|Morrison, Matthew - USEPA|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 2, 2006
Publication Date: May 23, 2006
Citation: Hicks, N.S., Bonta, J.V., Morrison, M.A., Gburek, W. 2006. The influence of record length and averaging time on flow duration curves [abstract]. American Geophysical Union Joint Assembly, May 23-26, 2006, Baltimore, MD. Technical Abstract: Flow duration curves (FDCs) provide a method for quantifying differences in the flow characteristics of different streams and for examining changes in flow due to the effects of land management. This study examines the effects of length of record, streamflow sampling frequency, and flow increment used for calculating FDCs. FDCs are based on a specific period of record (e.g., 10 years), and can use data of different sampling intervals (e.g., hourly) and different averaging times (e.g., average daily flow). Knowledge of how these factors affect FDCs is important for interpretation. If sufficient data are available, and this period of record represents the long-term flow regime of the stream, the curve can be viewed as a probability curve, allowing the estimation of future streamflow characteristics. We examine the length of record needed to adequately approximate the long-term FDC. The effects of season on FDCs are also investigated. The larger objective of this study is to evaluate the effectiveness of best management practices on agricultural watersheds in terms of hydrology and water quality. The analyses presented here provide the base for extending the duration curve method to include water quality analyses thru concentration and load duration curves.