WRRC/‘Ike Wai Seminar

April 16, 12:00pm - 1:00pm
Mānoa Campus, HIG 210

Characterizing the Stream and Its Association with the Ecosystem in Hawai‘i

by Dr. Yin-Phan Tsang

This presentation will consist of two parts, based on recent studies focusing on Hawiian streams and ecosystem.

Part I. Characterizing Natural Barriers to Non-native Stream Fauna in Hawai‘i—Waterfalls are natural barriers that influence the distribution and dispersion of aquatic species. In Hawai‘i, it is assumed that non-native species are unable to pass waterfall barriers, yet they are still present above some waterfalls, possibly facilitated by human introduction. In this study, we used a landscape approach to identify likely human introductions and examined the ability of 14 non-native stream fauna to bypass waterfalls when the possibility of human introduction is eliminated. This study highlights the role that people play in facilitating species introductions in otherwise inaccessible habitats.

Part II. Temporal Shifts in the Magnitude of Peak Streamflow and Its Associated Rainfall Across the Hawaiian Islands—Previous studies show that extreme rainfall events are becoming more common. However, there is little research available that examines the temporal and spatial trends of peak streamflow (peak flow) events associated with heavy rainfall events. We analyzed the annual peak flow and the annual maximum rainfall trends of 112 stream crest gages from the U.S. Geological Survey, and an additional 82 rain gages from the National Centers for Environmental Information, across the Hawaiian Islands from the water years 1970 to 2005. To add to the current knowledge of flood risk and management in Hawai‘i, our study discussed how the annual peak flows changed over time, patterns in their spatial distribution, and how they are associated with a rainfall.

Event Sponsor
WRRC, Mānoa Campus

More Information
Niels Grobbe, (808) 956-5857, ngrobbe@hawaii.edu

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