Using Digital Spatial Data Sets to Study the Impact of Reservoir Construction on Local Environment and Community

Abstract

Digital spatial and demographic data sets have been used to study the impact of the Randleman Reservoir on the local environment and demography of Randolph and Guilford counties, N.C. At surface water heights of 682, 685, 706, and 709 ft. above the mean sea level, the reservoir's capacities were 25,053, 29,242, 92,654, and 106,654 acre-ft., and total surface areas (reservoir plus 200ft. erosion/pollution control buffers) 3,081, 3,516, 7,403, and 8,233 acres, respectively. The capacities and total surface areas were lower than those reported in the environmental impact statement by the U.S. Army Corps of Engineers and those published at the Piedmont Triad Regional Water Authority's Web page. These underestimations were attributed to the inaccurate representation of the digital evaluation model (DEM) data used. After applying a 3 by 3 minimum spatial filter to the DEM data, the recomputed reservoir capacities and areal extents were very close to those reported and published as mentioned in the above. At the surface water heights of 682 and 706 ft., the recalculated capacities were 52,445 and 162,709 acre-ft., and reservoir (only) areas 2,958 and 7,035 acres, respectively.