Resistance versus resilience approaches in road planning and design in delta areas: Mekong floodplains in Cambodia and Vietnam

Engineering works in river basins that explicitly take into account floodplain hydraulic processes and dynamics, demonstrate a move towards more sustainable development in riparian areas. In this paper, this concept is applied to road planning and design in floodplains. The paper suggests that although a resilience strategy might require higher initial investments than a resistance strategy, in the longer term it will result in lower costs in terms of road damage and ecological damage. Results are presented from four cases in the Mekong floodplains where different strategies towards road planning, varying in resilience, have been assessed for their hydraulic, ecological, social and economic impacts based on a combination of modelling results, expert judgement and secondary data sources. The study finds that, with the exception of extreme cases, the impact of roads has a limited impact on the floodplain hydraulics. However, even small changes in flood dynamics (arrival of the peak, duration) may have large ecological impacts, especially if cumulative impacts of more road developments are taken into account. The results illustrate that road planning and design in floodplains is a complicated task that requires an integrated approach.