Sylvain Ferrant

Sylvain Ferrant
Institute of Research for Development | IRD · 113 - Centre for the Study of the Biosphere from Space (CESBIO)

PhD

About

48
Publications
11,820
Reads
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611
Citations
Introduction
"Agro-hydrology from space" project is supported by the ESA living planet program Agricultural practices impacts on water and nitrogen cycles for 2 agricultural water management issues: nitrate contamination in cultivated area in South-West of France and groundwater shortages in irrigated area in South-India. Sentinel-1 and 2 missions are an opportunity to detect agricultural practices, stress and simulate nitrogen excess and groundwater shortages with appropriate agro-hydrological models.
Additional affiliations
October 2017 - present
Paul Sabatier University - Toulouse III
Position
  • Researcher
Description
  • Researcher in environmental modelling for agricultural impacts on water resources. My research focus nowadays on the agro-hydrological variables restitutions from high spatial end temporal remote sensing for developping assimilation scheme into agro-hydrological modelling tools for water management issues in agricultural landscapes or carbon budget estimates from natural wetlands.
November 2012 - October 2014
Centre National d’Etudes Spatiales
Position
  • post-doctoral position
Description
  • Combining vegetation products derived from high resolution satellite images and agro-hydrological models to develop new spatial calibration strategy for crop growth, transpiration and soil parameters within an agro-hydrological modelling approach.
May 2012 - September 2012
National University of Singapore
Position
  • Research Associate in hydro-chemistry
Description
  • Involved in the National Park project on Singaporean river water acidification.
Education
June 2006 - December 2009
Paul Sabatier University - Toulouse III
Field of study
  • Environmental sciences
September 2002 - September 2005
École Nationale Supérieure Agronomique de Toulouse
Field of study
  • Agronomy, environmental ressources management

