Pacific Drought Knowledge Exchange presents climate and ranching tools to Hawaii County council committee

Council member Heather L. Kimball invited the Pacific Drought Knowledge Exchange (PDKE) to present climate and drought data tools to the Hawaii County Communication Reports and Council Oversight Committee on a request filed as Communication 735.

Christian Jardine, co-lead of the PDKE, introduced the team and Dr. Ryan Longman of the University of Hawaii Sea Grant College Program. Longman described PDKE's co-production approach with local managers and its ties to statewide data systems, saying the group aims to turn climate data into tools local resource managers can use.

"We stand behind that co-production model," Christian Jardine said, describing outreach with ranchers and resource managers that informs PDKE's tools. "We very much appreciate this opportunity to share some tools that the Pacific Drought Knowledge Exchange has produced over the last couple of years."

Derek, a PDKE geospatial data analyst, demonstrated the climate-portfolio generator: a free online mapping tool that can produce a site-specific PowerPoint portfolio (about 40 slides) containing historic and projected rainfall and temperature, drought histories, groundwater recharge maps from USGS data, and other localized metrics. "We have over 100 years of monthly rainfall data on it," Derek said, and showed examples of multi-decadal trends and ongoing drought conditions into 2025.

On groundwater recharge, Derek told the committee that USGS recharge maps are being integrated and gave an example of past drought impacts: "During that event, we saw an estimated reduction of 40% in groundwater recharge for this area, or over 33,000 gallons per year." He also summarized modeled futures: "By the end of the century we might be looking at a slight decrease in annual rainfall for [the example area], about 4% or 2.5 degree increase in air temperature," and under a drier scenario "potentially a 34% decrease in groundwater recharge by the end of the century."

Sherille Hu presented the Hawaii Rangeland Information Portal (HRIP), a ranch-focused tool launched in 2021 to help ranchers access localized dashboards, 12-month drought histories, and a forage production outlook developed with the Natural Resources Conservation Service (NRCS). Hu cited economic impacts from prior droughts to underscore need for planning: "In 02/2016, Hawaii experienced one of the worst droughts we've seen and in the ranching community specifically over $40,000,000 were lost as well as 20,000 cattle." HRIP allows ranchers to create or bookmark one-by-one mile grid squares tied to personalized dashboards showing rainfall, temperature, and forage projections.

Longman said PDKE's tools can also inform decisions about risk-management products. "We're working with the Risk Management Agency, RMA, and they have actually launched a PRF, pasture, forage rangeland insurance product on Hawaii last year," he said, adding PDKE is not selling insurance but helping make the data available that ranchers can use when assessing insurance or operational choices.

During a short Q&A, Council member Eustace asked about selecting grids in the portal; Sherille explained users can click or draw anywhere and the back end creates 1x1 mile squares that can be bookmarked and are offered free of charge. A member of the public who testified remotely raised concern about whether "man-made technologies" could be altering local rainfall patterns; Longman said he would need to analyze the data but suggested the recent Kona rainfall anomaly was more likely due to shifts in atmospheric circulation and trade-wind deviations than a direct, attributable effect of human-caused climate change. "I don't think... the crazy conditions we had were driven more by changes in atmospheric circulation, deviations of the trade winds, and really not particularly because of manmade climate change," he said.

After the presentation and questions, Council member Kimball moved to close the file on Communication 735, a motion seconded by Council member Kagiwada. The committee recorded nine votes in favor of closing the file. The committee adjourned and noted the next committee meeting was scheduled for 10:30.

The PDKE presenters said the portfolio and HRIP are updated regularly with new statewide datasets through the Hawaii Climate Data Portal and that the group will be available for follow-up with council staff and local stakeholders.