Assessing Soil-Water Status Via Albedo Measurement

• Main Authors: Idso, Sherwood B., Reginato, Robert J.
• Other Authors: ARS, USDA, U. S. Water Conservation Laboratory, Phoenix, Arizona 85040
• Language: en_US
• Published: Arizona-Nevada Academy of Science 1974
• Subjects: Hydrology > Arizona.; Water resources development > Arizona.; Hydrology > Southwestern states.; Water resources development > Southwestern states.; Soil moisture; Albedo; Moisture content; Soil surfaces; Evaporation; Topsoil; Water balance; Water loss; Radiation; Soil physical properties; Soil water movement; Drying; Air-earth interfaces; Clay loam; Vegetation effects; Irrigation; Rainfall; Bare soil albedo; Solarimeters; Soil drying
• Online Access: http://hdl.handle.net/10150/300329

From the Proceedings of the 1974 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 19-20, 1974, Flagstaff, Arizona === Reliable information on soil-water status is required in order to make accurate water balance studies of watersheds, to determine the survival probabilities of various types of vegetation between rainfalls in low rainfall areas, and to determine the susceptibility of the uppermost soil to wind erosion. Simple solarimeters may help to accomplish this objective. Bare soil albedo was a linear function of the water content of a very thin surface layer of soil, and albedo correlated well with water contents of thicker soil layers. In addition, albedo measurements could be used to delineate the 3 classical stages of soil drying. Albedo may also be used to differentiate between the initial potential rate phase of evaporation following an application of water, and the succeeding falling rate phase. Results of applying this technique to a field of Avondale clay loam indicate that 20% to 25% of the water applied by either irrigation or rain will be lost by stage 1 potential evaporation, independent of seasonal variations in evaporative demand. Presently the techniques developed are applicable only to bare soil surfaces.