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Land Surface Parameters

LDAS Topographical Illustrations and Data Sets


The 1/8th degree resolution topographic data sets and illustrations featured below are based on the GTOPO30 Global 30 Arc Second (~1km) Elevation Data Set. In particular, average elevation values over the LDAS domain were arrived at by isolating the relevant subset of data from the ~1km global data set, and then averaging up to the 1/8th degree LDAS resolution. Slope and aspect values were then derived from this 1/8th degree data. Maximum, minimum and standard deviation values, by contrast, were calculated directly from the ~1km values which lie within each 1/8th degree LDAS grid box. Raw data sets were supplied by Steve Graham, Department of Geological Sciences, University of Texas at Austin.

LDAS Topographical Illustrations

Mean elevation (meters) over 1/8th degree NLDAS domain. Values range up to 3600 meters over portions of the Rocky Mountains. Mean Elevation Over the LDAS Domain

Maximum elevation (meters) over 1/8th degree NLDAS domain. Values are greater than 3600 meters over portions of the Rocky Mountains. Maximum Elevation Over the LDAS Domain

Minimum elevation (meters) over 1/8th degree NLDAS domain. Values range up to 3200 meters over portions of the Rocky Mountains. Minimum Elevation Over the LDAS Domain

Standard deviation of elevation values over 1/8th degree NLDAS domain. Values can surpass 350 over western regions of the domain. Standard Deviation of Elevation Values Over the LDAS Domain

Slope values over 1/8th degree NLDAS domain. Values can surpass 1.6 over western regions of the NLDAS domain. Slope Values (In Degrees) Over LDAS Domain

Aspect values over 1/8th degree NLDAS domain. Values are generally 0-150 over the middle portion of the domain, and are greater than 150 over the remainder of the domain. Aspect Values Over LDAS Domain



LDAS Topographical Data Sets

* Use Right Mouse Button to Download * Point (1,1) Located at Lower Left of LDAS Grid *

Binary Data Sets


Mean elevation values (gtopomean15k.bin)
This file contains mean elevation data in binary format. You will need readbin5.f to read the file.

Maximum elevation values (gtopomax15k.bin)
This file contains maximum elevation data in binary format. You will need readbin6.f to read the file.

Minimum elevation values (gtopomin15k.bin)
This file contains minimum elevation data in binary format. You will need readbin7.f to read the file.

Standard deviation of elevation values (gtopostd15k.bin)
This file contains elevation standard deviation data in binary format. You will need readbin8.f to read the file.

Slope values in degrees (slope15k.bin)
This file contains slope data in binary format. You will need readbin9.f to read the file.

Aspect values (aspect15k.bin)
This file contains aspect data in binary format. You will need readbin10.f to read the file.



ASCII Data Sets

All of the ASCII data sets available below contain data in the following format:
Column 1 Grid Column Number
Column 2 Grid Row Number
Column 3 Latitude
Column 4 Longitude
Column 5 Data Value

Mean Elevation Values (gtopomean15k.asc)

Maximum Elevation Values (gtopomax15k.asc)

Minimum Elevation Values (gtopomin15k.asc)

Standard Deviation Values (gtopostd15k.asc)

Slope Values in degrees (slope15k.asc)

Aspect Values (aspect15k.asc)

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Developed and Maintained at NASA/GSFC		Brian Cosgrove: Brian.Cosgrove@gsfc.nasa.gov
Matthew Rodell: Matthew.Rodell@gsfc.nasa.gov
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