Hawaii StreamStats: A web application for defining drainage-basin characteristics and estimating peak-streamflow statistics

Abstract

eliable estimates of the magnitude and frequency of floods are necessary for the safe and efficient design of roads, bridges, waterconveyance structures, and flood-control projects and for the management of flood plains and floodprone areas. StreamStats provides a simple, fast, and reproducible method to define drainage-basin characteristics and estimate the frequency and magnitude of peak discharges in Hawaii's streams using recently developed regional regression equations (Oki and others, 2010). StreamStats allows the user to estimate the magnitude of floods for streams where data from stream-gaging stations do not exist. Existing estimates of the magnitude and frequency of peak discharges in Hawaii can be improved with continued operation of existing stream-gaging stations and installation of additional gaging stations for areas where limited stream-gaging data are available.

Spatially distributed groundwater recharge for 2010 land cover estimated using a water-budget model for the Island of O‘ahu, Hawai‘i

“…7). The boundaries of the drainage basins of selected stream-gaging stations are from Rosa and Oki (2010), and the boundary between windward and leeward regions is based on topographic divides and consistent with previous studies (Yamanaga, 1972;Oki and others, 2010). The runoff-to-rainfall ratio assigned to each catchment zone and used to calculate direct runoff was selected as one of the following (1) the observed seasonal runoff-to-rainfall ratio for the season, year, and location of interest, if available, (2) the observed mean seasonal runoff-to-rainfall ratio for the location of interest, or (3) the mean seasonal runoff-to-rainfall ratio estimated using a regression equation for the location of interest.…”

Panel regressions to estimate low‐flow response to rainfall variability in ungaged basins

“…Selected streams are not known to be influenced by groundwater withdrawals and are nonregulated upstream of the gaging station [ Fontaine , ], except three gaging stations for which complete daily mean diverted flow was also gaged by the USGS and reliable records of total streamflow representing nonregulated conditions could be reconstructed. Drainage basins were delineated for each selected gaging station using the USGS StreamStats application for Hawaii [ Rosa and Oki , ]. Selected physical basin characteristics (Table ) were computed for each drainage basin.…”

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

“…For this study, a gaged catchment zone is defined by the drainagebasin boundary of a streamgage station. Selected gaged catchment zones on Kauaʻi, Oʻahu, Molokaʻi, and Maui were delineated by Rosa and Oki (2010). No streamgages exist on Lānaʻi, leaving the island without any gaged catchment zones.…”