[ai-geostats] problem of spatial continuity of groundwater head
Title: problem of spatial continuity of groundwater head Hello list, A few days ago I had a discussion about spatial continuity of hydraulic heads and the following question: Is it allowed to use a krging technique for this variable? First Opinion: there are different processes which influence the groundwater heads, e.g.: - gravity (hydraulic gradient) - grounwater recharge - anthropogenic influence (pumping/injection) So there is a global trend which is overlayed from different additional trends like groundwater recharge and anthropogenic influence (pumping/injection) and you can´t seperate these processes. These are the reasons that you get problems with the ergodicity and it is not possible to use kriging techniques, because you haven´t a spatial continuity which is based on one process. Second Opinion: There is a basic process for the groundwater heads (the movement based on the Darcy law and that´s it) . There exist a global trend (but you can handle it with Universal kriging) and the differences depend on the other processes maybe give you another trend by large scale problems (and then you have problems with the ergodicity and have to use moving window statistics to divide you working area). So you have a spatial continuity which is not necesseraly influenced by problems with ergodicity and you can use kriging techniques. Maybe the anthropogenic influence could be a process which disturb the spatial continuity. I know it´s quite a hydrogeology problem but anyway I would like to hear your opinion or experiences on that topic. Looking forward to the answers, Kai Dipl. Kai Zoßeder Bayerisches Geologisches Landesamt Heßstr. 128 D-80797 München Tel.: 089-9214 2655 http://www.bayern.de/gla http://www.bis.bayern.de * By using the ai-geostats mailing list you agree to follow its rules ( see http://www.ai-geostats.org/help_ai-geostats.htm ) * To unsubscribe to ai-geostats, send the following in the subject or in the body (plain text format) of an email message to [EMAIL PROTECTED] Signoff ai-geostats
RE: [ai-geostats] problem of spatial continuity of groundwater head
Title: problem of spatial continuity of groundwater head Kai There has been some work in this area there are some references at the Ecole des Mines, Centre de Geostatistique website see the papers by Anne Dong and Chris Roth to start with http://www.bib.ensmp.fr/cgi-bin/pubinterro?mots=geostatistique Not all of these are published outside the center - but some are .for example Anne's 1988 paper (in English) was in the Avignon Geostats Conference and the reference is given at the site above Interesting area ...good luck! Regards Colin -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Tue 11/23/2004 12:16 PM To: [EMAIL PROTECTED] Cc: Subject: [ai-geostats] problem of spatial continuity of groundwater head Hello list, A few days ago I had a discussion about spatial continuity of hydraulic heads and the following question: Is it allowed to use a krging technique for this variable? First Opinion: there are different processes which influence the groundwater heads, e.g.: - gravity (hydraulic gradient) - grounwater recharge - anthropogenic influence (pumping/injection) So there is a global trend which is overlayed from different additional trends like groundwater recharge and anthropogenic influence (pumping/injection) and you canÂt seperate these processes. These are the reasons that you get problems with the ergodicity and it is not possible to use kriging techniques, because you havenÂt a spatial continuity which is based on one process. Second Opinion: There is a basic process for the groundwater heads (the movement based on the Darcy law and thatÂs it) . There exist a global trend (but you can handle it with Universal kriging) and the differences depend on the other processes maybe give you another trend by large scale problems (and then you have problems with the ergodicity and have to use moving window statistics to divide you working area). So you have a spatial continuity which is not necesseraly influenced by problems with ergodicity and you can use kriging techniques. Maybe the anthropogenic influence could be a process which disturb the spatial continuity. I know itÂs quite a hydrogeology problem but anyway I would like to hear your opinion or experiences on that topic. Looking forward to the answers, Kai Dipl. Kai ZoÃeder Bayerisches Geologisches Landesamt HeÃstr. 128 D-80797 MÃnchen Tel.: 089-9214 2655 http://www.bayern.de/gla http://www.bis.bayern.de DISCLAIMER: This message contains information that may be privileged or confidential and is the property of the Roxar Group. It is intended only for the person to whom it is addressed. If you are not the intended recipient, you are not authorised to read, print, retain, copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message. * By using the ai-geostats mailing list you agree to follow its rules ( see http://www.ai-geostats.org/help_ai-geostats.htm ) * To unsubscribe to ai-geostats, send the following in the subject or in the body (plain text format) of an email message to [EMAIL PROTECTED] Signoff ai-geostats
Re: [ai-geostats] problem of spatial continuity of groundwater head
Kai I would suggest you take a look at: Introduction to Geostatistics: Applications in Hydrogeology (Stanford-Cambridge Program) P. K. Kitanidis which is a great base to work from. Isobel http:///geoecosse.bizland.com * By using the ai-geostats mailing list you agree to follow its rules ( see http://www.ai-geostats.org/help_ai-geostats.htm ) * To unsubscribe to ai-geostats, send the following in the subject or in the body (plain text format) of an email message to [EMAIL PROTECTED] Signoff ai-geostats
[ai-geostats] CONFERENCE: EGU '05 Wavelet & time-frequency session
Apologies for any cross-posting - __ Dear Colleague, The purpose of this message is to announce a session at the European Geophysical Union meeting in Vienna, 24--29 April 2005, entitled "Wavelet and time-frequency analysis in the earth sciences" The session is being organized by J.M. Lilly and S.C. Olhede. A detailed description of the session, preliminary list of solicited speakers, and some additional information are provided below. Wavelet analysis and related approaches provide powerful new tools for attacking problems involving statistical nonstationarity and coherent structures, both in time series and in two or three dimensional fields. Our goal is to bring together researchers involved with the development of new mathematical and statistical methods with others whose interests require, and provide the impetus for, such new approaches. We would like to encourage colleagues in either of these two categories to submit abstracts. Abstract submission is now open, with a deadline of January 21, about two months from now. Please feel free to forward this to other interested researchers. Sincerely, Jonathan Lilly <[EMAIL PROTECTED]>, Universite Pierre et Marie Curie Sofia Olhede <[EMAIL PROTECTED]>, Imperial College London ** Preliminary List of Solicited Speakers Marie Farge Ecole Normale Superieure de Paris Patrick Flandrin Ecole Normale Superieure de Lyon Alfred Hanssen** University of Tromso Matthias Holschneider Universitat Potsdam Frederik J. Simons** University College London Andrew T. Walden** Imperial College London [** = member of scientific organizing committee] ** Session information for NP4.05 Wavelet and time-frequency analysis in the earth sciences Convener: J.M. Lilly Co-convener: S.C. Olhede Programme: Nonlinear Processes in Geophysics Many natural processes of great interest are neither periodic nor stationary. Wavelet and time-frequency (or time-scale) analysis therefore holds much potential for earth scientists. Despite the vast array of new methods which have emerged over the past decade, there is substantial scope for broader application of these methods to real-world problems, as well as for the development of further mathematical tools to address outstanding physical questions. The purpose of this session is to survey the most promising methods for the earth sciences, and to highlight specific examples of practical applications. Several areas of special interest are: --- nonstationary stochastic modelling --- extraction of signals immersed in noise --- wavelet decompositions in two and three dimensions --- multiple-window methods. Statistical considerations are particularly encouraged. ** Additional information Details on the Vienna EGU 2005 meeting are available online at http://www.copernicus.org/EGU/ga/egu05/ Information for this session (NP 4.05) is found by following the "Call for papers Programme" link followed by "Nonlinear Processes in Geophysics". Abstract submission is then handled online from this location. Do not hesitate to contact us ([EMAIL PROTECTED] or [EMAIL PROTECTED]) with any questions. * Jonathan Lilly [EMAIL PROTECTED] Université Pierre et Marie Curie Tel: 33 1 44 27 49 69 Tour 45/55, 5 ème étage, boîte 100 Fax: 33 1 44 27 38 05 4 place Jussieu US Fax: (530) 678-5835 75252 Paris cedex 05 * Sofia Olhede [EMAIL PROTECTED] Imperial College London Tel: 44 20 75 94 85 68 Department of Mathematics South Kensington Campus London SW7 2AZ UK * By using the ai-geostats mailing list you agree to follow its rules ( see http://www.ai-geostats.org/help_ai-geostats.htm ) * To unsubscribe to ai-geostats, send the following in the subject or in the body (plain text format) of an email message to [EMAIL PROTECTED] Signoff ai-geostats
[ai-geostats] Spatial Neighborhood Weighting Matrix for Lattice data
Group: I have an idea for designing a flexible weighting matrix for my county level data. In many of the texts on lattice analysis, I have found or rather not found any standard techniques of defining a neighborhood for irregular lattices. In regular lattices we have Rook, Queen, Bishop, etc. configurations. My thought is: given a spatial weight matrix, for example 0 1 0 0.5 X 0.5 0 1 0 Where the weighting is different horizontally than vertically. Can an adaptive weighting matrix be made that switches the direction of main weights (say 1) and minimum weights (say 0.5), based on a property of location X? For instance, looking at counties for a given state. Say each county has a main road traveling through it at some direction. I would assume the county to county influence would be aligned with the road. So take two counties A and B; A has a main road running north to south and B has a main road running east and west, can I build a weighting scheme that For A 0 1 0 0.5 X 0.5 0 1 0 For B 0 0.5 0 1 X 1 0 0.5 0 Where the weighting scheme is dependent on the direction of the main road? Who you think this violates the idea of translation invariance? Dean Monroe OSU Environmental Sciences * By using the ai-geostats mailing list you agree to follow its rules ( see http://www.ai-geostats.org/help_ai-geostats.htm ) * To unsubscribe to ai-geostats, send the following in the subject or in the body (plain text format) of an email message to [EMAIL PROTECTED] Signoff ai-geostats
[ai-geostats] Spatial Neighborhood Weighting Matrix for Lattice data
Group: I have an idea for designing a flexible weighting matrix for my county level data. In many of the texts on lattice analysis, I have found or rather not found any standard techniques of defining a neighborhood for irregular lattices. In regular lattices we have Rook, Queen, Bishop, etc. configurations. My thought is: given a spatial weight matrix, for example 0 1 0 0.5 X 0.5 0 1 0 Where the weighting is different horizontally than vertically. Can an adaptive weighting matrix be made that switches the direction of main weights (say 1) and minimum weights (say 0.5), based on a property of location X? For instance, looking at counties for a given state. Say each county has a main road traveling through it at some direction. I would assume the county to county influence would be aligned with the road. So take two counties A and B; A has a main road running north to south and B has a main road running east and west, can I build a weighting scheme that For A 0 1 0 0.5 X 0.5 0 1 0 For B 0 0.5 0 1 X 1 0 0.5 0 Where the weighting scheme is dependent on the direction of the main road? Who you think this violates the idea of translation invariance? Dean Monroe OSU Environmental Sciences * By using the ai-geostats mailing list you agree to follow its rules ( see http://www.ai-geostats.org/help_ai-geostats.htm ) * To unsubscribe to ai-geostats, send the following in the subject or in the body (plain text format) of an email message to [EMAIL PROTECTED] Signoff ai-geostats
