Spatial Precipitation Trends and Effects of Climate Change on the Hawaiian Hualalai Aquifer

Global climate has been drastically changing, with unprecedented changes observed in the last half-century. Temperatures have significantly warmed, with the rate of warming continuing to increase even more within the previous few decades. Changes in precipitation, however, are more varied and play a strong role in water resource availability.

The Kaloko-Honokohau National Historical Park (KAHO) sits at the base of the Hualalai Aquifer, where a strong precipitation gradient is observed as elevation increases from the coast to the top of Hualalai Volcano. KAHO is dependent upon water from this aquifer, which has experienced changes in freshwater recharge due to significant changes in precipitation over the area. Data from the Hawaii Rainfall Atlas were used to determine the spatial distribution of this change in precipitation over a 30-year period from 1978-2007. This new approach to analysis looked at both the significance and rate of change spatially over west Hawaii to better analyze climate trends already impacting water resources in the region.