Alain Dezetter

• Institute of Research for Development

Study region: Senegal River Basin in West Africa Study focus: This paper aims to evaluate the sensitivity of global hydrological models to potential evapotranspiration (PET) methods in the Senegal River Basin. Potential evapotranspiration is estimated using 21 methods and its influence on the performance of three GR models (GR4J, GR5J and GR6J) is...

Reference evapotranspiration (ET 0) is an essential parameter for hydrological modeling, irrigation planning and for studying the impacts of climate change on water resources. The Penman-Monteith method is recommended for estimating ET 0 under all climatic conditions, but its application is limited in regions where data is difficult to access. The...

Analysis of reference evapotranspiration (ET0) trends is essential for understanding the impacts of climate change on water resources. Thus, despite the continuous rise in temperatures, a decrease in evapotranspiration is noted in some parts of the world. This contrast is called the “evaporation paradox” and is thought to be related to the variatio...

A growing portion of scientists realises the need to not only alert about climate change, but also change their professional practices. A range of tools have emerged to promote more sustainable activities, yet many scientists struggle to go beyond simple awareness-raising to create concrete transition actions. Here we propose a game-based transitio...

Most of the global population lives in developing countries that are highly prone to hydrological phenomena (such as monsoons, floods, cyclones, droughts, aridity, etc [...]

Study region This study is focused on 6 catchments in Tunisia, in North Africa, under a semi-arid climate where daily river discharge and precipitation observations are available between 1992 and 2006. Study focus The distributed hydrological model LISFLOOD has been compared with a lumped model, GR4J, to reproduce river runoff and floods, using ob...

The freshwater supply and protection constitute a major challenge in the context of global change. Among other freshwater stocks, karst aquifers constitute heterogeneous hydro-systems with non-linear hydrogeological behavior. The high level of heterogeneity in such aquifers and the lack of knowledge of their internal structure lead to strong diffic...

Reference evapotranspiration (ET0) is an essential parameter for hydrological modeling, irrigation planning and for studying the impacts of climate change on water resources. The Penman-Monteith method is recommended for estimating ET0 under all climatic conditions, but its application is limited in regions where data is difficult to access. The al...

Analysis of reference evapotranspiration (ET0) trends is essential for understanding the impacts of climate change on water resources. Thus, despite the continuous rise in temperatures, a decrease in evapotranspiration is noted in some parts of the world. This contrast is called the "evaporation paradox" and is thought to be related to the variatio...

Study region Senegal River Basin in West Africa. Study focus This work aimed to assess reference evapotranspiration (ET0) trends and its sensitivity to climate variables on the period 2036–2065 in the Senegal River basin. Seven General Circulation Models (GCMs) and seven Regional Climate Models (RCMs) of the CMIP5 project were used under the scena...

The African continent is probably the one with the lowest density of hydrometric stations currently measuring river discharge despite the fact that the number of operating stations was quite important until the 1970s. This new African Database of Hydrometric Indices (ADHI) provides a wide range of hydrometric indices and hydrological signatures com...

The African continent is probably the one with the lowest density of hydrometric stations currently measuring river discharge, despite the fact that the number of operating stations was quite important until the 70s. This new African Database of Hydrometric Indices (ADHI) is compiling data from different sources carefully checked for quality contro...

Understanding evapotranspiration and its long-term trends is essential for water cycle studies, modeling and for water uses. Spatial and temporal analysis of evapotranspiration is therefore important for the management of water resources, particularly in the context of climate change. The objective of this study is to analyze the trend of reference...

Reference evapotranspiration (ET0) is a key element of the water cycle in tropical areas for the planning and management of water resources, hydrological modeling, and irrigation management. The objective of this research is to assess twenty methods in computing ET0 in the Senegal River Basin and to calibrate and validate the best methods that inte...

Le fleuve Sénégal draine un bassin de 300 000 km2, à cheval sur quatre pays que sont, d’amont en aval, la Guinée, le Mali, le Sénégal et la Mauritanie. Il est formé de plusieurs affluents, dont les principaux sont le Bafing, le Bakoye et la Falémé. Le fleuve Sénégal dispose d'important ressource en eau. En effet, à la station hydrométrique de Bakel...

Analyzing trends of annual rainfall and assessing the impacts of these trends on the hydrological regime are crucial in the context of climate change and increasing water use. This research investigates the recent trend of hydroclimatic variables in the Senegal River basin based on 36 rain gauge stations and three hydrometric stations not influence...

The present work aims to quantify the impact of climate change (CC) on the grain yields of irrigated cereals and their water requirements in the Tensift region of Morocco. The Med-CORDEX (MEDiterranean COordinated Regional Climate Downscaling EXperiment) ensemble runs under scenarios RCP4.5 (Representative Concentration Pathway) and RCP8.5 are firs...

