Abstract
Abstract. River basin lag time (LAG), defined as the elapsed time between the occurrence of the centroids of the effective rainfall intensity hyetograph and the storm runoff hydrograph, is an important factor in determining the time to peak and the peak value of the instantaneous unit hydrograph (IUH). In the procedure of predicting a sedimentgraph (suspended sediment load as a function of time), the equivalent parameter is the lag time for the sediment yield (LAGs), which is defined as the elapsed time between the occurrence of the centroids of sediment production during a storm event and the observed sedimentgraph at the gauging station. Data of over 150 events recorded in 11 small river catchments (located in Poland, Germany, UK and USA) with a drainage area of 0.02 km2 to 82 km2 have been analysed to estimate the ratio of LAGs/LAG. The ratio, in majority of cases was smaller than 1, and decreased with increase of river basin slope. Special attention is given to the data collected in a small agricultural catchment and also during snowmelt periods, which is located in central Poland.
Highlights
Sedimentgraphs are essential for: (i) sediment yield assessment, (ii) providing input data for prediction models of sediment deposition in reservoirs, (iii) designing efficient sediment control structures, and for (iv) water quality predictions
The data used in this paper for estimation the values lag time (LAG)/LAG were collected in 11 small catchments of various land use and steepness by research units of six universities (Warsaw University of Life Sciences, Cracow Agricultural University, University of Kassel, Free University of Berlin, Exeter University and University of Illinois at Urbana-Champaign) and were analysed in depth in separate studies
The mean ratio of LAGs/LAG, estimated on the basis of recorded individual rainfall–runoff sediment yield events, for each catchment is related to the steepness of the catchments
Summary
Sedimentgraphs (graphs of suspended sediment load associated with hydrographs caused by rainfall or snowmelt) are essential for: (i) sediment yield assessment, (ii) providing input data for prediction models of sediment deposition in reservoirs, (iii) designing efficient sediment control structures, and for (iv) water quality predictions. One of the first studies on sedimentgraphs, i.e. on the relationship between the ordinates of the streamflow hydrograph and the sedimentgraph for a small catchment was undertaken by Johnson (1943). He developed a distribution graph of suspended sediment concentration which is analogous to a hydrograph. Johnson’s idea was implemented in a sedimentgraph model by Williams (1978) This was further developed for predicting and regenerating the suspended sediment load as a response of a small catchment to heavy rainfall (Banasik and Woodward 1992, Banasik and Blay 1994, Banasik and Walling 1996). A new definition of the instantaneous unit sedimentgraph (IUSG) was developed (Banasik 1994, 1995; Banasik and Walling 1996) and incorporated into the sedimentgraph model (SEGMO), based on a lumped parametric approach
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Proceedings of the International Association of Hydrological Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
