Extreme precipitation occurs when there is anomalously high rainfall
within a given region or location. Extreme precipitation can lead to
flooding with impacts for water supply, agriculture, the environment,
emergency services, and infrastructure. The Queensland Future Climate
Science Program uses a number of extreme precipitation indices
selected from those recommended for use in Australia by the
Bureau of Meteorology.
Extreme precipitation indices
The Queensland Future Climate Dashboard and Regional Explorer
include the following extreme precipitation indices:
Maximum 1-day precipitation: Seasonal maximum 1-day precipitation
total
Maximum 5-day precipitation: Seasonal maximum consecutive 5-day
precipitation total
Extremely wet day precipitation: Seasonal total precipitation when
daily precipitation > 99th percentile of precipitation for that
season in the calibration period (1981 - 2010)
Simple daily intensity: Seasonal total precipitation divided by
the number of wet days (where precipitation ≥ 1 mm) within that
season
Consecutive dry days: Maximum number of consecutive days with
daily precipitation < 1 mm
Consecutive wet days: Maximum number of consecutive days with
daily precipitation ≥ 1 mm.
These indices are relevant to water managers, agriculture, and
emergency services, among other sectors. The maximum 1-day
precipitation is relevant to flooding, particularly in small to
medium sized catchments, while the maximum 5-day precipitation is
more closely linked to flooding in larger catchments.
Changes to the extremely wet day precipitation and the simple daily
intensity likewise have implications for the number of flood events,
erosion, and agriculture. The number of consecutive wet and dry days
are important metrics for evaluating water supplies and for
agricultural growing seasons.
Extreme precipitation on Queensland Future Climate
The Queensland Future Climate Science Program has used
state-of-the-art high-resolution downscaled climate simulations from
both CMIP5 and
CMIP6 global climate models to assess the
impact of climate change on extreme precipitation.
The main tools for viewing climate projections data on the
Queensland Future Climate website are the
Queensland Future Climate Dashboard
and
Regional Explorer. Please refer to the
user guide
for detailed information on how to access and interpret information
available from these resources.
Examples of the information on extreme precipitation available on
the Queensland Future Climate Dashboard and Regional Explorer are
shown below.
Sample map and plots from the Queensland Future Climate
Dashboard (CMIP6) showing the projected
change in maximum 1-day precipitation for Mareeba shire in 2070
under a high emissions scenario (SSP3-7.0). The information for
extreme precipitation can also be downloaded as tables or
shapefiles to enable further analyses.A sample timeseries chart from the Regional Explorer (CMIP6) showing projected changes in consecutive wet days for the
Mareeba shire under the 3 emissions scenarios.
