Southern France

Top PDF Southern France:

Flash flood forecasting in poorly gauged basins using neural networks: case study of the Gardon de Mialet basin (southern France)

Flash flood forecasting in poorly gauged basins using neural networks: case study of the Gardon de Mialet basin (southern France)

Abstract. In southern France, flash flood episodes fre- quently cause fatalities and severe damage. In order to in- form and warn populations, the French flood forecasting service (SCHAPI, Service Central d’Hydrom´et´eorologie et d’Appui `a la Pr´evision des Inondations) initiated the BVNE (Bassin Versant Num´erique Exp´erimental, or Experimental Digital Basin) project in an effort to enhance flash flood predictability. The target area for this study is the Gardon d’Anduze basin, located in the heart of the C´evennes range. In this Mediterranean mountainous setting, rainfall intensity can be very high, resulting in flash flooding. Discharge and rainfall gauges are often exposed to extreme weather condi- tions, which undermines measurement accuracy and conti- nuity. Moreover, the processes governing rainfall-discharge relations are not well understood for these steeply-sloped and heterogeneous basins. In this context of inadequate in- formation on both the forcing variables and process knowl- edge, neural networks are investigated due to their univer- sal approximation and parsimony properties. We demonstrate herein that thanks to a rigorous variable and complexity se- lection, efficient forecasting of up to two-hour durations, without requiring rainfall forecasting as input, can be derived using the measured discharges available from a feedforward model. In the case of discharge gauge malfunction, in de- graded mode, forecasting may result using a recurrent neural network model. We also observe that neural network mod- els exhibit low sensitivity to uncertainty in rainfall measure- ments since producing ensemble forecasting does not signif- icantly affect forecasting quality. In providing good results, this study suggests close consideration of our main purpose: generating forecasting on ungauged basins.
Show more

18 Read more

Spatially resolved strontium isotope micro analysis of lower and middle palaeolithic fauna from archaeological sites in Israel and Southern France

Spatially resolved strontium isotope micro analysis of lower and middle palaeolithic fauna from archaeological sites in Israel and Southern France

Palaeolithic reindeer are interpreted to migrate bi-annually, similar to the modern North American caribou (Bahn 1977). Cervid have been common in southern France since ~555 ka, with red deer (Cervus elaphus) the dominant species and reindeer (Rangifer tarandu) becoming common during colder periods (Boyle 1998). The reindeer played a dominant role in the Upper Palaeolithic economy in the Aquitaine region (Burke 1995). Reindeer appeared to exist in the Palaeolithic Perigord region in conditions less cold than observed for modern examples (Laville et al. 1980). Dama mesopotamica and Cervus elaphus have been found in Israel since the start of the Riss-Würm period of the Middle Pleistocene era (Tchernov 1979). Dama mesopotamica were particularly common in late Palaeolithic caves in Israel and became extinct in the region only during the last century (Qumsiyeh 1996). Red deer favour the subarctic forest, while reindeer favour a slightly more open environment (Gamble 1992:104). Reindeer were very mobile and red deer were somewhat mobile during the last glacial period (Gamble 1992). Reindeer and perhaps red deer and horse migrated principally in an east-west transect, taking advantage of a steepened ecological gradient between the Perigord and the Massif Central during glacial periods (Mellars 1996:53).
Show more

493 Read more

Late Holocene vegetation changes in relation with climate fluctuations and human activity in Languedoc (southern France)

Late Holocene vegetation changes in relation with climate fluctuations and human activity in Languedoc (southern France)

