1Civil Engineering Department, Birla Institute of Technology and Science, Pilani, Rajasthan, India.
2Civil Engineering Department, G.M.R. Institute of Technology, Rajam, Andhra Pradesh, India.
3Civil Engineering Department, New Mexico State University, Las Cruces, U.S.A. Email: phani@bitspilani.ac.in
Online published on 3 January, 2012.
The conventional aggregation tool in geographic information system (GIS) assumes that the aggregated grid resolution to be an integer multiple of the input grid resolution. This assumption is not always practicable, particularly in hydrologic applications, where the model resolution is decided based on number of other factors. A new tool in GIS (modified aggregation tool) is developed in the present study to generate the surface elevations and/or its derived parameters at any desired resolution. Applicability of the presented tool is tested for the Rincon Valley region in southern New Mexico, U.S.A. The 90 m digital elevation model (DEM) of the study area is aggregated and then smoothened to a uniform resolution of 402.3 m for use with the groundwater modelers and managers of the region. Surface elevations derived at model resolution using both conventional and modified aggregation tools are evaluated statistically. Results of the analysis conclude that the elevation data derived from the modified aggregation tool has resulted in minimal loss of spatial information content. The modified aggregation tool is developed such that the output dataset can be readily used by the hydrologists with no processing to the input DEM.
digital elevation model, aggregation, surface elevation, GIS, Rincon Valley
