Fluvial Processes

GPH511

 

Credits : 

3

Times :

MF  11:40-12:55???

Where:

SCOB 335???

Instructor:

Mark Schmeeckle

E-mail: 

schmeeckle@asu.edu

Phone: 

480-727-8199

Office Hours:

MF 1-3 in SCOB 243

 

Overview

Why do rivers meander? How do dunes, ripples, and bars form in rivers? What geomorphic changes in rivers occur in response to human influences such as dams or land use change? In this course we will study what is thought to be known about these questions. The course will start with the basics of fluid flow and sediment transport in rivers, and then proceed to show how flow and sediment transport give rise to channel and floodplain morphology. Finally we’ll tackle complex issues surrounding geomorphic response to changes in discharge, sediment input, and vegetation resulting from human influences, with focus on issues in the Southwest and Arizona.

 

Approach

The morphology of rivers is determined by the erosion and deposition of sediment. The erosion or deposition of sediment is determined by differences in how much sediment is transported into an area versus how much is exported. The rate of sediment transport is determined by the local river flow. Thus, a quantitative approach to river morphology requires first a mechanical understanding of the flow, and then the sediment transport field. Finally, erosion or deposition can be calculated from the sediment transport field using the equation for continuity of mass. These quantitative fundamentals comprise the first part of the course, and the final topics concerning specific channel forms will be based on these principles.

 

Prerequisites

A little bit of math and physics is unavoidable. Students should at least understand the concepts of a derivative, integral, and Newton’s Second Law (F=ma). However, extensive manipulation of equations will not be required of students. A degree of computer literacy is also required. Assignments will be given involving the use of spreadsheets and retrieval of data over the internet.

 

Requirements

  1. First the good news. There will be no tests.
  2. Homework assignments will be given periodically which will test and develop quantitative skills. Some of the assignments will require use of computer spreadsheets or a programming language. Also, some of the homework assignments will require work to be completed using the flume in my laboratory. This will require you to do work in the lab outside of class time.  
  3. We will have a field trip on a Saturday. There will be a preliminary assignment and a final assignment associated with the field trip.
  4. Lecture attendance is critical. Much of the material covered in class will not be in the assigned reading.

 

Grading

The homework will count for two thirds of the grade, and the field trip exercise will count for one third.

 

Reading and Topics

BOOKS

The following book is a required text for the course.

  • Robert, A., River Processes, Arnold, London, 2003 Paperback: 214 pp.

The following three books should be helpful and I will put them on reserve at Noble Science Library

  • Bridge, J.S., Rivers and Floodplains, Forms, Processes, and Sedimentary Record, Blackwell, Malden , MA, 2003 Paperback: 501 pp.
  • Knighton, D. 1998. Fluvial Forms and Processes : A New Perspective . London , Edward Arnold. 400 p.
  • G. V. Middleton and P. R. Wilcock - Mechanics in the Earth and Environmental Sciences; Cambridge University Press, 1994.

 

TOPICS AND JOURNAL ARTICLES

1. Fluid mechanics, turbulence, and open channel flow:

  • Textbook:  Chapter 1 and 2
  • Grass, A.J. (1971) Structural features of turbulent flow over smooth and rough boundaries, Journal of Fluid Mechanics, 50 (2), 233-255.

 

2. Sediment Transport

    A. Initial Motion and Bedload Transport

  • Textbook: Chapter 3
  • Wiberg, P.L. and Smith, J.D., 1987. Calculations of the critical shear stress for motion of uniform and heterogeneous sediments, Water Resour. Res., v. 23, p. 1471-1480.
  • Andrews, E.D., 1983. Entrainment of gravel from naturally sorted riverbed material, Geol. Soc. Amer. Bull., v. 94, p. 1225-1231.

    B. Suspended Load

  • Textbook: Chapter 3
  • Gelfenbaum, G., and Smith, J.D., 1986. “Experimental Evaluation of a Generalized Suspended-Sediment Transport Theory”, in Shelf Sands and Sandstones, edited by Knight, R.J., and McLean, J.R., Canadian Society of Petroleum Geologists, Memoir II, 133-144.
  •  

3. Erosion Equation

  • Class Handout

 

4. Hydraulic Geometry

  • Textbook: Chapter 1
  • Andrews, E.D., Bed-material entrainment and hydraulic geometry of gravel-bed rivers in Colorado , Bull. Geol. Soc. Am., 95, 371-378, 1984.
  • Parker, G., 1979. Hydraulic geometry of active gravel rivers, J. Hydraul. Engr . ASCE, v. 105 (HY 9), p. 1185-1201.

 

5. Bedforms

 

6. Bars and Meandering

  • Textbook: Chapter 5
  • Nelson, J.M. Class Handout.

 

7. Channel Patterns and Floodplains

  • Textbook: Chapter 5
  • Hupp, C. R., and W. R. Osterkamp (1996).  Riparian vegetation and fluvial geomorphic processes.  Geomorphology 14: 277-295.
  • Murray, A.B., and Paola, C.,Modelling the effect of vegetation on channel pattern in bedload rivers. Earth Surface Processes and Landforms , Volume 28, Issue 2, Date: February 2003, Pages: 131-143
  • Wolman, M.G. and Leopold, L.B., 1957. River flood plains: some observations on their formation, U.S. Geol. Surv. Prof. Paper 282-C, p. 89-109.

 

8. Longitudinal Profile, the Erosion Equation, Downstream Fining

  • Snow, R.S. and R.L. Slingerland, 1987.  Mathematical Modeling of Graded River Profiles, Geology, 95:15-33.  

 

9. Human Impacts- dams, exotic vegetation, urbanization, hyporheic zone.

  • Textbook: Chapter 6
  • Graf, William L., 1999.  Dam nation: A geographic census of American dams and their large-scale hydrologic impacts. Water Resources Research 35(4):1305-1311.
  • Trimble, Stanley W., 1997.  Contribution of stream channel erosion to sediment yield from an urbanizing watershed. Science 278:1442-1444.
  • Rubin, D. M., Topping, D. J., Schmidt, J. C., Hazel, J., Kaplinski, M., and Melis, T. S., 2002, Recent sediment studies refute Glen Canyon Dam hypothesis: Eos, 83(25): 273-278.
  • Grams, P.E., and Schmidt, J.C., 2002, Streamflow regulation and multi-level floodplain formation: channel narrowing on the aggrading Green River in the eastern Uinta Mountains, Colorado and Utah : Geomorphology , 44:337-360.
  • Rhoads, B. L. (1990). The impact of stream channelization on the geomorphic stability of an arid-region river. National Geographic Research 6: 157-177.