The Languedoc is located in southern France under both Mediterranean and Atlantic climatic influences. Numerous archeological and historical records are available for this re- gion, including archeobotanical studies valuable for assess- ing human impact on the environment (Durand, 2003; Cha- bal, 2007; Jorda et al., 2008; Cavero and Chabal, 2010; Figueiral et al., 2010). Various studies focus on the ru- ral world in the Languedoc from the Neolithic to mod- ern periods (Durand, 2003; Schneider et al., 2007; Gascò, 2010; Jallot, 2010; Janin, 2010; Ouzoulias, 2013). The va- riety of these archives may provide an extensive data set to compare climatic, archeological and historical records with the vegetation history in the Languedoc. Nonetheless, de- spite the existence of various Holocene pollen sequences in Languedoc such as those from Marsillargues (Planchais, 1982), Lez estuary (Planchais, 1987), Palavas (Aloïsi et al., 1978) and Embouchac (Puertas, 1998), Capestang is the only record which provides chronologically well-constrained high-resolution pollen data (Jalut et al., 2009).
Show more

16 Read more

A quantitative risk assessment approach for mosquito borne diseases: malaria re emergence in southern France

A quantitative risk assessment approach for mosquito borne diseases: malaria re emergence in southern France

the draining of marshes, rearing of livestock, improve- ment of housing and living conditions and the use of qui- nine [1]. Malaria disappeared from the Camargue after World War II: the last Plasmodium vivax malaria epidemic occurred in 1943, with about 400 estimated cases [2]. Recent entomological surveys reported huge Anopheles populations in this area [3-5], and considered Anopheles (Anopheles) hyrcanus as being the main potential malarial vector based on its anthropophilic feeding behaviour and abundance [4,6]. Thus, the Camargue is currently facing an "anophelism without malaria" situation. Moreover, autochthonous transmission was recently suspected in the French Mediterranean coast in 2006 [7], supporting the idea that southern France remains suitable for malaria transmission. The number of imported malaria cases have increased dramatically since the 1970s, in parallel with increased international travels, with an average of about 6,400 cases per year for the last ten years in France, leading to a massive Plasmodium introduction from endemic countries into France [8,9]. These observations suggest that the malaria situation needs to be re-examined, and the aim of this paper is to infer current risk of malaria re- emergence, to identify hot spots for malaria re-emergence
Show more

13 Read more

Streams of living water : the strigil motif on late antique sarcophagi reused in medieval southern France

Streams of living water : the strigil motif on late antique sarcophagi reused in medieval southern France

ensured that virtually all traffic to this new pilgrimage site came through France, providing a ready stream of new pilgrims and increasing veneration at local sites. The Via Tolosana, which officially began at Arles and ran directly across southern France, brought large numbers of pilgrims from central Europe and Italy through the heart of Gallia Narbonensis. Unlike other pilgrimage roads, the Via Tolosana had pilgrims moving in both directions, since it was also a primary access route from France to Saint Peter’s in Rome. 12 Some Italian pilgrims also traveled by sea to Marseille and then traveled overland from there. Cults on the primary pilgrimage routes to Santiago de Compostela achieved huge renown and led to the development of continually larger churches, the better to accommodate the pilgrims who came to touch the sarcophagi of saints, and even to sleep under the sarcophagi to be more assured of receiving heavenly intervention. In all these interactions, the body of the saint was the central focus, but mediated through a case of some sort, usually a sarcophagus. Although reliquaries have received the most attention in scholarship, many more saints, especially before the thirteenth century, maintained their contact with the living world through their
Show more

94 Read more

Identification of spatial and temporal contributions of rainfalls to flash  floods using neural network modelling: case study on the Lez basin (southern  France)

Identification of spatial and temporal contributions of rainfalls to flash floods using neural network modelling: case study on the Lez basin (southern France)

