An integrated hydrological and hydraulic modelling approach for the flood risk assessment over Po river basin

Abstract

Abstract. Identification of flood prone areas is instrumental for a large number of applications, ranging from engineering to climate change studies, and provides essential information for planning effective emergency responses. In this work we describe an integrated hydrological and hydraulic modeling approach for the assessment of flood-prone areas in Italy and we present the first results obtained over the Po river (Northern Italy) at a resolution of 90 m. River discharges are obtained through the hydrological model CHyM driven by GRIPHO, a newly-developed high resolution hourly precipitation dataset. Runoff data is then used to obtain Synthetic Design Hydrographs (SDHs) for different return periods along the river network. Flood hydrographs are subsequently processed by a parallelized version of the CA2D hydraulic model to calculate the flow over an ad hoc re-shaped HydroSHEDS digital elevation model which includes information about the channel geometry. Modeled hydrographs and SDHs are compared with those obtained from observed data for a choice of gauging stations, showing an overall good performance of the CHyM model. The flood hazard maps for return periods of 50, 100, 500 are validated by comparison with the official flood hazard maps produced by the River Po Authority (Adbpo) and with the Joint Research Centre's (JRC) pan-European maps. The results show a good agreement with the available official national flood maps for high return periods. For lower return periods the results and less satisfactory but overall the application suggests strong potential of the proposed approach for future applications.

A One-Way Coupled Hydrodynamic Advection-Diffusion Model to Simulate Congested Large Wood Transport

“…In Equations (9) and (10), the eigenvalue λ 4 refers to the wood transport equation, as well as the fourth term of the eigenvectors e 1 , e 2 , e 3 and the eigenvector e 4 . The symbols with tilde used in Equations (9) and (10) are the averaged values of the velocity components (u,v), celerity c and wood averaged concentration ϕ:…”

“…Focusing on wood, past and recent events demonstrated its effects both in terms of extension of flooded areas [10,11] and of potential/real damage to in-line structures, such as bridges and check dams (e.g., videos/pictures of events in Italy [12][13][14]). It is increasingly evident that wood transport should not be disregarded, especially in mountainous basins, to provide hydraulic simulations that can cope also with the residual risk connected to such phenomenon.…”

Flood Modeling of Imus River Basin, Cavite, Philippines at Different Climate and Land Cover Change Scenarios

“…In the case of Po River in Northern Italy, the assessment of ood prone areas was done through integrated hydrological and hydraulic modeling approach. Runoff data obtained from the hydrologic model was used to developed Synthetic Design Hydrographs for different return period and subsequently processed using a hydraulic model to calculate the ow over the digital elevation model of the area and considering the channel geometry [12]. The ood maps developed using hydraulic modeling of Medjerda Basin in Norther Tunisia was validated using a Sentinel -1 radar image showing the real ood extent in order to further evaluate performance of the model [13].…”

Risk assessment of urban rainstorm flood disaster based on land use/land cover simulation

“…The studies about urban flood disaster risk under the urbanization and Land use/cover change (LUCC) impacts fall into two categories: numerical modelling and comprehensive evaluation methods. The numerical modelling is usually based on hydraulic, hydrological or hydro‐dynamic models to explore the impacts of urbanization and LUCC on flood intensity and flood risk (Luo & Zhang, 2022; Nogherotto et al, 2019; Zhang et al, 2022; Zope et al, 2016). The comprehensive evaluation methods use multi‐index system, usually include socio‐economic changes (Ekmekcioğlu et al, 2022; Lee et al, 2017).…”