Nanée Chahinian

• PhD
• Institute of Research for Development

Segmenting Synthetic Aperture Radar (SAR) images is crucial for many remote sensing applications, particularly water body detection. However, deep learning-based segmentation models often face challenges related to convergence speed and stability, mainly due to the complex statistical distribution of this type of data. In this study, we evaluate th...

Effective wastewater and stormwater management is essential for urban sustainability and environmental protection. Extracting structured knowledge from reports and regulations is challenging due to domainspecific terminology and multilingual contexts. This work focuses on domain-specific Named Entity Recognition (NER) as a first step towards effect...

Morphometric properties of channel networks are useful tools to classify catchments and calculate their hydrological response. Scaling laws have been established for Optimal Channel Networks (OCNs), which are defined based on a generative geomor-phological mechanism of minimizing the total energy dissipation. However, sewer networks obey engineerin...

Nowadays, data on wastewater networks covering the same geographical territory are available from different sources. The fusion of multi-source spatial data provides a new and richer dataset that can serve several purposes such as quality improvement, decision making, or delivery of new services. It has given rise to several research works focused...

Devastating floods have plagued many West African cities in the past decades. In an attempt to reduce flood damage in Bamako (Mali), an early warning system (EWS) demonstrator (Raincell App) was developed for flash floods. On 16 May 2019, while the demonstrator was partially operational, an intense rainfall event led to devastating floods. We carri...

Hydraulic simulation represents a powerful tool for studying wastewater networks. In order to achieve this target, hydraulic software require a set of parameters such as pipe slopes, roughness, diameters, etc. However, these pieces of information are rarely known for each and every pipe. Moreover, underground networks are frequently expanded, repai...

Intensification of the hydrological cycle resulting from climate change in West Africa poses significant risks for the region's rapidly urbanising cities, but limited research on flood risk has been undertaken at the urban domain scale. Furthermore, conventional climate models are unable to realistically represent the type of intense storms which d...

Underground networks, particularly sewerage networks require accurate information for their management. To successfully and smoothly accomplish the required tasks for network expansion, reparation or simulation analysis, operators collect and analyse data coming from multiple sources. The various and heterogeneous sources available often provide di...

Wastewater networks are mandatory for urbanisation. Their management, including the prediction and planning of repairs and expansion operations, requires precise information on their underground components (manhole covers, equipment, nodes, and pipes). However, due to their years of service and to the increasing number of maintenance operations the...

We present the MeDO project, aimed at developing resources for text mining and information extraction in the wastewater domain. We developed a specific Natural Language Processing (NLP) pipeline named WEIR-P (WastewatEr InfoRmation extraction Platform) which identifies the entities and relations to be extracted from texts, pertaining to information...

Urban floods due to intense precipitation are a major problem in many tropical regionsas in Africa. Rainfall measurement using microwave links from cellular communicationnetworks has been proposed as a cost effective solution to monitor rainfall in theseareas where the gauge network is scarce. The method consists in retrieving rainfallfrom the atte...

Urban catchments are heterogeneous in terms of land use and have both natural and artificial drainage networks. Modelling them is not a straightforward task especially in data-scarce settings. This study investigates network representation in hydrological modelling using field data collected between 2008 and 2018 on the Oued Fez catchment. The road...

Urban floods due to intense precipitation is a major problem in many developing countries, especially in Africa. There are few available solutions for effective and yet affordable flood early warning systems for these regions. Weather radar is common in industrialized countries but too costly for most tropical cities. Satellite provides interesting...

Urban floods due to intense precipitation is a major problem in many developing countries, especially in Africa. There are few available solutions for effective and yet affordable flood early warning systems for these regions. Weather radar is common in industrialized countries but too costly for most tropical cities. Satellite provides interesting...

Accurate maps of wastewater networks in cities are mandatory for an integrated management of water resources. However, in many countries around the world this information is unavailable or inaccurate. A new mapping method is put forward to create maps using manhole cover locations which could be available via ground surveys, remote sensing techniqu...

RÉSUMÉ. Le projet "Mégadonnées, données liées et fouille de données pour les réseaux d’assainissement" (MeDo) a pour objectif de tirer profit des mégadonnées disponibles sur le web pour renseigner la géométrie et l’historique d’un réseau d’assainissement, en combinant différentes techniques de fouille de données et en multipliant les sources analys...

