Brief communication: Preliminary hydro-meteorological analysis of the flash flood of 20 August 2018 in Raganello Gorge, southern Italy

Avolio, Elenio; Cavalcanti, Ottavio; Furnari, Luca; Senatore, Alfonso; Mendicino, Giuseppe

doi:10.5194/nhess-19-1619-2019

Cited by 30 publications

(30 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several studies show that for short simulations such as those performed in this study it is very difficult that differences emerge in the precipitation fields due to the differences in soil moisture conditions. Among them, Avolio et al (2019), which for a case study rather similar to those analyzed by the authors found that correct SST representation is much more impacting. Therefore, more details should be provided by the authors about how they reached their results, and they should try to explain the reasons they got these results.…”

Section: Main Commentsmentioning

confidence: 68%

Comments on "Implementation of WRF-Hydro at two drainage basins in the region of Attica, Greece" by Galanaki et al.

2020

View full text Add to dashboard Cite

With their paper, Galanaki et al. perform a calibration and validation exercise of the fully coupled WRF-Hydro modelling system over the Attica Region, the most densely populated of Greece, considering 7 high rainfall events from 2011 to 2014. Even though the topic addressed is undoubtedly very interesting (an attempt to perform a complete meteo-hydrological forecast over small catchments in a densely urbanized area), my opinion is that, at least at this stage, the paper does not provide new insights, neither concerning methodology (for which I have some concerns) nor regarding results. The most important novelty, according to authors' words, is that "this outcome is important because WRF-Hydro is implemented under calibration with ground-truth observations for the first time in Greece", but in my opinion, it's not enough (otherwise, any first application of WRF-Hydro around the world should deserve publication). I've some C1 NHESSD

show abstract

Section: Main Commentsmentioning

confidence: 68%

Comments on "Implementation of WRF-Hydro at two drainage basins in the region of Attica, Greece" by Galanaki et al.

2020

View full text Add to dashboard Cite

show abstract

“…Norway, despite its high latitude, has a diverse range of climates, including northern Arctic, central alpine and southern maritime, and can exhibit an equally wide range of snow regimes (Pall et al, 2019). The role of snowmelt and rainfall is highly relevant for the seasonal flood regimes (Barnett et al, 2005;Vormoor et al, 2016). For example, south-central Norway has an alpine climate, which receives large amounts of precipitation as snowfall, approximately 30 % (Saloranta, 2012), and has high discharge dur- ing spring and early summer due to snowmelt.…”

Section: Discussionmentioning

confidence: 99%

The impact of initial conditions on convection-permitting simulations of a flood event over complex mountainous terrain

Pontoppidan

Sobolowski

et al. 2020

Hydrol. Earth Syst. Sci.

Self Cite

View full text Add to dashboard Cite

Abstract. Western Norway suffered major flooding after 4 d of intense rainfall during the last week of October 2014. While events like this are expected to become more frequent and severe under a warming climate, convection-permitting scale models are showing their skill with respect to capturing their dynamics. Nevertheless, several sources of uncertainty need to be taken into account, including the impact of initial conditions on the precipitation pattern and discharge, especially over complex, mountainous terrain. In this paper, the Weather Research and Forecasting Model Hydrological modelling system (WRF-Hydro) is applied at a convection-permitting scale, and its performance is assessed in western Norway for the aforementioned flood event. The model is calibrated and evaluated using observations and benchmarks obtained from the Hydrologiska Byråns Vattenbalansavdelning (HBV) model. The calibrated WRF-Hydro model performs better than the simpler conceptual HBV model, especially in areas with complex terrain and poor observational coverage. The sensitivity of the precipitation pattern and discharge to poorly constrained elements such as spin-up time and snow conditions is then examined. The results show the following: (1) the convection-permitting WRF-Hydro simulation generally captures the precipitation pattern/amount, the peak flow volume and the timing of the flood event; (2) precipitation is not overly sensitive to spin-up time, whereas discharge is slightly more sensitive due to the influence of soil moisture, especially during the pre-peak phase; and (3) the idealized snow depth experiments show that a maximum of 0.5 m of snow is converted to runoff irrespective of the initial snow depth and that this snowmelt contributes to discharge mostly during the rainy and the peak flow periods. Although further targeted experiments are needed, this study suggests that snow cover intensifies the extreme discharge instead of acting as a sponge, which implies that future rain-on-snow events may contribute to a higher flood risk.

