Amélioration de la prévision des crues à l'amont de Villeres

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Amélioration de la prévision des crues à l'amont de Villeres

Message  seon42 le Mar 2 Nov 2010 - 17:34

Amélioration de la prévision des crues à l'amont de Villerest

C'est le titre d'un mémoire de Hélène MARTIN-GOUSSET : http://engees-proxy.u-strasbg.fr/321/01/MARTIN_GOUSSET_Rapport.pdf

Je pense que ça en intéressera plus d'un. Il date de 2008 mais je ne le découvre qu'aujourd'hui.

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Re: Amélioration de la prévision des crues à l'amont de Villeres

Message  seon42 le Mar 2 Nov 2010 - 22:06

On ne va pas faire de jaloux : je vais aussi donner un lien vers une étude rhodanienne. C'est pas les Cévennes notre région mais il y a quand même pas mal de travaux sur l'hydrologie.

Thèse de Raouf GNOUMA : Aide à la calibration d'un modèle hydrologique distribué au moyen d'une analyse des processus hydrologiques : application au bassin versant de l'Yzeron

Lien : http://docinsa.insa-lyon.fr/these/2006/gnouma/

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Re: Amélioration de la prévision des crues à l'amont de Villeres

Message  seon42 le Sam 15 Déc 2012 - 17:40

Il y a un an jour pour jour était soutenue la thèse de Sonja Jankowfsky sur la bassin versant de l'Yzeron, Understanding and modelling of hydrological processes in small peri-urban catchments using an object-oriented and modular distributed approach. Application to the Chaudanne and Mercier sub-catchments (Yzeron catchment, France).

Je ne peux la mettre en ligne mais voici un extrait sur la partie pluviométrie :
Sonja Jankowfsky a écrit:3.2.2. Precipitation
3.2.2.1. Measurement stations

The locations of the rain gauges are visible in Figure 3.2.2 and the data availability is shown in table 3.2.1. At the end of 1996 the Cemagref installed a tipping bucket rain gauge in the Chaudanne and Mercier catchments, respectively. These rain gauges have been recording continuously using a variable time step since then. Only in 2001 the bucket capacity of the Chaudanne rain gauge was changed from 0.1 to 0.2 mm and in 2005 it was moved to the retention basins at the Pont de la Barge (PdB), see zoom in Figure 3.2.2. In 2005 the rain gauge at Croix du Ban, which is at an altitude of 602 m, compared to the altitudes of 320 and 313 m of the Chaudanne and Mercier rain gauges, was added (Braud, 2008a). This station gives more representative values for the upper part of the Mercier catchment, as it is located higher up in the Mont du Lyonnais. During the PhD thesis of Sarrazin (2012) two rain gauges (named Sarrazin-1 and 2) were installed in the Mercier catchment. The first one was installed in September 2008 close to Pollionnay (see Figure 3.2.2) and it was removed in March 2011. The other one was installed in April 2009 in the south of the catchment (Lagouy, 2009). A complete climate station, “Le Thiollet”, was set up on the top of the Yzeron catchment at Montromant (see Figure 3.1.1). It has a balance rain gauge to measure liquid and solid precipitation continuously (Thollet and Branger, 2008). The long-term Cemagref measurement stations are part of the OTHU program.

