單項(xiàng)水質(zhì)參數(shù)評(píng)價(jià)計(jì)算公式：

$$ S{i,j}=c{i,j}/c{si} $$

$$ S_{DO,j}= \frac {|DO_f-DO_j|}{DO_f-DO_s} $$ DO_j ≤ DO_s

$$ S_{DO,j}=10-9 \frac {DO_j}{DO_s} $$ DO_j < DO_s

$$ DO_f=468/(31.6+T) $$

$$ S_{pH,j}= \frac {7.0-pH_j}{7.0-pH_{sd}} $$ pH_j ≤ 7.0

$$ S_{pH,j}= \frac {pH_j-7.0}{pH_{su}-7.0} $$ pH_j > 7.0