African cities are prone to recurrent flooding due to unfavourable rainfall conditions, often insufficient drainage infrastructure and fast and poorly controlled urban development. It is thus important to put forward efficient tools to characterize flooding and its consequences over large urban areas, e.g. the entire agglomeration. However, scarce...

Water quality indexes (WQI) are a practical way to evaluate and compare the level of chemical contamination of different water bodies and to spatially and temporally compare levels of pollution. The purpose of this study was to check if these indexes are appropriate for intermittent rivers under arid and semi-arid climates. A literature review enab...

Urban growth is an ongoing trend and one of its direct consequences is the development of buried utility networks. Locating these networks is becoming a challenging task. While the labeling of large objects in aerial images is extensively studied in Geosciences, the localization of small objects (smaller than a building) is in counter part less stu...

Urban growth is an ongoing trend and one of its direct consequences is the development of buried utility networks. Locating these networks is becoming a challenging task. While the labeling of large objects in aerial images is extensively studied in Geosciences, the localization of small objects (smaller than a building) is in counter part less stu...

African cities are prone to recurrent flooding due to unfavorable rainfall conditions, often insufficient drainage infrastructure and fast and poorly controlled urban development. It is thus important to put forward efficient tools to characterize flooding and its consequences over large urban areas, e.g. the entire agglomeration. However, scarce d...

Accurate maps of sewer and stormwater networks in cities are mandatory for an integrated management of water resources. However, in many countries this information is unavailable or inaccurate. A new two-fold mapping method is put forward. The first step consists in using image processing techniques to detect buried network surface elements such as...

Mispositioning of buried utilities is an increasingly important problem both in industrialized and developing countries because of urban sprawl and technological advances. However, some of these networks have surface access traps, which may be visible on high-resolution airborne or satellite images and could serve as presence indicators. We put for...

Urban growth is an ongoing trend and one of its direct consequences is the development of buried utility networks. With growing needs among consumers, new networks are being in- stalled and more underground space is being occupied. Locating these networks is becoming a challenging task. Mispositioning of utility networks is an important problem for...

One of the direct consequences of urban growth is the multiplication of buried utility networks. It is difficult to obtain complete and accurate maps of these networks because they have often been produced by different parties at different times. This work aims at putting forward a methodology to detect manhole covers on high resolution images, in...

The detection of small objects from aerial images is a difficult signal processing task. To localise small objects in an image, low-complexity geometry-based approaches can be used, but their efficiency is often low. Another option is to use appearance-based approaches that give better results but require a costly learning step. In this paper, we t...

Oued Fez (one of the Sebou River tributaries – Morocco) allowed us to study and quantify the effect of the lack of wastewater treatment on surface water quality in semi-arid hydrological context. The analysis is based on field data collected from June 2009 to December 2011. Concentration and load patterns of nitrogen, phosphorus and chromium (used...

Organotin compounds (OTs) are exclusively anthropogenic and have been widely used for their biocidal properties and as stabilizers in various industrial applications. Hence organotins are common pollutants. Their high toxicity has led to their entry on the EU water framework's priority substances' list. However, few studies are available regarding...

Mediterranean catchments are often characterized by highly variable rainfall inputs and intermittent flows. In comparison to the existing knowledge on their hydrological behaviour, the interactions between flow conditions and pollution levels remain less documented. This study aims at filling that gap through a case study on Oued Fez (Morocco). Oue...

In the South of the Mediterranean basin, many rivers are characterized by an alternation of very long dry periods only cut by short flood events. Currently, the socio-economical development of these zones is limited by water scarcity and poor quality of the water resources. Indeed human activities, generally concentrated in overpopulated cities, ge...

Intermittent rivers have a specific hydrological behaviour which also influences water quality dynamics. The objective of this work was to model the flow and water quality dynamics of a coastal Mediterranean intermittent river using the Soil and Water Assessment Tool (SWAT 2005). Flow, sediment, nitrogen and phosphorus transport were simulated on t...

