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In this step, information is utilized from field stability indicators of deposition and meander pattern, width/depth ratio departure, sediment supply state and other variables to estimate bed stability changes from excess deposition. The assessment categories are summarized in Worksheet 14 (PDF version, 43 kb, 1 p., or Excel spreadsheet). The summary of individual ratings used for overall stability is shown in Worksheet 28 (PDF, 58 kb, 1 p.), Worksheet 29 (PDF, 78 kb, 1 p.) and Worksheet 30 (PDF, 29 kb, 1 p.) and summarized in Worksheet 14. Figure 127 summarizes interpretations of sediment supply categories to an overall rating of channel stability. The combination of the FLOWSED model, Bagnold equation or POWERSED (Steps 17-19) along with entrainment/competence calculations (Step 22 and Step 23) will quantify potential sediment transport conditions related to aggradation based on changes in energy and/or changes in supply/size. Departure from reference condition for excess sediment/aggradation is documented at this step.
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