On the prediction of the Toce alpine basin floods with distributed hydrologic models

Nat. Hazards Earth Syst. Sci.

et al. 2008

Abstract. In recent years, the interest in the prediction and prevention of natural hazards related to hydrometeorological events has grown due to the increased frequency of extreme rainstorms. Several research projects have been developed to test hydrometeorological models for real-time flood forecasting. However, flood forecasting systems are still not widespread in operational context. Real-world examples are mainly dedicated to the use of flood routing model, best suited for large river basins. For small basins, it is necessary to take advantage of the lag time between the onset of a rainstorm and the beginning of the hydrograph rise, with the use of rainfall-runoff transformation models. Nevertheless, when the lag time is very short, a rainfall predictor is required, as a result, meteorological models are often coupled with hydrological simulation. While this chaining allows floods to be forecasted on small catchments with response times ranging from 6 to 12 h it, however, causes new problems for the reliability of Quantitative Precipitation Forecasts (QPF) and also creates additional accuracy problems for space and time scales.The aim of this work is to evaluate the degree to which uncertain QPF affects the reliability of the whole hydrometeorological alert system for small catchments. For this purpose, a distributed hydrological model (FEST-WB) was developed and analysed in operational setting experiments, i.e. the hydrological model was forced with rain observation until the time of forecast and with the QPF for the successive period, as is usual in real-time procedures. Analysis focuses on the AMPHORE case studies in Piemonte in November 2002.

Section: The Hydrological Modelmentioning

confidence: 99%

“…The surface and subsurface flow routing is based on the Muskingum-Cunge method in its non-linear form with the time variable celerity (Montaldo et al, 2007).…”

Section: The Hydrological Modelmentioning

confidence: 99%

Verification of operational Quantitative Discharge Forecast (QDF) for a regional warning system – the AMPHORE case studies in the upper Po River

Rabuffetti¹,

Ravazzani

Nat. Hazards Earth Syst. Sci.

et al. 2008

“…Hydrological simulations were performed using the FEST-WB distributed water balance model (Montaldo et al, 2007;Rabuffetti et al, 2008;Ravazzani et al, 2008). FEST-WB computes the main processes of the hydrological cycle: evapotranspiration, infiltration, surface runoff, flow routing, subsurface flow and snow dynamics (Fig.…”

Section: The Hydrological Modelmentioning

confidence: 99%

“…The surface flow routing, computed on those cells not covered by snow, is based on the Muskingum-Cunge method in its non-linear form with the time variable celerity (Montaldo et al, 2007). Subsurface flow routing, similarly to the method implemented for the routing into the snow pack, is computed with a linear reservoir routing scheme (Ponce, 1989) with a celerity calculated as a function of the soil saturated conductivity.…”

Section: The Hydrological Modelmentioning

confidence: 99%

Elevation based correction of snow coverage retrieved from satellite images to improve model calibration

Hydrol. Earth Syst. Sci.

Ravazzani

Martinelli

et al. 2009

Abstract. The most widely used method for snow dynamic simulation relies on temperature index approach, that makes snow melt and accumulation processes depend on air temperature related parameters. A recently used approach to calibrate these parameters is to compare model results with snow coverage retrieved from satellite images. In area with complex topography and heterogeneous land cover, snow coverage may be affected by the presence of shaded area or dense forest that make pixels to be falsely classified as uncovered. These circumstances may have, in turn, an influence on calibration of model parameters.In this paper we propose a simple procedure to correct snow coverage retrieved from satellite images. We show that using raw snow coverage to calibrate snow model may lead to parameter values out of the range accepted by literature, so that the timing of snow dynamics measured at two ground stations is not correctly simulated. Moreover, when the snow model is implemented into a continuous distributed hydrological model, we show that calibration against corrected snow coverage reduces the error in the simulation of river flow in an Alpine catchment.

“…In particular the development of distributed hydrologic models (Noihlan and Planton, 1989;Famiglietti e Wood, 1994;Rabuffetti et al, 2008;Ravazzani et al, 2008;Troch et al,1993;Montaldo et al, 2007;Gurtz et al, 2002) gave the opportunity to better understand this problem of spatial scale of the hydrological variables (Anderson et al, 2004;McCabe and Wood, 2006;Kustas et al, 2004) due to the fact that a distributed model predicts averaged variable values in each pixel.…”

Section: Introductionmentioning

confidence: 99%

Land surface temperature representativeness in a heterogeneous area through a distributed energy-water balance model and remote sensing data

Hydrol. Earth Syst. Sci.

Sobrino

Mancini

et al. 2010

Abstract. Land surface temperature is the link between soilvegetation-atmosphere fluxes and soil water content through the energy water balance. This paper analyses the representativeness of land surface temperature (LST) for a distributed hydrological water balance model (FEST-EWB) using LST from AHS (airborne hyperspectral scanner), with a spatial resolution between 2-4 m, LST from MODIS, with a spatial resolution of 1000 m, and thermal infrared radiometric ground measurements that are compared with the representative equilibrium temperature that closes the energy balance equation in the distributed hydrological model. Diurnal and nocturnal images are analyzed due to the non stable behaviour of the thermodynamic temperature and to the non linear effects induced by spatial heterogeneity.Spatial autocorrelation and scale of fluctuation of land surface temperature from FEST-EWB and AHS are analysed at different aggregation areas to better understand the scale of representativeness of land surface temperature in a hydrological process.The study site is the agricultural area of Barrax (Spain) that is a heterogeneous area with a patchwork of irrigated and non irrigated vegetated fields and bare soil. The used data set was collected during a field campaign from 10 to 15 July 2005 in the framework of the SEN2FLEX project.