3.2.2.2. Main characteristics of rainfall series
Braud (2008a) analyzed and corrected the rain data of the Mercier and Chaudanne rain gauges for the period 1997 to 2007. The data were validated by comparison of the daily rainfalls of the Chaudanne and Mercier rain gauges. Periods with missing data were then replaced with the data of the other station (Chaudanne or Mercier), respectively. If no data were available for both stations, the average of four nearby stations from the Grand Lyon was taken (see Figure 3.1.1 for the location of the other stations). A time series with a time step of 6 min (time step of Grand Lyon data) was then generated. This lead to a complete rain data time series from 1997 to 2007 for both stations with variable, or 6 min time step, which is available as model input. Michel (2009) continued the analysis and correction of the data including the data of 2008. She used the same correction method as Braud (2008a), in which missing values were replaced by close-by rain gauge data. The Sarrazin-1 rain gauge was used additionally to fill the gaps. However, it had too many gaps to create an independent time series itself. Michel (2009) also processed the data of the Croix du Ban rain gauge by replacing the missing data with the average of the Mercier and St Consorce rain gauge. Chapuis (2010) corrected the 2009 data of the Mercier, Chaudanne, Croix du Ban and Le Thiollet rain gauges. He replaced the missing data with the data of the station with the best correlation, which could be the four mentioned stations or the stations of the Grand Lyon, when no records of the Cemagref gauges were available. Finally, the 2010 rain data were corrected by Braud et al. (2011b).
Michel (2009) calculated Thiessen polygons for the Yzeron catchment out of the Grand Lyon gauges and Mercier, Chaudanne, Croix du Ban and Le Thiollet. The Mercier and Chaudanne catchments can thus be covered with the values of Mercier, Chaudanne and Croix du Ban rain gauges, see Figure 3.2.2. This segmentation corresponds also relatively well to the altitude distribution of both catchments. For these reasons, the Thiessen polygons were considered sufficient as model input.
The precipitation has a strong inter annual variability with yearly rainfalls from 450 mm (1998) to 950 mm (2002) (Braud, 2008a). This means that there are relatively dry and in contrast wet years. The yearly rainfall data for the three stations Mercier, Chaudanne and Croix du Ban from 1997 to 2010 are shown in table 3.2.2 (Chapuis, 2010). The catchment average rainfall was calculated using weighted average of the gauging stations, based on Thiessen polygons. The average annual precipitation between 1997 and 2010 was thus 741 mm for the Mercier catchment and 744 mm for the Chaudanne Léchère catchment with standard deviations of 156 mm and 165 mm, respectively.
Daily maximal rainfall values can reach up to 130-140 mm, and each year from 2002 to 2009 there was at least one day with a total rainfall of 44.60 to 76.0 mm (see “annuaires hydrologiques du bassin versant de l’Yzeron” from 2001 on, Cemagref). The study of the rainfall regimes (Figure 3.2.3) shows that the rainfall is usually higher in October and November, which leads to a recharge of the groundwater table (Gnouma, 2006). The winter months from December to March are marked by relatively low rainfall rates. The extreme events can happen all over the year.
Braud (2008b) extracted rain events from the 1997-2007 data series using the software developed by Berthier (1999) and calculated frequency statistics for the Mercier and Chaudanne catchment (see also Morena (2004)). More than 275 events in both catchments were induced by a total rainfall of less than 10 mm and about 100 events had a total rainfall between 10 and 20 mm. Some extreme events reached a total rainfall of up to 140 mm. The maximal rain intensity is between 0 to 10 mm/hr for most events (around 300). Around 100 events per catchment reached a maximal rain intensity of 10 to 20 mm/hr. The highest measured rain intensity in the period 1997-2007 was around 130 mm/hr. The dry weather rainfall (sum of rainfall between events) is mostly between 0 and 5 mm, but can reach up to 50 mm in the Mercier catchment, and up to 40 in the Chaudanne catchment. Michel (2009) calculated the statistics for the period 2005-2008 with similar results.

Nouveau lien direct pour la thèse de Raouf GNOUMA : http://theses.insa-lyon.fr/publication/2006ISAL0084/these.pdf

Le bassin versant de l'Yzeron est étudié depuis longtemps, vous trouverez de nombreuses publications en ligne (http://scholar.google.fr/scholar?q=bassin+versant+de+l'yzeron ).

Edit : installation du Thiollet (Montromant), juste au-dessus du bourg d'Yzeron : http://goo.gl/maps/3YYy5


Dernière édition par seon42 le Sam 15 Déc 2012 - 17:49, édité 1 fois (Raison : ajout de la photo de l'installation du Thiollet)

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Re: Amélioration de la prévision des crues à l'amont de Villeres

Message  seon42 le Sam 15 Déc 2012 - 19:39

Je me demandais au cours de quelle discussion j'allais caser cela : trouvé aujourd'hui avec la balle d'égalisation pour la Loire.

Nos membres aussi publient.... mémoire de M1 intitulé Analyse spatiale et évaluation de l’influence des facteurs de l’érosion hydrique sur les bassins versants du rebord sud du plateau du Bessy : une approche par les Systèmes d'Information Géographiques.

Lien direct (16 Mo... long à charger) : http://ead-shs.univ-st-etienne.fr/claroline/backends/download.php?url=L21lbW9pcmVzX2FuY2llbnMvbWVtb2lyZV9maW5hbGVfLnBkZg%3D%3D&cidReset=true&cidReq=STAGEM1

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Re: Amélioration de la prévision des crues à l'amont de Villeres

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