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Modeling vegetation controls on fluvial morphological trajectories
Author(s) -
Bertoldi Walter,
Siviglia Annunziato,
Tettamanti Stefano,
Toffolon Marco,
Vetsch David,
Francalanci Simona
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl061666
Subject(s) - riparian zone , vegetation (pathology) , fluvial , environmental science , biomass (ecology) , flood myth , hydrology (agriculture) , vegetation type , ecology , geology , geomorphology , geography , grassland , geotechnical engineering , habitat , medicine , archaeology , pathology , structural basin , biology
The role of riparian vegetation in shaping river morphology is widely recognized. The interaction between vegetation growth and riverbed evolution is characterized by complex nonlinear feedbacks, which hinder direct estimates of the role of key elements on the morphological evolutionary trajectories of gravel bed rivers. Adopting a simple theoretical framework, we develop a numerical model which couples hydromorphodynamics with biomass dynamics. We perform a sensitivity analysis considering several parameters as flood intensity, type of vegetation, and groundwater level. We find that the inclusion of vegetation determines a threshold behavior, identifying two possible equilibrium configurations: unvegetated versus vegetated bars. Stable vegetation patterns can establish only under specific conditions, which depend on the different environmental and species‐related characteristics. From a management point of view, model results show that relatively small changes in water availability or species composition may determine a sudden shift between dynamic unvegetated conditions to more stable, vegetated rivers.