Gridded data, monthly flow rates, GIS layers Data sets of West and Central African basin gathering optimized parameters for hydrological modeling and improving the various studies of impacts on water resources. The general architecture of the directories and files are as follow : Main Directory: basin name The main directory contains: - sub-direc...

This file has been replaced by a newer one which you can find on the same ResearchGate project https://www.researchgate.net/publication/333566039_Gridded_data_monthly_flow_rates_GIS_layers_of_Ogooue_Basin_data_sets

Gridded data, monthly flow rates, GIS Data sets of West and Central African basins gathering optimized parameters for hydrological modeling and improving the various studies of impacts on water resources. The general architecture of the directories and files are as follow : Main Directory: watershed name: BasinName The main directory contains: - s...

Gridded data, monthly flow rates, GIS layers Data sets of West and Central African basin gathering optimized parameters for hydrological modeling and improving the various studies of impacts on water resources. The general architecture of the directories and files are as follow : Main Directory: basin name The main directory contains: - sub-dire...

Gridded data, monthly flow rates, GIS layers Data sets of West and Central African basins The general architecture of the directories and files are as follow : Main Directory: watershed name: BasinName The main directory contains: - sub-directories: x sub-directory named by main stations of the watershed: the description and format of the files ar...

This file has been replaced by a newer one which you can find on the same ResearchGate project https://www.researchgate.net/project/Gridded-data-set-for-West-and-Central-Africa-Basins

This research investigated the effect of climate change on the two main river basins of Senegal in West Africa: the Senegal and Gambia River Basins. We used downscaled projected future rainfall and potential evapotranspiration based on projected temperature from six General Circulation Models (CanESM2, CNRM, CSIRO, HadGEM2-CC, HadGEM2-ES, and MIROC...

La disponibilité de données climatiques au pas de temps journalier a fortement diminué ces dernières années en Afrique de l’Ouest et plus particulièrement pour le bassin du fleuve Sénégal à cause de leur coût d'acquisition élevé. De plus, lorsque ces données sont acquises, leur prix de vente les mets hors de portée de la plupart des acteurs du déve...

This study presents an original method to assess the effectiveness and robustness of measures aimed at reducing the gap between water resources and demand under climate and water use changes. A modeling framework integrating human and hydro-climatic dynamics and accounting for interactions between resource and demand was developed and applied in tw...

At the beginning of the drought in the Sahel in the 1970s and 1980s, rainfall decreased markedly, but runoff coefficients and in some cases absolute runoff increased. This situation was due to the conversion of the land cover from natural vegetation with a low annual runoff coefficient, to cropland and bare soils, whose runoff coefficients are high...

This paper assesses the sustainability of planned water uses in mesoscale river basins under multiple climate change scenarios, and contributes to determining the possible causes of unsustainability. We propose an assessment grounded in real-world water management issues, with water management scenarios built in collaboration with local water agenc...

The availability of climatic data, especially on a daily time step, has become very rare in West Africa over the last few years due to the high costs of climate data monitoring. This scarcity of climatic data is a huge obstacle to conduct hydrological studies over some watersheds. In this context, our study aimed to evaluate the capacity of Tropica...

Several satellite-based precipitation estimates are becoming available at a global scale, providing new possibilities for water resources modelling, particularly in data-sparse regions and developing countries. This work provides a first validation of five different satellite-based precipitation products (TRMM-3B42 v6 and v7, RFE 2.0, PERSIANN-CDR,...

The streamflow series for the upstream basin of the Senegal River is marked by considerable gaps. The objective of this article is to simulate and extend hydrological data, using the GR2M rainfall-runoff model. A sensitivity analysis of the model to rainfall and water holding capacity input data was performed. This analysis was performed after calc...

Ce travail vise à évaluer l’impact du changement climatique sur les apports en eau au barrage de Manantali. La démarche a consisté en : (i) la modélisation des écoulements du Bafing à la station de Bafing Makana ; (ii)l’élaboration de scénarios climatiques à l’horizon 2050 ; (iii) l’évaluation de la sensibilité de l'hydrosystème aux conditions clim...

This paper assesses the sustainability of planned water uses in mesoscale river basins under multiple climate change scenarios, and contributes to determining the possible causes of unsustainability. We propose an assessment grounded in real-world water management issues, with water management scenarios built in collaboration with local water agenc...

This study assesses water stress by 2050 in river basins facing increasing human and climatic pressures, by comparing the impacts of various combinations of possible future socio-economic and climate trends. A modelling framework integrating human and hydro-climatic dynamics and accounting for interactions between resource and demand at a 10-day ti...

