Yves Tramblay

Yves Tramblay
Institute of Research for Development | IRD · 050 - HydroSciences Montpellier (HSM)

PhD & HDR in Hydrology

About

133
Publications
46,816
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3,281
Citations
Introduction
I am a research scientist (CR) of the French Institute of Research for Development. I work on hydrological hazards in developing countries, to improve the modelling of floods, heavy rainfall and droughts in the context of climate change
Additional affiliations
January 2011 - December 2012
Institute of Research for Development
Position
  • Hydrological hazards in North Africa in a changing climate
January 2010 - December 2010
French National Centre for Scientific Research
Position
  • Detection of changes in extreme precipitation using non-stationary models with climatic covariates
January 2009 - December 2009
French National Centre for Scientific Research
Position
  • Assimilation of soil moisture in hydrological models and application to flood forecasting
Education
September 2004 - September 2008
September 2002 - September 2003
Université de Paris 1 Panthéon-Sorbonne
Field of study
  • Geography - Climatology

Publications

Publications (133)
Article
Full-text available
Over the past decades, drought has become a major concern in Morocco due to the importance of agriculture in the economy of the country. In the present work, the standardized precipitation index (SPI) is used to monitor the evolution, frequency, and severity of droughts in the High Atlas basins (N’Fis, Ourika, Rhéraya, Zat, and R’dat), located sout...
Article
Full-text available
The climate of Morocco is characterized by a strong spatial and inter-annual variability. This study provides an evaluation of high-resolution regional climate model (RCM) simulations of precipitation and temperature over Morocco and future projections based on two emission scenarios. The evaluation of the RCM ensemble over the historical period is...
Article
Long droughts periods can affect the Mediterranean region during the winter season, when most of annual precipitation occurs, and consequently have strong impacts on agriculture, groundwater levels and water resources. The goal of this study is to model annual maximum dry spells lengths (AMDSL) that occur during the extended winter season (October...
Conference Paper
Full-text available
Maghreb countries are strongly impacted by floods, causing twice as many deaths as in southern European countries in recent decades. However, due to the lack of data accessibility, there are no studies to analyze whether the frequency or intensity of floods are changing at the regional scale. In this work, a recent database of daily river discharge...
Conference Paper
Maghreb countries are strongly impacted by floods, causing twice as many deaths as in southern European countries in recent decades. However, due to the lack of data accessibility, there are no studies to analyze whether the frequency or intensity of floods are changing at the regional scale. In this work, a recent database of daily river discharge...
Article
Full-text available
Understanding hydrological variability is of crucial importance for water resource management in sub-Saharan Africa (SSA). While existing studies typically focus on individual river basins, and suffer from incomplete records, this study provides a new perspective of trends and variability in hydrological flood and drought characteristics (frequency...
Article
Full-text available
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...
Poster
Full-text available
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...
Conference Paper
Full-text available
Sub-Saharan Africa is affected by a high-level of temporal and spatial variability in climate, with large impacts on water resources, human lives and economies, notably through hydrological extremes, such as floods and droughts. Using a newly reconstructed 65-year daily streamflow dataset of over 600 stations distributed throughout sub-Saharan Afri...
Article
Full-text available
Study region Atlas Mountains located in Morocco. Study focus Mountainous regions constitute an area of water production, while water is used in downstream plains. In Central Morocco, the Atlas Mountains represent the most important water supply in the country. The solid part of precipitation forms seasonal snowpack. Snowmelt is important for the w...
Conference Paper
Satellite-based and Reanalysis rainfall products could be a valuable source of data for precipitation for hydrological modeling over data-scarce regions. The objective of this study is to assess the suitability of ERA5 Reanalysis and GPM IMERG V06 data (GPM-Early, GPM-Late and GPM-Final) for flood modeling over a Moroccan semi-arid watershed (Rhera...
Conference Paper
Full-text available
Sub-Saharan Africa is affected by a high-level of temporal and spatial climate variability, with large impacts on water resources, human lives and economies, notably through hydrological extremes, such as floods and droughts. Using a newly reconstructed 65-year daily streamflow dataset of over 600 stations distributed throughout sub-Saharan Africa,...
Conference Paper
Full-text available
Climate change, as one of the most significant challenges that humans currently face, is defined as a shift in climate patterns in response to increasing greenhouse gas emissions in the atmosphere. Notably, climate change has been associated with global warming temperature, regional changes in rainfall patterns and extreme events. Such changes in c...
Conference Paper
Full-text available
Medjerda is a key transboundary watershed (Algeria and Tunisia) in the Maghreb region. The analysis of rainfall regime in this basin is of paramount importance for water resources management and for regional economic development notably in relation with agriculture. This study examines the rainfall trends over the Medjerda watershed on a multi-temp...
Article
Full-text available
Soil moisture is a key variable for drought monitoring, but soil moisture measurements networks are very scarce. Land-surface models can provide a valuable alternative for simulating soil moisture dynamics, but only a few countries have such modelling schemes implemented for monitoring soil moisture at high spatial resolution. In this study, a soil...
Article
Full-text available
