  It is demonstrated that $\omega^{-4/3}$ law of the power spectrum with the
angular frequency $\omega$ in dissipative flows is produced by the emission of
dispersive waves from the antikink of an congested domain. The analytic theory
predicts the spectrum is proportional to $\omega^{-2}$ for relatively low
frequency and $\omega^{-4/3}$ for high frequency.
