Abstract
A reliable understanding of linkages between meteorological,
hydrological and agricultural droughts (MD, HD and AD respectively) is
crucial to building resilience and planning for future climate changes.
Despite Australia being prone to severe droughts, lagtimes of
propagation (and recovery) from meteorological to hydrological and
agricultural droughts across its large hydroclimatic regions are not
well understood. Therefore, we investigate the characteristics of
drought propagation and recovery time lags for droughts of four
timescales and a combination of drought onset and cessation criteria in
407 unregulated catchments within six major precipitation zones across
Australia. We find that the propagation and recovery lags are dependent
on climatic conditions, drought criteria and timescales. The average
propagation times from MD to HD across Australia varied from 0.8 to 1.7
months for monthly timescales, increasing to 2 to 4.5 months for
12-monthly timescales. The corresponding recovery lagtimes were 1.3 to
3.7 and 1.7 to 7.5 months respectively. Similarly, the average
propagation times from MD to AD ranged from 0.9 to 1.9 months for
monthly timescales, increasing to 0.8 to 5 months for 12-monthly
timescales. The corresponding recovery lagtimes were 0.7 to 2.8 and 0.3
to 9.4 months respectively. For droughts of smaller timescales,
propagation and recovery lags are linearly correlated with recovery
lagtimes consistently greater than the propagation times. As the
timescale increases, these relationships weaken suggesting effects of
other catchment attributes (e.g. groundwater contributions) on lag
relationships. Notably, recovery lagtimes are generally longer for the
high-yielding catchments in eastern Australia compared to the other
regions