Estimates were made of the net radiation for a number of cases (1. no radiation data and 2. measured incident short wave radiation) and compared to the field monitored values. These data were in turn used to estimate the potential evapotranspiration (ETp) from the embankment. The results indicate that the net radiation and hence ETp derived entirely from estimated data are significantly higher than those derived with measured shortwave or net radiation. Results for estimates of ETp derived from monitored shortwave and net radiation data are a close match to each other.
In order to investigate the potential effects on slope stability, an assessment of soil moisture deficit was undertaken. The results indicate that numerical models using the varying estimates of ETp would likely produce different results in terms of generated suctions and suction dissipation and so undergo different magnitudes of shrink-swell cycling, in turn leading to varying rates of strain softening behaviour, differing calculated factors of safety and differing modelled time to failure.