Abstract. Flash floods pose significant hazards in urbanised zones and have important implications financially and for humans alike in both the present and future due to the likelihood that global climate change will exacerbate their consequences. It is thus of crucial importance to improve the models of these phenomena especially when they oc- cur in heterogeneous and karst basins where they are diffi- cult to describe physically. Toward this goal, this paper ap- plies a recent methodology (Knowledge eXtraction (KnoX) methodology) dedicated to extracting knowledge from a neu- ral network model to better determine the contributions and time responses of several well-identified geographic zones of an aquifer. To assess the interest of this methodology, a case study was conducted in southern France: the Lez hy- drosystem whose river crosses the conurbation of Montpel- lier (400 000 inhabitants). Rainfall contributions and time transfers were estimated and analysed in four geologically delimited zones to estimate the sensitivity of flash floods to water coming from the surface or karst. The Causse de Viols- le-Fort is shown to be the main contributor to flash floods and the delay between surface and underground flooding is esti- mated to be 3 h. This study will thus help operational flood warning services to better characterise critical rainfall and develop measurements to design efficient flood forecasting models. This generic method can be applied to any basin with sufficient rainfall–run-off measurements.
Show more

14 Read more

Uncertainty analysis in model parameters regionalization: a case study involving the SWAT model in Mediterranean catchments (Southern France)

Uncertainty analysis in model parameters regionalization: a case study involving the SWAT model in Mediterranean catchments (Southern France)

Abstract. In this study a method for propagating the hy- drological model uncertainty in discharge predictions of un- gauged Mediterranean catchments using a model parameter regionalization approach is presented. The method is devel- oped and tested for the Thau catchment located in Southern France using the SWAT hydrological model. Regionaliza- tion of model parameters, based on physical similarity mea- sured between gauged and ungauged catchment attributes, is a popular methodology for discharge prediction in ungauged basins, but it is often confronted with an arbitrary criterion for selecting the “behavioral” model parameter sets (Mps) at the gauged catchment. A more objective method is provided in this paper where the transferrable Mps are selected based on the similarity between the donor and the receptor catch- ments. In addition, the method allows propagating the mod- eling uncertainty while transferring the Mps to the ungauged catchments. Results indicate that physically similar catch- ments located within the same geographic and climatic re- gion may exhibit similar hydrological behavior and can also be affected by similar model prediction uncertainty. Further- more, the results suggest that model prediction uncertainty at the ungauged catchment increases as the dissimilarity be- tween the donor and the receptor catchments increases. The methodology presented in this paper can be replicated and used in regionalization of any hydrological model parame- ters for estimating streamflow at ungauged catchment.
Show more

21 Read more

Role of the repartition of wetland breeding sites on the spatial distribution of Anopheles and Culex, human disease vectors in Southern France

Role of the repartition of wetland breeding sites on the spatial distribution of Anopheles and Culex, human disease vectors in Southern France

Tran et al. (2008) [16] proposed a framework to build a predictive environmental model for immature and adult mosquito distribution that analyzes the relation- ship between landscape characteristics and mosquito field collections (larvae and adults). They successfully applied this approach on Anopheles hyrcanus (Pallas), a potential malaria vector, in the Camargue region of southern France. They demonstrated that the repartition of this species ’ breeding sites was the main driver behind the distribution of the adult population. In this paper, we aimed to evaluate the impact of the reparti- tion of wetland breeding sites on the spatial distribution of Culex modestus Ficalbi, Cx. pipiens Linnaeus, and An. maculipennis Complex. For the latter, we focussed on An. atroparvus Van Thiel, a former plasmodium vector in southern France, and An. melanoon Hackett, which is competent to transmit malaria parasites, although its preference for large mammal hosts may limit its poten- tial role as a vector [17-20]. Both Culex species are effi- cient and active vectors of the West Nile virus (WNV) in the Camargue region [21-24]. We applied the same methodology developed by Tran et al. (2008) [16] on An. hyrcanus on An. melanoon, Cx. modestus and Cx. pipiens. The results for the four species consequently can be compared and discussed.
Show more

8 Read more

The chronology of Late Pleistocene thermal contraction cracking derived from sand wedge OSL dating in central and southern France

The chronology of Late Pleistocene thermal contraction cracking derived from sand wedge OSL dating in central and southern France

Andrieux, E., Bateman, M.D. orcid.org/0000-0003-1756-6046 and Bertran, P. (2018) The chronology of Late Pleistocene thermal contraction cracking derived from sand wedge OSL dating in central and southern France. Global and Planetary Change, 162. pp. 84-100. ISSN 0921-8181