Organotins (OTs) are anthropogenic molecules used in many industrial applications for their thermoresistant and biocidal properties. Because of their toxicity and widespread use these molecules are on the EU water directive's list of prioritary substances. Organotins are prone to adsorption, can bond easily to particulate matter and "migrate" from...

This study aims to characterise and quantify the pollutant concentrations and fluxes in various locations of the Oued Fez hydrological network and assess their impact on the Sebou River, which is considered as a national priority zone in Morocco. Eight observation sites have been set up to quantify the temporal and spatial variability of pollutant...

In the southern Mediterranean many rivers are characterized by an alternation of long dry periods interrupted by short floods. In this context, understanding the catchment's hydrological behaviour, especially during flood generation is essential to quantifying pollutant fluxes. This situation is observed in all the Maghreb countries, of which the f...

A conceptual lumped rainfall-runoff flood event model was developed and applied on the Gardon catchment located in southern France and various mono-objective and multi-objective functions were used for its calibration. The model was calibrated on 15 events and validated on 14 others. The results of both the calibration and validation phases are com...

Flash floods have a number of impacts on the water quality of river systems because the later is the resultant of pollutant input into the river and its transformation along its course. In the case of intermittent rivers this impact is increased by the long drought periods that usually precede such floods. Indeed, the pollutants are known to accumu...

Butyltins, and most particularly TBT were widely used by the industry in the 1970s and 1980s, namely as anti-fouling paints on ships. Although banned since 2003 in Europe, surveys still point out the presence of these compounds both in coastal and terrestrial environments. The resilience of organotin (OT) compounds can be explained by their high ad...

Organotins (OTs) have been increasingly used in industrial applications because of their thermoresistant and biocidal properties: in the 1970s and 1980s Tributyltin (TBT) based anti-fouling paints were used on ships and vessels of all kinds. However, studies pointed out the highly toxic nature of these compounds and their active role as an endoctri...

A multi-site validation approach is necessary to further constrain distributed hydrological models. Such an approach has been tested on the Gardon catchment located in the mountainous Mediterranean zone of southern France using data gathered over a 10 year period on nine internal subcatchments. A spatially distributed hydrological model linked to a...

Tillage operations are known to greatly influence local overland flow, infiltration and depressional storage by altering soil hydraulic properties and soil surface roughness. The calibration of runoff models for tilled fields is not identical to that of untilled fields, as it has to take into consideration the temporal variability of parameters due...

Soil surface crusts are widely reported to favour Hortonian runoff, but are not explicitly represented in most rainfall-runoff models. The aim of this paper is to assess the impact of soil surface crusts on infiltration and runoff modelling at two spatial scales, i.e. the local scale and the plot scale. At the local scale, two separate single ring...

A description of each of the 15 models used in MOPEX (the Model Parameter Experiment), as reported at the MOPEX workshops in 2004 and 2005, is provided. The following models are included: AFFDEF, GR4H, GR4J, HBV, HYDROTEL, IHACRES, MODSPA, MORDOR, NOAH, RRMT, SAC-SMA, SMAR, SWAP, SWB and VIC. Each is described systematically by the original author(...

As part of the MOPEX 2004 workshop, the participants were asked to submit simulations using the common database provided for the workshop (see Chahinian et al., this issue). The simulations were then analysed and the evaluation criteria computed to compare the models' performance for the gauged and ungauged modes using six criteria describing the m...

The need to work on a large number of basin data sets during hydrological modeling research is discussed. The model intercomparisons can be useful in improving the basin models, provided they are based on the large data sets. The intercomparisons will be extremely instructive in helping to improve models and assessing their generality. The large da...

Recent progress in collecting spatialized data with remote sensing techniques should allow the accounting for: (i) the spatial variability of rainfall and (ii) the basins' physical characteristics in rainfall-runoff models. To benefit from this spatial information, lumped approaches can quite easily be replaced by semi-distributed approaches. Howev...

The MOPEX 2004 workshop was held in Paris in July 2004. As for former workshops, the participants were asked to test their models and explore new parameter estimation strategies using the common databases. However, for this workshop a new series of 40 French catchments was added to the existing MOPEX database. The new data consists of hourly estima...

This paper presents three different spatially distributed hydrological models and discusses the possibility of using them for flow simulation when only lumped information is available for the meteorological input. The three models, namely, AFFDEF, HYDROTEL and ModSpa, are applied on three French catchments from the MOPEX database. The purpose of th...

