Vulnerability of pastoral farming in Hawke's Bay to future climate change: Development of a pre-screening (bottom-up) methodology

Although future climate change will significantly affect New Zealand's climate, how regional climates will be changed remains highly uncertain. As a consequence, pre-screening sensitivity analysis is recommended for climate-sensitive activities. A 'bottom-up' approach intended to serve this purpose in the context of non-irrigated pasture is developed and demonstrated in the Hawke's Bay context. This is achieved using a simple daily water balance model to simulate near-surface hydrological processes and empirical relationships between transpiration and pasture dry matter production. The Hawke's Bay case study indicates that the methodology has merit and is worthwhile pursuing nationally (with refinements).