This study presents a new data set of gauged streamflow (N = 3,224) for Europe spanning the period 1962–2017. The Monthly Streamflow of Europe Dataset (MSED) is freely available at http://msed.csic.es/. Based on this data set, changes in the characteristics of hydrological drought (i.e., frequency, duration, and severity) were assessed for differen...
Article
Full-text available
Medjerda is a key transboundary watershed in the Maghreb region, crossing from the Algerian mountains through northern Tunisia. Therefore, the analysis of the rainfall regime in this basin is of paramount importance for water resources management and regional economic development, notably concerning agriculture. This study examines the rainfall tre...
Article
Full-text available
Approximately 10 years ago, convection‐permitting regional climate models (CPRCMs) emerged as a promising computationally affordable tool to produce fine resolution (1–4 km) decadal‐long climate simulations with explicitly resolved deep convection. This explicit representation is expected to reduce climate projection uncertainty related to deep con...
Chapter
Full-text available
Ce chapitre a été produit par 17 chercheurs de différentes disciplines (hydrologie, hydrogéologie, géographie, science politique, sciences de gestion…), appartenant à une communauté de recherche régionale sur l’eau bien structurée et identifiée aux niveaux national et international. Les contributions réunies ici présentent un état synthétique et ac...
Article
Mediterranean countries are strongly affected by reduced surface water resources. This study aims to assess the climate change impacts on runoff supply to the Bin El Ouidane dam in Morocco, the largest in terms of hydropower production. A water balance model coupled with a stochastic calibration method to provide confidence intervals on simulated d...
Article
Full-text available
Africa is severely affected by floods, with an increasing vulnerability to these events in the most recent decades. Our improved preparation against and response to this hazard would benefit from an enhanced understanding of the physical processes at play. Here, a database of 399 African stream gauges is used to analyze the seasonality of observed...
Article
Full-text available
RESUME Les crues ont des impacts socio-économiques importants tout particulièrement dans les régions méditerranéennes et il existe une forte interrogation quant à une éventuelle augmentation de leur intensité due au changement climatique. Sur le pourtour Méditerranéen, il est désormais établi que les précipitations extrêmes pourraient augmenter dan...
Conference Paper
Full-text available
Africa is affected by a high-level of temporal and spatial variability in climate, with large impacts on water resources, human lives and economies. Due to data scarcity, the impact of multi-year climate variations on hydrological variability and extremes, i.e. flood and drought, as well as how catchment properties could modulate those impacts, are...
Poster
Full-text available
The Mediterranean region is identified as a climate change hotspot, where future scenarios indicate an increase of temperature associated with a decrease of precipitation. Providing future scenarios of water resource availability considering both climate and anthropogenic changes on karst catchments remains a major challenge for hydrological scienc...
Article
Full-text available
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...
Article
The Mediterranean region is a climate change hotspot where the rate of climate change exceeds the global mean. The rapidly changing climate in combination with an increase in anthropogenic pressures cause water resources in the Mediterranean basin to become increasingly scarce. Modelling future water resource availability considering both climate a...
Article
Full-text available
In semiarid areas, the climate is characterized by strong spatiotemporal variability while the meteorological ground network is often very sparse. In this context, the spatial distribution of meteorological variables is thus a real issue for watershed hydrology, agronomy and the study of surface–atmosphere retroaction in these regions. The aim of t...
Article
Full-text available
Future climate scenarios for the Mediterranean region indicate a possible decrease in annual precipitation associated with an intensification of extreme rainfall events in the coming years. A major challenge in this region is to evaluate the impacts of changing precipitation patterns on extreme hydrological events such as droughts and floods. For t...
Article
Full-text available
Intermittent rivers are prevalent in many countries across Europe, but little is known about the temporal evolution of intermittence and its relationship with climate variability. Trend analysis of the annual and seasonal number of zero-flow days, the maximum duration of dry spells and the mean date of the zero-flow events is performed on a databas...
Preprint
Full-text available
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...
Article
Full-text available
The Mediterranean region is characterized by intense rainfall events giving rise to devastating floods. In Maghreb countries such as Morocco, there is a strong need for forecasting systems to reduce the impacts of floods. The development of such a system in the case of ungauged catchments is complicated, but remote-sensing products could overcome t...
Article
Full-text available
Floods represent a major natural hazard in Africa, causing over 27000 fatalities during the period 1950-2019. Despite its relevance, little is known about changes in flood hazard across this continent due to the lack of long-term high-quality streamflow records. Here we use a newly assembled discharge dataset of African rivers, and provide a long-t...
Article
Full-text available
A new precipitation dataset is provided since 2014 by the Global Precipitation Measurement (GPM) satellite constellation measurements combined in the Integrated Multi-satellite Retrievals for GPM (IMERG) algorithm. This recent GPM-IMERG dataset provides potentially useful precipitation data for regions with a low density of rain gauges. The main ob...
Article
Droughts can have strong environmental and socioeconomic impacts in the Mediterranean region, in particular for countries relying on rain-fed agricultural production, but also in areas in which irrigation plays an important role and in which natural vegetation has been modified or is subject to water stress. The purpose of this review is to provide...
Article
Full-text available
