Net Radiation and the Prediction of Evaporation from Sloped Soil Surfaces

For the study of net radiation on slopes, Placer-Dome's Equity mine site in the central interior British Columbia was selected as a research site. In the design of soil covers for waste disposal sites, evaporation is an important factor affecting the overall water balance for the cover. The net radiation incident on a soil surface is a major factor driving evaporation from that surface. It is therefore potentially important to quantify variations in net radiation that may occur due to differences in the orientation of the soil surface. To help quantify the effects of slope and direction of exposure on net radiation, a numerical model (SunModel) has been developed to estimate the net radiation on sloped surfaces at any given site, based on the net radiation received on a horizontal surface at the same site.