Originator: Spatial Analysis Unit, Carolina Population Center
Publication_Date: 2000
Title: East ISA Digital Elevation Model
Geospatial_Data_Presentation_Form: raster digital data
Description:
Abstract:
This digital elevation model (DEM) contains hydrologically-correct terrain elevation data in a digital raster format for the Eastern Intensive Study Area (ISA) of the CPC Ecuador Projects, in the northern Oriente of Ecuador. It consists of a sampled array of elevations interpolated from elevation contours and a sampled array of elevations for ground positions at a relatively normally-spaced interval. The spatial resolution of this DEM is 30 meters, meaning that each raster pixel represents a 30m by 30m area on the ground, and each pixel has one elevation value, in meters above sea level.
Purpose:
The DEM can be used for any analyses that require an elevational component, or for simple three-dimensional representation of the ISA.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 1993
Currentness_Reference: publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -76.752607
East_Bounding_Coordinate: -76.501410
North_Bounding_Coordinate: -0.002758
South_Bounding_Coordinate: -0.337303
Keywords:
Theme:
Theme_Keyword_Thesaurus: Ecuador
Theme_Keyword: elevation
Theme_Keyword: digital elevation model
Theme_Keyword: DEM
Access_Constraints:
Data is available to the public, made possible through the NASA LBA program.
Use_Constraints:
There are no use constraints. However, potential users should be aware that the resolution of this data set makes it inappropriate for any analyses where the scale of analysis is finer than 30 meters.
The DEM was generated by Brian Frizzelle, of the Spatial Analysis Unit, Carolina Population Center.
Security_Information:
Security_Classification: Unclassified
Native_Data_Set_Environment:
Microsoft Windows NT Version 4.0 (Build 1381) Service Pack 6; ESRI ArcCatalog 8.2.0.700
Cross_Reference:
Citation_Information:
Title: East ISA Elevation Contours
Cross_Reference:
Citation_Information:
Title: East ISA Point Elevations
Cross_Reference:
Citation_Information:
Title: Hydrography of Northern Oriente (1:50,000)
Cross_Reference:
Citation_Information:
Title: North ISA Digital Elevation Model
Cross_Reference:
Citation_Information:
Title: South ISA Digital Elevation Model
Cross_Reference:
Citation_Information:
Title: East ISA Terrain Aspect
Cross_Reference:
Citation_Information:
Title: East ISA Terrain Slope
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The elevation values assigned to the pixels in the data set were generated through an iterative finite difference interpolation technique in ARC/INFO. Elevations were interpolated based on nearby contours and point elevations. An accuracy assessment of the elevation values has not been performed.
Completeness_Report: Data are complete for the ISA.
Lineage:
Process_Step:
Process_Description:
The East ISA Elevation Contour data and the East ISA Point Elevation data were used to generate the DEM in ARC/INFO. The TOPOGRID command was used. The contour data were the primary basis for the interpolation, with the point elevations enhancing the quality of the interpolation. An East ISA subset of the 1:50,000 hydrography data was also inputted to make the DEM hydrologically correct. A 60-meter margin was applied to the process to allow TOPOGRID to more accurately interpolate the pixels on the boundaries of the ISA. A tolerance of 10 was applied to the process to assist in the smoothing of the surface and the removal of sinks in the drainage enforcement process. This value was chosen as half of the contour interval.
