  We investigate the resolved relation between local extinction and star
formation surface density within nearby star-forming galaxies selected from the
MaNGA survey. Balmer decrement measurements imply an extinction of the
H{\alpha} line emission which scales approximately linearly with the logarithm
of the star formation surface density: $ A_{H{\alpha}} = 0.46
\log(\Sigma_{SFR}) + 1.53$. Secondary dependencies are observed such that, at a
given $\Sigma_{SFR}$, regions of lower metallicity and/or enhanced H{\alpha}
equivalent width (EW) suffer less obscuration than regions of higher
metallicity and/or lower H{\alpha} EW. Spaxels lying above the mean relation
also tend to belong to galaxies that are more massive, larger and viewed under
higher inclination than average. We present a simple model in which the
observed trends can be accounted for by a metallicity-dependent scaling between
$\Sigma_{SFR}$ and $\Sigma_{dust}$ via a super-linear Kennicutt-Schmidt
relation ($n_{KS} \sim 1.47$) and a dust-to-gas ratio which scales linearly
with metallicity (DGR($Z_{\odot}$) = 0.01). The relation between the resulting
total dust column and observed effective extinction towards nebular regions
requires a geometry for the relative distribution of H{\alpha} emitting regions
and dust that deviates from a uniform foreground screen and also from an
entirely homogeneous mixture of dust and emitting sources. The best-fit model
features an H{\alpha} EW and galactocentric distance dependent fraction of the
dust mass in a clumpy foreground screen in front of a homogeneous mixture.
