Turbulence injection timescale (or timescale of massive star formation) compared to turbulence dissipation timescale in dwarf galaxies with rotational velocities of 20 km s^-1, 40 km s^-1, and 80 km s^-1. The timescales are shown as a function of star formation surface density. The critical star formation surface density is found to be ~ 10^-5M_⊙ kpc^-2 yr^-1, with only a weak dependence of the rotational velocity. The size of the star-forming region is assumed to be 0.5 kpc.