Future Performance of Coastal Drainage Systems under Climate Uncertainty

A Sensitivity Analysis

Abstract

Due to increased noticeable effects of climate change, coastal cities are urged to simultaneously protect against rising sea levels and maintain, and enhance, well-functioning stormwater drainage systems. Given the significant uncertainties associated with future projections, this work aims to evaluate the sensitivity of the drainage system to selected future scenarios. To achieve this, a total of 27 projected scenarios were generated for three time-horizons, combining sea level rise and rainfall in one-year long time series using openly available data from the Swedish Meteorological and Hydrological Institute (SMHI). These scenarios were tested using a hydrodynamic 1D model of the pipe system in Landskrona, Sweden. 

The results indicate that the system performs well up until 2070 across all investigated scenarios. By 2100, however, performance indicators reveal the crossing of a threshold, resulting in greater variability between scenarios and a decline compared to earlier levels. Further analysis will focus on determining the exact threshold level and identifying the key contributing parameters. Additionally, more performance indicators will be incorporated, and the results will be analysed geographically to provide enhanced guidance for urban planners.