An assessment of the impact of 1.5 versus 2 and 2.5°C global temperature increase on flooding in Jamaica: a case study from the Hope watershed.

Climate change models project that, within the Caribbean basin, rainfall intensity is likely to increase toward the end of this century, although the region is projected to be drier overall. This may affect the frequency and severity of floods in Jamaica and the Caribbean Small Island Developing States. We investigate how flood hazards may be affected by increases in global mean surface temperature of 1.5, 2.0 and 2.5°C above pre- industrial levels using a case study of a Jamaican watershed. Rainfall projections from the PRECIS regional climate model for the Caribbean are analysed. Six members from the Quantifying Uncertainty in Model Predictions (AENWH, AEXSA, AEXSC, AEXSK, AEXSL and AEXSM) were used to create 100-year flood inundation maps for the Hope river for different global warming levels using hydrological and hydraulic models. Model runs projected peak discharges at 2.0, 2.5 and 1.5°C warming that were higher than discharges in the historical record of events that damaged sections of the watershed. Projections from the hydraulic model show increased flow area, depth and extent for 1.5 followed by 2.0 and 2.5°C rises in temperature. These results imply continued flood risk for the vulnerable areas of the watershed. [ABSTRACT FROM AUTHOR]