Catchment-scale drought: capturing the whole drought cycle using multiple indicators

Abraham J. Gibson, Danielle C. Verdon-Kidd, Greg R. Hancock, Garry Willgoose
2019 Hydrology and Earth System Sciences Discussions  
<p><strong>Abstract.</strong> Global agricultural drought policy has shifted towards promoting drought preparedness and climate resilience in favor of disaster relief-based strategies. For this approach to be successful, drought predictability and methods for assessing the many aspects of drought need to be improved. Therefore, this study aims to bring together meteorological and hydrological measures of drought, along with vegetation and soil moisture data to assess how droughts begin,
more » ... ghts begin, propagate and subsequently terminate for a catchment in eastern Australia. For the study area, thirteen meteorological drought periods persisting more than six months were identified over the last 100 years. During these, vegetation health, soil moisture and streamflow declined, however, all indicators recovered quickly post drought, with no evidence of extended impacts on the rainfall-runoff response, as has been observed elsewhere. Further, drought initiation and propagation were found to be tightly coupled to the combined state of large-scale ocean-atmosphere climate drivers (e.g. El Niño Southern Oscillation, Indian Ocean Dipole and Southern Annular Mode), while termination is caused by persistent synoptic systems (e.g. low-pressure troughs). The combination of climatic factors, topography, soils and vegetation are believed to be what makes the study catchments more resilient to drought than others in eastern Australia. The study diversifies traditional approaches to studying droughts by quantifying catchment response to drought using a range of measures that could also be applied in other catchments globally. This is a key step towards improved drought management.</p>
doi:10.5194/hess-2019-311 fatcat:i3rvtmx22rbybnto7d2ata36lu