show abstract

“…Finally, both as an additional comparison and with the aim of highlighting its relative impact with respect to the effects of different boundary conditions provided by different GCMs and/or more detailed SST fields, a data assimilation technique is also used for both of the test cases. Specifically, a 3D-Var assimilation scheme (Barker et al, 2004;Huang et al, 2009;Barker et al, 2012) is adopted, introducing conventional meteorological observations into the initial conditions and adjusting boundary conditions to improve simulation performance.…”

Section: Wrfmentioning

confidence: 99%

Impact of high-resolution sea surface temperature representation on the forecast of small Mediterranean catchments' hydrological responses to heavy precipitation

Senatore

Furnari

Mendicino

2020

Hydrol. Earth Syst. Sci.

Self Cite

View full text Add to dashboard Cite

Abstract. Operational meteo-hydrological forecasting chains are affected by many sources of uncertainty. In coastal areas characterized by complex topography, with several medium-to-small size catchments, quantitative precipitation forecast becomes even more challenging due to the interaction of intense air–sea exchanges with coastal orography. For such areas, which are quite common in the Mediterranean Basin, improved representation of sea surface temperature (SST) space–time patterns can be particularly important. The paper focuses on the relative impact of different resolutions of SST representation on regional operational forecasting chains (up to river discharge estimates) over coastal Mediterranean catchments, with respect to two other fundamental options while setting up the system, i.e. the choice of the forcing general circulation model (GCM) and the possible use of a three-dimensional variational assimilation (3D-Var) scheme. Two different kinds of severe hydro-meteorological events that affected the Calabria region (southern Italy) in 2015 are analysed using the WRF-Hydro atmosphere–hydrology modelling system in its uncoupled version. Both of the events are modelled using the 0.25∘ resolution global forecasting system (GFS) and the 16 km resolution integrated forecasting system (IFS) initial and lateral atmospheric boundary conditions, which are from the European Centre for Medium-Range Weather Forecasts (ECMWF), applying the WRF mesoscale model for the dynamical downscaling. For the IFS-driven forecasts, the effects of the 3D-Var scheme are also analysed. Finally, native initial and lower boundary SST data are replaced with data from the Medspiration project by Institut Français de Recherche pour L'Exploitation de la Mer (IFREMER)/Centre European Remote Sensing d'Archivage et de Traitement (CERSAT), which have a 24 h time resolution and a 2.2 km spatial resolution. Precipitation estimates are compared with both ground-based and radar data, as well as discharge estimates with stream gauging stations' data. Overall, the experiments highlight that the added value of high-resolution SST representation can be hidden by other more relevant sources of uncertainty, especially the choice of the general circulation model providing the boundary conditions. Nevertheless, in most cases, high-resolution SST fields show a non-negligible impact on the simulation of the atmospheric boundary layer processes, modifying flow dynamics and/or the amount of precipitated water; thus, this emphasizes the fact that uncertainty in SST representation should be duly taken into account in operational forecasting in coastal areas.

show abstract

Brief communication: Preliminary hydro-meteorological analysis of the flash flood of 20 August 2018 in Raganello Gorge, southern Italy

Cited by 30 publications

References 11 publications

Comments on "Implementation of WRF-Hydro at two drainage basins in the region of Attica, Greece" by Galanaki et al.

Comments on "Implementation of WRF-Hydro at two drainage basins in the region of Attica, Greece" by Galanaki et al.

The impact of initial conditions on convection-permitting simulations of a flood event over complex mountainous terrain

Impact of high-resolution sea surface temperature representation on the forecast of small Mediterranean catchments' hydrological responses to heavy precipitation

Contact Info

Product

Resources

About