To provide up to date flood magnitude estimations for New Zealand catchments to inform the decision making and design of built infrastructure.
This tool represents a new model of flood magnitude for New Zealand catchments, and a re-assessment of the uncertainty inherent in the existing method that this work is intended to replace.
The previous method for flood estimation, dating from 1989, needed updating because more extreme events have been observed in the interim, and because of the probable effect of climate change, which will increase into the future.
The new dataset has twice as many sites, and three times the annual maxima than the previous study. The uncertainty of the previous model for estimating mean annual flood is larger than originally stated. This is confirmed by testing the current dataset tested against the earlier method.
Maps of catchments included in 1989 modelling (left) and current 2016 modelling (right)
The derivation of a new model for mean annual flood has proved more difficult than expected, at least to the extent that the eventual uncertainty is more than twice the previously published estimate of ~±22%.
The initial intention for redevelopment of this tool was to provided a web-tool to provide access to the new estimations. However due to the current performance of the new model this has not been finalised. The proposed next step for this tool is follow-up consultation with regional council stakeholders to determine future actions for refinement and delivery.
|State of Development||Unknown|
|Management Domains||Natural Hazards|
|Intended End Users||
|Steady State or Dynamic||Unknown|
|Open/Closed Source||Closed Source|
|Operating Systems||MS Windows, Mac OS X|
|User Interface||Please Select|
|Ease of Use||Please Select|
|Keywords||Flood estimates, Hazards, infrastructure|
Tools for estimating the effects of climate change on flood flow: A guidance manual for local government in New Zealand - Ministry for the Environment online report