During a flood event over a karst watershed, the connections between surface and ground waters appear to be complex ones. The karst may attenuate surface floods by absorbing water or contribute to the surface flood by direct contribution of karst waters in the rivers (perennial and overflowing springs) and by diffuse resurgence along the hillslopes...

The use of lumped, conceptual models in hydrological impact studies requires placing more emphasis on the uncertainty arising from deficiencies and/or ambiguities in the model structure. This study provides an opportunity to combine a multiple-hypothesis framework with a multi-criteria assessment scheme to reduce structural uncertainty in the conce...

The aim of this study was to assess the balance between water demand and availability and its spatial and temporal variability from 1971 to 2009 in the Herault (2500 km2, France) and the Ebro (85 000 km2, Spain) catchments. Natural streamflow was evaluated using a conceptual hydrological model. The regulation of river flow was accounted for through...

During a flood event over a karst watershed, the connections between surface and ground waters appear to be complex ones. The karst may attenuate surface floods by absorbing water or contribute to the surface flood by direct contribution of karst waters in the rivers (perennial and overflowing springs) and by diffuse resurgence along the hillslopes...

This study aims at defining the main stakes in the development of a generic, multidisciplinary approach to evaluate water supply capacity and its spatial and temporal variability over long time periods. A common modelling framework was applied over two Mediterranean basins with different physical and anthropogenic characteristics: the Ebro (85 000...

The use of lumped, conceptual models in hydrological impact studies requires placing more emphasis on the uncertainty arising from deficiencies and/or ambiguities in the model structure. This study provides an opportunity to combine a multiple-hypothesis framework with a multi-criteria assessment scheme to reduce structural uncertainty in the conce...

Flash floods, particularly in Mediterranean regions, are a rare but destructive event, and difficult to forecast. This difficulty is due to the high rainfall intensities and total amount, the high spatial variability of rainfall, the short response time of small watershed, but also to the lack of observations during these events. Moreover, the pres...

In the upstream basin of the Senegal River in general and its Guinean part in particular, streamflow series often show gaps, are non continuous or too short and consequently are difficult to use for reliable hydrological analysis. Thus the objective of this work was to simulate and extend hydrological data, using the GR2M rainfall-runoff model. In...

Trois modèles globaux de relation pluie débit (CREC, GR3 et MODGLO) sont utilisés en zone de savanes soudanaises dans le Nord-Ouest de la Côte d'Ivoire, dans un but de prévision des apports décadaires et de gestion des ressources en eau. Après la sélection d'un critère de calage et de la mise au point d'un module d'évaluation comparative des hydrog...

Assessing water supply capacity is crucial, notably in the Mediterranean region, identified as a hot-spot of climate change and where water demands have been continuously increasing. The Hérault River catchment (France) is representative of this context since its discharge has undergone a significant decrease over recent decades. A modelling framew...

Assessing water supply capacity is crucial, notably in the Mediterranean region, identified as a hot-spot of climate change and where water demands have been continuously increasing. The Hérault River catchment (France) is representative of this context since its discharge has undergone a significant decrease over recent decades. A modelling framew...

This paper aims to evaluate and compare two downscaling methods for daily precipitation over the Ebro catchment in Spain (85 000 km2). The two downscaling methods are probabilistic and assume that the change in precipitation simulated by the climate model can be transferred to the distribution of the precipitation at the local scale. The first meth...

This study aims to develop an integrated modeling approach to assess current and future trends in water availability for agricultural purposes on the upper Elqui basin (Chile). A hydrological model including a snow reservoir was combined with an agricultural water demand model to provide an index of the capacity to meet water needs. Particular acco...

Since the late 1970s, a negative trend in river discharge has been observed at the outlet of the Ebro catchment (Spain). This can be attributed to a decrease in mean precipitation, a rise in mean temperature, and a water consumption increase. Moreover, over 230 storage-dams were built to regulate river discharge in the basin. An integrated water re...

Assessing water supply capacity is crucial to meet stakeholders' needs, notably in the Mediterranean region. This region has been identified as a climate change hot spot, and as a region where water demand is continuously increasing due to population growth and the expansion of irrigated areas. The Hérault River catchment (2500km(2), France) is a t...

2013): Current state of Mediterranean water resources and future trends under climatic and anthropogenic changes, Hydrological Sciences Journal, 58:3, 498-518 This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or...

The perspective of climate change today raises many questions on the evolution of water resources in western Africa. Indeed, water in these regions is a key aspect for the various human activities such as agriculture, power production or water supply. In this context, this article proposes an evaluation of the impact of climate change on flows in t...

The Mediterranean basin has been identified as one of the world's most vulnerable regions to climatic and anthropogenic changes. A methodology accounting for the basin specific conditions is developed to assess the current and future water stress state of this region. The medium-term evolution of water stress is investigated using climatic scenario...