37 Read more

Using remote sensing to map larval and adult populations of Anopheles hyrcanus (Diptera: Culicidae) a potential malaria vector in Southern France

Using remote sensing to map larval and adult populations of Anopheles hyrcanus (Diptera: Culicidae) a potential malaria vector in Southern France

Background: Although malaria disappeared from southern France more than 60 years ago, suspicions of recent autochthonous transmission in the French Mediterranean coast support the idea that the area could still be subject to malaria transmission. The main potential vector of malaria in the Camargue area, the largest river delta in southern France, is the mosquito Anopheles hyrcanus (Diptera: Culicidae). In the context of recent climatic and landscape changes, the evaluation of the risk of emergence or re-emergence of such a major disease is of great importance in Europe. When assessing the risk of emergence of vector-borne diseases, it is crucial to be able to characterize the arthropod vector's spatial distribution. Given that remote sensing techniques can describe some of the environmental parameters which drive this distribution, satellite imagery or aerial photographs could be used for vector mapping.
Show more

12 Read more

West Nile Virus Outbreak in Horses, Southern France, 2000: Results of a Serosurvey

West Nile Virus Outbreak in Horses, Southern France, 2000: Results of a Serosurvey

est Nile virus (WNV) is an arbovirus of the genus Fla- vivirus, family Flaviridae. Its natural transmission cycle involves birds and mosquitoes, mainly of the Culex genus. During late summer and autumn 2000, a WNV outbreak in southern France resulted in 76 clinical cases in equines; 21 horses died (1). The cases occurred near the Camargue region, a large wet area that corresponds to the delta of the Rhône River (Figure 1), near the Mediterranean coast. The area has a rich avifauna (2,3); >300 bird species, mostly water birds have been observed there. Among these species, some are migra- tory: Camargue is an important resting area for birds migrating between western Africa and northern Europe. Camargue is also a breeding area for some species and a wintering area for others. Mosquito density is high in this wet area (3,4). Among Culex species, C. pipiens and C. modestus are the most abundant.
Show more

6 Read more

Deriving pedotransfer functions for soil quartz fraction in southern France from reverse modeling

Deriving pedotransfer functions for soil quartz fraction in southern France from reverse modeling

Abstract. The quartz fraction in soils is a key parameter of soil thermal conductivity models. Because it is dif- ficult to measure the quartz fraction in soils, this information is usually unavailable. This source of uncertainty impacts the simulation of sensible heat flux, evapotranspiration and land surface temperature in numerical simu- lations of the Earth system. Improving the estimation of soil quartz fraction is needed for practical applications in meteorology, hydrology and climate modeling. This paper investigates the use of long time series of routine ground observations made in weather stations to retrieve the soil quartz fraction. Profile soil temperature and water content were monitored at 21 weather stations in southern France. Soil thermal diffusivity was derived from the temperature profiles. Using observations of bulk density, soil texture, and fractions of gravel and soil organic matter, soil heat capacity and thermal conductivity were estimated. The quartz fraction was inversely estimated using an empirical geometric mean thermal conductivity model. Several pedotransfer functions for estimating quartz content from gravimetric or volumetric fractions of soil particles (e.g., sand) were analyzed. The soil volumetric fraction of quartz (f q ) was systematically better correlated with soil characteristics than the
Show more

