Cloud Water Interception in Hawai‘i

Developing Capacity to Characterize the Spatial Patterns of Cloud Water Interception and Its Effects on Water and Ecological Processes

Overview

On Hawai‘i’s mountains, cloud droplets propelled by winds are captured by plants and drip to the ground, adding water to the soil and recharging groundwater. Cloud water interception (CWI) can be a substantial water source and varies largely through space and time. The a better understanding of the spatial pattern of CWI and its interaction with plants is necessary to predict the effects of climate change on water supply and ecosystem. The purpose of this project is to improve our knowledge of the hydrological and ecological role of fog in the Hawaiian cloud forests through field measurements of CWI and climate variables, monitorig the survial and physiological responses of native plant species, and modeling.

To assess spatial patterns and map current and projected cloud water interception (CWI) in Hawaii, atmospheric variables and vegetation characteristics are measured at 5 field sites on 3 of the major Hawaiian Islands. The empirical CWI model (Katata et al. 2011) is compared and optimized using field measured data, and the output is provided to the collaborating team for climate model validation and state-wide mapping. Passive fog gauge (Juvik type), canopy water balance, leaf wetness sensors, time-lapse imagery are compared against liquid water content estimated using a visibility sensor to test low-cost alternative method for LWC measurement. Another two collaborating teams examine 1) the native plants’ responses to fog using sap flow, high resolution dendrometer, and survey of seedling growth and survival; and 2) contribution of CWI to soil water and recharge using volumetric soil moisture sensors and tensiometers.

People

Ecohydrology Lab

Thomas Giambelluca (Principle investigator)

Yoshiyuki Miyazawa (Plant ecophysiologist, post-doctoral fellow)

Michael Nullet (Technician, data manager)

Han Tseng (PhD student, graduate assistant)

Collaborators

Ecology Team:

Stephanie G Yelenik (Ecologist; USGS Pacific Island Ecosystems Research Center)

Lucas Fortini (Ecologist; Pacific Islands Climate Change Cooperative/USGS Pacific Island Ecosystems Research Center)

Hydrological Modeling Team:

Delwyn Oki (Hydrologist; USGS Pacific Islands Water Science Center)

Alan Mair (Hydrologist; USGS Pacific Islands Water Science Center)

Climate Modeling Team:

Yuqing Wang (International Pacific Research Center, University of Hawai'i)

Chunxi Zhang (International Pacific Research Center, University of Hawai'i)

Field sites

Findings

Coming soon!

Resources

Papers & Presentations

Photos

Links

USGS project page

https://nccwsc.usgs.gov/display-project/4f8c650ae4b0546c0c397b48/559afca9e4b0b94a64016ff9

References

Katata, G., M. Kajino, T. Hiraki, M. Aikawa, T. Kobayashi, and H. Nagai (2011), A method for simple and accurate estimation of fog deposition in a mountain forest using a meteorological model, J. Geophys. Res., 116, D20102, doi:10.1029/2010JD015552.