Understanding the impact of climate change on pavements with CMIP5, system dynamics and simulation

There is an increasing awareness regarding the impact of climate change on performance and durability of pavements. The objective of this paper is to present a framework of using the global climate forecasts, system dynamics and Monte Carlo analyses to evaluate the rate of change in climate change parameters and understand the impact of climate change on pavements. Changes in maximum air temperature and annual precipitation levels were determined for seven cities across the US, for RCP 4.5 and RCP 8.5 scenarios, using downscaled CMIP5 model output. A system dynamics model was utilised to link the changes in climate change-related parameters to deterioration and life of pavements. Percent of roads that need rehabilitation at different times, up to a time span of 100 years were predicted with simulations of the system dynamics model. Using regression equations developed on the basis of the output data, Monte Carlo analyses were then conducted to obtain distribution and 90% confidence intervals for percent of roads requiring rehabilitation at 50 and 100 years, for no climate change, climate change and climate change with different mitigation scenarios. The results clearly show the significant increase in deterioration of roads as a result of predicted climate change, compared to a ‘no climate change’ scenario. The conclusions are that the CMIP5 model output can be utilised successfully to obtain statistical data regarding climate change parameters that are relevant for pavement design and that a sequential use of the tool, system dynamic and Monte Carlo simulation can be utilised by public agencies to estimate climate change-related parameters for different scenarios, the risk of negative impact of such change on pavement lives and evaluate the effectiveness of various mitigation approaches. This can help them in making justifiable decisions regarding the consideration of climate changes in design of pavements