Harwood Evapotranspiration EAA (Actual Evaporation topo-corrected) v01

## **Abstract** \n\nThis dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party (CSIRO) and are presented here as originally supplied.\n\n\n\nClimate change presents a challenge for the management of water resources and for the management of systems dependent on those water resources. In particular, the effect of water flow across and below the ground surface is rarely adequately represented. Our motive was to capture this effect for water limited Australia, to assist with the identification of climate change refugia. We present a new algorithm for the rescaling of actual evapotranspiration (ETa) under future climate. The algorithm uses standard topographic adjustment of radiation and temperature to spatially rescale remotely sensed ETa, estimated for current conditions in accordance with the Budyko framework. Calculations were limited by those inputs which could reasonably be derived from Global Circulation Model (GCM) outputs with minimal assumptions. Priestley-Taylor potential evapotranspiration was calculated based on topographically adjusted temperature and radiation, and annual total ETa was subsequently calculated as the sum of monthly ETa using the Budkyo framework, incorporating a best estimate of plant available water holding capacity as a tipping bucket. The discrepancy between modelled and remotely derived ETa under present conditions was used to generate a cell by cell correction along the Budyko curve which was then applied to GCM driven future ETa. The approach assumes a consistent large scale spatial pattern of surface and ground water movement. \n\n\n\nProjecting remotely derived estimates of actual evapotranspiration (ETa) under climate change in Australia. CSIRO Climate Adaptation Flagship Thomas Harwood, Randall Donohue, Tim McVicar, Kristen J Williams, Justin Perry, Jeremy Vanderwal, Cassandra James, Simon Ferrier (http://apo.org.au/files/Resource/Williams-Climate-change-refugia-for-terrestrial-biodiversity_0.pdf).\n\n## **Purpose** \n\nThese data were used to help determine water dependence of assets\n\n## **Dataset History** \n\nThis evapotranspiration grid were developed by Tom Harwood et al (Projecting remotely derived estimates of actual evapotranspiration (ETa) under climate change in Australia. CSIRO Climate Adaptation Flagship Thomas Harwood, Randall Donohue, Tim McVicar, Kristen J Williams, Justin Perry, Jeremy Vanderwal, Cassandra James, Simon Ferrier\n\n(http://apo.org.au/files/Resource/Williams-Climate-change-refugia-for-terrestrial-biodiversity_0.pdf).\n\n\n\nAnnual total ETa was calculated as the sum of monthly ETa using the Budkyo framework, incorporating a best estimate of plant available water holding capacity as a tipping bucket. The discrepancy between modelled and remotely derived ETa under present conditions was used to generate a cell by cell correction along the Budyko curve which was then applied to GCM driven future ETa. The approach assumes a consistent large scale spatial pattern of surface and ground water movement. \n\n\n\nThese data were used in the assessment of water dependence of assets.\n\n## **Dataset Citation** \n\nCSIRO (2015) Harwood Evapotranspiration EAA (Actual Evaporation topo-corrected) v01. Bioregional Assessment Source Dataset. Viewed 05 July 2017, http://data.bioregionalassessments.gov.au/dataset/baf0a32a-24e1-4882-b3f6-fb690476f0f0.