Multipurpose Use of Artificial Channel Networks for Flood Risk Reduction: The Case of the Waterway Padova–Venice (Italy)

Abstract

Many rivers are increasingly threatened by extreme floods, and effective strategies for flood risk mitigation are difficult to pursue, especially in highly urbanized areas. A flexible and multipurpose use of the complex networks of artificial channels that typically cross these regions can play a role in flood risk mitigation. A relevant example concerns the possible completion of a waterway from Padova to the Venice Lagoon, in North-Eastern Italy. Once completed, the waterway can boost shipping (which is considerably more climate and environment friendly than road transport), can lead to a urban re-composition of the territory and, serving as a diversion canal for the Brenta River, can reduce hydraulic hazard as well. The goal of the present work was to assess this last point. To this purpose, the 2DEF hydrodynamic model was used to reproduce the complex Brenta–Bacchiglione river network. This network includes river reaches, diversion canals, bed sills, pump stations, and control structures that assures the proper operation of the system in case of flood events. The mixed Eulerian–Lagrangian, semi-implicit formulation of the model provided accurate and computationally efficient results for subcritical regimes. The model results showed that the waterway can divert a significant part of the Brenta floodwaters toward the Venice Lagoon, thus reducing flood hazard in the Brenta River downstream of Padova. The benefits also extend to the Bacchiglione River, whose floodwaters can be diverted into the Brenta River through an existing flood canal; indeed, the waterway withdrawal produces a drawdown profile in the Brenta River that allows diverting larger flow rates from the Bacchiglione River as well. Finally, by conveying the sediment-laden floodwaters of the Brenta River within the Venice Lagoon, the waterway could contribute to counteract the generalized erosion affecting the lagoon.

A Simplified Method for an Evaluation of the Effect of Submerged Breakwaters on Wave Damping: The Case Study of Calabaia Beach

“…In this study, we propose a simplified method based on the implementation of Goda's formula directly on the domain, avoiding the 2D modeling of the barrier but keeping the high accuracy of the results. Similar approaches are widely implemented into mathematical models available in the literature by developing a set of specific links to reproduce the presence of long and narrow structures, such as sills and levees [63][64][65][66].…”

“…The hydrodynamic of the barrier is solved by the HD and SW modules, without any change in bottom elevation, by disabling the use of the sedimentological model. implemented into mathematical models available in the literature by developing a set of specific links to reproduce the presence of long and narrow structures, such as sills and levees [63][64][65][66].…”

Inclusion of flood diversion canal operation in the H08 hydrological model with a case study from the Chao Phraya River basin: model development and validation

“…In addition, Wang et al (2019) examined the impacts of interbasin water diversion on flood control and drainage processes in a waterreceiving lake basin in China using the MIKE model. Subsequently, Mel et al (2020b) identified the optimal floodgate operation rules for diverting floodwater in the Bacchiglione-Brenta river network in Italy, using the 2DEF hydrodynamic model; they also evaluated the applicability of those rules (Mel et al, 2020a). Although the use of hydrodynamic models to simulate floodwater diversion has greatly clarified the effects of such operations on flood risk reduction, these studies have mainly considered the relationships between regional flood characteristics and associated diversion canal operation schemes, which have limited global applicability as well in other regions.…”

Redesign of stormwater collection canal based on flood exceedance probability using the ant colony optimization: study area of eastern Tehran metropolis

“…A significant point in the above studies is the optimal redesign of the flood control canal capacities in rehabilitation projects. However, since in many dense urban areas, the total renovation of the drainage canal network, widening or deepening, is limited by financial and spatial constraints, identifying the problematic canals and locally redesigning and renovating them is a practical and effective option (Mel et al 2020). Therefore, using optimization tools to locally redesign the canals by considering flood probability as the constraint allows for the maximum flow capacity for flood discharge with the minimum reconstruction cost.…”