Journal
ENVIRONMENTAL PROCESSES-AN INTERNATIONAL JOURNAL
Volume 8, Issue 2, Pages 511-531Publisher
SPRINGER INT PUBL AG
DOI: 10.1007/s40710-021-00501-7
Keywords
Water temperature; Warm water pollution; Dam; GAM; Freshwater; Snowy River
Categories
Funding
- NSW Department of Planning, Industry and Environment
Ask authors/readers for more resources
The study shows that large reservoirs can alter the thermal regime of rivers, leading to abnormal water temperatures downstream; GAMs and selected reference streams are useful tools in assessing thermal regime changes; Future research should focus on determining whether slight deviations in water temperatures result in significant ecological consequences in snowmelt streams.
Large reservoirs can alter the natural thermal regime and result in the delivery of water with unseasonal water temperatures downstream. Establishing a detailed understanding how a river's thermal regime has changed from its natural state is a critical step required before mitigation options can be investigated. Our study focussed on one of Australia's most iconic rivers, the Snowy River which is regulated by multiple headwater regulating structures. We used mean daily pre-dam water temperature (1962-1967) data from the Snowy River to develop generalized additive models (GAMs) to predict the natural (daily mean, max and min) water temperatures in the Snowy River. Daily modelled natural water temperatures were compared with daily observed water temperatures in the regulated Snowy River and two nearby analogue reference streams. Using the GAMs, we identified a reduced thermal range (max and min) and water temperatures >= 2 degrees C warmer than natural between the cooler months of April and July for at least 50 % of the study period. Temperatures rarely (< 15 % of study period) exceeded 4 degrees C above natural. We show that both GAMs and appropriately selected reference streams are useful for assessing thermal regime change. Future work should focus on clearly identifying if small deviations from natural water temperatures during these periods results in significant ecological consequences in snowmelt streams.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available