Date of Graduation

Spring 2001

Degree

Master of Science in Geospatial Sciences

Department

Geography, Geology and Planning

Committee Chair

Robert Pavlowsky

Subject Categories

Hydrology | Sedimentology | Water Resource Management

Abstract

This study of the Kings River Basin provides a watershed-scale assessment of streambed sediment-Phosphorus (P) and its sources on the landscape. The Kings River drains into Table Rock Lake where surface algal blooms have concerned water scientists and disrupted summer tourism. There are questions about how sediment loads, widespread poultry and cattle operations, and sewage treatment plants are affecting water quality. Previous water quality studies across the U.S. have generally evaluated watercolurnn P. In contrast, few studies have used streambed sediment monitoring to detect P levels at a watershed-scale, and none have been attempted in the Kings River Basin. Sediment samples may be preferred over water column samples for their ability to concentrate a range of pollutants, be less affected by fieldwork error, and incur fewer processing costs. Land cover/use in the watershed consists of forest (68%), pasturelands (32%), and one urban area, Berryville. Eighty-nine streambed sediment samples and six reference samples were collected from 100 river miles of the Kings River and its seven major tributaries. Variables included for analysis were sediment geochemistry, upstream drainage area, land use, geology, quantity of chicken houses, and sediment particle size. Values were quantified and entered into a Geographical Information System (GIS) to cr,eate a nonpoint source Prisk model. The mean sediment-P concentration was 209 micrograms per gram (ug/g), ranging from 40 ug/g near a pristine forested area to 1,280 ug/g downstream from the only sewage treatment plant in the watershed, below the city of Berryville. Regression analysis revealed that sediment composition and land use were the dominant factors affecting sediment-P variability in the watershed. A "best-fit" regression equation (r2 = 0.83) was developed to estimate sediment-P concentrations using organic matter content, sand content, poultry index, Fe and Al. This equation suggests that poultry operations and other nonpoint sources account for 11 % of the sediment-P, on average, with a range of0.5% to 50%. Piney Creek and Sweden Creek sub-watersheds proved to be the most and least affected by nonpoint sources, respectively. This study gives credibility to the integration of streambed sediment monitoring and GIS analysis in Ozarks watersheds. The quantitative results will aid scientists and natural resource managers in their ongoing attempts to compile baseline nutrient concentrations for Ozarks watersheds.

Copyright

© Jason W. White

Open Access

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