Skip navigation.
Home
Enlightening Research

resistivity inversion

Getting started with 2D resistivity interpretation using RES2DINV

Presentation, embedded below was developed to bring users up to speed in interpretation of their resistivity data. Class for end users was conducted in Indonesia and included training on field data collection with SibER-48 using ~ 900 m long profile in Wenner-Schlumberger and pole-dipole (remote electrode) 2D tomography. On the second day users received hands-on instructions on data import into RES2DINV software, quality assurance of the data based on visual approach as well as through RMS of the interpretation model. 

General discussion about non-uniquness of the subsurface interpretation modl for 1D, 2D, and 3D representations has followed this class. 

Slides can be viewed on http://www.slideshare.net/LarisaGolovko/training-on-res2dinv-and-siber48

Sign up for webinar "Application of Geophysical Methods to Agriculture: Methods Employed"

Dr. Larisa Golovko (President of Landviser, LLC) will be presenting "Geophysical Methods of Electrical Resistivity and Self-Potential in Agriculture" in first of 

 

 

Agricultural Geophysics Webinar Series: "Application of Geophysical Methods to Agriculture: Methods Employed"

A live webinar on the application of geophysics to agriculture will be offered on:

Tuesday, February 18, 2014, from 3pm - 4:30pm EST
(2:00 - 3:30 CST, 1:00 - 2:30 MST, 12:00 - 1:30 PST)

This first in a series of agricultural geophysics webinars will focus on the near-surface geophysical methods presently being used for agricultural purposes, which include resistivity, self-potential, electromagnetic induction, ground penetrating radar, dielectric sensors, VIS/NIR/MIR spectrometry, gamma ray spectrometry, mechanical soil compaction sensors, and ion selective potentiometry. Five presenters will provide a short overview of agricultural geophysical methods during the first 30 minutes of the webinar. The last hour of the webinar will be devoted to a panel discussion with the presenters, who will answer questions from the audience.

Location

28° 8' 11.7564" N, 90° 50' 5.8596" W

Evaluating cultivation level of sandy soils in European Russia with electro-geophysical methods

Electrical resistivity vs cultivation degree of sandy soils Update: Full PDF of the paper is now available!

Electrical resistivity of cultivated sandy soils of humid areas is a complex characteristic based on three fundamental properties of soil matrix, such as soil texture, total organic matter (carbon content) and cation exchange capacity (CEC). Relationship of electrical resistivity (ER) with those properties has been approximated with exponential equation ER=a*exp(-b*x), where x is any of the properties above. The correlation coefficients for ER as function of CEC, texture, or organic matter were between 0.82 and 0.91 for the soils of Klin-Dmitrov watershed near Moscow and Kirov, which suggests their applicability for other humid areas. We present a new approach to approximate exponential relationship ER=a*exp(b*x) with a linear “piece-wise” function based on the age of cultivation for each field.This approach was used to develop management zones based on ER to separate uniform areas of similar organic matter, CEC and clay content. Those basic properties are the foundation of soil fertility in humid areas. They influence biomass and bioactivity of soil microorganisms, thus the exponential relationship between ER and soil microorganisms was also observed. The approach based of electrical resistivity or conductivity was used to evaluate fertility and degree of cultivation of sandy soils in humid areas and for detail soil mapping and delineation of management zones in adaptive precision agriculture. The field and laboratory electrical geophysical methods are recommended for quick and accurate soil mapping and management in sustainable farming.

*at SAGEEP 2013, March 17-21 in Denver, CO, Larisa Golovko, Ph.D. will also present "Basic Theory of Measuring Electrical Resistivity, Conductivity and Self-Potential in Soils and Plants" with LandMapper ERM-02 and other commercially available geophysical equipment at post-conference workshop "Agricultural Geophysics: Theory and Methods".
SAGEEP 2013 logo
Cite this presentation as:

Anatoly Pozdnyakov, P.I. Eliseev, Larisa Golovko, Lev A. Pozdnyakov, Maria S. Dubrova, and E.P. Makarova. “Evaluating Cultivation Level of Sandy Soils in European Russia with Electro-geophysical Methods.” In New Views of the Earth. Denver, CO: Environmental and Engineering Geophysical Society, 2013. http://www.eegs.org/AnnualMeetingSAGEEP/SAGEEP2013/SessionsAbstracts.aspx

