# Presentation: 213780

## Hydrometeorological 

**Measurements**

- Melanie A. Wetzel

*** ******Desert Research Institute***

***University of Nevada, Reno***

*and*

- January 2001 -- AMS Short Course on Instrumentation

- Hydromet

## Components of the Hydrologic Cycle

- January 2001 -- AMS Short Course on Instrumentation

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## Processes of Transport and Transformation

*Water resources distribution is controlled by the radiation balance, movement of air masses with contrasting temperature and moisture contents, terrain features and local airflow patterns*

- January 2001 -- AMS Short Course on Instrumentation

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## Primary Elements of Hydromet Monitoring

***Atmospheric Vapor***
***     ******Cloud Water***
***         ******Rainfall***
***             ******Snowfall***
***                 ******Snowpack***
***                     ******Groundwater***
***                         ******Streamflow***
***                            ******Water Quality***

- January 2001 -- AMS Short Course on Instrumentation

- Hydromet

## Atmospheric Humidity

-   Ground-based temperature/humidity monitoring
-   Rawinsondes to provide vapor transport
-   Role of wind-driven evaporation
-   Impact of soil type and other surface parameters

- January 2001 -- AMS Short Course on Instrumentation

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## Evapotranspiration

*Lysimeters measure the loss of water by mass balance from a surface layer usually containing soil and vegetation*

- January 2001 -- AMS Short Course on Instrumentation

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## Evaporation

*Water loss from open water is a large source of atmospheric moisture. Evaporation from snow in dry or high altitude zones also causes significant loss. *

- January 2001 -- AMS Short Course on Instrumentation

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## Measurement of Cloud Water Content

*Hot Wire Sensors*
*Optical Probes*
*Impaction Collectors*
*Cloud Sieves*

- January 2001 -- AMS Short Course on Instrumentation

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## Tipping Bucket Raingages

*Calibrated per-tip volume is converted to equivalent depth per unit area.  Errors due to sticking of snow on sides of funnel, debris, and unrepresentative capture at collection aperture.*

- January 2001 -- AMS Short Course on Instrumentation

- Hydromet

## Weighing Bucket and Snow Gages

*Use of heating, anti-freeze solutions and apparatus for wind screening improve the measurement of total rain and snow equivalent depths.*

- January 2001 -- AMS Short Course on Instrumentation

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## Snow Depth Sensors

*Applications which require monitoring of physical snow depth (such as at ski areas) can utilize acoustic snow depth sensors.   Amounts are under-represented when snow has a low density due to sound transfer into the snowpack.*

- January 2001 -- AMS Short Course on Instrumentation

- Hydromet

## Measurement of Snow Water Equivalent

***Snow pillows monitor mass of overlying snow, and snow cores provide column water amount.***

- January 2001 -- AMS Short Course on Instrumentation

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## Fuel (Vegetation) Moisture

*Fuel Rod devices are designed to simulate moisture content of trees within forest environments, for monitoring fire potential.   Fuel moisture is a direct function of atmospheric humidity, precipitation and soil moisture.*

- January 2001 -- AMS Short Course on Instrumentation

- Hydromet

## Streamflow Monitoring

*Stream discharge is estimated from measurements of the stream stage height.*

- Stage height instruments:
- 	*Staff gage*
- 	*Stilling well / float*
*	**Bubbler*
*	**Pressure Transducer*
*	**Acoustic* *Sensor*

- January 2001 -- AMS Short Course on Instrumentation

- Hydromet

## Stream Cross-Sections

*Flumes and weirs control flow into a known cross-section, so that river stage height can be monitored visually or automatically.   Stage height is related to volumetric discharge using stream profile measurements.*

- January 2001 -- AMS Short Course on Instrumentation

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## Current Meters and Profiles

*Stream velocity follows a vertical profile similar to boundary layer winds, and measurement depths are selected to according to this profile.*

- January 2001 -- AMS Short Course on Instrumentation

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## Discharge Calculations

*Number and location of current measurements across the channel are determined from stream width and depth.*

- January 2001 -- AMS Short Course on Instrumentation

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## Flood Recurrence Interval

*Numerical ranking of peak streamflow is used to estimate the probability of flood conditions. *

- January 2001 -- AMS Short Course on Instrumentation

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## Water Quality

*Contaminants include sediment, bacteria, metals, aerosols, biogenic chemicals and many others.*

- January 2001 -- AMS Short Course on Instrumentation

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## Water Chemistry and Turbidity

*Sample collection and automated sensing are used to monitor sediment and pollutant concentrations*.

- January 2001 -- AMS Short Course on Instrumentation

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## Networks of Hydrometeorological Sensors

- January 2001 -- AMS Short Course on Instrumentation

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## Effects of Local Changes

*Alterations of the stream channel, soil and vegetation are analogous to modification in the airshed due to construction and urbanization*

- January 2001 -- AMS Short Course on Instrumentation

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## References

*Nathanson, J.A., 1997:  Basic Environmental Technology.  Prentice **	**Hall, New Jersey, 440 pp.*
*Ward, A.D., and W.J. Elliot,  1996:  Environmental Hydrology.  **	**Lewis, Boca Raton, 496 pp.*
*Watts, S., and L. Halliwell, ed., 1996:  Essential Environmental **	**Science: Methods and Techniques.  Routledge, New York, **	**512 pp.*

- January 2001 -- AMS Short Course on Instrumentation

- Hydromet