Some Metrological Limitations to Rain Impact Computation in Storm Erosivity as Defined in the Revised Universal Soil Loss Equation, Version 2 (RUSLE2)

摘要

The theoretical and the instrumental metrological basis for computation of rainfall impact in storm erosivity as defined in the Revised Universal Soil Loss Equation, version 2 (RUSLE2) are considered. The present determination of rainfall erosivity is based on two factors: E, representing the rainfall kinetic energy, and I30, the maximum 30-minutes intensity for a given precipitation event. The present short review evidences some of the existing metrological limitations: (1) the non separation between the impact of falling rain and shallow flow of water; (2) the use of a non-universal semi-empirical approach, (3) the absence of a clear model with respect to rain flow, runoff and soil wetting; (4) the use of a hybrid measure unit; (5) the intrinsic limitation of measuring technologies. The improvement of the existing parameter calculation techniques or a transition from a prevailing semi-empirical to a mainly physical-based approach would be desirable, even if this transformation shouldn't affect the usability of the developed tools for practitioners.