READMEnc.txt - HYDRA NetCDF input files description

This file describes each of the NetCDF input files. NOTE: HYDRA is not currently 
set up to read in the .nc geomorphology files. It is designed to read the 
geomorphology files as HDF

GEOMORPHOLOGY

> basin.nc
This is a map of each individual river basin on the globe. Each basin is 
arbitrarily assigned a separate number. This file is only used to limit 
simulations to a specific basin. It may not be necessary in all cases.

> rivdir.nc
This is the river direction file. It parameterizes which of 8 possible 
directions that water will flow across the land surface. In other words it 
points to the downstream grid cell. The values range from 1 to 8 with 1 being 
North, progressing clockwise to 8 which is NW.

> mflac.nc
This file specifies the places on the land surface where water will pool if
R+P > E. These are the potential water bodies. They are derived from an 
iterative examination of the land surface topography. The technique for deriving 
them is described in Coe, M.T. (1998). A linked global model of terrestrial 
hydrologic processes: Simulation of modern rivers, lakes, and wetlands. Journal 
of Geophysical Research 103(D8), 8885-8899. The values in the file are the 
elevation of the sill height in meters above sea level. The sill height is the 
elevation at which water will spill out of the basin into the downstream basin.

> outnewi.nc
> outnewj.nc
These two files are the i and j sill locators, respectively. They tell HYDRA 
where the sill (outlet location) is for any given potential water body (mflac). 

> tbase.nc  
This is the land elevation file. It is based on the TerrainBase DEM of the USGS 
EROS Data Center. It registers theelevation in m.a.s.l. 

CLIMATE DATA

The following four files are climate input for the Lake Chad basin. The files 
can be used to test the model against published results for the Lake Chad basin. 
HYDRA is currently set up to read these files. They represent 708 months of data 
from 1946-1994 and are derived from an IBIS model run forced with data from the 
Climate Research Center at East Anglia. These files are the same as those used 
in the model runs by Coe (2000) : Modeling terrestrial hydrologic systems at the 
continental scale: Testing the accuracy of an atmospheric GCM, J. Clim., in 
press

srunoff.nc Surface runoff in mm/day

drainage.nc Sub-surface drainage in mm/day

rain.nc Precipitation in mm/day

evap.chadf.nc Evaporation from open water in mm/day