Near Real-Time USGS Rain and Stream Gauges
Near Real-Time USGS Rain and Stream GaugesPosted May 9, 2014
Voyager’s “water resources” category now includes near real-time measurements for rain gauges and stream gauges across Hawaiʻi managed by the U.S. Geological Survey (USGS) National Water Information System (NWIS). Critical for monitoring water resources and flood conditions, these gauges provide measurements of precipitation, cumulative precipitation, stream gauge height, and stream discharge every 15 minutes.
Prior to now, these Voyager overlays showed a simple marker at each gauge location with a pop-up window providing basic information and a link for externally accessing data on the USGS website. These overlays now have extended capabilities that allow the user to browse data within Voyager itself.
As with Voyager’s other dynamic near real-time station categories—including “waves”, “tide and water level”, and “water quality”—marker icons can be color-coded according to the latest measurement values of a given parameter, whose range is indicated in a corresponding map legend. Hovering over a marker icon provides the station identifier, location name, and most recent data value and sample time. In addition, a pop-up window appears with an interactive time series plot of the selected parameter, along with options to go backwards in time or view a statistical summary. Clicking on the “more info” link in this pop-up window presents additional information about the station as well as links to produce plots or download data over a variety of different time spans. From the category’s “advanced options” in the left-hand menu, furthermore, users can access historical data or modify the overlay in numerous ways.
Voyager screenshot of Kauaʻi’s Mount Waiʻaleʻale, one of the rainest places on Earth, showing 17 inches of rain over the past month:
Voyager can plot precipitation either cumulatively (left) or not (right); cumulative plots are good for showing the total amount of rain that has accumulated over a given time period, while instantaneous plots are useful for showing the timing and intensity of each rain event:
Voyager screenshot of stream gauge height near the University of Hawaiʻi at Mānoa; this shows Mānoa stream rising over a foot after recent rainfall:
Stream gauges measure gauge height (left) and discharge (right), although the latter is not provided at some gauges:
Example of further options and utilities provided when clicking on “more info” in the pop-up window: