WG3: High precipitation events, floods and flash-floods

Hydrological observation and modelling strategy

Scientific questions

• WG3-SQ1: What are the characteristics of extreme hydro-meteorological events in the Mediterranean ?

• WG3-SQ2: How can we improve heavy rainfall process knowledge and prediction ?

• WG3-SQ3: How can we improve flash-flood process knowledge and prediction?

• (WG5-SQ?: How can we mitigate the flash-flood and flood societal impact?)

• WG3-SQ4: How extreme hydrometeorological events will evolve under future climate conditions during the XXIst century?

(Very brief) summary of the ISP

• Predictability of HPE still rather poor in terms of intensity and localization

• Hydrological impact depends on geomorphology (relief, geology, soils…), land-use (urbanization, infrastructures) and initial conditions (soil humidity state)

• Vulnerability: high in cities but also dispersed habitat, road users, green tourism adepts

Spatially-detailed rainfall and flood prediction with relevant lead times (< 1-6 hours typically) at the Mediterranean scale.

Coupling with meteorology and human sciences

1. Make best use of existing operational observation systems

2. Develop a set of « super-sites » (research watersheds of some 10-km²) dedicated to hydrological process studies

3. Develop a set of « pilot-sites » (research watersheds of some 1000-km²) dedicated to distributed observation and modelling studies at the regional scale

4. Perform post-event surveys after major events occurring in the

Mediterranean

Long-term Hydrometeorological Observatories

Long-term Hydrometeorological Observatories:1. Make best use of existing operational observation systems

Oppoul

Sembadel

Montclar

Bollène

Nîmes

Radar and raingauge networks Main watersheds and stream gauges

Ardèche

Gardon

Hérault

Aude

Orb

Cèze

Agly

Têt

Vidourle

e.g., the Cévennes-Vivarais Mediterranean Hydrometeorological Observatory (OHMCV)

Long-term Hydrometeorological Observatories:2. Develop a set of « super-sites »

Research watersheds of some 10-km² dedicated to process studies

e.g. in France

CVMHO Valescure CVMHO Lez-Coulazou ORE Draix-BléoneGranite and schists Karsts Marls (Alps)

Hillslopes, water pathes, riparian zoneSurface and sub-surface flows and storagesRiver monitoring (hydrometry, sediment transport)Evapotranspiration…

Long-term Hydrometeorological Observatories3. Develop a set of « pilot-sites »

Research watersheds of some 1000-km² dedicated to distributed observation and modelling studies at the regional scale

Nested watersheds including super-sitesSoil and landscape descriptionRainfall QPE (operational + research radars+ disdrometer and raingauge networks)Soil moisture monitoringRiver monitoring (distributed hydrometry, sediment transport and flood plains)Vulnerability monitoring

Valescure (5 km²)Gardon de Saint Jean (200 km²)

Gardon (2000 km²)

Long-term Hydrometeorological Observatories4. Post-event surveys after major events occurring in the Mediterranean

e.g., 18 September 2007 in Zelezniki, Selska Sora river, Slovenia, HYDRATE project

Collation of :Rainfall data (raingauges and radar)Maximum discharge estimates from water marksWitness accounts (flood dynamics, sociologic parameters…)

Process understanding through hydrologic and hydraulic modelling

Distributed hydrological models

LISFLOOD, Joint Research Center Ispra Italy

AFFDEF, University of Bologna Italy

Coupled MesoNH/SURFEX/Topmodel CNRM Toulouse France

n-Topmodels, EDYTEM Chambéry and LTHE Grenoble, France

ATHYS (HSM Montpellier) and LIQUID (Cemagref Lyon, LTHE Grenoble, Hydrowide): hydrological modelling platforms

1D-hydraulic models

Posted contributions

Cévennes = target region #1 with several projects of OHMCV

1. Knowledge and Predictability of Heavy Precipitation Events (HPE) in Southeastern France (part of)

2. Shallow orographic convection contribution to the water resources in Mediterranean: proposition of an observation system within the framework of HyMEx

3. Impact of rainfall variability and soil moisture redistribution on the continental hydrological cycle and the genesis of flash floods in the Cévennes region (in relation with WG2).

4. Karst hydrosystems: water resources and flood dynamics (in relation with WG2)5. Observations for vulnerability and social adaptation (WG5)6. Multi-disciplinary post-event surveys (in cooperation with WG5)

Another project in French Southern Alps:1. Erosion and sedimentary transport from sources down to piedmont (in relation with

WG2 and SICMED)

Target regions?

Catalonia

Cévennes + LR

CA + Liguria

Ticino Friuli Veneto Croatia

Crete

North Africa?

Israël?

