Pollution risks and water management at airports and roads in a changing climate

Management of surface runoff formed during snowmelt is a challenge in many urban areas. Even in areas with normally high infiltration capacity, the ground surface can become impermeable during snowmelt. Climate change is expected to increase precipitation during autumn and give more frequent temperature fluctuations around 0*C in Norway. This is likely to affect the infiltration regime throughout the winter and during snowmelt. It is hypothesised that these changes will reduce infiltration capacity and he nce have important implications for surface runoff management. Increased use of de-icing chemicals and reduced infiltration capacity will increase the risk of polluting groundwater and surface waters. Oslo airport, the main northern bound motorway (E6) an d railway are all situated on the largest unconfined sandy aquifer in Norway, Gardermoen. The flow and transport pattern as well as the structural architecture have been widely characterised at the site. Because it also hosts the extensively equipped rese arch site, Moreppen, it is an appropriate location for studies related to climate change risk assessment purposes. Joint efforts with Oslo airport and the Norwegain Road Authorities to perform statistical analysis of historical data of climatic conditions and associated winter weather operations will provide information about likely consequences for management practices in a changing climate. State- of the art non-destructive tomographic and surface imaging tools based on electrical measurements will quan tify the infiltration process in the field at different scales; at a reference site, Moreppen, along the runway, and below temporarily formed surface ponds. The infiltration pattern will be related to physical conditions at the site. To identify the need for adaptation strategies, a 3D unsaturated flow and transport model will be calibrated on the field data at different scales and used to examine possible pollution effects of different climate change scenarios.