  We perform a homogeneous analysis of an unprecedented set of spatially
resolved scaling relations (SRs) between ISM components and other properties in
the range of scales 0.3-3.4 kpc. We also study some ratios: dust-to-stellar,
dust-to-gas, and dust-to-metal. We use a sample of 18 large, spiral, face-on
DustPedia galaxies. All the SRs are moderate/strong correlations except the
dust-HI SR that does not exist or is weak for most galaxies. The SRs do not
have a universal form but each galaxy is characterized by distinct
correlations, affected by local processes and galaxy peculiarities. The SRs
hold starting from 0.3 kpc, and if a breaking down scale exists it is < 0.3
kpc. By evaluating all galaxies at 3.4 kpc, differences due to peculiarities of
individual galaxies are cancelled out and the corresponding SRs are consistent
with those of whole galaxies. By comparing subgalactic and global scales, the
most striking result emerges from the SRs involving ISM components: the
dust-total gas SR is a good correlation at all scales, while the dust-H2 and
dust-HI SRs are good correlations at subkpc/kpc and total scales, respectively.
For the other explored SRs, there is a good agreement between small and global
scales and this may support the picture where the main physical processes
regulating the properties and evolution of galaxies occur locally. Our results
are consistent with the hypothesis of self-regulation of the SF process. The
analysis of subgalactic ratios shows that they are consistent with those
derived for whole galaxies, from low to high z, supporting the idea that also
these ratios could be set by local processes. Our results highlight the
heterogeneity of galaxy properties and the importance of resolved studies on
local galaxies in the context of galaxy evolution. They also provide
observational constraints to theoretical models and updated references for
high-z studies.