15 Read more

Organic viticulture and soil quality: A long term study in Southern France

Organic viticulture and soil quality: A long term study in Southern France

Through our experimental design, we studied long-term effects of different changes of agricultural practices inherent to organic viticulture on soil quality. In this study, we have demonstrated that a transition period of 7–11 years, depending on the considered indicator, was needed to clearly separate Conventional and Organic farming practices in Southern French vineyards. Apart from classi- cal sensitive indicators used to study organic transition like organic matter content, soil microbial biomass, or bulk density, the easy-to- use chemical available P and K contents should also be considered as sensitive indicators. Moreover, our results address the important question of P and K mining with organic practices during transition period. However afterwards, the increase of soil organic matter and related biological activities could partly counteract the observed decrease during the transition period. According to our results, the utilization of soil nematodes as bioindicators of soil quality shall be promoted. Indeed, the study of microbivorous provided some infor- mation about microbial biomass and bacteria/fungi ratio. As for omnivore and predator nematodes, they were reliable indicators of environmental perturbations. Despite the diversity of indicators, we have highlighted the difficulty to show the benefits of organic farming on global soil quality in this particular pedoclimatic area, and for the set of farming practices that were investigated.
Show more

8 Read more

Correcting the radar rainfall forcing of a hydrological model with data assimilation: application to flood forecasting in the Lez catchment in Southern France

Correcting the radar rainfall forcing of a hydrological model with data assimilation: application to flood forecasting in the Lez catchment in Southern France

Abstract. The present study explores the application of a data assimilation (DA) procedure to correct the radar rain- fall inputs of an event-based, distributed, parsimonious hy- drological model. An extended Kalman filter algorithm was built on top of a rainfall-runoff model in order to assimilate discharge observations at the catchment outlet. This work fo- cuses primarily on the uncertainty in the rainfall data and considers this as the principal source of error in the sim- ulated discharges, neglecting simplifications in the hydro- logical model structure and poor knowledge of catchment physics. The study site is the 114 km 2 Lez catchment near Montpellier, France. This catchment is subject to heavy oro- graphic rainfall and characterised by a karstic geology, lead- ing to flash flooding events. The hydrological model uses a derived version of the SCS method, combined with a Lag and Route transfer function. Because the radar rainfall in- put to the model depends on geographical features and cloud structures, it is particularly uncertain and results in signifi- cant errors in the simulated discharges. This study seeks to demonstrate that a simple DA algorithm is capable of ren- dering radar rainfall suitable for hydrological forecasting. To test this hypothesis, the DA analysis was applied to estimate a constant hyetograph correction to each of 19 flood events. The analysis was carried in two different modes: by assimi- lating observations at all available time steps, referred to here as reanalysis mode, and by using only observations up to 3 h before the flood peak to mimic an operational environment, referred to as pseudo-forecast mode. In reanalysis mode, the
Show more

18 Read more

Occurrence of Leishmania infantum Parasitemia in Asymptomatic Blood Donors Living in an Area of Endemicity  in Southern France

Occurrence of Leishmania infantum Parasitemia in Asymptomatic Blood Donors Living in an Area of Endemicity in Southern France

The visceral form of leishmaniosis (VL) affects approxi- mately half a million new patients each year. Due to systemic parasite dissemination, the disease is fatal if untreated (27). The main areas of concern are Sudan, Eastern India, Bang- ladesh, and Nepal (Leishmania donovani) and Brazil and the area around the Mediterranean (Leishmania infantum) (34). Those infected with the viscerotropic Leishmania species may, however, remain asymptomatic (3, 27). The documentation of individuals who have no history of VL but whose leishmanin skin tests (LST) are positive—specific evidence of delayed antileishmanial hypersensitivity—is not new (3, 21, 26). The mechanisms implicated in susceptibility in humans are not fully elucidated, although much has been learned about leishmani- osis in a murine model (29). Immunosuppression, such as in AIDS patients, is one of the factors responsible for increased vulnerability to a primary Leishmania infection or to reactiva- tion of a latent infection (14; for a review, see reference 1). Coinfection with human immunodeficiency virus (HIV) and L. infantum is becoming increasingly frequent; to date, 1,400 VL- AIDS cases have been reported in southern Europe (34).
Show more

5 Read more

<p>Objective and perceived oral health status of elderly nursing home residents: a local survey in southern France</p>

<p>Objective and perceived oral health status of elderly nursing home residents: a local survey in southern France</p>