To be done here:

Define target regions (in relation with other WGs) Define long-term HOs, pilot-sites and super-sites Coordination of the HOs Contribution to the definition of TTOs, TTMs and TSs for

continental surfaces monitoring

– Coastal regions: Catalonia, Languedoc-Roussillon, Côte d’Azur, Liguria– 3 major cities (Barcelona, Marseille Genova)– Medium and high-elevation mountains: Pyrénées, Cévennes, southern

Alps, Ticino, Friuli

HyMeX WG3 observation strategy based on long-term hydrometeorological observatories

Main target regions in the NW Mediterranean

Catalonia

Cévennes

Languedoc-Roussillon

French S. Alps

Liguria

Ticino Friuli

Croatia

Task teams for observation (TTO)

TTO2 Monitoring continental surfaces

…TTO2-x The OHM-CV observatory

(deep and shallow convection, multi-scale water budget; distributed flash flood prediction; karsts and floods;

social adaptation)TTO2-x The Draix-Bléone observatory (erosion and sediment

transport)…TTO2-x The Catalan Observatory (…)TTO2-x The Ligurian Observatory (…)TTO2-x The Friuli Observatory (…)…TTO2-x Post-event surveys after extreme events occurring in the

Mediterranean

TTO3 Measuring surface fluxes over land ?TTO6 Measuring land-sea fluxes ?TTO7 Monitoring vulnerability factors ?

Task team for modelling (TTM)

…TTMx Multiscale modelling of the continental surfaces…

TASK SUPPORTS

TS1 – Data Base TS1-a Geographical information systems; landscape descriptorsTS1-b Hydrometeorological data from operational services…TS2 – Coordination of hydrometeorological observatories …TS4 – Satellite products…

TASK SUPPORTS

TS1 – Data Base TS1-a Geographical information systems; landscape descriptorsTS1-b Hydrometeorological data from operational services…TS2 – Coordination of hydrometeorological observatories …TS4 – Satellite products…

MEDYCYSS: karsts – water ressources and floods

Lez catchment: fresh-water resource for the city of Montpellier

Coulazou watershed: a « toy model » for studying the influence of the river-karst interactions on the propagation and intensity of surface floods

R1 R3 R4

R2

G1

G2

GW+

UR-

UR+

GW-

Runoff Runof

f

Runoff

Ardèche

Gardon

Hérault

Aude

Orb

Cèze

Draix-Bléone: erosion and sediment transport

Draix-Bléone

Nested watersheds:Ore Draix : 0.0013 à 1.08 km²Galabre : 20 km²; Bouinenc : 22 km²Duyes : 124 km²; Bès : 165 km²Bléone (Malijai) : 897 km²

Instrumentation:Raingauge networkDisdrometerStream gauges with suspended load samplersand sediment trapsRFID transponders for bedload trackingHydrophone for bedload transportLIDAR geomorphological surveys with drones

On-site studiesContribution/expertise for other sites and during post-event surveys

TASK TEAMS FOR OBSERVATION (TTO)

TTO1 Sounding the atmosphere

TTO1-a Radiosounding (LOP/EOP/SOP)TTO1-b Balloons (SOP)TTO1-c UHF/VHF profilers (LOP/EOP)TTO1-d GPS (LOP/EOP/SOP)TTO1-e Lidars (EOP/SOP)TTO1-f Radars (LOP/EOP/SOP)TTO1-h Microphysics (LOP/EOP/SOP)TTO1-i Aérosols (SOP)TTO1-j Lightning (LOP/EOP/SOP)

TASK TEAMS FOR OBSERVATION (TTO)

TTO2 Monitoring continental surfaces…observatories to be sorted by thematics in a second step?...TTO2-x The OHM-CV observatory

(deep and shallow convection, multi-scale water budget and distributed flash flood prediction; social adaptation)

TTO2-x The Draix-Bléone observatory (erosion and sediment transport)

TTO2-x The MEDYCYSS observatory (karsts, water resources and floods)

…TTO2-x The Catalan Observatory (…)TTO2-x The Ligurian Observatory (…)TTO2-x The Friuli Observatory (…)…TTO2-x Post-event surveys after extreme events occurring in the

Mediterranean

TTO3 Measuring surface fluxes over land ?TTO6 Measuring land-sea fluxes ?TTO7 Monitoring vulnerability factors ?

TASK TEAMS FOR MODELLING (TTM)

…TTMx Multiscale modelling of the continental surfaces…

TASK SUPPORTS

TS1 – Data Base TS1-a Geographical information systems; landscape descriptorsTS1-b Hydrometeorological data from operational services…TS2 – Coordination of (in-land) hydrometeorological

observatories …TS4 – Satellite products…

Structure d’un « Task Team » d’AMMA(pas de distinction TTO, TTM ; la logistique est

incluse)

1) Scientific justification and objectives2) Observation strategy (overall strategy;

experimental sites; modelling platforms; satellite products; list of instruments and relevant maps)

3) Deployment (planning ; logistical considerations)4) Partnership (field observation ; training program)5) Organisation of the TT (lists of leaders - core

group - members; internal coordination; how to handle new requests e.g. about additional instrument; reporting)

6) Coordination with other TTs

Film Sébastien Klotz

OHM-CV : équipes OHM-CV, MF, SPCGDConvection profonde et peu profonde ; (extension LR, SPCMO à agréger)Processus et bilans hydrologiques ;prévision distribuée des crues, adaptation sociale

Draix-Bléone : Cemagref, LTHE, …SPCGD, EDFérosion et transport sédimentaire

MEDYCYSS : MEDYCYSS, …BRGMKarst : ressources en eau, crues

… autres ? Marseille, NOVIMET+Cemagref Var, EDF/LTHE sur Durance)

Les observatoires en France

inter WG(2, 3 et 5)

MEDYCYSS

Marseille

OHM-CV Draix-Bléone

OHM-CV: deep and shallow convection studies

Radars mobiles bande XRéseaux de disdromètresRéseaux GPSRadiosondages renforcés