Classification of evapotranspiration units in major discharge areas of Death Valley regional flow system, Nevada and California

The data set was created to delineate the aerial extent and quantify acreage of
the different ET units found within the many major discharge areas of the Death
Valley regional flow system.

The raster-based classification of evapotranspiration (ET) units is for nine
major discharge areas in the Death Valley regional flow system. The ET units
delineate general areas of similar vegetation and soil-moisture conditions.
Classifications were derived from Landsat Thematic Mapper imagery data acquired
June 13, 1992; Sept. 1, 1992; and June 21, 1989.

Introduction

The raster-based classification of ET units within the major discharge areas of
the Death Valley regional flow system determined from Landsat Thematic Mapper
(TM) imagery data acquired June 13, 1992, Sept. 1, 1992; and June 21, 1989.
Background information on classification procedures can be found in American
Society of Photogrammetry (1983). Except for Sarcobatus Flat, all discharge
areas were classified using the 1992 TM imagery. An accurate classification of
Sarcobatus Flat could not be attained from 1992 TM imagery because of extensive
cloud cover over the area. Instead, Sarcobatus Flat was classified from TM data
acquired June 21, 1989.

Reviews

The final classification of ET units within each major discharge area was
checked for consistency and accuracy during data processing. Two external
reviews were done. The reviewers were asked to check metadata and other
documentation files for completeness and accuracy. Reviewers also were asked to
check the topological consistency, tolerances, projections, and geographic
extent.