The NSW Combined Drought Indicator (CDI) is used by the Department of Primary Industries and Regional Development (DPIRD) to classify drought in New South Wales. It integrates weather, climate, soil, and land-use datasets into a single framework to help decision making.
The CDI combines meteorological, hydrological and agronomic definitions of drought using indicators for rainfall (RI), soil water (SWI), and plant growth (PGI). From these, a fourth index, the Drought Direction Index (DDI), is developed. Used together, these indices classify the five categories of drought. By using multiple indicators, the CDI provides an overall indication of drought conditions in NSW.
The CDI is a long-term drought indicator which tracks events that are at least 9-12 months in duration. It is not overly sensitive to short term climatic events and for this reason can lag field conditions.
For more information on the CDI and its underlying indicators, see https://www.dpi.nsw.gov.au/climate_applications/interactive-drought-map/Learn-more/understanding-the-cdi-phases
CDI online interactive map https://www.dpi.nsw.gov.au/climate_applications/interactive-drought-map
DPIRD's interactive CDI map provides free access to current and historical drought information at the NSW parish level (~10-20 farms), while the underlying monitoring occurs at 1 square kilometre resolution (data provided by ANUClimate). The interactive map is updated daily and displays the latest (4 days lag) CDI and drought indicator values for NSW.
Time series CDI and indicator data for up to 5 years before present for a particular location can be obtained by using the location search bar or by clicking on the LLS, LGA, then Parish of interest. Time series can be downloaded as figure files (.jpg).
CDI data cannot be downloaded directly from the interactive map. For access to the data that is displayed on the map, please visit the Seasonal Conditions Information Portal (SCIP) https://edis.spaceport.intersect.org.au/
The Seasonal Conditions Information Portal provides access to monthly snapshots of CDI data in several forms:
Monthly CDI and indicator GIS .zips containing .shp, .shx, .dbf, and .prj (2020 January to present),
Monthly CDI and indicator .csv files (2020 January to present),
Monthly LGA percentages in drought .csv files (2016 January to present),
Weekly updating high-quality parish-level time series figures (.jpg) (2 years before present to present), and
Extended parish time series by decade (1970 – 2020).
The NSW State Seasonal Update https://www.dpi.nsw.gov.au/climate_applications/state-seasonal-update contains a verified version of CDI information released as monthly report and accompanying text.
Includes: statewide overviews of monthly indicators, including the CDI, rainfall, temperature, remotely-sensed vegetation and water availability Regional (Local Land Service) breakdowns of seasonal conditions Climate driver updates Seasonal forecasts of rainfall, temperature, and drought.
NSW Drought in a Changing Climate Report: The NSW-CDI has also been utilised to assesses the longer term risk of future drought using CMIP6 climate projections to drive the EDIS system. A report summarising the project and its results are available here https://www.dpi.nsw.gov.au/dpi/climate/seasonal-conditions-and-drought/key-research/drought-under-climate-change.
Additional data available by request by contacting seasonal.conditions@dpird.nsw.gov.au
