Online Rainfall Atlas of Hawai‘i

Abby Frazier
Thomas Giambelluca
Qi Chen
University of Hawaii at Manoa, Honolulu, HI
Donna Delparte
Jonathan Price
University of Hawaii at Hilo, Hilo, HI

Water Resources
Monday March 5, 2012 - 3:15 to 4:30 pm

The Hawaiian Islands have one of the most diverse rainfall patterns on earth. Knowledge of these patterns is vitally important for a number of resource management issues, including the restoration and protection of native ecosystems, ground water and surface water development and protection, and planning for the effects of global warming. A new set of digital maps of mean monthly and annual rainfall from 1978-2007 for the major Hawaiian Islands has been developed. A monthly rainfall database was assembled with over 1,000 stations, using several gap-filling techniques to address missing values in the station records. "Virtual raingage" sites were estimated in remote areas based on patterns of natural vegetation. The final gridded maps were created using a Bayesian data fusion method that merged the station data with three predictor maps derived from Radar rainfall, MM5 model rainfall, and PRISM rainfall maps.

A new interactive website was created to make the rainfall maps, data, and related information easily accessible. Users can download map images, GIS and Google Earth layers, and station data or obtain information via an interactive map. To access the website, visit:

http://rainfall.geography.hawaii.edu/.