Stream temperatures are on the rise in the Pacific Northwest, creating problems for native fish and wildlife. As a result, a lot of ecologists, scientists, and regulators collect water temperature data. High quality, multi-year temperature data is critical for understanding the status and trends of our local streams and the species that inhabit them.
Relatively inexpensive, temperature probes produce large volumes of data — hourly observations produce over 8,000 records/year — and are often deployed by water quality, habitat, and fish monitoring programs. However, the effort required to quality-check and "clean" temperature data often exceeds the effort to collect it.
Bonneville Power Administration (BPA) and the National Oceanic and Atmospheric Administration (NOAA) recently asked Sitka, as part of its efforts to automate the data flows for the Columbia Habitat Monitoring Program (CHaMP), to reduce the cost and time to review, quality-check, and fix stream temperature data anomalies. Borrowing an approach used by the financial sector to quickly analyze stock market trends, Sitka created a data visualization tool called True Temp™.
Starting with a broadsheet [PDF], Sitka sketched the problem, identified an advisory group, outlined the current workflow, and then designed an improved workflow that made use of this new data visualization tool. Sitka also worked with its advisors to enumerate a set of quality assurance (QA) tests configurable by watershed in order to calibrate for local conditions. For example, True Temp flags duplicate observations, readings outside of thermal minimums and maximums, and greater than expected variations in daily and hourly means and ranges.
Today, a relatively untrained user can immediately see these anomalies on the time-series graph — green readings pass, orange readings are suspect.
While Sitka integrated True Temp in the CHaMP data system, they built it in a way that could be leveraged by other organizations facing the same challenges and needing to stretch their monitoring dollars further.
Want to see True Temp in action? Contact us.