Bathymetry and Storage Capacity of Gillham Lake, Arkansas (ver. 1.1, April 2020)

A bathymetric survey of Gillham Lake, Arkansas, was conducted in June, 2018, by the Lower Mississippi-Gulf Water Science Center (LMG WSC) of the U.S. Geological Survey (USGS) using methodologies for sonar surveys similar to those described by Wilson and Richards (2006) and Richards and Huizinga (2018). Point data from the bathymetric survey were merged with point data from an aerial LiDAR survey conducted in 2016 by the National Resources Conservation Service (NRCS). From the combined point dataset, a terrain dataset (a type of triangulated irregular network, or TIN, model) was created in Esri ArcGIS, version 10.5, for the area encompassing the approximate extent of the flood pool of the lake as defined by the 569.102 ft, North American Vertical Datum of 1988 (NAVD88), contour of the LiDAR data. Products in this data release include an Esri file geodatabase and three digital elevation models (DEMs). The Esri file geodatabase contains feature classes of point data from the bathymetric and LiDAR surveys, a clipping polygon of the area encompassing the flood pool extent, the terrain dataset, a polygon feature class of the 570 ft NAVD88 contour, a feature class of bathymetric contours at 10-ft intervals, and a table of storage capacity (volume) of the lake at 1-ft increments in water surface elevation from 425-570 ft NAVD88, conservation pool elevation 502.102 NAVD88, and flood pool elevation 569.102 ft NAVD88. The three digital elevation models (DEMs) are provided in GeoTiff format, and include two of the extent of the LiDAR data used in the project, one in units of meters and the other in feet, and one of the extent of the flood pool in units of feet. References: Richards, J.M. and Huizinga, R.J., 2018, Bathymetric contour map, surface area and capacity table, and bathymetric difference map for Clearwater Lake near Piedmont, Missouri, 2017: U.S. Geological Survey Scientific Investigations Map 3409: 1 sheet, https://doi.org/10.3133/sim3409; U.S. Geological Survey, 2017, Lidar Point Cloud - USGS National Map 3DEP Downloadable Data Collection: U.S. Geological Survey. Wilson, G.L., and Richards, J.M., 2006, Procedural Documentation and Accuracy Assessment of Bathymetric Maps and Area/Capacity Tables for Small Reservoirs: U.S. Geological Survey Scientific Investigations Report 2006-5208, https://pubs.usgs.gov/sir/2006/5208/.