Speaker:	Dr. Kristin Jaeger
Institution:	Washington Water Science Center
	U.S. Geological Survey
Seminar Date:	Thursday, Apr. 1st, 2021, 3:30-4:50 PM

When, where, and for how long water flows in streams is fundamental to understanding water availability and water quality. Identifying the location and hydroperiod of flow/no-flow conditions, collectively referred to here as flow permanence, remains a knowledge gap throughout the United States, particularly for lower order headwater streams, which comprise the vast majority of channel length in stream networks. The PRobability Of Streamflow PERmanence (PROSPER) model provides annual predictions of a 30-m stream segment having year-round flow for all streams in the National Hydrography Dataset medium resolution for the HUC 17 Pacific Northwest Region, an area that encompasses Washington, Idaho, and most of Oregon). The model uses Random Forest and is based on monthly or annually updated values of climatic conditions and static physiographic variables associated with the upstream basin. Predictions correspond to any pixel on the channel network consistent with the medium resolution National Hydrography Dataset channel network stream grid. The approach uses simple flow/no flow that represents a departure from conventional time-series streamflow data at USGS gages that are temporally rich (e.g. high accuracy 15-minute data) but are limited to only a few locations in a catchment that tend to be perennial. To that end, in partnership with the U.S. Forest Service, the USGS has developed a mobile-application field survey to facilitate the rapid, standardized collection of qualitative flow/no flow observations that are archived in a publicly available master database.