Objective and perceived state of oral health ( Figure 3 ) Secondly, we examined the oral state of health reported by the residents according to the three GOHAI categories which we associ[r]

11 Read more

Polymorphism and Drug Selected Mutations in the Protease Gene of Human Immunodeficiency Virus Type 2 from Patients Living in Southern France

Polymorphism and Drug Selected Mutations in the Protease Gene of Human Immunodeficiency Virus Type 2 from Patients Living in Southern France

DNA and RNA pol analysis. The resulting PCR-amplified DNA fragments were purified using Multiscreen PCR (Millipore, Molshein, France) as specified by the manufacturer. The PCR product was used as the DNA template for nucleotide sequencing analysis of the HIV-2 protease-RT coding region with eight primers (forward: H2Mp3; H2Mp6, 5⬘-AAAAGAGATCTGTGCAAAAA TGG, 2,482 bp; H2Mp9, 5⬘-GGATGATATCTTAATAGCTAG, 2,932 bp; re- verse: H2Mp5, 5⬘-AGTTTTGGTCCATCTTTCCC, 2,441 bp; H2Mp7, 5⬘-GGG TATTATAAGGATTAGTTGG, 2,555 bp; H2Mp8, 5⬘-AATTGCTGGTGATC CCTTC, 2,857 bp; H2Mp10, 5⬘-GATGTCATTGACTGTCC, 3,151 bp; H2Mp4). Cycle sequencing of both strands was performed on the GeneAmp PCR system 9600 instrument (Applied Biosystems, Branchburg, N.J.) with the Big Dye Ter- minator cycle-sequencing kit (Applied Biosystems). Excess dye-labeled termina- tors were removed from the extension products on Sephadex G-50 Superfine on NAHVN 4550 plates (Millipore), and the purified products were sequenced on an ABI Prism 3100 genetic analyzer (Applied Biosystems). The nucleotide se- quences of the protease-RT genes were aligned and translated with the Auto Assembler and Sequence Navigator software programs (Applied Biosystems) by
Show more

8 Read more

Biology and dynamics of potential malaria vectors in Southern France

Biology and dynamics of potential malaria vectors in Southern France

Anopheles claviger s.s., Anopheles petragnani and Anopheles plumbeus have been reported several times in south-east France. They were not captured during the survey con- ducted in 2005 because their ecological niches were rare or absent of the two sites and this study did not focus on their breeding sites (which correspond to tree holes for An. plumbeus, rivers stream and small, cold and fresh water collection for the others) [14,21,24,25]. However, An. plumbeus and An. claviger, which were considered as sec- ondary vectors, could be more abundant in some others places, and particularly places close to humans.
Show more

9 Read more

Agricultural resources investigations in Northern Italy and Southern France. Nasa landsat satellites investigations. AGRESTE Project.

Agricultural resources investigations in Northern Italy and Southern France. Nasa landsat satellites investigations. AGRESTE Project.

The aim of the experiment was to evaluate the potentiality of remote sensing facilities under such European conditions as a support to agronomic research and land-use management, identif[r]

179 Read more

First evidence of accumulation of mega boulders on the Mediterranean rocky coast of Provence (southern France)

First evidence of accumulation of mega boulders on the Mediterranean rocky coast of Provence (southern France)

Fig. 6. Profiles on seaward side of blocks 3 and 10. (A) Clast deposits viewed from the sea and (B) clift-top clast deposits forming elongate train parallel to the coast in the upper part in the northern sector. (C) Clast accumulations in the southern sector of Arnette calanque forming three ridges parallel to the coast, which are successive in the case of ridges 2 and 3. (D), (E), (F) Tilted characteristic forms of littoral karst and notch after landward transport. (G), (H), (I), (J) Biological encrustation on boulders. (G) Lithophaga lithophaga. (H) Balanus sp. and microperforations of boring sponge (Cliona sp.). (I) Vermitidae. (J) Rim of Lithophyllum bisso¨ıdes.
Show more

10 Read more

Show all 7854 documents...