Bari, M.A.; Khan, U.; Amirthanathan, G.E.; Tuteja, M.; Laugesen, R.M. Simulation of Gauged and Ungauged Streamflow of Coastal Catchments across Australia. Water2024, 16, 527.
Bari, M.A.; Khan, U.; Amirthanathan, G.E.; Tuteja, M.; Laugesen, R.M. Simulation of Gauged and Ungauged Streamflow of Coastal Catchments across Australia. Water 2024, 16, 527.
Bari, M.A.; Khan, U.; Amirthanathan, G.E.; Tuteja, M.; Laugesen, R.M. Simulation of Gauged and Ungauged Streamflow of Coastal Catchments across Australia. Water2024, 16, 527.
Bari, M.A.; Khan, U.; Amirthanathan, G.E.; Tuteja, M.; Laugesen, R.M. Simulation of Gauged and Ungauged Streamflow of Coastal Catchments across Australia. Water 2024, 16, 527.
Abstract
Australia is a unique continent surrounded by the ocean and the majority of catchments flow to the coast. Some of these catchments are gauged and others are ungauged. There are 405 gauged catchments covering 2,549,000 km2 across the coastal regions of 12 drainage divisions in Australia. Whereas there are 771 catchments conceptualised as ungauged covering additional 835,000 km2. The mean annual rainfall and PET and its spatial and temporal distribution vary significantly from one drainage division to another. We developed a continuous daily streamflow time series of all gauged and ungauged catchments from 1993 onwards. We applied the GR4J lumped conceptual model to these catchments. The performance of gauged catchments was analysed through (i) visual inspection of daily hydrographs, flow duration curves and daily scatter plots, and (ii) performance metrics including NSE and PBias. Based on the NSE and PBias, performance ratings of 80% and 96% of the models respectively were found 'good'. There was no relationship found between the catchment area and model performance. The ungauged catchments were divided into four categories based on distance from potential donor catchments where observed data are available for GR4J model calibration, and Köppen climate zone. The total ungauged catchments represent 24.7% of the total drainage division areas. The streamflow from ungauged catchments was estimated using GR4J model based on the parameters of their donor catchments. Overall, runoff ratios from ungauged catchments were found to be higher compared to their donor gauged catchments, likely driven by their higher rainfall and less PET. This tendency was particularly evident in two drainage divisions – the Carpentaria Coast (CC) and Tanami-Timor Sea Coast (TTS) where ungauged areas comprised 51% and 43% respectively. The mean gauged annual streamflow varied significantly across drainage divisions – 230 GL from South Australian Gulf (SAG) to 146,150 GL in TTS. The streamflow from all ungauged catchments was estimated at 232,200 GL per year. Overall, the average streamflow from all drainage divisions, including gauged and ungauged areas, across the coastal regions of Australia was estimated at 419,950 GL per year. This nationwide estimate of streamflow dataset could potentially enhance our understanding of coastal processes and improvements of marine modelling systems and tools.
Environmental and Earth Sciences, Water Science and Technology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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