Coupling human preferences with biophysical processes: modeling the effect of citizen attitudes on potential urban stormwater runoff

Green infrastructure (GI) is gaining wide popularity as a means to reduce urban stormwater runoff. The challenges to long-term success of many GI policies, however, depend on citizen understanding and willingness to be engaged in the process of GI implementation. In this study, we developed a conceptual model that incorporated human preferences and biophysical processes in a coupled manner to estimate stormwater runoff variation at the sewershed scale under different acceptable GI implementation scenarios. To investigate resident receptivity toward GI implementation, we conducted surveys in selected Syracuse sewersheds and developed the scenario of residents implementing rain barrels and rain gardens in their private properties based on the survey results. We simulated this scenario at the lot level using the model we developed within the framework of the EPA SWMM 5 model to estimate reductions in peak flow and total runoff volume for major storm events. With our model, we also tested the effect of planned government tree planting scenarios. The scenario simulations were applied in three urban sewersheds of varying socio-economic and biophysical structures in the City of Syracuse, New York. The simulation results indicated that both the government participation and household participation scenarios, compared to pre-GI-development conditions, would contribute to a modest reduction in stormwater peak flow (> 4 %) and total runoff volume (> 5 %) across the simulated sewersheds. This study provides decision makers with a scientific methodology to quantify how human decisions can shape ecosystem function, and thus support sustainable stormwater management planning while addressing citizen preferences and needs.