Comparing hydrologic simulations for select
Oregon watersheds: influence of resolution


The purpose of this work is to compare the results of hydrologic simulations performed at 1/16th degree (~6 km) with those performed at 30 arc-second (~800 m) resolution. Hydrologic simulations are performed using the Variable Infilteration Capacity (VIC, Liang et al., 1994) macroscale hydrologic model over the 58 study basins shown in Figure 1. The simulations are forced using data from previous CIG projects at both 1/16th degree (Hamlet et al., 2010) and 30 arc-second resolution. Table 1 lists the variables that are archived for each set of simulations. The summaries include gridded monthly summaries for each variable as well as basin-averages for select variables.

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Study Watersheds

Figure 1 Map showing watersheds seleceted for this study. The basins range in size from roughly 60 to 100,000 km2.

Table 1 List of hydrologic variables archived (more details on these variables and how they are calculated can be found in Hamlet et al., 2010).
Variable Name Description Monthly Agg. Monthly Summ. Basin Avg
tavg average temperature, degC average Y Y
precip precipitation, mm total Y Y
isr incoming shortwave radiation, W/m2 average Y N
olr outgoing longwave radiation, W/m2 average Y N
rh relative humidity, % average Y N
vpd vapor pressure deficit, Pa average Y N
runoff runoff, mm total Y Y
baseflow baseflow, mm total Y Y
combinedflow runoff+baseflow, mm total N Y
swe snow water equivalent, mm 1st day Y Y
snodep snow depth, cm 1st day Y N
soilm1 soil moisture, layer 1, mm 1st day Y Y
soilm2 soil moisture, layer 2, mm 1st day Y Y
soilm3 soil moisture, layer 3, mm 1st day Y Y
soilmoist total column soil moisture, mm 1st day N Y
et evapotranspiration, mm total Y Y
pet1 potential evapotranspiration, w veg resist., mm total Y N
pet2 potential evapotranspiration, open water, mm total Y N
pet3 potential evapotranspiration, no veg resist., mm total Y N
pet4 potential evapotranspiration, tall crop, mm total Y Y
pet5 potential evapotranspiration, short crop, mm total Y Y

Accessing the Data

Please use the contact information below to let us know how you plan to use the data -- we'd really like to know!

1/16th degree data:

30 arc-second data:


This project was funded by ... need to get Nate to fill this part in.


Hamlet A.F. et al., 2010: Statistical downscaling techniques for global climate model simulations of temperature and precipitation with application to water resources planning studies. Chapter 4 in Final Project Report for the Columbia Basin Climate Change Scenarios Project.

Liang, X., D. P. Lettenmaier, E. F. Wood, and S. J. Burges, 1994: A Simple hydrologically Based Model of Land Surface Water and Energy Fluxes for GSMs, J. Geophys. Res., 99(D7), 14,415-14,428.


Questions regarding this dataset can be directed to:

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