Running trend analysis for mean annual runoff from 1911 to 2016 for 23 streams across the Hawaiian Islands
Dates
Publication Date
2022-12-22
Citation
Hannah Clilverd, Yinphan Tsang, Dana Infante, Abigail Lynch, and Ayron Strauch, 2022, Running trend analysis for mean annual runoff from 1911 to 2016 for 23 streams across the Hawaiian Islands: https://doi.org/10.21429/qz8v-3k47
Summary
This dataset is a running trend analysis of runoff from USGS stream gage records from as early as 1911 to 2016 for 23 unregulated streams across the five largest Hawaiian Islands: Kauai, Oʻahu, Molokaʻi, Maui, and Hawaiʻi. First, we separated mean daily flow into direct run‐off and baseflow with the “lfstat” separation procedure in R, which employs the Institute of Hydrology (1980) standard baseflow separation procedure of 5‐day blocks to identify minimum flow, called a turning point. The turning points are then connected to obtain the baseflow hydrograph. For each stream, Sen's slope and Mann–Kendall statistic were calculated incrementally using the R package “trend” to give window sizes from 10‐107 years depending on length of the [...]
Summary
This dataset is a running trend analysis of runoff from USGS stream gage records from as early as 1911 to 2016 for 23 unregulated streams across the five largest Hawaiian Islands: Kauai, Oʻahu, Molokaʻi, Maui, and Hawaiʻi. First, we separated mean daily flow into direct run‐off and baseflow with the “lfstat” separation procedure in R, which employs the Institute of Hydrology (1980) standard baseflow separation procedure of 5‐day blocks to identify minimum flow, called a turning point. The turning points are then connected to obtain the baseflow hydrograph. For each stream, Sen's slope and Mann–Kendall statistic were calculated incrementally using the R package “trend” to give window sizes from 10‐107 years depending on length of the flow record. Initial mean daily stream flow data were obtained from the U.S. Geological Survey (https://waterdata.usgs.gov/nwis/rt).
The data were used to assess stream runoff trends and their persistence through time to assess the impacts of changing flow regime and habitat availability for native stream biota in Hawaiʻi. This analysis provides an updated temporal and spatial assessment of streamflow trend magnitudes across the Hawaiian Islands.
