Coupling the probability of connectivity and RUSLE reveals pathways of sediment transport and soil loss rates for forest and reclaimed mine landscapes

Abstract

Coupling erosion formulae with sediment connectivity methods is one promising approach to better represent structural and functional variability of sediment processes. To advance this goal, the probability of connectivity approach is coupled with the revised universal soil loss equation (RUSLE) in a basin with forest and reclaimed mine landuses. Model evaluation showed unforeseen codependency between connectivity formulae and RUSLE. For example, the RUSLE P factor was codependent with the probability of downstream transport within the connectivity formula. Researchers should use feedback calibration schemes to resolve lack of model independence. Connectivity modelling advanced prediction of sediment processes because it simulated the unforeseen impact of legacy terracing on sediment connectivity and soil loss. Structural control dominates connectivity in this study, and soil loss and connectivity are self-similar. The structural control is contrary to recent suggestions that functional, dynamic processes control sediment connectivity in all landscapes. Self-similarity also remains an open topic because a number of studies show poor correlation between soil loss and connectivity. On average 12% of forested land and 47% of reclaimed mine land was connected for events studied. Predicted soil loss rates in the reclaimed mine were approximately 30 times greater than the forest land despite the fact that the reclamation is classified as phase 3. Spatially explicit results highlight pathways that should be targeted for remediation, and this study supports the idea of the Forestry Reclamation Approach for remediation of excess soil loss.