This data release has three components for each of the eight surveys that were conducted in 2018: 1) a geospatial dataset of the processed data; 2) tabular data of the processed waterborne resistivity profiling data and associated water-quality data; 3) tabular data of the raw waterborne resistivity data and associated water-quality data. In addition to the newly collected data from 2018, the waterborne resistivity data from 2016 (Miller and others, 2016) is included and has been re-processed to be consistent with the processing steps currently utilized and described herein.
In fresh water aquifers, the geoelectric resistivity of earth materials commonly has a positive correlation with hydraulic conductivity (Faye and Smith, 1994). Throughout 2018, continuous resistivity profiling data were collected, as a proxy for streambed hydraulic conductivity, along reaches of eight streams in the Mississippi Alluvial Plain of Mississippi, Arkansas, and Missouri. A total of 906 kilometers (km) of continuous resistivity profiles were collected on 4 major streams and 4 reservoirs/lakes during several field excursions in 2018. Individual lengths of surveyed profiles per river include; 445 km on the White River, 225 km on the Black River, 76 km on the Cache, and 23 km on the Quiver River. Additionally, length of surveyed profiles on the reservoirs and lakes include; 64 km on Eutah Bend, 41 km on Roebuck Lake, 19 km on a United States Department of Agriculture On-Farm Storage Reservoir (USDA_OFS), and 13 km on Sky Lake. These river reaches and lakes were selected to aid in calibration of a regional groundwater model, specifically with regards to surface water-groundwater interaction. Stream reaches surveyed in 2016, which are included as part of this data release include; 50 km on the Quiver River, 70 km on the Sunflower River, and 61 km on the Tallahatchie River.
The electrical resistance is calculated by dividing the measured voltage by the applied current. The apparent resistivity is determined by multiplying the electrical resistance by a geometric factor. Apparent resistivity is not the true resistivity because a homogeneous subsurface is assumed. To estimate the true resistivity or the resistivity structure where the subsurface is heterogeneous and/or anisotropic, the apparent resistivity data were processed using an inverse modeling software program. Since these data have not been modeled they should only be used qualitatively. Methodology relating to field data collection and data processing can be found in Miller and others (2018).
Data collected during each survey include: Latitude, longitude, elevation of the water surface, water depth, water resistivity, injected current, voltage, measured apparent resistivity, and electrode location (referenced to the position of the GPS receiver). References: Faye, R.E., and Smith, W.G., 1994, Relations of borehole resistivity to the horizontal hydraulic conductivity and dissolved-solids concentration in water of clastic coastal plain aquifers in the southeastern United States., U.S. Geological Survey Water Supply Paper 2414, 33 p, https://doi.org/10.3133/wsp2414. Miller, B.V., Wallace, D.S., and Kress, W.H., 2016, Water-borne continuous resistivity profiling data from select streams of the Mississippi Alluvial Plain in northwestern Mississippi: U.S. Geological Survey data release, https://doi.org/10.5066/F7FT8J68. Miller, B.V., Adams, R.F., Stocks, S.J., Wilson, J.L., Smith, D.C., and Kress, W.H., 2018, Waterborne resistivity surveys for streams in the Mississippi Alluvial Plain, 2017: U.S. Geological Survey data release, https://doi.org/10.5066/F71J98ZQ.