Zero or not? Causes and consequences of zero-flow stream gage readings

Area of Science:

• Hydrology
• Ecology
• Biogeochemistry

Background:

• Streamflow data from gages are vital for understanding riverine processes.
• Zero-flow readings from stream gages can be misinterpreted, leading to inaccurate ecological and hydrologic predictions.

Purpose of the Study:

• To identify and discuss various causes of zero-flow gage readings beyond stream drying.
• To highlight the environmental implications of misinterpreting zero-flow data.
• To present methods for accurately determining flow presence and interpreting zero-flow events.

Main Methods:

• Review of common causes for zero-flow gage readings (e.g., ice, flow reversals, instrument error, upstream losses).
• Discussion of the implications of different zero-flow interpretations.
• Highlighting complementary methods for flow determination (direct observation, statistical analysis, hydrologic models).

Main Results:

• Zero-flow readings have multiple potential causes, not exclusively stream drying.
• Misinterpretation of zero-flow events can lead to significant errors in environmental modeling and analysis.
• Various methods can be employed to accurately diagnose the cause of zero-flow readings.

Conclusions:

• Accurate interpretation of zero-flow gage readings is essential for understanding river network connectivity and dynamics.
• Improved interpretation is critical for predicting streamflow behavior in a changing hydrologic climate.
• Integrated approaches are needed to understand surface flow dynamics across river networks.