Land-Cover Sampling Designs, Data-Collection Procedures, and Land-Cover Data
for the Central Nebraska Basins, 1993-94
By Ronald B. Zelt, Jack T. Dugan and Michael S. Kelley
ABSTRACT:
Within the U.S. Geological Survey's National Water-Quality Assessment (NAWQA)
Program, land-cover data are used in characterizing drainage areas upstream from surface-
water sampling sites and areas selected for spatially distributed ground-water sampling.
During the period of time when the initial 20 NAWQA study-unit investigations were
evaluating existing land-cover data, a Prototype 1990 Conterminous U.S. Land Cover
Characteristics Data Set was produced by the Survey's EROS Data Center in Sioux Falls,
South Dakota. As part of the Central Nebraska Basins (CNB) study-unit investigation, a
method was developed to estimate the areal extent of the principal land-cover types within
selected seasonally distinct land-cover (SDLC) regions defined in the 1990 prototype data
set.
This report describes the sampling designs and methods used to collect land-cover data
in the CNB study unit. Data collected at 309 sampling sites during the summers of 1993 and
1994 are presented and statistically summarized. Eleven land-cover categories were
quantified, including major field crops and broad noncropland cover types.
CITATION:
Zelt, R.B., Dugan, J.T., and Kelley, M.S., 1995, Land-cover sampling designs, data-collection
procedures, and land-cover data for the Central Nebraska Basins, 1993-94: U.S. Geological
Survey Open-File Report 95-166, diskette.
For additional information Copies of the report can be
write to: purchased from:
District Chief U.S. Geological Survey
U.S. Geological Survey, WRD Earth Science Information Center
406 Federal Building Open-File Reports Section
100 Centennial Mall, North Box 25286, MS 517
Lincoln, Nebraska 68508 Denver Federal Center
Denver, CO 80225