WMS:Rain Gage

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The rain gage coverage in WMS is designed for use with HEC-1, HEC-HMS, and GSSHA. Attributes can only be assigned to points in the rain gage coverage. WMS automatically computes and displays Thiessen polygons for all of the gages defined on a rain gage coverage according to their x,y coordinates.

HEC Gages

Manage the rain gage data required by HEC hydrologic models, including the x,y gage location, storm total precipitation values, and the temporal distribution. When gages are present, weights are assigned to each basin from the Thiessen polygon network as the basin data are computed. See Weighted Average Precipitation for instructions on how to use rain gages in HEC-1 to compute a weighted average precipitation.


Choose one of the following types of precipitation data to apply to all gages on the coverage:

  • GAGES – rainfall accumulation (mm) over the last time period
  • RADAR – rainfall rate (mm/hr) for the last time interval
  • RATES – rainfall rate (mm/hr) for the next time interval
  • ACCUM – cumulative amount of rainfall up until that time period (mm)

Enter the name, x,y locationand precipitation values corresponding to the precipitation type for each gage. When entering data some guidelines to be aware of include:

  • Precipitation types (GAGES, RADAR, RATES, and ACCUM) cannot change within a storm event (on a rain gage coverage)
  • The time interval can be any value, but there must be a rainfall value at each regular time interval.

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