Estimation of the peak flows in the catchment area of Batna (Algeria) (original) (raw)

Statistical modeling of annual maximum precipitation in Oued El Gourzi Watershed, Algeria

Applied Water Science

This study aims to model annual maximum precipitation based on extreme value theory for the Oued El Gourzi Watershed, Algeria. A generalized extreme value (GEV) distribution was used to determine the probability distribution of extreme values and their dependency on time for the five stations distributed across the watershed. The non-stationary models are used to represent the GEV parameters assumed an invariant shape parameter and linear functions as location and scale parameters. The best model was selected using Akaike’s information criterion and Bayesian information criterion. Stationary and non-stationary return levels for different return periods have been proposed for the study area.

Estimation and Mapping of Extreme Rainfall in the Catchment Area of Batna (Algeria)

2016

Statistical estimation of rainfall associated with extreme events is of major interest for hydrologists in terms of risk prevention. Comprehending the spatial distribution of extreme rainfalls that cover the entire catchment area, the impluvium, of Batna, requires as a first step a frequency analysis of annual maximum daily rainfall time series with the application of empirical distributions, namely the GEV distribution, the Gumbel distribution and the log-normal distribution. This has allowed us to estimate the quantiles of extreme rainfall with return periods of 5, 10, 20, 50 and 100 years for ten rainfall stations. Subsequently, this has allowed us to map the quantiles matching the centennial return period using three types of interpolations.

Assessment of the hydrological response of the watershed through a distributed physically-based modeling for extreme events Application in the Raghay Catchment (Medjerda) (Northern Tunisia)

This research study consists on the validation of the physically and distributed hydrological model, throw the application of the ATHYS platform for hydrological modeling, for the case study of a catchment area situated in the left bank of the high valley of the Medjerda basin, the catchment area of the Raghay wadi having an area of approximately 322 km². This watershed is characterized by a very important morphological, climatic and physical variability in time and space, often presenting very important floods because of the not measured flow coming from the Algerian frontier part instead of the large difference of atitude from 165 to 1180 in the Tunisian part. The choice is fixed on six events distributed over three different seasons, recorded on the level of two pluviographic stations for an hour time-step and which control the flow in the discharge system of the catchment area. The parameters of entry of the GREEN and AMPT production function are maps having the variability of the physical parameters of the soil as well as the variation of altitude and of the directions of drainage. The advantage of this function is related on its physical base, and the theoretical possibility to estimate and optimize the parameters starting from data of grounds or “in situ” measurements. The evaluated criteria for optimization are the Nash criteria which is varying between 0.73 and 0.98 for the calibration phase, and between 0.62 and 0.75 for the validation for the three seasons, instead of the Arithmetic Mean Error for the volume and the peak flow giving very good errors for the Wintry season, good errors for the Autumnal season and medium errors for the Springer season. The results of simulations show that the selected model is well validated for the Raghay catchment than, its performance in the comprehension of the hydrological answer of a Mediterranean watershed, which provide important information for decision makers in order of protection against floods of the area

Estimation of Peak Discharge in a Poorly Gauged Catchment Based on a Specified Hyetograph Model and Geomorphological Parameters: Case Study for the 23–24 October 2008 Flood, KALAYA Basin, Tangier, Morocco

Hydrology

The determination of discharge from stage measurement is an essential procedure in surface hydrology. Due to limited data availability in terms of discharges and rainfalls, a number of non-flood water levels have been used for deriving a rating curve based on an indirect method with specific cross-sections, longitudinal slope of the river, and bed roughness at the KALAYA gage station. In addition, instantaneous rainfall recordings across the Meloussa gage station are available from 23 October 2008 storm event that have been collected in order to develop temporal distribution (hyetograph). Thereby, it provides the necessary input to generate a continuous rainfall-runoff time series, with the derived instantaneous discharge allowed us to calibrate the simulated stage-discharge hydrograph that covers the entire time of the storm event period from 23 to 24 October. An empirical equation was derived in order to provide the peak flow as a function of the given rainfall quantities, its sta...

Modeling the Rainfall–Runoff Relationship with TOPMODEL in the Wadi El Kebir Watershed

Journal of water management modeling, 2023

The rainfall-runoff relationship was studied in the Wadi El Kebir watershed, located in Northeastern Algeria, using TOPMODEL (topography based hydrological model). This is a geomorphological and semi-distributed model which is used to predict the hydrological behaviour of watersheds, and to calculate the water storage deficit of an aquifer in any location. It uses topographic information of the watershed to predict the extent of contributing areas in the production of runoff. TOPMODEL was applied with event-based rainfall-runoff modeling where 13 hourly rainfall series were used to predict the discharge at the basin outlet. A digital elevation model (DEM) was also used to define the contours of the basin and to map out the drainage directions and the topographic index. TOPMODEL was calibrated and validated using the measured discharges and various objective functions such as Nash (Nash-Sutcliffe) and coefficient of determination (R 2). The TOPMODEL results showed a high-performance level. Indeed, after the calibration and validation procedure, the performance of the model oscillates between satisfactory and very good. For the calibration, Nash varied between 0.59 and 0.91, and R 2 between 0.66 and 0.91. However, the values of these criteria coefficients were slightly reduced during the validation phase, Nash (0.53 to 0.84) and R 2 (0.59 to 0.87). Also, the proposed model shows the weak contribution of groundwater flows in the hydrological response of the study area.

