Long term infiltration and tracer transport in fractured rocks: Field observations and model analyses

2011 ◽  
Vol 396 (1-2) ◽  
pp. 33-48 ◽  
Author(s):  
Guoping Lu ◽  
Hui-Hai Liu ◽  
Rohit Salve
Keyword(s):  
Fractured Rocks ◽  
Field Observations ◽  
Tracer Transport

scholarly journals Genetic Consequences of Fence Confinement in a Population of White-Tailed Deer

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 126
Author(s):  
Emily K. Latch ◽  
Kenneth L. Gee ◽  
Stephen L. Webb ◽  
Rodney L. Honeycutt ◽  
Randy W. DeYoung ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
Wildlife Management ◽  
Field Observations ◽  
Adaptive Potential ◽  
Population Isolation ◽  
Potential Benefits ◽  
Wildlife Populations ◽  
Mtdna Diversity

Fencing wildlife populations can aid wildlife management goals, but potential benefits may not always outweigh costs of confinement. Population isolation can erode genetic diversity and lead to the accumulation of inbreeding, reducing viability and limiting adaptive potential. We used microsatellite and mitochondrial DNA data collected from 640 white-tailed deer confined within a 1184 ha fence to quantify changes in genetic diversity and inbreeding over the first 12 years of confinement. Genetic diversity was sustained over the course of the study, remaining comparable to unconfined white-tailed deer populations. Uneroded genetic diversity suggests that genetic drift is mitigated by a low level of gene flow, which supports field observations that the fence is not completely impermeable. In year 9 of the study, we observed an unexpected influx of mtDNA diversity and drop in inbreeding as measured by FIS. A male harvest restriction imposed that year increased male survival, and more diverse mating may have contributed to the inbreeding reduction and temporary genetic diversity boost we observed. These data add to our understanding of the long-term impacts of fences on wildlife, but also highlight the importance of continued monitoring of confined populations.

Impact of fluid–rock chemical interactions on tracer transport in fractured rocks

2013 ◽  
Vol 154 ◽  
pp. 42-52 ◽  
Author(s):  
Sumit Mukhopadhyay ◽  
H.-H. Liu ◽  
N. Spycher ◽  
B.M. Kennedy
Keyword(s):  
Fractured Rocks ◽  
Tracer Transport ◽  
Chemical Interactions

scholarly journals Impact of numerical choices on water conservation in the E3SM Atmosphere Model Version 1 (EAM V1)

2017 ◽  
Author(s):  
Kai Zhang ◽  
Philip J. Rasch ◽  
Mark A. Taylor ◽  
Hui Wan ◽  
Lai-Yung Ruby Leung ◽  
...  
Keyword(s):  
Water Conservation ◽  
Time Integration ◽  
Moisture Flux ◽  
Horizontal Resolution ◽  
Earth System ◽  
Tracer Transport ◽  
Error Sources ◽  
Surface Moisture ◽  
Earth System Models

Abstract. The conservation of total water is an important numerical feature for global Earth system models. Even small conservation problems in the water budget can lead to systematic errors in century-long simulations for sea level rise projection. This study quantifies and reduces various sources of water conservation error in the atmosphere component of the Energy Exascale Earth System Model. Several sources of water conservation error have been identified during the development of the version 1 (V1) model. The largest errors result from the numerical coupling between the resolved dynamics and the parameterized sub-grid physics. A hybrid coupling using different methods for fluid dynamics and tracer transport provides a reduction of water conservation error by a factor of 50 at 1° horizontal resolution as well as consistent improvements at other resolutions. The second largest error source is the use of an overly simplified relationship between the surface moisture flux and latent heat flux at the interface between the host model and the turbulence parameterization. This error can be prevented by applying the same (correct) relationship throughout the entire model. Two additional types of conservation error that result from correcting the surface moisture flux and clipping negative water concentrations can be avoided by using mass-conserving fixers. With all four error sources addressed, the water conservation error in the V1 model is negligible and insensitive to the horizontal resolution. The associated changes in the long-term statistics of the main atmospheric features are small. A sensitivity analysis is carried out to show that the magnitudes of the conservation errors decrease strongly with temporal resolution but increase with horizontal resolution. The increased vertical resolution in the new model results in a very thin model layer at the Earth’s surface, which amplifies the conservation error associated with the surface moisture flux correction. We note that for some of the identified error sources, the proposed fixers are remedies rather than solutions to the problems at their roots. Future improvements in time integration would be beneficial for this model.

