Geology topics
K.E. Kolm
Publications and source records attributed to K.E. Kolm.
Evaluation of techniques for mapping land and crops irrigated by center pivots from computer-enhanced Landsat imagery in part of the James River basin near Huron, South Dakota
The objective of this study was to evaluate remote sensing techniques for mapping irrigated crop types and acreages in part of the James River basin of South Dakota, using Landsat imagery. The results demonstrated that a subtraction (band 7 minus band 4) method was best for identifying the location of cropland irrigated by groundwater. Two separate principal-spectral-components analyses (analysis of the second principal-spectral component and the simultaneous analysis of the first three principal-spectral components) were best for identifying the crop type and estimating crop acreages. However, only 50 percent of the irrigated lands could be identified and only 79 percent of these could be classified accurately by crop type. Therefore, a 39 percent overall accuracy was achieved in irrigated crop-type identification. (USGS)
A two-dimensional, finite-difference model of the high plains aquifer in southern South Dakota
The High Plains aquifer is the principal source of water for irrigation, industry, municipalities, and domestic use in south-central South Dakota. The aquifer, composed of upper sandstone units of the Arikaree Formation, and the overlying Ogallala and Sand Hills Formations, was simulated using a two-dimensional, finite-difference computer model. The maximum difference between simulated and measured potentiometric heads was less than 60 feet (1- to 4-percent error). Two-thirds of the simulated potentiometric heads were within 26 feet of the measured values (3-percent error). The estimated saturated thickness, computed from simulated potentiometric heads, was within 25-percent error of the known saturated thickness for 95 percent of the study area. (USGS)