Integrating connectivity theory within watershed modelling is one solution to overcome spatial and temporal shortcomings of sediment transport prediction, and Part I and II of these companion papers advance this overall goal. In Part II of these companion papers, we investigate sediment flux via connectivity formula discretized over many catchments and then integrated via sediment routing; and we advance model evaluation technology by using hysteresis of sensor data. Model evaluation with hysteresis indices provides nearly a 100% increase in model statistics. Hysteresis loop evaluation shows a shift from near linear behavior at low to moderate events and then clock-wise loops for larger events indicating the importance of proximal sediment sources. Catchment-scale sediment flux varies as function of the probability of timing and extent of connectivity of an individual catchment. Watershed-scale sediment flux shows self-similarity for the main stem of the river channel as the 181 catchments are integrated moving down gradient. Sediment flux varies from event-to-event as a function of the most sensitive connected pathways, including ephemeral gullies and roadside ditches in this basin. These sensitive pathways contribute disproportionately large amounts to overall sediment yield regardless of the total rainfall depth. Prediction requires the connectivity formula, erosion formula and sediment routing formula; and the probability of connectivity alone was a poor predictor for sediment transport. The result highlights the importance of coupling connectivity simulations with sediment transport formula, and our method provides one such approach.
|Journal||Science of the Total Environment|
|State||Published - Oct 20 2020|
Bibliographical noteFunding Information:
We gratefully acknowledge the financial support of this research under National Science Foundation Award 163288 . We thank the associate editor Paulo Alexandre da Silva Pereira and two anonymous reviewers for comments and criticisms that have greatly improved the quality of this manuscript.
We gratefully acknowledge the financial support of this research under National Science Foundation Award 163288. We thank the associate editor Paulo Alexandre da Silva Pereira and two anonymous reviewers for comments and criticisms that have greatly improved the quality of this manuscript.
© 2020 Elsevier B.V.
- Sediment transport
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Waste Management and Disposal