Spatial distribution of triazine residues in a shallow alluvial aquifer linked to groundwater residence time

The spatial distribution of biomass of main commercial fish species was mapped to estimate the supply of a provisioning fishery service in the Curonian lagoon. Catch per unit effort (CPUE) was used as a proxy to estimate the efficiency of commercial fishing and, subsequently, the potential biomass of fishes. The relationship between distinctive characteristics of the fishing areas and corresponding commercial catches and CPUE was analyzed using multivariate analysis. The total catch values and CPUE used in the analyses were derived from the official commercial fishery records. RDE analysis was used to assess the variation of both catch and CPUE of commercial fish species, while the percentages of bottom sediment type coverage, average depth, annual salinity, and water residence time in each of the fishing squares were used as explanatory variables. This distance e-based redundancy analysis allowed for the use of non-Euclidean dissimilarity indices. Fisheries data spatial distribution map indicated the lack of coherence between the spatial patterns of commercial catches and CPUE distribution in the northern part of the lagoon. Highest CPUE values were estimated in the central-eastern part of the lagoon as compared to the western part of the lagoon where CPUE values were substantially lower. Both total catch and CPUE appeared not to be related to the type of bottom habitats statistically while being spatially correlated in-between. However, the impact of salinity and water residence time calculated using the 3D hydraulic circulation model on the distribution of both CPUE and commercial catches was statistically significant.

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Evaluation of groundwater residence time in a high mountain aquifer system (Sacramento Mountains, USA): insights gained from use of multiple environmental tracers

Hydrogeology Journal ◽

10.1007/s10040-016-1400-4 ◽

2016 ◽

Vol 24 (4) ◽

pp. 787-804 ◽

Cited By ~ 5

Author(s):

Lewis Land ◽

Stacy Timmons

Keyword(s):

Residence Time ◽

High Mountain ◽

Environmental Tracers ◽

Aquifer System ◽

Sacramento Mountains ◽

Groundwater Residence Time

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Radiocarbon and Other Environmental Isotopes in the Groundwater of the Sites for a Planned New Nuclear Power Plant in Lithuania

Radiocarbon ◽

10.1017/s0033822200058100 ◽

2013 ◽

Vol 55 (2) ◽

pp. 951-962 ◽

Cited By ~ 5

Author(s):

Jonas Mažeika ◽

Tõnu Martma ◽

Rimantas Petrošius ◽

Vaidotė Jakimavičiūtė-Maselienė ◽

Žana Skuratovič

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Residence Time ◽

Nuclear Power ◽

Safety Assessment ◽

Depth Interval ◽

Near Surface ◽

Helium Content ◽

Aquifer System ◽

Groundwater Residence Time

The assessment of construction sites for the new Visaginas Nuclear Power Plant (Visaginas NPP), including groundwater characterization, took place over the last few years. For a better understanding of the groundwater system, studies on radiocarbon; tritium; stable isotopes of hydrogen, oxygen, and carbon; and helium content were carried out at the location of the new NPP, at the Western and Eastern sites, as well as in the near-surface repository (NSR) site. Two critical depth zones in the Quaternary aquifer system were characterized by different groundwater residence times and having slightly different stable isotope features and helium content. The first shallow interval of the Quaternary multi-aquifer system consists of an unconfined aquifer and semiconfined aquifer. The second depth interval of the system is related to the lower Quaternary confined aquifer. Groundwater residence time in the first flow system was mainly based on tritium data and ranges from 6 to 60 yr. These aquifers are the most important in terms of safety assessment and are considered as a potential radionuclide transfer pathway in safety assessment. Groundwater residence time in the lower Quaternary aquifers based on 14C data varies from modern to several thousand years and in some intervals up to 10,500 yr.

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