Distributed hydrodynamic modelling for assessing flood impacts on crops: Assessing flood-resilient crop management in a coastal basin of central Italy

Nuisance flooding phenomena do not only affect urban areas, but also agriculture, determining catastrophic damages to crops. The impact of floods on crops has been an underrated topic in scientific literature that focuses more on urban areas, probably because they tend to have higher densities of population, infrastructure, industries, and real estate properties, which translates into more substantial human and economic losses during floods. In this work, we proposed a quantitative physically based method for crop damage assessment based on distributed hydrodynamic modelling of flood events. It exploited a combined high-resolution 1D-2D hydraulic model and crop resistance interlinked dynamics. The method allows to quantify, with unprecedented high resolution, the spatially distributed probability of crop losses for different crop types for different flood recurrence intervals. The methodology is applied in a relevant case study in central Italy, the Marta River basin, that experienced impactful floods on the extended riverine agricultural lands. Modelling results allow to represent combined maximum water levels per flood scenario, ponding time of water on the field, and the maximum flow velocities considering growth stages of different crops. Results showed that April is the most vulnerable month with the greatest potential losses (4.47 × 109 kcal for the 200-year return period), due to the high concentration of winter cereals (>50 %) with high fragility at the flowering stage. A set of alternative crops that demonstrate to be more flood tolerant or to grow in a period offset from the peak flood occurrence were also assessed showing the potential use of the proposed methodology towards better agricultural management in floodplains.