Modelled flow stress in Victorian unregulated rivers under current and climate change scenarios

The hydrological database is composed of baseline (post-1975 conditions), “current” (represented by post-1997 conditions) and multiple climate change scenarios for a large set of unregulated rivers in Victoria. This is supplied together with pre-compiled information on resulting flow stress, mapped at state scale and for each CMA region individually. 

The dataset differs from existing datasets in several features, including (i) its fine scale of application—to 563 unregulated catchments pre-defined in DEECA's Flow Stress Ranking dataset; (ii) in the careful manner in which natural climate variability is represented, which is important information against which to contextualise future changes; (iii) in the generation of future scenarios that go beyond the recycling of the historic sequence to consider a wider range of future sequences; (iv) in the representation of impacts from interception, namely farm dams and private diverters, on unregulated river flow; and (v) in the incorporation of leading DEECA sponsored research into hydrological simulation under climate variability and change. 

To facilitate (ii) and (iii), a stochastic approach is implemented to generate climatic (and thus streamflow) sequences. The climate information used to define future changes is sourced directly from DEECA's 2020 Guidelines for assessing the impact of climate change on water availability in Victoria. The guidelines also allow for a post-1997 climate conditions scenario, which is used here to characterise current stress on rivers, including exploring options to ameliorate this stress.

The folder "Empty" contains the following shapefiles without appended data:

UnregRivers_Catchments_GDA2020.shp
Contains the shapes, areas and identification numbers of the individual FSR catchments being considered in this analysis.

UnregRivers_Streamlines_GDA2020.shp
Contains the shapes, areas and identification numbers of the individual reaches of stream being considered in this analysis.

Folders "Catchments" and "Streamlines" each contain folders "Shapefiles" and "Spreadsheets". Data in "Catchments" is mapped to individual FSR catchments, while that in "Streamlines" is mapped to individual reaches of stream. 

The folder "Spreadsheets" contains subfolders "RCP4.5" and "RCP8.5", which refer to the representative concentration pathways which the modelling results within each subfolder pertain to.
Each subfolder has the same files (with differing results):
dl_12 - Low Flow Spell Duration
dl_12_stress - stress score of the above metric
dl_17 - Number of Zero Flow Months per Year
dl_17_stress - stress score of the above metric
ma_1 - Mean Annual Flow
ma_1_stress - stress score of the above metric
ma_6 - Mean February Flow
ma_6_stress - stress score of the above metric
ma_12 - Mean August Flow
ma_12_stress - stress score of the above metric
ma_13 - Mean September Flow
ma_13_stress - stress score of the above metric
mh_7 - High Flow Volume
mh_7_stress - stress score of the above metric
th_1 - Julian date of Annual Maximum Flow
th_1_stress - stress score of the above metric

Each csv file has the following column headings, these are limited to 10 characters for ease of input into mapping software:
Catch_num - the identification number of the relevant catchment
baseunim - metric as per baseline (post 1975) unimpacted flow
baseFD - metric as per baseline flow with extractions for farm dams
basePD - metric as per baseline flow with extractions for private diverters
baseFDPD - metric as per baseline flow with extractions for farm dams and private diverters
currunim - metric as per current (Post 1997) unimpacted flow
currFD - metric as per current flow with extractions for farm dams
currPD - metric as per current flow with extractions for private diverters
currFDPD - metric as per current flow with extractions for farm dams and private diverters
unimmd2040 - median metric as per 2040 unimpacted flow (based on results of 39 Global Circulation Models)
FDmd2040 - median metric as per 2040 flow with extractions for farm dams
PDmd2040 - median metric as per 2040 flow with extractions for private diverters
FDPDmd2040 - median metric as per 2040 flow with extractions for farm dams and private diverters
unim52040 - 5th percentile metric as per 2040 unimpacted flow
FD52040 - 5th percentile metric as per 2040 flow with extractions for farm dams
PD52040 - 5th percentile metric as per 2040 flow with extractions for private diverters
FDPD52040 - 5th percentile metric as per 2040 flow with extractions for farm dams and private diverters
unim952040 - 95th percentile metric as per 2040 unimpacted flow
FD952040 - 95th percentile metric as per 2040 flow with extractions for farm dams
PD952040 - 95th percentile metric as per 2040 flow with extractions for private diverters
FDPD952040 - 95th percentile metric as per 2040 flow with extractions for farm dams and private diverters
unimmd2065 - median metric as per 2065 unimpacted flow (based on results of 39 Global Circulation Models)
FDmd2065 - median metric as per 2065 flow with extractions for farm dams
PDmd2065 - median metric as per 2065 flow with extractions for private diverters
FDPDmd2065 - median metric as per 2065 flow with extractions for farm dams and private diverters
unim52065 - 5th percentile metric as per 2065 unimpacted flow
FD52065 - 5th percentile metric as per 2065 flow with extractions for farm dams
PD52065 - 5th percentile metric as per 2065 flow with extractions for private diverters
FDPD52065 - 5th percentile metric as per 2065 flow with extractions for farm dams and private diverters
unim952065 - 95th percentile metric as per 2065 unimpacted flow
FD952065 - 95th percentile metric as per 2065 flow with extractions for farm dams
PD952065 - 95th percentile metric as per 2065 flow with extractions for private diverters
FDPD952065 - 95th percentile metric as per 2065 flow with extractions for farm dams and private diverters

The csv files can be joined using mapping software with the "UnregRivers_Catchments_GDA2020.shp" and "UnregRivers_Streamlines_GDA2020.shp", with the field 'Catch_num' aligning.

The folders "RCP45" and "RCP85" under "Shapefiles" contain shapefiles for each of the metrics above, prejoined to the "UnregRivers_Catchments_GDA2020.shp" or "UnregRivers_Streamlines_GDA2020.shp" files.

Tags: Environment, Inland waters
Organization: Department of Energy, Environment and Climate Action