  We present a study of water vapour in the Venus troposphere obtained by
modelling specific water vapour absorption bands within the 1.18 \mu m window.
We compare the results with the normal technique of obtaining the abundance by
matching the peak of the 1.18 \mu m window. Ground-based infrared imaging
spectroscopy of the night side of Venus was obtained with the Anglo-Australian
Telescope and IRIS2 instrument with a spectral resolving power of R ~ 2400. The
spectra have been fitted with modelled spectra simulated using the radiative
transfer model VSTAR. We find a best fit abundance of 31 ppmv (-6 + 9 ppmv),
which is in agreement with recent results by B\'ezard et al. 2011 using
VEX/SPICAV (R ~ 1700) and contrary to prior results by B\'ezard et al. 2009 of
44 ppmv (+/-9 ppmv) using VEX/VIRTIS-M (R ~ 200) data analyses. Comparison
studies are made between water vapour abundances determined from the peak of
the 1.18 \mu m window and abundances determined from different water vapour
absorption features within the near infrared window. We find that water vapour
abundances determined over the peak of the 1.18 \mu m window results in plots
with less scatter than those of the individual water vapour features and that
analyses conducted over some individual water vapour features are more
sensitive to variation in water vapour than those over the peak of the 1.18 \mu
m window. No evidence for horizontal spatial variations across the night side
of the disk are found within the limits of our data with the exception of a
possible small decrease in water vapour from the equator to the north pole. We
present spectral ratios that show water vapour absorption from within the
lowest 4 km of the Venus atmosphere only, and discuss the possible existence of
a decreasing water vapour concentration towards the surface.
