Regional ensemble forecast for early warning system over small Apennine catchments on Central Italy

Abstract

Abstract. The weather forecasts for precipitation have considerably improved in recent years thanks to the increase of computational power. This allows to use both a higher spatial resolutions and the newly developed parameterization schemes for representing sub-grid scale physical processes. However, precipitation estimation is still affected by errors that can impact on the response of hydrological models. To the aim of considering the uncertainties in the precipitation forecast and how they propagate in the hydrological model, an ensemble approach is investigated. A meteo-hydro ensemble system is built to forecast events in a complex orography terrain where catchments of different size are present. In this context, the meteo-hydrological forecast system is implemented and tested for a severe hydrological event occurred over Central Italy on November 15, 2017. During this period, a flash flood hit the Abruzzo region causing precipitation up to 200 mm/24 hours and producing damages with a high impact on social and economic activities.The newly developed meteo-hydro ensemble system is compared with a high resolution deterministic forecast and with the observations over the same area, showing a very good response. In addition, the ensemble allows for an estimation of the predictability of the event a few days in advance and of the uncertainty of this flood. Although the modelling framework is implemented on the basins of Abruzzo region, it is portable and applicable to other areas.

Geomorphology-Based Analysis of Flood Critical Areas in Small Hilly Catchments for Civil Protection Purposes and Early Warning Systems: The Case of the Feltrino Stream and the Lanciano Urban Area (Abruzzo, Central Italy)

“…This system, thus structured, is based on forecast-based information and real-time data (especially the amount of rainfall, the water level in critical areas, and the main river) for the alerting of critical areas. More specifically, the system is based on three levels of alert/alarm input: (1) forecast-based alerting bulletins provided by Allarmeteo (regional warning system); (2) passing of rainfall thresholds (measured in real-time by the sensors) based on the previous floods and statistical analysis of rainfall dataset, and in agreement with existing studies regarding the study area [10,53,91] (the verification and calibration of the rainfall thresholds is ongoing and will be improved in the early stages of the EWS activity); (3) water level increase measured in real-time in the main flood critical areas within the city center. These inputs and the overall system provide different levels of alert/alarm and flood critical areas scenarios to the municipal civil protection for the management of the heavy rainfall events.…”

“…Urban flooding is a common type of natural hazard caused by intense rainfall and can interrupt transportation and power transmission, damage properties, and threaten people's lives [10,11]. The expansion of urban areas and infrastructures over the last 50 years has led to a marked increase in flood risk [12,13].…”

Geomorphology of landslide–flood-critical areas in hilly catchments and urban areas for EWS (Feltrino Stream and Lanciano town, Abruzzo, Central Italy)

“…These events induced several landslide and flood (especially urban flash flood) events (i.e. in January 2003, December 2013, February-March 2015, January-February 2017, November 2017 and June 2018; Piacentini et al, 2018Piacentini et al, , 2020Ferretti et al, 2019).…”

“…Thereby, EWSs can respond to local needs and support/integrate the regional/national scale alerting systems (e.g. Chen et al, 2015;Ferretti et al, 2019) as a tool for risk prevention and civil protection purposes (Acosta-Coll et al, 2018;Azid et al, 2015;Brandolini et al, 2012;Piacentini et al, 2020;Rosi et al, 2017).…”

On the Use of Original and Bias-Corrected Climate Simulations in Regional-Scale Hydrological Scenarios in the Mediterranean Basin

“…For this reason, we decided to identify flood events as we do in operational applications, by means of a hydrological stress index, which has been calibrated over the Abruzzo Region in collaboration with the Civil Protection Functional Centre, in the framework of a specific agreement with CETEMPS (officially appointed as Civil Protection competence centre). Hydrological stress index thresholds were calibrated and validated upon hydrometric level thresholds, and used to predict flood events, as described in References [67,68].…”