Date on Master's Thesis/Doctoral Dissertation

8-2014

Document Type

Doctoral Dissertation

Degree Name

Ph. D.

Department

Civil and Environmental Engineering

Committee Chair

Parola, Arthur C.

Committee Co-Chair (if applicable)

French, Mark N.

Committee Member

French, Mark N.

Committee Member

Rockaway, Thomas D.

Committee Member

DePuy, Gail W.

Subject

River channels--Classification

Abstract

A streambed is the channel bottom of a stream, river, or creek; the physical confine of the normal water flow. It provides necessities for fish and microinvertebrate including shelter, food, and breeding spots. Therefore, it is an essential part of aquatic animal habitats and often seen as an index of stream health. There is no generally accepted method to quantify streambed physical components and depending upon state and organization a variety of methods are used. The procedure provided in the rapid bioassessment protocol (RBP) (Kaufmann et al., 1999; Sylte and Fischenich, 2002) is probably the most widely used method to assess the effect of various land use activates on stream habitat for management purposes in the United States. The RBP method was not intended as a procedure to assess streambed habitat; although it is often used for this purpose. This approach reduces the streambed physical components into the two variables: embeddedness and epifaunal substrate. Definitions and sampling procedure of these variables are vague and subjective. Streambed components with varying characteristics are grouped under the same category and some streambed components as important as gravel are not included in the categorizing of the streambed habitat. A measurement method that combines a photographic technique and grid sampling was developed to assess streambed components in a direct and simple way at the required level of accuracy. The portable photographic box (PPB) device utilizes a photographic technique to record images of physical streambed components under typical base flow of wadeable gravel-bed streams. Recorded images were digitized manually and the area of each streambed component in each grid cell was estimated to evaluate projected area of streambed component. The PPB facilitates sampling of streambed components of unit population with adequate picture quality rapidly. Five scenarios for sampling methods with varying accuracy and field and laboratory time requirements for quick and simple inventory of impaired stream habitat were recommended. Based on statistical analysis, residual was reduced from 33% in the rapid bioassessment to 28%, 14%, 7%, 5% and 0% in the first, second, third, fourth, and fifth scenario, respectively. In addition, measurement of the dissolved oxygen and temperature in ten riffles indicated that temperature in the first layer of subsurface was similar to those measured in the water column. No evidence was found to support substrate measurement of temperature. However, the dissolved oxygen concentration varied significantly for embedded and free patches. In contrast to the free gravel and epifaunal substrate, the DO content in fine material, embedded gravel, and embedded epifaunal substrate components was in anoxia and hypoxia. Hypoxia and anoxia lasted for several days after flood events.

Download

Share

COinS