W atershed models serve as a means of organizing and interpreting research data while also providing continuous water quality predictions that are economically feasible and time efficient. A long history of legislation has made water quality assessments of river systems a critical issue throughout the country. Examples of national legislation include the creation of the United States Environmental Protection Agency (USEPA, 1979), the passage of the Clean Water Act in 1972, and the 1985 and 1990 Farm Bills. Efforts of Kentucky to protect statewide water resources through watershed management have been demonstrated by the establishment of the Kentucky River Authority and the passage of the Agriculture Water Quality Act (1996). The goal of the Agriculture Water Quality Act was to protect surface and groundwater resources from pollution resulting from agriculture and silviculture activities in Kentucky. This will be done by requiring all landowners with at least 10 contiguous acres of agriculture or silviculture production to develop and implement a water quality plan based upon guidance from the Statewide Agriculture Water Quality Plan. Many agencies, universities, and scientists have responded to legislation by developing models to simulate water and chemical transport. Models are important tools because they can be used to understand hydrologic processes, develop management practices, and evaluate the risks and benefits of land use over various periods of time. Models such as the Hydrological Simulation Program-FORTRAN (HSPF) developed under EPA sponsorship by Johansen et al. (1984) is an example of a model used to simulate hydrologic and water quality processes in natural and man-made water systems. Since its initial development, the HSPF model has been applied throughout North America and numerous countries with various climatic regimes around the world; it enjoys the joint sponsorship of both the EPA and the U.S. Geological Survey. However, the required calibration of the empirical equations to the target watershed is a drawback to the HSPF. Other models that have been developed for short-term runoff simulations include HEC-1 (US Army Corps of Engineers, 1981

Controlling agricultural nonpoint source pollution from livestock grazing is a necessary step to improving the water quality of the nation's streams. The goal of enhanced stream water quality will most likely result from the implementation of an integrated system of best management practices (BMPs) linked with stream hydraulic and geomorphic characteristics. However, a grazing BMP system is often developed with the concept that BMPs will function independently from interactions among controls, climatic regions, and the multifaceted functions exhibited by streams. This paper examines the peer reviewed literature pertaining to grazing BMPs commonly implemented in the southern humid region of the United States to ascertain effects of BMPs on stream water quality. Results indicate that the most extensive BMP research efforts occurred in the western and midwestern U.S. While numerous studies documented the negative impacts of grazing on stream health, few actually examined the success of BMPs for mitigating these effects. Even fewer studies provided the necessary information to enable the reader to determine the efficacy of a comprehensive systems approach integrating multiple BMPs with pre‐BMP and post‐BMP geomorphic conditions. Perhaps grazing BMP research should begin incorporating geomorphic information about the streams with the goal of achieving sustainable stream water quality.

No abstract

The traditional means of tracking animal location in a field is by visual observation. Not only is this method labor intensive, it is also prone to error as the observer can alter cattle movement, observation periods are often too short to obtain confidence in general daily behavior patterns, and observer fatigue becomes an issue. In the 1990s, the University of Kentucky began using GPS collars on cattle to track their position with the goal of incorporating this information into cattle management practices. One of the key unanswered questions regarding the GPS collars is the accuracy of the position data recorded by the collar. The objective of this work was to assess the capabilities and limitations of using GPS collars to track animal movement in grazed watersheds. Static tests were conducted in an open field, under trees, and near fence lines to ascertain the impacts of various field features on collar performance. Dynamic tests were carried out to examine the errors associated with the collars while operated under real−world conditions. Results from these tests indicate that the collars generally provide data with horizontal accuracies of 4 to 5 m. This information will assist researchers in the development of experiments based on collar capabilities and limitations.

No abstract