?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F20072%2F&rft.title=Morphodynamics+of+the+Anabranching+Structures+on+the+Upper+Amazon+River+Basin&rft.creator=Frias%2C+Christian&rft.description=Recent+research+in+numerical+modeling+of+large+rivers+has+focused+in+reproducing+typical+morphodynamic+planform+shapes.+One+of+the+typical+planform+shapes+of+large+river+systems+is+the+anabranching+structure%2C+which+is+characterized+by+a+main+channel+and+several+secondary+channels.+Although+current+models+reproduce+planform+shapes+very+realistically%2C+there+is+still+a+lack+of+data+to+validate+such+models+and+therefore+any+outcome+from+these+predictions+are+questionable.+To+overcome+this+issue%2C+an+analysis+of+the+morphodynamics+on+large+river+systems+at+different+scales+is+carried+out.+This+research+will+provide+a+better+understanding+of+the+processes+involved+in+anabranching+planforms+that+could+be+used+to+improve+prediction+of+morphodynamic+features+by+using+high-resolution+mathematical+models.+First%2C+the+effect+of+the+main+channel+sinuosity+in+an+anabranching+planforms+at+two+selected+locations+in+the+Amazon+River+at+Peru+is+assessed+with+field+measurements%2C+numerical+modeling+and+satellite+imagery+characterization.+Next%2C+a+three+dimensional+hydrodynamic+model+for+a+bend+of+the+Wabash+River+(at+the+Stateline+between+Indiana+and+Illinois)+is+carried+out+to+study+the+modulation+of+the+bank+shear+stresses+due+to+the+presence+of+bed+forms.+Lastly%2C+a+three+dimensional+model+to+study+the+turbulence+of+the+bed+amalgamation+process+is+performed.+From+the+analysis+of+the+two+locations+along+the+Amazon+River%2C+it+was+confirmed+that+in+a+medium+to+high+sinuosity+stage%2C+the+secondary+channels+behave+as+non-developed+meanders.+Also%2C+it+was+concluded+that+in+all+sinuosity+stages%2C+the+planforms+of+the+secondary+channels+are+controlled+by+the+main+channel+migration.+On+the+other+hand%2C+the+model+of+the+Wabash+River+confirmed+that+the+bank+shear+stress+is+greater+when+bed+forms+are+present.+Finally%2C+the+modeling+of+the+amalgamation+processes+showed+that+there+was+a+region+of+high+shear+stresses+associated+to+turbulence+production%2C+in+which+the+streamwise+velocity+fluctuations+were+associated+to+the+modification+of+the+bed+morphology.+Also%2C+the+Turbulence+Horseshoes+Vortices+(THV)+were+more+frequent+at+the+beginning+of+the+amalgamation+process+while+the+frequency+of+bursting+events+was+highest+when+the+amalgamation+process+is+at+the+middle+stage.&rft.date=2014-01-29&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F20072%2F7%2Ffrias_etd2013.pdf&rft.identifier=++Frias%2C+Christian++(2014)+Morphodynamics+of+the+Anabranching+Structures+on+the+Upper+Amazon+River+Basin.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++