Emergent geometries of groundwater-fed rivers

Thesis: Ph. D. in Geophysics, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2017.

Bibliographic Details
Main Author: Yi, Robert Sngho
Other Authors: Daniel H. Rothman.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2018
Subjects:
Online Access:http://hdl.handle.net/1721.1/113794
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author Yi, Robert Sngho
author2 Daniel H. Rothman.
author_facet Daniel H. Rothman.
Yi, Robert Sngho
author_sort Yi, Robert Sngho
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description Thesis: Ph. D. in Geophysics, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2017.
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spelling mit-1721.1/1137942019-04-11T05:13:58Z Emergent geometries of groundwater-fed rivers Yi, Robert Sngho Daniel H. Rothman. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences. Earth, Atmospheric, and Planetary Sciences. Thesis: Ph. D. in Geophysics, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2017. Cataloged from PDF version of thesis. Includes bibliographical references (pages 99-107). Groundwater-fed rivers form stunning geometries over a range of scales. These rivers grow as water from an underground aquifer reemerges and erodes the overlying topography. Both the aquifer and the overlying topography generate flows along diffusive gradients. We study three features produced by these gradients over different scales: the shape of the valley that forms around a single stream, the network-averaged planform stream shape, and the shape of the drainage basin. First, we identify a new feature in stream valleys - a spatially variable diffusivity - that gives rise to a theoretical valley shape that agrees with the shapes of real valleys. Next, we present evidence and theory for a 120° opening stream confluence angle as a result of lateral rearrangement of streams in response to the pressure field generated by the aquifer. We then study how this mechanism exerts itself on the scale of the network. Finally, we widen our scope and analyze river planform morphology on a continental scale. We identify how branching angles can predict a river basin aspect ratio. We find a relationship between this aspect ratio and river basin scaling exponents with local climate. by Robert Sngho Yi. Ph. D. in Geophysics 2018-02-16T20:06:05Z 2018-02-16T20:06:05Z 2017 2017 Thesis http://hdl.handle.net/1721.1/113794 1022851464 eng MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. http://dspace.mit.edu/handle/1721.1/7582 107 pages application/pdf Massachusetts Institute of Technology
spellingShingle Earth, Atmospheric, and Planetary Sciences.
Yi, Robert Sngho
Emergent geometries of groundwater-fed rivers
title Emergent geometries of groundwater-fed rivers
title_full Emergent geometries of groundwater-fed rivers
title_fullStr Emergent geometries of groundwater-fed rivers
title_full_unstemmed Emergent geometries of groundwater-fed rivers
title_short Emergent geometries of groundwater-fed rivers
title_sort emergent geometries of groundwater fed rivers
topic Earth, Atmospheric, and Planetary Sciences.
url http://hdl.handle.net/1721.1/113794
work_keys_str_mv AT yirobertsngho emergentgeometriesofgroundwaterfedrivers