https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33558 via SO2/4⁻ release and limestone dissolution. Very acidic water (pH 2-3) was neutralised naturally by lake refill, but aerial limestone dosing was required for neutralisation of water acidity during the drought period. The Lower Lakes are characterized as hypereutrophic with much higher salinity, nutrient and algae concentrations than guideline levels for aquatic ecosystem. These results suggest that, in the Lower Lakes, drought could cause water quality deterioration through water acidification and increased nutrient and Chl-α concentrations, more effective water management in the lake catchment is thus crucial to prevent the similar water quality deterioration since the projected intensification of droughts. A comparative assessment on lake resilience and recovering processes should be undertaken with a post-drought monitoring program.]]> Tue 20 Nov 2018 09:39:20 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38755 pCO₂), CO₂ degassing and their potential controls. The pCO₂ levels ranged from 50 to 6019 µatm with averages of 1573 (SD. ±1060) in dry Autumn and 1276 (SD. ±1166) µatm in wet Summer seasons. 94% of samples were supersaturated with CO₂ with respect to the atmospheric equilibrium (410 µatm). Monsoonal precipitation controlled pCO₂ seasonality, with both the maximal and minimal levels occurring in the wet season, and showing the overall effects of dilution. Riverine pCO2 could be predicted better in the dry season using pH, DO% and DTP, whereas pH and DOC were better predictors in the wet season. We conclude that in-situ respiration of allochthonous organic carbon, rather than photosynthesis, resulted in negative relationships between pCO₂ and DO and pH, and thus CO₂ supersaturation. Photosynthetic primary production was effectively limited by rapid flow velocity and short residence time. The estimated water-to-air CO₂ emission rate in the TGR rivers was 350 ± 319 in the Autumn and lower, yet more variable at 326 ± 439 mmol/m2/d in Summer. Our calculated CO₂ areal fluxes were in the upper-level magnitude of published data, demonstrating the importance of mountainous rivers and streams as a global greenhouse gas source, and urgency for more detailed studies on CO₂ degassing, to address a global data gap for these environments.]]> Mon 24 Jan 2022 11:24:02 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33391 Mon 12 Apr 2021 15:39:53 AEST ]]>