Effects of Drought and Cloud-Water Interception on Groundwater Recharge and Wildfire Hazard for Recent and Future Climate Conditions, Kauaʻi, Oʻahu, Molokaʻi, Maui, and the Island of Hawaiʻi
Links
- Document: Report (12 MB pdf)
- Related Work: Scientific Investigations Report 2023-5130 - Estimated Groundwater Recharge for Mid-Century and End-of-Century Climate Projections, Kaua‘i, O‘ahu, Moloka‘i, Lāna‘i, Maui, and the Island of Hawai‘i
- Data Releases:
- USGS Data Release - Mean annual groundwater recharge rates for Kauaʻi, Oʻahu, Molokaʻi, Maui, and the Island of Hawaiʻi, for a set of drought and land-cover conditions
- USGS Data Release - Frequency characteristics of soil moisture, evapotranspiration, and climatic water deficit for Kauaʻi, Oʻahu, Molokaʻi, Maui, and the Island of Hawaiʻi, for a set of rainfall and land-cover conditions
- Download citation as: RIS | Dublin Core
Abstract
The Water-budget Accounting for Tropical Regions Model (WATRMod) code was used for Kauaʻi, Oʻahu, Molokaʻi, Maui, and the Island of Hawaiʻi to estimate the spatial distribution of groundwater recharge, soil moisture, evapotranspiration, and climatic water deficit for a set of water-budget scenarios. The scenarios included historical and future drought conditions, and a land-cover condition where shrubland and forest within the cloud zone were converted to grassland. For the historical drought condition, island-wide mean annual recharge estimates range from a decrease of 30 percent (239 million gallons per day [Mgal/d]) for Kauaʻi to a decrease of 39 percent (2,706 Mgal/d) for the Island of Hawaiʻi, relative to the reference condition consisting of 1978–2007 rainfall and 2020 land cover. For the future drought condition, estimates of island-wide mean annual recharge range from a decrease of 40 percent (477 Mgal/d) on Maui to a decrease of 51 percent (116 Mgal/day) on Molokaʻi. Complete conversion of all shrubland and forest within the cloud zone to grassland for each drought condition produces estimated land-cover-related decreases in island-wide mean annual recharge (in addition to the drought-related decreases) of 11–12 Mgal/d on Oʻahu, 119–135 Mgal/day on Maui, and 689–849 Mgal/d on the Island of Hawaiʻi. The spatial distributions of increases in conditions indicative of moisture stress and potential wildfire hazard were quantified using the relative frequency of soil moisture less than a selected threshold value (monthly mean soil moisture less than 0.074, expressed as a fraction of available water capacity), evapotranspiration less than a selected threshold value (monthly evapotranspiration less than 0.96 inches), and climatic water deficit greater than a selected threshold value (monthly climatic water deficit greater than 0.77, expressed as fraction of potential evapotranspiration). For the historical drought condition, the greatest increases in the relative frequency for the moisture-stress indicators occur across parts of east and southwest Kauaʻi; central, east, and west Oʻahu; central Molokaʻi; central Maui and low- to mid-altitude parts of West Maui volcano; and the northwestern and southern parts of the Island of Hawaiʻi. For the future drought condition, the greatest increases in the relative frequency of the moisture-stress indicators occur across parts of west Kauaʻi; central and west Oʻahu and Molokaʻi; a band of mid-altitude area on the southern slope of West Maui volcano and across the southwestern slope of Haleakalā; and mid-altitude areas of the northwestern and southern parts of the Island of Hawaiʻi. Complete conversion of all shrubland and forest within the cloud zone to grassland for each drought condition results in land-cover-related increases in the relative frequency of moisture-stress indicators around Kaʻala in the Waiʻanae Range and the southeastern part of the Koʻolau Range on Oʻahu, the southern part of West Maui volcano and the southwestern slope of Haleakalā on Maui, and the upland regions of the western and southern parts of the Island of Hawaiʻi.
Suggested Citation
Mair, A., Oki, D.S., Kāne, H.L., Johnson, A.G., and Rotzoll, K., 2024, Effects of drought and cloud-water interception on groundwater recharge and wildfire hazard for recent and future climate conditions, Kauaʻi, Oʻahu, Molokaʻi, Maui, and the Island of Hawaiʻi: U.S. Geological Survey Scientific Investigations Report 2023–5141, 98 p., https://doi.org/10.3133/sir20235141
ISSN: 2328-0328 (online)
Study Area
Table of Contents
- Acknowledgments
- Abstract
- Introduction
- Study Area
- Selection of Climate and Land-Cover Conditions
- Water-Budget Model
- Groundwater-Recharge Estimates
- Soil Moisture, Evapotranspiration, and Climatic Water Deficit Frequency Characterization
- Implications of Drought and Reduced Cloud-Water Interception for Groundwater Recharge, Soil Moisture, Evapotranspiration, and Climatic Water Deficit
- Study Limitations
- Summary
- References Cited
- Appendix 1. Model Input
- Appendix 2. Evaluation of Moisture-Stress Thresholds for Soil Moisture, Evapotranspiration, and Climatic Water Deficit
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Effects of drought and cloud-water interception on groundwater recharge and wildfire hazard for recent and future climate conditions, Kauaʻi, Oʻahu, Molokaʻi, Maui, and the Island of Hawaiʻi |
| Series title | Scientific Investigations Report |
| Series number | 2023-5141 |
| DOI | 10.3133/sir20235141 |
| Year Published | 2024 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Contributing office(s) | Pacific Islands Water Science Center |
| Description | Report: viii, 98 p.; 2 Data Releases |
| Country | United States |
| State | Hawaii |
| Online Only (Y/N) | Y |
| Google Analytic Metrics | Metrics page |