MARC details
| 000 -LEADER |
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| fixed length control field |
03950nam a2200253Ia 4500 |
| 003 - CONTROL NUMBER IDENTIFIER |
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| control field |
MX-MdCICY |
| 005 - DATE AND TIME OF LATEST TRANSACTION |
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| control field |
20250625162501.0 |
| 040 ## - CATALOGING SOURCE |
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| Transcribing agency |
CICY |
| 090 ## - LOCALLY ASSIGNED LC-TYPE CALL NUMBER (OCLC); LOCAL CALL NUMBER (RLIN) |
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| Classification number (OCLC) (R) ; Classification number, CALL (RLIN) (NR) |
B-21093 |
| 008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION |
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| fixed length control field |
250602s9999 xx |||||s2 |||| ||und|d |
| 245 10 - TITLE STATEMENT |
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| Title |
The impact of hydrochemical boundary conditions on the evolution of limestone karst aquifers |
| 490 0# - SERIES STATEMENT |
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| Volume/sequential designation |
Journal of Hydrology, 276(1-4), p.240-253, 2003 |
| 520 3# - SUMMARY, ETC. |
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| Summary, etc. |
The early evolution of karst aquifers depends on a manifold of initial and boundary conditions such as geological setting, hydrologic properties of the initial aquifer, and petrologic properties of the rock. When all water entering at various inputs into the aquifer has equal chemical composition with respect to the system H2O-CO2-CaCO3 early evolution under conditions of constant head exhibits breakthrough (BT)behaviour. If the chemical compositions of the input waters are different, deep in the aquifer where the saturated solutions mix renewed aggressiveness occurs, and additional dissolutional widening of fractures by mixing corrosion (MC)changes the hydrologic properties of the aquifer. To study the impact of MC on the evolution of karst we have modelled a simple karst aquifer consisting of a confined limestone bed, with two symmetrically located inputs at constant head and open flow conditions along the entire width at base level. To calculate dissolutional widening of the fractures the well-known dissolution kinetics of limestone was used, which is linear up to 90 percent of saturation with respect to calcite and then switches to a nonlinear fourth order rate law. First, two extremes are modelled: (a)Both inputs receive aggressive water of equal chemical composition with [Ca2+]=0.75[Ca2+]eq. In this case two channels migrate downstream with that from one input more competitive and reaching base level first, causing BT. (b)Water at both inputs is saturated with respect to calcite, but in equilibrium with different partial pressures of CO2. Therefore, dissolution widening can occur only where these waters mix. A central channel starts to grow extending down-head until base level is reached. Flow rates through the aquifer first rise and become constant after the channel has reached base level. In the following runs these two extreme modes of karstification are combined. The waters entering have different chemical compositions and therefore different equilibrium concentrations [Ca2+]eq. This allows MC to be active. They are also undersaturated with the inflowing solutions at concentration [Ca2+]in=f[Ca2+]eq where f is the ratio of saturation. In comparison to the extreme limit (a)the action of MC now creates permeability where the solutions mix and diverts the evolution of conduits into this region. Finally one conduit reaches base level and causes BT. This behaviour is found for f=0.7, 0.9, and 0.96. For solutions more close to equilibrium with respect to calcite (f=0.99, 0.9925, and 0.995)BT behaviour is replaced by a steady increase in flow rates. In the early state as in the case of MC controlled evolution (case b)a central channel not connected to the input is created by MC and reaches base level. After this event, further increase in flow rates is caused by slow dissolutional widening by the slightly undersaturated input solutions flowing towards the central channel. Comparison of the various model aquifers at termination of the computer runs reveals significant differences in their properties caused solely by changes of the hydrochemical boundary conditions. |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
KARST HYDROLOGY |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
KARSTIFICATION |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
HYDROCHEMISTRY |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
MODELLING |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
MIXING CORROSION |
| 700 12 - ADDED ENTRY--PERSONAL NAME |
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| Personal name |
Romanov, D. |
| 700 12 - ADDED ENTRY--PERSONAL NAME |
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| Personal name |
Gabrovsek, F. |
| 700 12 - ADDED ENTRY--PERSONAL NAME |
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| Personal name |
Dreybrodt, W. |
| 856 40 - ELECTRONIC LOCATION AND ACCESS |
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| Uniform Resource Identifier |
<a href="https://drive.google.com/open?id=1-xMMjPbRDkEEwYTgUM7pf-0-8w9ZEls_&usp=drive_copy">https://drive.google.com/open?id=1-xMMjPbRDkEEwYTgUM7pf-0-8w9ZEls_&usp=drive_copy</a> |
| Public note |
Para ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) |
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| Source of classification or shelving scheme |
Clasificación local |
| Koha item type |
Documentos solicitados |