As part of the MOPEX 2004 workshop, the participants were asked to submit simulations using the common database provided for the workshop (see Chahinian et al this issue). The simulations were then analysed and the evaluation criteria computed to compare the models' performance for the gauged and ungauged modes using six criteria describing the mod...

The following section presents a synthetic description of the models that were used in the various articles of this Red Book. The following models are covered (descriptions can be found in alphabetical order) : AFFDEF, GR4H, GR4J, HBV, HYDROTEL, IHACRES, MODSPA, MORDOR, NOAH, RRMT, SAC-SMA, SMAR, SWAP, SWB, VIC.

There is nowadays such a wealth of publications in hydrology, that it seems unlikely that any hydrologist can find the time to read even a decent part of it. Therefore, we have planned this preface as a rapid introduction to the papers that constitute this volume. Our aim is to convince you, the reader, to keep reading in order to discover the orig...

The MOPEX 2004 workshop was held in Paris in July 2004. As for former workshops, the participants were asked to test their models and explore new parameter estimation strategies using the common databases. However, for this workshop a new series of 40 French catchments was added to the existing MOPEX database. The new data consists in hourly estima...

Cette ouvrage rassemble un ensemble de contributions soumises par les groupes de recherche qui ont participé au programme MOPEX, et qui s'appuient pour l'essentiel sur des échantillons importants de bassins versants.

Recent progress in collecting spatialised data with remote sensing techniques should allow the accounting for (i) the spatial variability of rainfall and (ii) the basins' physical characteristics in rainfall-runoff models. To benefit from this spatial information, lumped approaches can quite easily be replaced by semi-distributed approaches. Howeve...

Most runoff simulation and infiltration models have been developed at the global-catchment scale or the local-soil column scale. Few models have been specifically developed at the scale of agricultural fields and there are no guidelines to help modellers choose an adequate model to simulate overland flow and hence analyse the impact of different so...

A systemic, process-based conceptual model of the soil-shrinkage curve (SC) for characterizing and parameterizing the soil–water medium is presented in this chapter. The model demonstrates a unique link between soil water properties of nonrigid aggregated soil medium and its internal volume change. This leads to a physically based and functional mo...

Hortonian overland flow by rainfall excess seems to be the main runoff process in semi-arid areas as demonstrated directly through observations and measurements of rainfall-runoff events, and indirectly from isotopic, geochimical and biological tracer tests. Examples taken from semi-arid tropical zone (Burkina Faso and Senegal) and the Mediterranea...

Hortonian overland flow by rainfall excess seems to be the main runoff process in semi-arid areas as demonstrated directly through observations and measurements of rainfall-runoff events, and indirectly from isotopic, geochimical and biological tracer tests. Examples taken from semi-arid tropical zone (Burkina Faso and Senegal) and the Mediterranea...

Soil surface crusts are widely reported to restrict infiltration, and thereby to favour overland flow. However, most hydrological models at the catchment scale do not take explicitly into account the crust effect and consider the soil surface to be homogeneous with respect to soil hydraulic properties. The aim of this study is to estimate the bias...

Tillage operations are known to change the structure of agricultural soils. In this paper we seek a calibration methodology to take into account the impact of tillage on overland flow simulation at the scale of a tilled field located in southern France. The study site is a 3240 m2 vineyard equipped with a Venturi flume and a tipping bucket rain gau...

Field limits, tillage practices and ditch network constitute man-made hydrological discontinuities in farmed catchments, and are expected to influence hydrological response during flood events. The purpose of this study is to assess the role of human impact, especially the existence of tillage practices and ditch network, on flood events. The study...

Flood events can vary in intensity and duration and are known to cause considerable material damage through soil erosion, pollutant transport and property destruction. Therefore, a good understanding and modelling of such flood events in essential for sustainable water management. The aim of this work was to apply Philip's model to 28 flood events...

In agricultural catchments, hydrological processes are largely variable in space due to human impact causing hydrological discontinuities such as ditch network, field limits and terraces. The ditch network accelerates runoff by concentrating flows, drains the water table or replenishes it by reinfiltration of the runoff water. During extreme flood...