means. The study of probability and frequency, the analysis of the links between precipitation and maximum recorded flows, and the analysis of historical flood data, on the other, led to the development of some empirical models to extrapolate the results of the assessment of flows (decimal, fiftieth and centennial floods) to identify reference floods for the establishment of flood risk prevention schemes at the level of the area in which the study was conducted. The results obtained can feed a surface model (HEC-RAS 5.0.3) allowing us to remotely scan the topography of flood residues by knowing the width and depth of the water-covered area, the flow distribution and the flow velocity. All of these data are necessary for the mapping of hazard zones. These documents are capable of responding to the protection and protection requirements as well as preserving the property in the flood areas within the framework of sustainable development.
Keyword : Soummam watershed, Flood, cartography, modeling

The objective of this work is to estimate soil losses by erosion at the Oued Boussellam watershed in northeastern Algeria through the use of Geographic Information Systems. The Wischmeier model has been adopted for modeling the main factors involved in erosive phenomena. The Boussellam watershed extends over an area of 4296 square kilometers, elongated from south-east to north-west.. The comparison of the different maps of these parameters made it possible to deduce the erosion map from which, it appears that the erosion phenomenon affects the whole area of the Boussellam watershed but at different levels. Thus, the average rate of soil losses is 6.35 t / ha / year. Erosion rates differ from one area of the watershed to another, depending on the influence of the different factors that control erosion. The distribution of soil losses is not proportional to the areas; in fact, 3.73% of the basin area contributes to 33.73% of total soil losses.
Key Words: Boussellam watershed, erosion, RUSLE model, GIS. Teledetection, Algeria.

L’objectif de ce travail est d’estimer les pertes en sol par érosion au niveau du bassin versant de l’Oued Boussellam dans le Nord-est de l’Algérie par l’utilisation des Systèmes d’Information Géographique. Le modèle de Wischmeier a été adopté pour la modélisation des principaux facteurs impliqués dans les phénomènes érosifs. Le bassin versant de Boussellam s’étend sur une superficie de 4296 Km2, de forme allongée du Sud -est au Nord -ouest.. La confrontation des différentes cartes de ces paramètres a permis de déduire la carte d’érosion à partir de laquelle, il ressort que le phénomène d’érosion touche l’ensemble du bassin versant de Boussellam mais à des niveaux différents. Ainsi, le taux moyen des pertes en sol est de 6.35 t/ha/an. Les taux d’érosion diffèrent d’une zone à l’autre du bassin versant, selon l’influence des différents facteurs qui contrôlent l’érosion. La répartition des pertes en terre n’est pas proportionnelle aux surfaces ; en effet, 3.73% de la surface du bassin contribuent à 33.73 % des pertes totales.
Mots-clés : Bassin versant Boussellam, érosion, modèle RUSLE, SIG. Télédétection, Algérie

The objective of this study is the quantification of the amount of soil erosion in the Soummam basin (Northeastern Algeria) using the Universal Soil loss Equation (USLE) integrated in a Geographical Information system ArcGIS.
The results obtained show that the soils of the Soummam basin undergo the effect of several factors supporting the phenomenon of erosion to knowing the importance of the slopes, vegetable cover and the erodibility of the soils. They also state that the basin is subjected to an erosion with losses varying from 22.5 to 300 t/ha/an. Weak losses below the tolerance level < 6.2 t/ha/an. This serious situation is supported by the factors of erosion which are also combined to accelerate erosion, the strong slopes (59.52% of the surface of the Soummam basin present a factor LS between 5 and 50), an alarming degradation of vegetable cover and 60 % of the soils show a factor K > 0.06.

The objective of this study is to define a methodology for the quantification of solid transport in a section of river (Sidi Aich - Béjaia) of the Soummam Wadi basin by the application of HEC-RAS.
Three functions of transport (Ackers-white, Engelund and Laursen) by using the function of evolution of the sedimentary bed of Exner and the sedimentation function of Ruby were tested for various risings. The found results were compared with another work in the literature and those observed by the hydrometric station of Sidi-Aich (ANRH).

Organisation de concours de doctorat LMD Hydraulique
Préparation et correction des sujets

Les deux ressources naturelles essentielles exigées pour la production agricole de n'importe quel pays sont sol et eau. La productivité nette des récoltes dépend de la gestion et de l'utilisation appropriée de ces deux ressources. La satisfaction a des besoins industrielles et d'urbanisation, rend l'eau une ressource rare et la satisfaction des besoins agricole est délicate dans presque tous les endroits à travers le monde. De nombreux chercheurs ont employés beaucoup de méthodes pour simuler, évaluer, et prévoir les effets de l'urbanisation sur la réponse hydrologique des bassins versants. La gestion du bassin versant implique l'utilisation judicieuse de toutes les ressources en terre et en eau. Les outils d'aide à la décision peuvent aider dans de meilleures options de développement pour que les humains contrôlent l'eau, la terre et les potentiels. Une réponse et approche fiables à ce défi est l'utilisation des modèles hydrologiques appropriés pour la gestion efficace des bassins versant et les écosystèmes (Yener et autres, 2012), la modélisation hydrologique est un outil utilisé généralement pour estimer la réponse hydrologique du bassin due à la précipitation. Elle prévoit la réponse hydrologique à de diverses pratiques de gestion de bassin versant et avoir un meilleur arrangement des impacts de ces pratiques (Kadam, 2011). Elle est évidente de l'examen étendu de la littérature que les études sur l'évaluation comparative des modèles du bassin versant pour des simulations hydrologiques sont beaucoup limitées dans les pays en voie de développement comprenant l'Inde (Kumar et Bhattacharya, 2011), cela explique la nécessité pour entreprendre l'étude de simulation hydrologique par le développement d'un modèle approprié du bassin. Le système de modélisation hydrologique de centres hydrologiques de technologie (HEC-HMS) est un modèle très utilisé pour simuler le processus d'écoulement e de précipitations. Cette étude vise à faire une modélisation hydrologique type pluie-débit sur le bassin d’Oued Cheliff- Ghrib, par le biais du modèle HEC-HMS. Après, ce modèle est utilisée pour prédire la réponse hydrologique du bassin à des scénarios de changement de climat et d’occupation du sol. La calibration du modèle a été faite sur deux phases, la première pour choisir les événements, le formalisme de la fonction de transfert et l’averse NRCS appropriés. La deuxième pour en déduire le jeu de paramètres optimisés qui est employé dans la validation. En utilisant le jeu de paramètres optimisés, on a pu prédire l’impact des averses quantiles, des changements d’occupation du sol dû à l’urbanisation, la déforestation et le reboisement sur le débit de pointe et le volume du ruissellement. Vers la fin, on a reconfirmé que l’influence de l’occupation du sol diminue pour des orages extrêmes.
Mots clés : Modélisation – Pluies- Débits –HEC HMS- Bassin versant – Ghrib - Algérie

