Resumen
Australia?s 560 Councils are responsible for assets worth approximately $270 billion, many of which have a life span >50 years and so will be affected by climate change. Maintenance and replacement of Council infrastructure is guided by principles, models and tools in the International Infrastructure Management Manual that currently do not allow for climate change impacts or the likely flow-on effects to asset and financial management. This paper describes a financial simulation model developed to calculate the financial impacts of climate change on three major asset classes of importance to Australian Councils: hotmix sealed, spray sealed and unsealed roads. The research goes beyond previous studies of climate change impacts on roads in that it provides a location specific toolkit that is designed to assist councils in their asset management and planned maintenance programmes. Two categories of inputs are required for the model: climate inputs, relating specifically to baseline temperature and rainfall distributions and climate change parameters for temperature and rainfall; and engineering inputs, relating specifically to the three road types and the key parameters of their performance and useful lives over the scenario period. The baseline distributions are then shifted mathematically within the model by the mean change as projected by a selected Global Climate Model (GCM) scenario. Outputs of the model are the historical baseline climate variable distributions and the climate change (CC) impacts on road performance are in the form of changes to the useful life of the asset and associated changes in asset resurfacing and rehabilitation costs. Ten case study local councils in southern Australia are examined. Using IPCC AR4 scenarios, the results suggest that the incremental impact of climate change on all three types of road infrastructure modelled will be generally low. There are small cost reductions over the period for all road types as a result of the expected drying and warming trends in the climate.