DRAINAGE AREA-REGIME EQUATIONS TO QUANTIFY CHANNEL MORPHOLOGY OF AN OZARKS RIVER, SOUTHWEST MISSOURI

The James River basin (3,771 km²) drains a portion of the Ozark Highlands of southwest Missouri and is unique due to its karst geology, bedrock influence, abundant gravel supply, land-use history, and population growth. However, a watershed scale geomorphic study of this basin and its response to natural and anthropogenic variables is lacking. The purpose of this study is to collect and analyze geomorphic data on longitudinal profile, cross-section, grain size, large woody debris (LWD), and channel stability to quantify downstream changes in channel morphology for the main stem of the James River (~160 km). Data collected at segments between third order and larger tributary confluences (n=17) will be used to generate drainage area-bankfull channel equations. In addition, the influence of channel slope, substrate grain size, bedrock control, and LWD on channel form will be evaluated using multivariate regression. Further, a GIS-based historical aerial photography analysis will aid in determining channel stability trends since the early 1950s. Finally, discharge records from three USGS gage stations on the James River will link flow frequency to channel capacity at key stages including bankfull conditions. The results of this work will expand the geomorphic knowledge of Ozark rivers that can be compared with other studies in the Ozarks and Midwest region to develop a better understanding of the continuum of geomorphic process and form. In addition, the regime equations developed will provide management benefits by providing geomorphic models useful for restoration design and habitat improvements.