We present a long-term assessment of precipitation trends in Southwestern Europe (1850–2018) using data from multiple sources, including observations, gridded datasets and global climate model experiments. Contrary to previous investigations based on shorter records, we demonstrate, using new long-term, quality controlled precipitation series, the...
Article
Full-text available
This article introduces a Matlab© code to implement the General Differential Split Sample Test (GDSST) (Dakhlaoui et al., 2019). As an illustration, the GDSST is applied to five catchments in northern Tunisia over 30-year reference period and compared to three benchmark Split Sample Test (SST) methods. The techniques are compared as regards to the...
Article
Full-text available
North Africa is considered a climate change hot spot. Existing studies either focus on the physical aspects of climate change or discuss the social ones. The present article aims to address this divide by assessing and comparing the climate change vulnerability of Algeria, Egypt, Libya, Morocco, and Tunisia and linking it to its social implications...
Preprint
Full-text available
Future climate scenarios for the Mediterranean region indicate a possible decrease in annual precipitation associated with an intensification of extreme rainfall events in the coming years. A major challenge in this region is to evaluate the impacts of changing precipitation patterns on extreme hydrological events such as droughts and floods. For t...
Article
We analyzed long‐term variability and trends in meteorological droughts across Western Europe using the Standardized Precipitation Index (SPI). Precipitation data from 199 stations spanning the period 1851‐2018 were employed, following homogenisation, to derive SPI‐3 and SPI‐12 series for each station, together with indices on drought duration and...
Preprint
Full-text available
The Mediterranean region is characterized by intense rainfall events giving rise to devastating floods. In Maghreb countries such as Morocco, there is a strong need for forecasting systems to reduce the impacts of floods. The development of such a system in the case of ungauged catchments is complicated but remote sensing products could overcome th...
Article
Full-text available
Flash floods are common in small Mediterranean watersheds and the alerts provided by real-time monitoring systems provide too short anticipation times to warn the population. In this context, there is a strong need to develop flood forecasting systems in particular for developing countries such as Morocco where floods have severe socioeconomic impa...
Book
Water Resources in the Mediterranean Region summarizes and collates scientific developments around water resources in the mediterranean socio-economic environment through a multidisciplinary framework synthesizing hydrology, hydrogeology, climate, bioclimatology, economics, and geography. As such, it provides essential information for any reader lo...
Article
Full-text available
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...
Article
Full-text available
Dry spells are natural hazards which have strong impacts on the environment and on many socioeconomic sectors. Their evolution in the Mediterranean Basin is a major issue because it is one of the most extreme hot spots of climate change world-wide. Very long dry spells are defined as climatic events characterized by their location, spatial extent,...
Article
Full-text available
The High Atlas of Morocco is a semi-arid mountainous environment that frequently suffers from natural hazards. For example, the watersheds upstream of Marrakech city are subject to extreme floods, caused by heavy rains. These episodes are frequent and often devastating, as was the August 1995 event that caused hundreds of deaths in the Ourika Valle...
Article
Full-text available
Recent events in Western Attica in Greece (24 deaths in November 2017), in the Balearic Islands (13 deaths in October 2018), and in southern France (15 deaths in October 2018) show that flood-related mortality remains a major concern in Mediterranean countries facing flash floods. Over the past several years, many initiatives have arisen to create...
Article
Full-text available
Floods have strong impacts in the Mediterranean region and there are concerns about a possible increase in their intensity due to climate change. In this study, a large database of 171 basins located in southern France with daily discharge data with a median record length of 45 years is considered to analyze flood trends and their drivers. In addit...
Article
Full-text available
To define a dry day, the most common approach is to identify a fixed threshold below which precipitation is considered equivalent to zero. This fixed threshold is usually set to account for measurement errors and precipitation losses due to the atmospheric evaporation demand. Yet, this threshold could vary in time according to the seasonal cycle an...
Article
Full-text available
Floods have strong impacts in the Mediterranean region and there is a questioning about a possible increase in their intensity due to climate change. In this study, a large database of 171 basins located in South France with daily discharge data with a median record length of 45 years is considered to analyze flood trends and their drivers. In addi...
Article
Full-text available
A new high‐resolution (5 km) gridded daily precipitation dataset for Tunisia between 1979 and 2015 is introduced. This product combines 960 rain gauges with the SAFRAN analysis to produce the precipitation gridded data. A validation approach on two different datasets reveals that the SAFRAN analysis outperforms other standard interpolation methods...
Article
This study proposes a general differential split-sample test (GDSST) based on an oriented bootstrap to assess the transferability of conceptual rainfall-runoff models to climatically contrasting periods. Compared to existing benchmark techniques, the GDSST allows a larger number of climatically contrasted discontinuous periods to be sampled, and is...
Article
Full-text available
Purpose The purpose of this paper is to identify vulnerable areas for flood hazard and to analyze stakes exposed in touristic valley of Morrocan mountains. The three goals are: methodological (low-cost diagnosis without starting data), operational (to show the risk and identify avenues of prevention in Ourika) and incentive (to reproduce this on ot...