Sensitivity Analysis of an Integrated Urban Flood Model

Abstract

In this paper, the model parameter sensitivity of an integrated urban flood model, including groundwater system, overland flow, sewer network, and river network, is investigated. The sensitivity analysis quantifies how influential the individual and correlated model parameters are to the simulated flood depth and area for an urban catchment in Aalborg, Denmark. The key parametric contributors to output sensitivity are analyzed by: (i) identify the most sensitive model parameters using a Morris screening; (ii) using the generalized Sobol’ method to investigate the sensitivity of the individual input parameters and the interaction between each parameter. The results indicate that the groundwater system, overland flow, and river network contribute most to the flood depth and as such, they need to be considered in urban flood modelling.