Frequency and Distribution of Hydrologic Drought in the Columbia Basin

Keywords: Hydrologic Drought, Human Disturbances, Hydroclimatic variation, Streamflow Variability
Abstract Type: Poster Abstract

Abstract

Hydrologic drought is influenced by both natural and human factors. This research investigates the spatiotemporal distribution of drought in the Columbia River Basin from WY 1994-2024, considering the geologic, meteorologic, and land cover conditions as they relate to the phenomenon. By assessing the status of hydrologic droughts at long term USGS gage stations with long term time series, this study will first assess the distribution of hydrologic drought across tributaries of the Columbia. First, a frequency analysis will be performed to determine Q90 low flows at each gage site, in an effort to assess which part of each river experiences the most intense drying. Subcatchments will be delineated upstream of each gage, and a cluster analysis will be performed to examine if there is any synchronicity, similar size class, or location among the sampled basins. Finally, parameters including station elevation, continentality, and land cover will be included as proxies for meteorological and human disturbance parameters. This observational study hypothesizes that urban catchments with higher proportion of impervious surfaces will experience more frequent low flows, as well as segments of catchments that see major surface water withdrawals.