 

Locations

Denver 39° 44' 15.2412" N, 104° 59' 4.9848" W
Klin, MOS 56° 19' 18.5304" N, 36° 42' 30.8772" E
KIR 58° 36' 16.8984" N, 49° 39' 58.5504" E

Cenozoic Shale Formations as a New Frontier Area - detecting shallow natural gas fields

methane emission on peat bogGuest post by Dr. Leonid Anisimov, Principal Scientist of Lukoil-Engineering, Volgograd, Russia. VolgogradNIPImorneft – scientific center of the LUKOIL Oil Company for the South Volga, Caspian Region and Middle East.

Shalow gas accumulations in shale deposits are unconventional energy resources. However those are hazardous objects for drilling especially in the offshore areas.
Seismic is a principal instrument to detect shallow gas pockets but electromagnetic methods may have advantage. The presentation below shows principal geography and techniques for detection and development of shale gas fields. A pilot project of Landviser LLC in using VES for monitoring accumulation and release of methan in peat bogs of Eastern Siberia is attached.

Locations

Houston 29° 45' 36.6948" N, 95° 22' 9.804" W
56° 52' 40.7964" N, 60° 55' 48.6336" E
43° 46' 4.5048" N, 11° 15' 8.5644" E

Formatting Array Input Data File in RES2DINV: surface electrodes for any geometry

pseudosection for 2D resistivity surveys

Example of electrodes arrangement and measurement sequence that can be used for a 2-D electrical imaging survey is shown on the left. Many different multi-electrode systems have been developed over the past 15 years using different arrangements of the cables and measurement strategies (Loke, 2011). This program is designed to invert large data sets (with about 200 to 100000 data points) collected with a system with a large number of electrodes (about 25 to 16000 electrodes). The survey is usually carried out with a system where the electrodes are arranged along a line with a constant spacing between adjacent electrodes. However, the program can also handle data sets with a non-uniform electrode spacing. RES2DINV program can be used for surveys using the Wenner, pole-pole, dipole-dipole, pole-dipole, Wenner-Schlumberger, gradient and equatorial dipole-dipole (rectangular) arrays. In addition to these common arrays, the program even supports non-conventional arrays with an almost unlimited number of possible electrode configurations (Loke et al. 2010). You can process pseudo sections with up to 16000 electrode positions and 70000 data points at a single time on a computer with 4 gigabytes (GB) of RAM. Besides normal surveys carried out with the electrodes on the ground surface, the program also supports aquatic and cross-borehole surveys.

Locations

Los Angelos 34° 3' 8.0424" N, 118° 14' 37.266" W
5° 49' 22.6488" S, 34° 58' 49.6884" E

Vertical Electrical Sounding to detect peat deposit thickness and drying depth

VES to detect peat deposit depthThe valley landscapes of humid areas are dominated with peat soils of various origins, which become the most productive soils after the proper drainage and cultivation. The high fertility and proximity to water make peat soils the most desirable for vegetable production. However, these soils are also subject to quick degradation during agricultural usage. Excess drainage increases the unproductive decomposition and mineralization of peat and can cause spontaneous ignition of peat soils, whereas little or no drainage can be non-sufficient for normal agricultural practices. Therefore, drainage design and the following agriculture practice on peat soils should be based on careful studies of the peat soil genesis and hydrology of the areas.

 Method VES is suitable for detection the resistivity in different soil and geological strata without digging or boring. Usually, peat shows not much difference in electrical properties along the profile. Water content of cultivated peat soils is close to the field capacity during the whole growing season.

1D Vertical Electrical Sounding (VES) with LandMapper Procedure

standard big manual VES cable set by LandviserThe technique and procedure described here can be performed with LandMapper ERM-01 or ERM-02 (set in resistivity mode). The electrode spacings provided in this example are identical to Landviser's supplied "big manual VES" cable set made to measure 16 layers of topsoil down to approximately 9 m. The worksheet for pre-set electrode spacings in such cable re-calculating measured resistivities to 1D VES profile can be downloaded as Manual 1D VES workbook (MS Excel format).

