The following graphs show how quickly soil moisture has dropped in NSW in the last year. The insidious rise in dryness is lurking behind the little episodes of rainfall we have had in the last eight months.
With dry and windy months ahead, the drop in moisture levels show no sign of abating in most parts of the state. In some small pockets of NSW, soil moisture levels are at their lowest of all time.
The Bureau of Meteorology compiles the maps using expert data.
This is how the state’s soil moisture situation looked last year and this year so far:
The Bureau has noted a drying trend for 20 years during the winter growing season in South-East Australia.
Dr Amgad Elmahdi, head of Water Resources Section (STWR), at the Bureau, provided the following information for The Land:
“The information presented on the Australian Landscape Water Balance website is produced by the Bureau's operational Australian Water Resources Assessment Landscape model (AWRA-L). AWRA-L is a daily 0.05° grid-based, distributed water balance model, conceptualised as a small unimpaired catchment,” Dr Elmahdi said.
“It simulates the flow of water through the landscape from the rainfall entering the grid cell through the vegetation and soil moisture stores and then out of the grid cell through evapotranspiration, runoff or deep drainage to the groundwater.
“In NSW over 2017: Soil moisture has steadily declined over the majority of NSW over 2017, following low monthly rainfall totals over 2017 (Feb, Jun, July in particular), with the exception of NSW North Coast following Ex-tropical cyclone Debbie in Late March.
“This has caused soil moisture to be below average across much of the state, and is in stark contrast following an exceptionally wet year in 2016 and many flooding events in central NSW.”
John Ellicott
journalist and author
journalist and author