The use of deslorelin implants for the long-term contraception of lionesses and tigers

2008 ◽  
Vol 35 (6) ◽  
pp. 525 ◽  
Author(s):  
H. J. Bertschinger ◽  
M. A. de Barros Vaz Guimarães ◽  
T. E. Trigg ◽  
A. Human
Keyword(s):  
South Africa ◽  
Effective Means ◽  
Panthera Leo ◽  
Ovarian Activity ◽  
Panthera Tigris ◽  
Field Observations ◽  
The Mean ◽  
Free Ranging ◽  
Mean Time

Contraception is an essential tool for controlling reproduction in captive and free-ranging lions. This paper describes the treatment and contraception of 23 captive and 40 free-ranging lionesses (Panthera leo) and four captive tigers (Panthera tigris) in South Africa using 3 × 4.7 mg, 2 × 4.7 mg, 9.4 mg or 4.7 + 9.4 mg deslorelin implants. Thirty-one lionesses were treated more than once at 11- to 60-month intervals. In Brazil, two lionesses were treated with 9.4-mg implants and faecal progesterone and oestradiol concentrations were monitored for 920 days. All combinations of deslorelin showed the length of contraception to be around 30 months with one 3 × 4.7 mg treatment lasting 40 months in one captive lioness. The mean time taken to reconception was 30.1 months for the 3 × 4.7 mg combination. The faecal analyses of the lionesses in Brazil reflected quiescent ovarian activity for periods of 17 and 30 months, respectively, when small oestradiol peaks but no progesterone peaks started to appear. This confirmed the field observations in South Africa. No side effects occurred although several of the lionesses were treated repeatedly for up to 8 years. Deslorelin (Suprelorin) is a safe and effective means of controlling reproduction in captive or free-ranging populations of lions. Where contraception is to be maintained, the implementation of implants at 24-month intervals is recommended.

scholarly journals Long-term Field Observations on Seasonality in Chlorophyll-a Concentrations in a Shallow Coastal Marine Ecosystem, the Wadden Sea

2009 ◽  
Vol 33 (2) ◽  
pp. 286-294 ◽  
Author(s):  
Catharina Johanna Maria Philippart ◽  
Jolanda Martine van Iperen ◽  
Gerhard Cornelis Cadée ◽  
Alain François Zuur
Keyword(s):  
Chlorophyll A ◽  
Wadden Sea ◽  
Marine Ecosystem ◽  
Field Observations ◽  
Coastal Marine Ecosystem ◽  
Coastal Marine ◽  
Term Field

Subsoil investigation of ice lensing at the Calgary, Canada, frost heave test facility

1988 ◽  
Vol 25 (2) ◽  
pp. 307-319 ◽  
Author(s):  
L. E. Carlson ◽  
J. F. (Derick) Nixon
Keyword(s):  
Key Words ◽  
Potential Model ◽  
Frost Heave ◽  
Test Facility ◽  
Field Observations ◽  
Silty Soil ◽  
Temperature Environment ◽  
Segregation Potential ◽  
Control Section

Several frost heave mitigation modes were studied at the Calgary, Canada, chilled pipeline frost heave test facility. These included deeper burial (to increase the pressure on the frost front below the pipe) and replacement of the silty soil around the pipe with gravel for a noninsulated pipe. Frost heave at the deep-burial section and at the gravel section was less than the heave at a control section. Other pipe sections tested the effects of insulation of the pipe on the long-term frost heave, as well as the effects of replacing the silt around an insulated pipe with gravel. Summer thawing of the frost bulb around the insulated pipe results in seasonal thaw settlement of the pipe, thus reducing the long-term pipe heave, at least for the warmer ground temperature environment at the Calgary facility.Thermal simulations of the frost bulb growth and predictions of frost heave using the segregation potential model agree well with the observations.Recent excavation of two frost bulbs in silty soil led to field observations of the interior of the frost bulbs, and subsequent laboratory analysis of frost bulb samples. Ice distribution was logged and photographed following excavation of each frost bulb. Key words: frost heave, pipeline, silt, mitigation, instrumentation, field observations.

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