scholarly journals Diagnostic Plots Applied to Well-Tests in Karst Systems

2014 ◽  
pp. 127-137
Author(s):  
Jean-Christophe Maréchal ◽  
Bernard Ladouche ◽  
Benoît Dewandel ◽  
Perrine Fleury ◽  
Nathalie Dörfliger
Keyword(s):  
Diagnostic Plots ◽  
Well Tests ◽  
Karst Systems

HUMAN INFLUENCED SEDIMENTS IN KARST SYSTEMS

2019 ◽  
Author(s):  
Ira D. Sasowsky ◽  
Keyword(s):  
Karst Systems

scholarly journals CO2 dynamics and heterogeneity in a cave atmosphere: role of ventilation patterns and airflow pathways

2021 ◽  
Author(s):  
Lovel Kukuljan ◽  
Franci Gabrovšek ◽  
Matthew D. Covington ◽  
Vanessa E. Johnston
Keyword(s):  
Temporal Variations ◽  
Observation Point ◽  
Spatially Distributed ◽  
Combined Action ◽  
Karst Systems ◽  
The Relationship ◽  
Co2 Dynamics ◽  
Global Carbon

AbstractUnderstanding the dynamics and distribution of CO2 in the subsurface atmosphere of carbonate karst massifs provides important insights into dissolution and precipitation processes, the role of karst systems in the global carbon cycle, and the use of speleothems for paleoclimate reconstructions. We discuss long-term microclimatic observations in a passage of Postojna Cave, Slovenia, focusing on high spatial and temporal variations of pCO2. We show (1) that the airflow through the massif is determined by the combined action of the chimney effect and external winds and (2) that the relationship between the direction of the airflow, the geometry of the airflow pathways, and the position of the observation point explains the observed variations of pCO2. Namely, in the terminal chamber of the passage, the pCO2 is low and uniform during updraft, when outside air flows to the site through a system of large open galleries. When the airflow reverses direction to downdraft, the chamber is fed by inlets with diverse flow rates and pCO2, which enter via small conduits and fractures embedded in a CO2-rich vadose zone. If the spatial distribution of inlets and outlets produces minimal mixing between low and high pCO2 inflows, high and persistent gradients in pCO2 are formed. Such is the case in the chamber, where vertical gradients of up to 1000 ppm/m are observed during downdraft. The results presented in this work provide new insights into the dynamics and composition of the subsurface atmosphere and demonstrate the importance of long-term and spatially distributed observations.

Diagnostic plots for departures from proportional hazards in cohort study data

1987 ◽  
Vol 40 ◽  
pp. 125S-132S ◽  
Author(s):  
David G. Clayton ◽  
John M. Kaldor
Keyword(s):  
Cohort Study ◽  
Proportional Hazards ◽  
Study Data ◽  
Diagnostic Plots
Sign in / Sign up

Export Citation Format

Share Document