The objective of this study is to define a methodology for the quantification of solid transport in a section of river (Sidi Aich - Béjaia) of the Soummam Wadi basin by the application of HEC-RAS. Three functions of transport (Ackers-white, Engelund and Laursen) by using the function of evolution of the sedimentary bed of Exner and the sedimentation function of Ruby were tested for various risings. The found results were compared with another work in the literature and those observed by the hydrometric station of Sidi-Aich (ANRH).
Key Words: Soummam Wadi basin, Solid transport, HEC-RAS, WMS.

The objective of this study is the quantification of the amount of soil erosion in the Soummam basin (Northeastern Algeria) using the Universal Soil loss Equation (USLE) integrated in a Geographical Information system ArcGIS. The results obtained show that the soils of the Soummam basin undergo the effect of several factors supporting the phenomenon of erosion to knowing the importance of the slopes, vegetable cover and the erodibility of the soils. They also state that the basin is subjected to an erosion with losses varying from 22.5 to 300 t/ha/an. Weak losses below the tolerance level < 6.2 t/ha/an. This serious situation is supported by the factors of erosion which are also combined to accelerate erosion, the strong slopes
(59.52% of the surface of the Soummam basin present a factor LS between 5 and 50), an alarming degradation of vegetable cover and 60 % of the soils show a factor K > 0.06.
Key Words: Soummam basin, Soil erosion, ArcGIS, USLE.

Soil erosion is a natural process which is undoubtedly widely responsible for the current geomorphology. The “soil erosion” term cannot be used in a threatened environment or
a damage that it is about accelerated erosion, beyond moderate rates, based on anthropogenic factors, which will cause loss of one or several functions of the soil. Detection of eroded soils, and so factors evaluations which control erosion and their characteristics, are complex tasks but can be resolved with integration of several data sources (spatial data, measures and investigation on the ground and satellite pictures) and geo-spatial treatment system such as geographic information system. There are several soil erosion models with different levels of complexity. Although a wide variety of models is available for erosion risk estimation, the majority requests many more data-sources than their application at a regional scale, becomes a problem. The well-known equation USLE (Wischmeier and Smith 1978) has been used because this is the model that requires less data sources and it has been widely applied to all scales (Fistikoglu et al. 2002). Basically, USLE has the advantage to supply long term average annual soil loss information from small areas and it is considered as an “appropriate model” if the goal of the modelling is to reach global estimations of soil erosion. However, the model is limited in the case it cannot simulate erosion of a deposit bed or gullies (Foster 1988).

Keywords
Erosion , Modeling , USEL ,SIG , Wadi sahel Soummam-Algeria

The watershed of wadi Chelif-Ghrib is characterised by a semi-arid climate. Soils are more and more degraded and sediments derived from erosion contribute to the withholding sloughing of the Ghrib’s dam. Thematic maps integration of different factors of the Universal Soil Equation Loss in geographic information system (ARC GIS) with their database, allowed with a rapid and efficient manner to illuminate complexity and factors interdependence in the erosion risks analyses. The SIG techniques and data coming from the
remote sensing have been used successfully to determine soil erosion factors.
The resulting map for soils losses, with an average erosion rate of 18.31 t /ha/year shows a weak erosion (<7.41t/ha/year) which covers 28.24% of the total area of the basin, and a medium erosion (7.41 to 19.77t/ha/year), which represents 35.64% of the area. Areas with high erosion rates exceeding 30 t/ha/yearcover more than 16% of the basin area.
Key Words: Erosion – Solid transport – Modeling – USEL – SIG – Wadi Cheliff Ghrib- Algeria.

The purpose of this study is to make a hydrologic modelling type of rain–flow on watershed of wadi Cheliff- Ghrib, by means of HEC-HMS model. Afterwards, this model is used to predict hydrologic response of the basin to the climate changes scenarios and land use. The model calibration was made in two phases; the first one is to select events, formalism of transfer function and appropriate NRCS downpour. The second is to deduce optimised parameters set which is used in validation. By using optimised parameters set, we were able to predict impact of quantiles downpours, changes in land use due to urbanisation, deforestation and reforestation on the peak flow and on runoff volume. Towards the end, we reconfirmed that influence of land use decreases for extreme storms.
Key words: Algeria, HEC-HMS – watershed, modelling, rain–flow, wadi Cheliff-Ghrib