In most urban settings in New Zealand, city authorities make use of rain gauges to understand rain events but it is difficult to know if the heaviest rain has fallen on a rain gauge or elsewhere in a catchment. Auckland Council, serving an area with extremely high rainfall variability, identified a need for more accurate short-term rainfall forecasts to support customer requests for service, emergency flood management operations and predictive hydraulic modelling.
We further developed our existing operational rainfall radar platform and incorporated a short-term (0-2 hours) nowcasting service for Auckland Council. Nowcasting takes in real observations of approaching rainfall and, by estimating direction and velocity, predicts where rain is likely to occur, allowing more accurate estimates of potential flooding issues. The system will be hosted on our H2knOw-how web platform, which will allow easy access for any authenticated stakeholder to all radar data generated both in real time and retrospectively for post-event reporting and planning models.
Access to complete, continuous, and consistent rainfall radar data across the region will assist in managing day-to-day operational issues and support Auckland Council’s real-time response to major flooding events, helping it inform customers and mobilise ground staff as required. In addition, the system’s ability to archive data will provide benefit when analysing historic events for long-term strategic flood risk management and prioritising investment in large-scale capital infrastructure projects.