Modeling Watershed Operation: Case Study of the Chaffia Dam (Algerian Extreme North East)

2017

The modeling of the hydrological behavior of watersheds is unavoidable when one is interested in problems related to the prediction, assessment and optimal management of water resources. This is illustrated by a quantitative aspect in countries like Algeria where water supply is a limiting factor. Such models are particularly useful for many applications where the estimation of the parameters and characteristics of a dam and to go back to the origin of the flows (the rains) makes it possible to extend the period of quantitative forecasting of water which gives a future statistical vision.

Modelling rainfall-discharge at a mean inter-yearly scale in northern Algeria

Journal of Hydrology, 2004

The aim of this work is to highlight the relationships between hydrological conditions and available surface water. The application has been carried out in northern Algeria, which has a surface area of 325,000 km 2. The hydrological characteristics of surface flow which have been taken into account are climatic parameters (e.g. pluviometry, potential evapotranspiration, real evapotranspiration) and physical parameters (e.g. geology and topographical relief). The data from 467 pluviometric stations were used to generate the map of the median annual rainfall. This map was established by taking account of altitudes (Z) and geographical coordinates (longitude (X) and latitude (Y)). These parameters explain 67% of the variance in precipitation; the remaining 33% constitutes the residuals. There was a trend in the data and a second order stationary model was considered appropriate in order to permit the interpolation of the residuals by kriging. The grid of the residuals obtained is combined with the grids of different parameters highlighted by the regression model (longitude (X), latitude (Y) and altitude (Z)) in order to obtain a map of median annual rainfall. The study of the rain-discharge relationship on an inter-annual average scale is based on the observations made from 50 hydrometric stations distributed through the zone of study. This step consisted of establishing the relationship, which binds the discharge to the physical (geology) and climatic (median annual rainfall) parameters by using a multiple regression model. The results showed that 86% of the variation in discharge is explained by this model. Our study presents a model for rainfalldischarge in northern Algeria and provides a useful tool for hydrological management and evaluation of water resources.

Hydrological modeling of floods in the Wadi Bechar watershed and evaluation of the climate impact in arid zones (southwest of Algeria)

Applied Water Science, 2018

Precise knowledge regarding the quantities of water available in the Wadi Bechar watershed and better management of this resource is necessary to initiate the transformation of rainfall data into hydrometric data (simulated flow); this is the main objective of the hydrological rainfall-runoff modeling. The primary focus of this paper is the rainfall-runoff modeling on an annual and monthly scale in the Wadi Bechar watershed which covers an area of 6858 km 2. We employ the rural engineering model (GR) for annual timestep GR1A and for the monthly timestep GR2M. The input parameters are precipitation (P) and evapotranspiration (ETP) calculated by the Turc method; the output parameter is elapsed water slide (Q). The results obtained indicate that the model takes into account the different atmospheric and underground exchanges, as well as the capacities of the production tank and routing tank. With this work, the contribution of precipitation to flows downstream of the watershed can be evaluated and quantified. On an annual scale, the potential evapotranspiration modulator coefficient X is equal to 2.20 > 1. This indicates that the water from the Wadi Bechar watershed seeps into the ground or into the adjacent watersheds of Wadi Zousfana and Wadi Guir. On a monthly scale, we calibrate and cross-validate the model with the selected input data, determining the model parameter sets that best reflect the transformation of rainfall into flow. The calibration was done with several passages in computer. The value of the capacity of the estimated production tank X1 is equal to 4.74 mm, which reflects the production function, and subsequently indicates the rainfall capacity transformed into a water flow available for runoff at the Wadi Bechar watershed scale. The value of the estimated underground exchange coefficient parameter X2 is equal to 0.02; it reflects the transfer function, which indicates the movement of this surface flow toward the watershed outlet.

Determination of Design Floods by Aspects of Peak Flow and Flood Hydrograph in Watershed of Larbaâ River, Taza (Morocco)

Journal of Hydrogeology and Hydrologic Engineering, 2013

The major task of a hydrology study is to compute the design flow. There are conceptual and empirical methods for computation of design flow. The following paper shows the Gradex method estimating the design flood and the volumes corresponding of flows. This approach allowed us to know the design floods by aspects of peak flow and flood hydrograph. The study is based on long series of observations (49 years) of the annual maximum daily rainfall, and the Intensity-Duration-Frequency curves of the raingauge station of Taza located in the Larbaâ catchment. The Gradex method aims to find the maximum flow of floods for the rare frequency of occurrence (return time over 100 years). Hence, we attempted to explains why and how the combined use of rainfall and floods of different sub-catchments of Larbaâ River.

Rainfall-runoff modeling: flow characterization of Hammam Melouane Wadi Algeria

Arabian Journal of Geosciences, 2019

Rainfall-runoff modeling is considered to be a technic that has gained momentum in the field of runoff characterization, flood predetermination, and the water resource management at watershed scale during the last years. In this work, the "Génies Rural" models with two monthly parameters (GR2m) and four daily parameters (GR4j) were chosen in order to determine the characteristics of the latter for the Hammam Melouane Wadi watershed, covering an area of 390 km 2 , and use them in the characterization of superficial water flows and the evolution of the water resources based on climate data (precipitation and evapotranspiration). In this study, we calibrated and evaluated the performance criteria for both hydrological models in order to characterize and simulate the flows in the watershed of Hammam Melouane Wadi. The results obtained indicate that the quality criteria (Nash and R 2 coefficients) of the models with a monthly and daily times step are satisfactory with values higher than 78%.