ABSTRACT
Soil evaporation can significantly influence energy flux partitioning of partially vegetated surfaces, ultimately affecting plant transpiration. While important, quantification of soil evaporation, separately from canopy transpiration, is challenging. Techniques for measuring soil evaporation exist and continually improve. The large variability in soil water content requires that there be careful thought to the design of soil evaporation measurements in the field. Numerical models for simulating soil evaporation have been developed and are shown to be fairly robust. However, the required inputs for defining model parameters often limit their application. For many operational applications where detailed soils and ancillary weather data are unavailable or where daily evaporation values are only needed, some of the analytical models described may provide the necessary level of accuracy. Moreover, in the application of weather forecast and hydrologic models, the use of simplified approaches is necessitated by the computational requirements or the lack of adequate data or both for defining more complex numerical model inputs. For large area estimation, the use of remotely sensed soil moisture and surface temperature offer the greatest potential for operational applications.
