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| Format: | Artículo científico |
| Langue: | en |
| Publié: |
Universitat de Barcelona
2004
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| Accès en ligne: | https://www.redalyc.org/articulo.oa?id=50520203 |
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- New technologies in groundwater exploration. Surface Nuclear Magnetic Resonance U. Yaramanci Ciencias de la Tierra Pore size Water content Ground water exploration Surface Nuclear Magnetic Resonance As groundwater becomes increasingly important for living and environment, techniques are asked for animproved exploration. The demand is not only to detect new groundwater resources but also to protect them.Geophysical techniques are the key to find groundwater. Combination of geophysical measurements with boreholesand borehole measurements help to describe groundwater systems and their dynamics. There are a numberof geophysical techniques based on the principles of geoelectrics, electromagnetics, seismics, gravity andmagnetics, which are used in exploration of geological structures in particular for the purpose of discoveringgeoresources. The special geological setting of groundwater systems, i.e. structure and material, makes it necessaryto adopt and modify existing geophysical techniques. A new discipline called hydrogeophysics has beenformed and is growing fast. Efforts for direct detection of groundwater led recently to a new technique: SurfaceNuclear Magnetic Resonance (SNMR). The principle of nuclear magnetic resonance, well known in physics,physical chemistry as well as in medicine, has successfully been adapted to assess the existence of groundwaterand the aquifer parameters. This technique allows for the first time detecting and assessing water directly byonly surface measurements allowing quantitative information about mobile water content as well as pore structureparameters leading to hydraulic conductivities. Function, results, interpretation, advantages and drawbacksof SNMR are reviewed in this paper showing the current state of art and developments. A comprehensive exampleof SNMR is presented with measurements conducted at the site of Nauen near Berlin. The site has Quaternaryaquifers with differing layering of sand and till. The results are very satisfying as aquifers down to 50 mdepth can be identified quite reliably. The water content is estimated with a high degree of accuracy and relaxationtimes allowed to derive hydraulic conductivities. Supplementary measurements with geoelectrics andradar made possible to complement and confirm the information achieved with SNMR as well as to apply ajoint multimethod approach to aquifer assessment. 2004 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50520203 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.2 Vol.2