RESERVOIR SEDIMENTATION ASSESSMENT GUIDELINE - Aneel

Reservoir Sedimentation Assessment GuidelineFigure 13.5 – Tractive power in relation to the transportable sediments diameter(Strand, 1974)Linha de força gradual = gradual tension lineForça gradual = gradual tensionValor recomendado para canais com alta concentração de finos = value recommended for channels with high concentration of finematerialRecomendado para canais com areia fina com água contendo colóides = recommended for channels with fine sand with watercontaining colloidsRecomendado para canais com areia = recommended for channels with sandValores recomendados para canais com baixa concentração de finos = values recommended for channels with low concentration offine materialValores recomendados para canais com mat. não coesivos = values recommended for channels with non-cohesive materialValores recomendados para águas claras = values recommended for clear waterValores de Straub de força trativa crítica = Straub values for critical tractive powerRecomendado para canais de areia fina e águas claras = recommed for channels with fine sand and clear watersForça trativa crítica = critical tractive powerUse of Meyer-Peter & Muller equation – The Meyer-Peter & Muller equation for nullsediment discharge is expressed by:S =Q019Q⎛ n⎜⎝ Ds,16 /B 90p⎞⎟⎠3/2D(13.7)where,Q = total net discharge (ft 3 /s)Q B = part of the net discharge influencing the bed (ft 3 /s)n s = Manning roughness coefficient for the total sectionD 90 = diameter of the particle for which 90% of bed sediment is lower (mm)p = average channel depth (ft)D = minimum average diameter transportable present in the bed material (mm)Based on that equation, D may be computed and, afterwards, the shield thickness.Therefore, from Meyer-Peter & Muller equation, considering Q/Q b = 1:526 , SpD= Dc=⎛ n ⎞s⎜ ⎟16 /⎝ D ⎠903/2(13.8)Use of Schoklitsch equation - Schoklitsch equation for null sediment discharge has thefollowing expression:3/4DBS = ⎛ ⎝ ⎜ 0,00021 ⎞⎟Q ⎠where B is the channel width (ft).(13.9)Evidencing the value of D for the equation, we have:ANEEL – Brazilian Electricity Regulatory Agency / SIH – Hydrologic Studies and Information Department83