A Stochastic Approach to Modeling Tidal Creek Evolution: Exploring Environmental Influences on CreekTopologies Through Ensemble Predictions. Issue 23 (12th December 2019)

• Record Type: Journal Article
• Authors: Li, Xiaorong; Leonardi, Nicoletta; Plater, Andrew J.
• Is Part Of: Geophysical research letters. Volume 46:Issue 23(2019)
• Page Start: 13836
• Page End: 13844
• Publication Date: 2019-12-12
• Subjects: tidal creek evolution -- stochastic simulation -- ensemble predictions -- wetland topography -- vegetation -- reduced complexity model; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2019GL085214
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: A numerical tool integrating hydrodynamics, vegetation growth, stochastic selection, and Monte‐Carlo simulation is developed to predict channel network evolution in a newly inundated back‐barrier wetland. Focusing on the formation and evolution of tidal channels, model simulations suggest a clear tendency towards specific creek topologies with high probability despite creek evolution being subject to random perturbations. These creek topologies are primarily determined by wetland topography while the influence of vegetation is secondary. Ensemble results of Monte‐Carlo simulations identify threshold points leading to bimodal separation of the emergent creek networks characterized by different complexity and efficiency. This, in turn, assists the recognition of necessary human interventions to encourage the formation of complex and far‐reaching creek networks that can promote exchange of materials between estuaries and salt marshes and, hence, maintain salt marsh ecosystem structure and function. Plain Language Summary: A large part of the world's low‐lying areas is heavily managed to protect lives, assets, and landscapes from marine‐derived natural hazards. However, climate change is putting unprecedented pressure on these managed environments, forcing the adoption of "no active intervention" or "managed realignment" strategies in areas where "hold the line" options cannot be justified due to financial constraints. This leads to the very likely possibility that unmaintained coastal defenses will begin to fail, raising questions as to the potential impacts on low‐lying regions as well as the options available to mitigate impacts through targeted interventions. Of particular interest is the question of whether it is possible to facilitate the shift of managed coastal wetlands towards intertidal environments in which tidal creeks form and evolve to support salt marshes. Combining the use of a numerical model and multiple model runs, we find that although the evolution of tidal creeks is subject to random disturbances, creek networks are likely to form with a clear tendency towards specific types. Grouped results of multiple, random simulations are useful in identifying interventions that are necessary for developing far‐reaching tidal creek networks. Influence of vegetation is found to be secondary compared to the wetland topography in terms of influencing tidal creek evolution. Key Points: A reduced complexity model is developed based on simple rules for projecting tidal creek network development The influence of vegetation in determining probabilities of creek formation is secondary compared to wetland topography Ensemble prediction of tidal creek evolution is effective for identifying threshold points and targeted interventions