RESERVOIR SEDIMENTATION ASSESSMENT GUIDELINE - Aneel

Reservoir Sedimentation Assessment Guidelinetable with the percentage of some diameters and characteristic values for usual bedmaterial (D 10 , D 35 , D 50 , D 65 and D 90 ).7.5.1 Continuous, hourly and daily measurementsContinuous, hourly and daily measurements shall also be tabulated and thesediment discharge must be computed. The preliminary work consists of calibratingconcentration values, as based on the correlation with the hydrometrist’s data. If a valueis not available because it was not measured, than a graph with a discharge hydrogramis prepared, as well as the respective plotting on concentration or suspended discharge,for obtaining the lacking values. Those values may also be obtained from the ratingcurve sediments equation prepared with the values measured.After the daily tabulation, it is possible to obtain monthly and annual tabulation,containing the summaries of average net and load discharges. Following, an annualsummary is prepared, presenting total annual transport (runoff load D s ), annual averagetransport (average annual sediment discharge Q s ), sediments contribution (production ofsediments P s ) and other values. Table 7.10 presents an example of semi-annual bulletinof computations performed by CEMIG. The average for average annual values will beused for the sedimentation assessment computations.ANEEL – Brazilian Electricity Regulatory Agency / SIH – Hydrologic Studies and Information Department32