Conference proceeding
Groundwater discharge into intermittently closed and open lakes and/or lagoons (ICOLLs) via radon-222
American Geophysical Union Fall Meeting, Vol.2015
American Geophysical Union 2015 fall meeting (San Francisco, 14/12/2015 - 18/12/2015)
12/2015
Metrics
37 Record Views
Abstract
Intermittently Closed and Open Lakes and Lagoons (ICOLLs) are brackish coastal water bodies with an intermittent connection to the ocean that is closed periodically due to the accumulation of marine sediment forming an entrance berm. ICOLLs have dynamic coastal systems that may be vulnerable to minor changes in catchment hydrology. However, little is known regarding the impacts of groundwater on the hydrological cycles of ICOLLs. The relative contribution of rainfall versus groundwater discharge in two ICOLLs (Welsby, and Mermaid Lagoon) and a nearby wetland (South Welsby Lagoon) located on Bribie Island (Australia) were investigated using radon ( (super 222) Rn) as natural geochemical groundwater tracer. Four seasonal surveys were undertaken to quantify the temporal and spatial groundwater dynamics of the ICOLLs. Radon contour maps revealed temporal and spatial changes over the study period. The estimated groundwater discharge rates from a radon-mass balance were 3.4+ or -3.1, 7.3+ or -9.8 and 2.6+ or -3.8 cm d (super -1) in Weslby, South Weslby and Mermaid Lagoons, respectively. These values are at least 8-fold greater than rainfall (1420 mm per year, or 0.4 cm d (super -1) ). Assuming very minor surface water flows (not perceived during field surveys), this demonstrates that these systems are groundwater-dominated and their hydrology can be influenced by regional changes in groundwater level.
Details
- Title
- Groundwater discharge into intermittently closed and open lakes and/or lagoons (ICOLLs) via radon-222
- Creators
- Mahmood Sadat-Noori - Southern Cross UniversityIsaac R SantosD. R TaitA McMahonSean KadelDamien T MaherAnonymous
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2015
- Conference
- American Geophysical Union 2015 fall meeting (San Francisco, 14/12/2015 - 18/12/2015)
- Publisher
- American Geophysical Union
- Identifiers
- 991012978055002368
- Academic Unit
- Faculty of Science and Engineering; Science
- Language
- English
- Resource Type
- Conference proceeding