The effect of a rise in mean sea level on the New Plymouth coastline : a GIS investigation : a thesis submitted in fulfilment of the requirements for the degree of Master of Philosophy in Geographic Information Systems at Massey University, Palmerston North, New Zealand

Abstract

The world’s sea levels are predicted, by the international scientific community, to rise anywhere between 0.18 metres to 2.2 metres by the year 2100, 87 years away. As a large portion of the population of both the World and New Zealand live by the sea, this prediction is of concern to those in its vicinity. With such a large range in the predicted sea rise level, a range of scenarios have been investigated to determine what effect the rising sea will have on the New Plymouth Coastline, its people, its properties and its places. This study uses a GIS, in conjunction with property and census datasets, to investigate the areas of potential inundation that should be of most concern to our planners and local authorities. Using 3D models of the coastline and seabed and by projecting the predicted sea level rise onto the 3D model, an assessment of the value of property and numbers of people potentially affected was determined. Erosion / accretion are also considered in the investigation and modelled into the coastal topography of the New Plymouth coastline. The key findings from this research are that there are areas of high value, high importance or population that are critically exposed to moderate levels of sea rise. Infrastructure such as Port Taranaki, The CBD, New Plymouth Airport and sewage systems are all greatly affected, whilst populations in Waitara and other populations close to river mouths are also at risk from a rising sea.