Assessing climate change-induced flooding mitigation for adaptation in Boston's Charles River watershed, USA

Climate change is projected to have increased temperature and more frequent and intense rainfalls in the northeast of the United States. Green infrastructure has been identified as a critical strategy for stormwater management and flooding mitigation as well as for climate change adaptation. Climate science plays an important role in understanding a range of climate change impacts and the effects of green infrastructure for climate change planning. Nevertheless, a lack of down-scaled climate change data and place-based assessment has discouraged local communities to pursue further climate change plans. This study proposed a transdisciplinary planning framework assessing the effects of detention in mitigating climate change-induced flooding, using a case in the Charles River watershed, Massachusetts, USA. Derived from a climate sensitivity test in the watershed, 36 climate change conditions were modeled using Soil and Water Assessment Tool (SWAT) and compared to IPCC scenarios. Statistical analyses revealed that detention is more efficient in reducing flooding hazards in low and moderate emission scenarios than those at high emission scenarios. A range of extra land area designated for detention would be needed for mitigating floods under various climate change scenarios. Planning implications include the needs for effective siting of detention areas combined with soil conservation in watershed planning, innovations in adaptive land planning and urban design, and a call for an integration of climate science and hydrological assessment in the transdisciplinary planning processes to better inform and facilitate decision-making using green infrastructure for climate change adaptation in local communities.