Regional Curves – Master’s Thesis

"Development of Bankfull Discharge and Channel Geometry Relationships for Natural Channel Design in Oklahoma Using a Fluvial Geomorphic Approach"

Abstract

For many years humans have been altering stream systems to achieve one or more objectives of society. In addition, increasing development and changes in land use practices have altered surface hydrology such that many of this nation's creeks, streams and rivers have become unstable and are experiencing accelerated bank erosion, channel aggradation (deposition), channel degradation (down-cutting), or a combination thereof. This loss of dynamic stability has resulted in habitat alteration and destruction, and a decline in aquatic species diversity and abundance. The most common approaches to stream bank erosion problems have, until recently, utilized hard control. Concrete, riprap, gabion baskets, used tires and even car bodies have been used in attempts to prevent bank erosion and control streams and rivers. In the last few years, however, there has been an increasing interest in taking a fluvial geomorphic approach to riparian management and stream bank stabilization. Restoration projects or channel alteration projects that attempt to emulate natural channels are currently in vogue. The current study evaluated morphology and hydrology data at 48 sites in Oklahoma, Missouri, Kansas and Texas to develop "Regional Curves" that relate "bankfull" dimensions and "bankfull" discharge versus drainage area that may be used for natural channel design in Oklahoma. A short discussion on fluvial geomorphology and stream classification is followed by a discussion on the significance of regional curves and the methodology used to develop them. Curves showing the relationship of bankfull discharge, bankfull area, bankfull width and bankfull depth versus drainage area are presented for the entire data set. The results of sorting the data based on stream type are also presented, although this was determined to be insignificant. The state of Oklahoma was then divided into different regions based on river basin, climate zone, mean annual precipitation, and eco-region to determine if the state should be split into more than one hydro-geographic province. The data indicated that the state should be divided into two hydro-geomorphic provinces with the dividing line being roughly along I-35 (which corresponds, incidentally, to the tree line in Oklahoma- an obvious delineation to aviators). Regional curves for each of the hydro-geomorphic provinces are presented.

Regional Curves

The regional curves and equations for the bankfull discharge, bankfull area and bankfull width versus drainage area curves as developed for Oklahoma using eco-regions to separate the data are presented below.  A map showing the eco-regions present in the state is also shown.  If more information is desired, click here to go to the thesis.

Locations of Oklahoma’s Eco-regions (Omernik, 1987).

Bankfull Discharge versus Drainage Area By Eco-region.

Bankfull Area versus Drainage Area By Eco-region.

Bankfull Width versus Drainage Area By Eco-region.

Thesis Text (PDF)

Thesis Pictures (PDF)

Address:

1504 Ann Arbor Drive

Norman, Oklahoma 73069-5363

Contact Us:

“Serious problems cannot be dealt with at the level of thinking that created them.”  Albert Einstein