Conceptual diagram of the tiered data collection approach

Detailed Description
The tiered approach to data collection balances the cost and data resolution & accuracy associated with each data source. Conventional streamgaging may produce high-resolution data at a few key locations, whereas observational data, which is relatively low-cost to obtain, may fill in many of the gaps. When integrated, these sources capture a more complete picture of streamflow permanence across the landscape, from individual watersheds to entire regions.
Sources/Usage
Public Domain.