Publications

Publications (48)
Article
Full-text available
Sentinel-2 (S2) earth observation satellite mission, launched in 2015, is foreseen to promote within-field decisions in Precision Agriculture (PA) for both: (1) optimizing crop production; and (2) regulating environmental impacts. In this second scope, a set of Leaf Area Index (LAI) derived from S2 type time-series (2006-2010, using Formosat-2 sate...
Article
Full-text available
Local groundwater levels in South India are falling alarmingly. In the semi-arid crystalline Deccan plateau area, agricultural production relies on groundwater resources. Downscaled Global Climate Model (GCM) data are used to force a spatially distributed agro-hydrological model in order to evaluate Climate Change (CC) effects on local groundwater...
Article
Full-text available
The growing availability of high-resolution satellite image series offers new opportunities in agro-hydrological research and modeling. We investigated the possibilities offered for improving crop-growth dynamic simulation with the distributed agro-hydrological model: topography-based nitrogen transfer and transformation (TNT2). We used a leaf area...
Poster
Full-text available
Description of an extensive method for the validation of GRACE-derived downscaled GWS with in situ data
Preprint
GRACE (Gravity Recovery and Climate Experiment) and its follow-on mission have provided since 2002 monthly anomalies of total water storage (TWS), which are very relevant to assess the evolution of groundwater storage (GWS) at global and regional scale. However, the use of GRACE data for groundwater irrigation management is limited by their coarse...
Article
Full-text available
We here submit a proposal based on various fieldworks carried out in some of the countries affected by the violence of the fundamentalist sects known as Boko Haram. On-site surveys show that, due to strong demographic growth, the absence of land reserves and the fact that land inheritance is in practice reserved for the eldest male, there is a larg...
Article
This study evaluates the risk of groundwater contamination from unlined oil pits, in the Northern Ecuadorian Amazon (NEA). Applying spatial analysis, several maps were provided for its integration in land use planning, public health improvement and future site-specific investigations. Two main maps were produced: (1) a vulnerability indexed map usi...
Article
Full-text available
Water stock monitoring is a major issue for society on a local and global scale. Sentinel-1&2 satellites provide frequent acquisitions to track water surface dynamics, proxy variables to enable water surface volume monitoring. How do we combine such observations along time for each sensor? What advantages and disadvantages of single-date, monthly o...
Article
Mapping soil properties is becoming more and more challenging due to the increase in anthropogenic modification of the landscape, calling for new methods to identify these changes. A striking example of anthropogenic modifications of soil properties is the widespread practice in South India of applying large quantities of silt from dry river dams (...
Article
Full-text available
This paper reports atmospheric profiles of N2O retrieved from Metop/IASI with the Software for the Retrieval of IASI Data (SOFRID) for the 2008–2018 period and their validation with FTIR data from 12 stations of the Network for the Detection of Atmospheric Composition Changes (NDACC). SOFRID retrievals performed in the 2160–2218 cm−1 spectral windo...
Article
The hydrochemical time series of stream water from a cultivated catchment were investigated at different time scales and survey frequencies. A 35-year time series of nitrate concentration and discharge, a 15-year time series of major elements and dissolved organic carbon (DOC) concentrations were analysed from a yearly to a daily/ hourly basis duri...
Article
Full-text available
Indian agriculture relies on monsoon rainfall and irrigation from surface and groundwater. The inter-annual variability of monsoon rainfalls is high, which forces South Indian farmers to adapt their irrigated area extents to local water availability. We are developing and testing an automatic methodology for monitoring spatio-temporal variations of...
Article
Full-text available
Optimizing management practices at the plot scale is sometimes not sufficient to reach water framework directive objectives for nitrate pollution. Land management measures involving targeted setting aside of croplands is a promising solution, but its efficiency depends on the local context. We used a distributed agro-hydrological model to compare m...
Article
Full-text available
Since the 1970s, the northern part of the Amazonian region of Ecuador has been colonized with the support of intensive oil extraction that has opened up roads and supported the settlement of people from Out-side Amazonia. These dynamics have caused important forest cuttings but also regular oil leaks and spills, con-taminating both soil and water....
Poster
Full-text available
The Aurade catchment (328 ha), mainly cultivated (94% of wheat and sunflower in rotation), drains calcareous soils on Miocene molassic deposits (impermeable substratum). The climate is continental semi-arid (P=700-800 mm.y-1; Q= 80-120 mm.y-1), with severe drought periods and flash flood events. The hydrochemical monitoring has been set up in 1982...
Technical Report
Full-text available
Sentinel-1 (S1) radar and Sentinel-2 (S2) optical detections of agricultural areas allow spatio-temporal monitoring of crop growth and surface water dynamics since 2015 at the global scale. This project have explored two ways of exploiting these newly data at high spatial and temporal resolution (respectively 10-20 meters and 5-10 days): 1- the lon...
Article
An innovative approach for regionalizing the 3-D effective-porosity field is presented and applied to two large, overexploited and deeply weathered crystalline aquifers located in southern India. The method derives from earlier work on regionalizing a 2-D effective-porosity field in that part of an aquifer where the water table fluctuates, which is...
Chapter
Full-text available
Agriculture brings with it a number of issues: agricultural production and food security, water and soil resource conservation, limiting the impact of farming on the quality of our environment (water, air, soil). In the context of global changes and the challenges they pose for agriculture sustainability, our ability to characterize how croplands f...
Conference Paper
Full-text available
In the context of global changes and population growth, agricultural activities are a growing factor influencing water resources availability in term of quantity and quality. Water management strategies have to be analyzed at a regional catchment scales. Yet, agricultural practices, crop water and nutrient consumption that drive the main water and...
Chapter
Natural and anthropogenic forcing factors and their changes significantly impact water resources in many river basins around the world. Information on such changes can be derived from fine scale in situ and satellite observations, used in combination with hydrological models. The latter need to account for hydrological changes caused by human activ...
Article
Full-text available
Natural and anthropogenic forcing factors and their changes significantly impact water resources in many river basins around the world. Information on such changes can be derived from fine scale in situ and satellite observations, used in combination with hydrological models. The latter need to account for hydrological changes caused by human activ...
Article
Agriculture brings with it a number of issues: agricultural production and food security, water and soil resource conservation, limiting the impact of farming on the quality of our environment (water, air, soil). In the context of global changes and the challenges they pose for agriculture sustainability, our ability to characterize how croplands f...
Book
Natural and anthropogenic forcing factors and their changes significantly impact water resources in many river basins around the world. Information on such changes can be derived from fine scale in situ and satellite observations, used in combination with hydrological models. The latter need to account for hydrological changes caused by human activ...
Research
Full-text available
This is a technical report that explains the methodology behind the project SHIVA: "Socio-economic Assessment of the rural Vulnerability of water users under stressors of global changes in the Hard rock area of South India". The Soil Water Assessment Tool (SWAT) has been used to simulate the water extraction, groundwater recharge and storage in th...
Article
Full-text available
The growing availability of high-resolution satellite image series offers new opportunities in agro-hydrological research and modeling. We investigated the possibilities offered for improving crop-growth dynamic simulation with the distributed agro-hydrological model: topography-based nitrogen transfer and transformation (TNT2). We used a leaf area...
Technical Report
Full-text available
The recent and forthcoming availability of high resolution satellite image series offers new opportunities in agro-hydrological research and modeling. We investigated the perspective offered by improving the crop growth dynamic simulation using the distributed agro-hydrological model, Topography based Nitrogen transfer and Transformation (TNT2), us...
Conference Paper
Full-text available
Agro-hydrological modeling is a powerful tool to study the interactions between agricultural practices, catchment physiographic variables and their impact on hydrology, stream water quality and crop productivity. At the catchment scale, numerous factors control crop growth: soil water content, nitrogen availability, local climatic variables, topogr...
Article
Full-text available
Field evidence is presented to demonstrate that a very large landslide blocked the Jinsha River (the main stem of the Yangtze) near the present day town of Qiaojia, Yunnan Province. The discovery is significant because no persistent river-blocking landslide has been reported so far downstream in a major catchment. At the location of the landslide d...
Article
Field evidence is presented to demonstrate that a very large landslide blocked the Jinsha River (the main stem of the Yangtze) near the present day town of Qiaojia, Yunnan Province. The discovery is significant because no persistent river-blocking landslide has been reported so far downstream in a major catchment. At the location of the landslide d...
Article
Full-text available
A nitrate sensor has been set up to measure every 10 min the nitrate signal in a stream draining a small agricultural catchment dominated by fertilized crops during a 2-year study period (2006–2008) in the south-west of France. An in situ sampling protocol using automatic sampler to monitor flood events have been used to assume a point-to-point cal...
Article
tThe agro-hydrological model TNT2 was used to explore for a period of 14 years (1987–2001) the likely consequences of mitigation scenarios on nitrate contamination of the stream water in a small agricultural catchment. The Best Management Practices (BMPs) historically designed and implemented in 1992 and two devised agricultural scenarios (catch cr...
Article
Full-text available
The coupling of an hydrological and a crop model is an efficient approach to study the impact of the interactions between agricultural practices and catchment physical characteristics on stream water quality. We analyzed the consequences of using different modeling approaches of the processes controlling the nitrogen (N) dynamics in a small agricul...
Conference Paper
Full-text available
In most parts of India, and particularly in South India, groundwater levels are hazardously declining, while agricultural groundwater use is increasing. The current issue is to address the probable evolution of water table levels in relation with climate and agricultural changes. The aim of the SHIVA-ANR project (http://www.shiva-anr.org) is to pro...
Conference Paper
Full-text available
Pesticide monitoring, understanding of pesticide fate and pollution quantification have become major concerns in Europe since the introduction of the Water Framework Directive in 2000. Pesticides can be transported from agricultural catchments to stream networks in either the soluble or particulate phase, depending on their physicochemical properti...
Thesis
Full-text available
Ce travail a eu comme objectif de comprendre et quantifier les transferts d'azote agricoles dans les rivières des bassins versants Gascons, afin d'évaluer l'efficacité de scénarii agricoles sur la teneur en azote nitrique des rivières. Un protocole de mesure en continue dans le petit bassin versant agricole d'Auradé (Gers, Sud-Ouest de la France) d...
Conference Paper
Full-text available
The comprehension of surface water contaminant dynamics (pesticides, metals) is of great importance in order to better improve water quality management. In this context, the quantification of Suspended Sediment (SS) dynamics in surface water at the watershed scale is the first study step as SS corresponds to the carrier phase for some contaminants....
Conference Paper
Full-text available
Agriculture is known to have a great impact of nutrients enrichment on continental water resources. In south-West of France (Gascogne region), water resource are essentially surface water and shallow aquifer. Nitrogen dynamic in river is complex and highly variable throughout season and year, depending on hydrology, landuse, removal in stream. In t...
Conference Paper
Full-text available
Nitrogen exports in catchments are known to be greatly variable because nitrogen cycle in watershed is controlled by different factors such as landuse, farm management practices, climate, soil type and hydrological setting. Our aim is to study the relative importance of the processes controlling nitrogen losses at catchment scale in the long term u...

Projects

Projects (3)
Archived project
Project
Project
The synergetic use of Sentinel-1 radar and Sentinel-2 optical detection of vegetation and wetness index of cultivated areas for two agricultural region in south of France and south of India. The aim is to evaluate the benefit of spatial calibration of agro-hydrological model based on remote sensing time series. In south of France, the nitrogen cycle is highly hinging on the high spatial variability of crop growth along soil depth and position in the slopes. Are the spatial calibration of crop growth will improve the simulation of stream water nitrogen pollution? In south India, the water cycle highly depends on monsoon variability and groundwater pumping for irrigation. Groundwater table drop in case of low monsoon recharge. The first farmers adaptation strategy to groundwater shortages is to reduce the irrigated area extents. They are varying in time from 2 to 10 % of the total area in semi-arid areass of the Deccan plateau. Is it possible to monitor this strategy at large scale with Sentinels?