The knowledge of water resources and their seasonal variations in the upstream basin of the Senegal River in general and its Guinean part in particular is weak because of missing or too short hydrological time series. Streamflow series often show gaps, are non continuous or too short and consequently are difficult to use for reliable hydrological a...

Worldwide studies modelling the hydrological response to global changes have proven the Mediterranean area as one of the most vulnerable region to water crisis. It is characterised by limited and unequally distributed water resources, as well as by important development of its human activities. Since the late 1950s, water demand in the Mediterranea...

This study aims to simulate the complex interrelationships between climate forcing, human pressure and dynamics of groundwater and surface water of the upper Elqui catchment (5 660 km2) in the Chilean Andes. The water resources of this mountainous, semi-arid catchment has been undergoing a growing pressure because of high climate variability and of...

A conceptual hydrological model (GR2M) is applied to a large, poorly gauged catchment in West Africa. The purpose is to simulate the rainfall–runoff relationship at a monthly time step over the period 1982–2000 during which marked hydro-climatic changes took place. The model is based on two parameters: X1 for the production function and X2 for the...

Runoff and consequently water resources constitute the response of watersheds to pluviometric impulses. In Central and West Africa, one attends since the 1970s with a without precedent dryness just as a great space and temporal variability of the rainfall, characteristic of the tropical field. The objective of this work is to define this space-time...

This paper describes the monitoring of flooding in the Inner Niger Delta (Mali) from September 2008 to April 2010 using high resolution radar (C-band quad-polarization from Radarsat-2) and optical imagery (SPOT 4 and 5). Treatments, based on statistical parameters calculated using co-occurrence matrices, supervised classifications and three field s...

The Mediterranean basin is characterized by limited and unequally distributed water resources, as well as by important development of its anthropogenic activities. The latter has led to continuously increasing water withdrawals. Moreover, the region should be particularly affected by climate change, with rising temperatures and more frequent and in...

Dans l'optique d'aménagements ultérieurs et dans un contexte de changement climatique, il apparaît nécessaire de mettre à jour nos connaissances des régimes hydropluviométriques du fleuve Niger et de ses affluents. Le travail présenté s'intéresse au principal affluent du Niger dans sa partie supérieure, le Bani. Les résultats montrent que sur le ba...

Le changement climatique et environnemental est au coeur des préoccupations politiques et scientifiques actuelles. Pour l'Afrique de l'Ouest, déjà fragilisée, la question est vitale. L'objectif de ce travail est de prendre en compte de manière optimale la variabilité spatio-temporelle des états de surface et de la pluie dans la modélisation pluie-d...

Baisse des pluies et augmentation des e ´coulements au Sahel : impact climatique et anthropique sur les e ´coulements du Nakambe au Burkina Faso Résumé Le bassin du Nakambe à Wayen (Burkina-Faso) occupe une surface de près de 21 000 km 2 en domaine sahélien. Malgré la baisse de la pluviométrie depuis 1970, ses débits de pointe et ses coefficients d...

La réalisation d'une base de données de pluies mensuelles pour l'Afrique est une valorisation par le Laboratoire HydroSciences Montpellier-HSM d'un fond de données pluviométriques africaines, hérité entre autres de l'Orstom, et de son expérience en gestion de bases de données hydroclimatiques en zone intertropicale. Les grilles de données créées pe...

Dans le contexte sahélien, les études menées depuis une vingtaine d'années montrent que les effets conjoints du changement climatique et des activités humaines sur les états de surface sont à l'origine d'un " paradoxe hydrologique ". On observe, en effet, depuis les années 1970 que sur certains bassins versants de cette région les coefficients d'éc...

In a development and climatic change context, it appears necessary to update our knowledge of the hydrology of the Niger River and its tributaries. The presented work focuses on the Bani, principal tributary of the Upper Niger. The results show that the basin rainfall dropped by 15-25% since the beginning of the drought in 1970, but at the outlet o...

Climatic and environmental change is a major political and scientific concern, even more for western Africa, already weakened by three decades of drought. This work aims at an optimal consideration of the spatiotemporal variability of land-use changes and rain in the monthly rainfall-runoff modelling of water resources of the upper Niger River. A d...

The problem of using data outputs from general circulation models (GCMs) to assess the impacts of climate change on runoff in West Africa is addressed. The annual and monthly precipitation data from four GCMs used in the Third Assessment Report of the IPCC were studied over the 1950–1998 period: the CSIRO-Mk2, ECHAM4, HadCM3 and NCAR-PCM models. Tw...

In the Sahel, the studies conducted over the past two decades show that the combined effect of climate change and human activities on the surface conditions is the cause of a "hydrological paradox" seen since the 1970s on some watersheds in this region: the runoff coefficients have risen significantly, sometimes flows are higher than before, despit...