RunoffRunoffRunoffRunoff

Creating a spatially explicit runoff grid

GoalGoal

• Create a grid based surface in which each cell represents runoff transport

• Used for estimating streamflow

• Loadings and concentrations of water quality

• Driving factor in equations

http://www.prism.oregonstate.edu/ http://www.prism.oregonstate.edu/

ASCII to RasterASCII to Raster

Defining a projection for the precip gridDefining a projection for the precip grid

Regression relationshipRegression relationship

For 5 gauging stations located within the Cheat and Tygart Drainage Basins (vicinity of study area) I found 30yr average annual precip and 30yr annual depth of stream flow - both values were in mm.

Best fit was:

Depth of streamflow in mm = (.655474) * annual precip total in mm

Runoff gridRunoff grid

Now for cumulative annual runoffNow for cumulative annual runoff

Part A Part B

Cumulative runoffCumulative runoff

Streamflow from cumulative runoffStreamflow from cumulative runoff

We multiply cu_runoff2 (which is in m3 per year) by the number of cubic feet per cubic meter (35.2875) and divide by the number of seconds per year (31557600).

For result called est_flow will have the 30yr annual average flow in cfs.

Estimated flowEstimated flow

Flow for stream cells onlyFlow for stream cells only

Checking the value to the gaugeChecking the value to the gauge

421 cfs for 30yr annual gauge average

compared to

471 modeled

(within 89%)

Questions / Comments?Questions / Comments?