Analysis of radionuclide migration with consideration of spatial and temporal change of migration parameters due to uplift and denudation

2015 ◽  
Vol 1744 ◽  
pp. 229-234
Author(s):  
Taro Shimada ◽  
Seiji Takeda ◽  
Masayuki Mukai ◽  
Masahiro Munakata ◽  
Tadao Tanaka
Keyword(s):  
Ground Water ◽  
Flow Velocity ◽  
Safety Assessment ◽  
Ground Surface ◽  
Disposal Site ◽  
Radionuclide Migration ◽  
Water Flow Velocity ◽  
Term Change ◽  
Hydraulic Conditions

ABSTRACTIntegrated safety assessment methodology that analyzes radionuclide migration reflecting the spatial and temporal changes of disposal systems was developed for a geological disposal site with uplift and denudation, and then some case analyses for an assumed site were carried out. The combination of uniform uplift and denudation has the largest effect on the radionuclide migration because the ground water flow velocity increases with decreasing depth from the ground surface. In the case without denudation, tilted uplift has more effect than uniform uplift because flow velocity in tilted uplift increases with increasing hydraulic gradient. The long-term change of the geological structures including the uplift and denudation, the hydraulic conditions, and the recharge and outlet of the ground water around a candidate site should be carefully investigated to determine the appropriate the place, depth and layout of the repository.

Temporal changes of groundwater pressure in a natural slope of nonfissured clay

1984 ◽  
Vol 21 (1) ◽  
pp. 138-146 ◽  
Author(s):  
T. C. Kenney ◽  
K. C. Lau
Keyword(s):  
Safety Factor ◽  
Soft Clay ◽  
Ground Surface ◽  
Field Measurements ◽  
Test Site ◽  
Field Investigation ◽  
Direct Result ◽  
Natural Slope ◽  
Hydraulic Conditions

This paper presents results from a field investigation in which groundwater pressures were measured in a natural slope of soft clay over a 10 year period. Measurements of piezometric levels are reported together with calculated annual changes of safety factor of the slope.Using consolidation theory, predictions were made of changes of piezometric levels for the condition of zero infiltration based on the postulate that these changes were the direct result of changes of hydraulic conditions at the ground surface. The predictions were in agreement with the field measurements.A method is suggested for estimating the most severe groundwater pressures that a clay slope can be expected to experience. Using this method, estimates were made of the minimum expected value of safety factor of the slope at the test site. Keywords: natural slope, clay, pore pressures, field measurements, stability, long-term.

scholarly journals Peculiarities of Long-Term Changes in Air Temperatures Near the Ground Surface in the Central Baltic Coastal Area

Climate ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 22
Author(s):  
Agu Eensaar
Keyword(s):  
Air Temperature ◽  
Coastal Area ◽  
Ground Surface ◽  
Significance Level ◽  
Frequency Distributions ◽  
Saint Petersburg ◽  
Monthly Average ◽  
Air Temperatures ◽  
Term Change

The peculiarities of the long-term change of the annual and monthly average air temperatures until 2017 in five cities of the coastal area of the Central Baltic region—Stockholm, Tallinn, Riga, Helsinki, and Saint Petersburg—were studied. The anomalies of the annual and monthly average air temperatures in relation to the average characteristics 1961–1990 were analyzed. The trends in the air temperature changes during 1980–2017, which come to 0.5 °C per ten years, have been found in the cities of the Central Baltic coastal area. The average air temperature in the Central Baltic cities has grown faster than the global and northern hemisphere. For the longer period of 1850–2017, the average annual rise of air temperature was within the range of 0.1 °C per ten years. The rise in temperature in different months is different, and the rise of the of the average temperature in the summer period has not occurred (at a significance level of 0.05). With the analysis of the frequency distributions of the average annual air temperatures and Welch’s t-test, it is demonstrated that the air temperature (at a significance level of 0.05) has risen in all the months only in Saint Petersburg during 1901–2017 in comparison to the 19th century. There has been no reliable rise of the air temperature during the century in February and from June to September in Riga, from June to October in Helsinki, from June to September in Stockholm, and in August and September in Tallinn. It was found that the average air temperature trends have a certain annual course. The air temperature has risen most in March and April, reaching 0.09 °C (Stockholm, Tallinn) up to 0.23 °C (Saint Petersburg) per ten years. From June to September, the rise of air temperature is considerably lower, remaining below 0.04 °C per ten years. The changes in air temperature are small during the summer and mid-winter; the air temperature has significantly risen in autumn and spring.

Vivid Imagers Are Better at Detecting Salient Changes

2006 ◽  
Vol 27 (4) ◽  
pp. 218-228 ◽  
Author(s):  
Paul Rodway ◽  
Karen Gillies ◽  
Astrid Schepman
Keyword(s):  
Individual Differences ◽  
Change Detection ◽  
Visual Imagery ◽  
Detection Task ◽  
Level Of Detail ◽  
Detection Accuracy ◽  
Change Detection Task ◽  
Term Change ◽  
High Level

This study examined whether individual differences in the vividness of visual imagery influenced performance on a novel long-term change detection task. Participants were presented with a sequence of pictures, with each picture and its title displayed for 17  s, and then presented with changed or unchanged versions of those pictures and asked to detect whether the picture had been changed. Cuing the retrieval of the picture's image, by presenting the picture's title before the arrival of the changed picture, facilitated change detection accuracy. This suggests that the retrieval of the picture's representation immunizes it against overwriting by the arrival of the changed picture. The high and low vividness participants did not differ in overall levels of change detection accuracy. However, in replication of Gur and Hilgard (1975) , high vividness participants were significantly more accurate at detecting salient changes to pictures compared to low vividness participants. The results suggest that vivid images are not characterised by a high level of detail and that vivid imagery enhances memory for the salient aspects of a scene but not all of the details of a scene. Possible causes of this difference, and how they may lead to an understanding of individual differences in change detection, are considered.

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