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ARS Home » Pacific West Area » Tucson, Arizona » SWRC » Research » Publications at this Location » Publication #64642
Title: USE OF HAND-HELD RADIOMETERS TO EVALUATE THE COVER AND HYDROLOGIC CHARACTERISTICS OF SEMIARID RANGELANDS

Author
item POST, D. - UNIV. OF ARIZ.
item MARTIN, E. - UNIV. OF ARIZ.
item Simanton, John - Roger
item SANO, E. - UNIV. OF ARIZ.

Submitted to: Arid Soil Research And Rehabilitation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/14/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Remote sensing of rangeland vegetative and surface cover characteristics can be a useful and time saving tool in evaluating runoff and erosion susceptibility. Hand-held remote sensing (radiometer) measurements made on experimental plots in the semiarid rangelands of southeastern Arizona were related to measured runoff and sediment yields. The relations developed indicated that runoff and vegetative cover could be estimated from reading taken with the radiometer and that the remotely sensed data could be used to estimate input parameters for soil erosion predictions models such as the Revised Universal Soil Loss Equation.

Technical Abstract: The spectral reflectance characteristics of eleven rainfall simulator plots were measured on semiarid rangeland surfaces, Walnut Gulch Experimental Watershed, Tombstone, AZ. Three soils were evaluated and the vegetative types were grass-dominated, shrub-dominated, and a mixture of grass and shrubs. Spectral measurements were taken in 1984 and 1994 at 38-43 and 74- -Regression relationships between spectral reflectance and % vegetative cover, % runoff, and eroded sediments were computed. Highly significant correlations were measured between % vegetative cover and % runoff for the wet soil moisture rainfall simulation condition; relations with eroded sediment were mostly not significant. The NDVI vegetation index was the best predictor of % vegetative cover, with shrubs being most strongly correlated to reflectance. The regression relation between 1984 and 1994 spectral reflectance and vegetative cover were very different, even though cover percentages were similar the standing biomass was different.