Abstract
Land-use change and climate variability have the potential to alter river flow and groundwater resources dramatically, especially by modifying actual evapotranspiration. Seven catchments with intermittent flow dominated by either winter-active perennial pastures (4 catchments) or Eucalyptus globulus plantations (3 catchments), located in 3 geologic settings of southeastern Australia, were studied for over 6 years to determine the primary controls on water resources. Groundwater levels in the pasture sites were stable through the 2011–2016 study period, while levels in the plantations declined in the same period. Streamflow occurred mainly during winter. Annual streamflow showed no difference clearly attributable to pasture versus plantation land use. The presence of grass buffers along streams enhances groundwater recharge and saturation-dependent overland flow, reducing the impacts of the plantations on streamflow. Site water balances indicated that the average annual actual evapotranspiration was 87–93% of precipitation for pasture catchments and 102–108% of precipitation for plantation catchments. Actual evapotranspiration greater than precipitation at the plantations was attributed to uptake of groundwater by the root system in parts of the catchments. Thus, change to groundwater storage is a critical component in the water balance. Actual evapotranspiration from pasture catchments was higher than previously estimated from global pasture and cropping data, instead matching global precipitation versus actual evapotranspiration curves for treed catchments.
Original language | English |
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Pages (from-to) | 723-739 |
Number of pages | 17 |
Journal | Journal of Hydrology |
Volume | 564 |
DOIs | |
Publication status | Published - 1 Sept 2018 |
Funding
This study was initiated and funded by the Victoria Department of Economic Development, Jobs, Transport, and Resources. Over the years, additional support was provided by the Australian Research Council ( ARC ) and the National Water Commission through Program 4 (Groundwater–Vegetation–Atmosphere Interactions) of the National Centre for Groundwater Research and Training ( ARC project SR0800001 ) and through the ARC Linkage Project LP140100871 . The authors are grateful to the pasture landowners (Marcia Field, Rob Lawrence, Georgie Luckock, and Harry Youngman) and the plantation managers and landowners (Macquarie Bank Foundation and PF Olsen Australia) for granting access to their land. Technical officers Mark Holmberg and Phil Cook were indispensable to the success of the project. This paper was greatly improved by technical editing by Beverly Johnston and input from the journal editor, associate editor, and two anonymous reviewers. The data used in this study are available from the Victorian Department of Economic Development, Jobs, Transport and Resources data repository by contacting [email protected]. Appendix A
Funders | Funder number |
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Victoria Department of Economic Development | |
National Centre for Groundwater Research and Training | SR0800001 |
National Water Commission | |
Australian Research Council | LP140100871 |
Azərbaycan Respirator Cəmiyyəti |
Keywords
- Australia
- Evapotranspiration
- Groundwater
- Intermittent catchments
- Land-use change
- Plantation forestry