Adaptive planning of stormwater management measures to mitigate pluvial flooding under climatic and socio-economic uncertainties

Abstract

The undertaken thesis work conducts a research study based on the study area — Laakhaven, The Hague, to develop an implementation example of the Adaptation Pathway approach, in order to support long-term adaptive stormwater management planning on urban adaptation measures to mitigate pluvial flooding under the climatic and socio-economic uncertainties.

The methodology is presented in the stepwise procedure to develop adaptation pathways. The core part of this method is expressed as the risk-based approach, which considers the flood risk from the aspects of the probability and the consequence. Different climate and socio-economic scenarios are developed to represent the uncertain environment for policymaking resulting from long-term changes. An urban water balance model is applied to produce the novel empirical performance indicator for the effectiveness of adaptation measures as the critical input to this assessment. Sell-by dates of adaptation actions
are computed based on the assumption that, once a policy action reaches the perspective-based socially acceptable risk, it is said to encounter an adaptation tipping point thus requiring additional interventions. With the computed sell-by dates, the adaptation pathways maps are assembled under certain rules that exclude illogical sequences. Robust adaptation pathways that can succeed over various future scenarios are outlined from the pool of pathways. The developed adaptation pathways map provides the policymakers with a range of possible options. The results indicate the significance of investing in the modular rainwater harvesting devices on private space since it is effective and flexible action
that supports the development of dynamic robust strategies for the long-term adaptive stormwater management planning. The implementation methodology of this case study is theoretically viable and its potential to make a more comprehensive study has been proven. Therefore, it is recommended to take the undertaken study as a starting point and further improve it to find the ultimate answer through sub-selecting preferred pathways.