Do model emission line galaxies live in filaments at z~1?
  Current and future cosmological surveys are targeting star-forming galaxies
at $z\sim 1$ with nebular emission lines. We use a state-of-the-art
semi-analytical model of galaxy formation and evolution to explore the large
scale environment of star-forming emission line galaxies (ELGs). Model ELGs are
selected such that they can be compared directly with the DEEP2, VVDS,
eBOSS-SGC and DESI surveys. The large scale environment of the ELGs is
classified using velocity-shear-tensor and tidal-tensor algorithms. Half of the
model ELGs live in filaments and about a third in sheets. Model ELGs which
reside in knots have the largest satellite fractions. We find that the shape of
the mean halo occupation distribution of model ELGs varies widely for different
large scale environments. To interpret our results, we also study fixed number
density samples of ELGs and galaxies selected using simpler criteria, with
single cuts in stellar mass, star formation rate and [OII] luminosity. The
fixed number density ELG selection produces samples that are close to L[OII]
and SFR selected samples for densities above $10^{-4.2}h^{3}{\rm Mpc}^{-3}$.
ELGs with an extra cut in stellar mass applied to fix their number density,
present differences in sheets and knots with respect to the other samples.
ELGs, SFR and L[OII] selected samples with equal number density have similar
large scale bias but their clustering below separations of $1h^{-1}$Mpc is
different.
