Montserrat flash-flood event

Implementation of the fully-distributed and physically-based FEST-WB modelA. AmengualGrup de Meteorologia, Departament de Fsica, Universitat de les Illes Balears, Palma, Mallorca, Spaine-mail: arnau.amengual@uib.es

Universitat de les Illes BalearsReunin PREDIMED 2014A5-6 Junio1Implementation of the physically-based distributed FEST-WB modelOverview of the FEST-WB model

The Serpis flash-flood event

Preliminary results

Future tasks

2

1. Overview of the FEST-WB model Flash-flood Event-based Spatially-distributed rainfall-runoff Transformation including Water Balance Computes the main processes of the hydrological cycle:

EvapotranspirationInfiltrationSurface runoffFlow routingSubsurface flowGroundwater flow Snow dynamics1. Overview of the FEST-WB model

41. Overview of the FEST-WB model Computational domain is meshed with a net regular square cells (200 meters) Continuous soil moisture accounting:

Runoff is computed according to a modified SCS-CN method. Potential maximum retention, S, is updated as a linear function of the degree of saturation ():

Actual evapotranspiration, EVT, calculated using the Hargreaves equation

Surface and sub-surface routing: Muskingum-Cunge method in its non-linear form

Reservoir: Flow routing is described using the level pool scheme.

2. The Serpis flash-flood event: synoptic situation

1. Upper-level closed trough

2. Strong high pressures over Western Europe

3. Low pressures overnorthern Africa

4. Low-level jet: advection of warm and moist air toward Valencia from the Mediterranean

5. Orographic lifting(Sierra de Aitana) 6

2. The Serpis flash-flood event: synoptic situationQuasi-stationary MCSs7 Torrential precipitation took place on 11 and 12 October 2007 Accumulated precipitation amounts above 400 mm

The Serpis catchment is a small size basin with an area of 752.8 km2 and a length close to 74.5 km. Accumulated rainfall above 300 mm from 00 to 12 UTC 12 October 2007 inside this basin

2. The Serpis flash-flood event: observations8Peak discharges:

Vernissa: Qp=315 m3s-1Beniarrs: Qp=260 m3s-1Carrs: Qp=200 m3s-1

1 fatality. 200 people evacuated

2. The Serpis flash-flood event: observations9

3. Preliminary results103. Preliminary results

3. Preliminary results

3. Preliminary results

3. Preliminary results

11-12 Oct 2007

VernissaBeniarrsCarrsNSE0.010.500.79RMSE (m3s-1)59.537.020.8Error V 1.390.800.01Error Qp -0.26-0.02-0.06Error Tp (h)-1.0-1.0-5.0143. Preliminary results

11-12 Oct 2007

VernissaBeniarrsCarrsNSE0.010.500.79RMSE (m3s-1)59.537.020.8Error V 1.390.800.01Error Qp -0.26-0.02-0.06Error Tp (h)-1.0-1.0-5.0153. Preliminary results

11-12 Oct 2007

VernissaBeniarrsCarrsNSE0.010.500.79RMSE (m3s-1)59.537.020.8Error V 1.390.800.01Error Qp -0.26-0.02-0.06Error Tp (h)-1.0-1.0-5.0163. Preliminary results

174. Future tasksHow can we improve flash-flooding process knowledge and forecasting?

1. Which are the hydrological characteristics of extreme floods in the semi-arid Mediterranean environment? 1.1 To determine which are the main hydrological processes involved in flash-flooding for semi-arid river basins in the Mediterranean.

1.2 To assess which is the specific role of the infiltration mechanism, soil moisture content and Hortonian flow before flash-floods in semi-arid river basins.

2. How can we improve the hydrometeorological forecasting of flash-floods?

2.1 To study the predictability of high impact weather related to intense rainfall and flash-flooding.

2.2 To assess how meteorological uncertainties propagate through the hydrological models.

2.3 To examine flash-flood predictability through advanced ensemble prediction hydrometeorological systems.18