Other electrode spacings are possible for custom-made cable arrays to reach deeper profiles. For example, we developed and tested with LandMapper a 60m-long cable, measuring down to ~ 20 m for one custom hydrology project

This manual VES technique is most convenient to use with three people. Follow step-by-step instructions below. If you need further help, do not hesitate to contact Landviser, LLC @ +1-609-412-0555 or info@landviser.com. Register on our site and download 7 related publications and software!

Locations

San Antonio 29° 25' 26.8392" N, 98° 29' 37.0608" W
Dmitrov 56° 20' 39.0192" N, 37° 31' 2.5716" E

Evaluation of stone contents in soils with electrical geophysical methods to aid orchard planning

VES of stony soils in Crimea

Establishments of orchards and vineyards are long-term and money-intensive, but highly pay-off projects. This study allowed developing procedure for incorporating geophysical survey data into recommendations of usage skeletal soils under orchards. Geophysical methods of electrical resistivity, such as VES and four-electrode profiling provided the information about spatial distributions of stones in skeletal soils.  The resistivity of rocks or stones is much higher (about 104-1012 ohm m) than the resistivity of soil horizons with any texture. Therefore, high resistivity will indicate the presence of stones in soil profiles.

Study was conducted on skeletal soils (Paleoxerolls and Lithic Xerorthents) formed on carbonate-cemented marine deposit, limestone, or pebbles of alluvial origin in western part of Crimea Peninsula, Ukraine. The stone content varied from 2 to 90% of fragments coarse than 2 mm by volume and stony layers occurred in soil profiles at the depth as shallow as 12 cm.

Location

Saky

Vertical Electrical Sounding and Self-Potential Methods to Survey for Placement of Potable Water Wells

Science of Geophysics vs Art of DowsingWater is a precious commodity  in most urban and rural areas. Luck of local  potable  water sources threatens not only thriving but a mere survival of rural communities all over the world.  Establishing potable water wells requires a lot of fundings and resources and often cost prohibitive for local governments in South America and Africa.

Searching for shallow groundwater require knowledge of subsurface layers and locating intensity and directions of water fluxes, which can be accomplished with geophysical methods of vertical electrical sounding (VES) and self-potential (SP).  A method of VES can distinguish differences in electrical resistivity or conductivity at the multiple (10+) layers in soil profiles. These differences reveal the changes in soil texture and structure  between water-bearing and waterproof  layers,  which form a framework for  the subsurface water fluxes. 

The directions and intensities of the fluxes  can then be evaluated with the self-potential method. However, conventional equipment for VES and SP is very expensive, bulky and complicated to operate. We tested a simple low-cost handheld device, LandMapper ERM-02, to evaluate layers in the ground with VES method and results were well  correlated with drilled profiles in Central TX.  Information is provided for the VES array assembly, field measuring procedure and interpretation of sounding results. Previously, device was used in Astrakhan area, Russia for estimation of the groundwater table and salinity layers in the soil profiles. The method of self-potential was used to estimate subsurface water flux directions and intensities through the measured variation in electrical potential on the soil surface and direct potable wells placement in Kiev, Urkaine and Dmitrov, Russia.

Cite this presentation:SAGEEP 25 - 2012 - Tucson, AZ
 
Golovko, Larisa, Anatoly Pozdnyakov, and Terry Waller. “A Vertical Electrical Sounding and Self-Potential Methods to Survey for Placement of Potable Water Wells.” In Making Waves: Geophysical Innovations for a Thirsty World. Tucson  AZ: Environmental and Engineering Geophysical Society, 2012. http://www.landviser.net/webfm_send/89

Locations

Water For All International San Angelo, TX 31° 27' 49.5792" N, 100° 26' 13.3368" W
SAGEEP 2012 Tucson, AZ 32° 13' 18.2748" N, 110° 55' 35.3244" W

RES3DINV - 3D inversion geophysical software for resistivity and induced polarization data

RES3DINV software -Create 3D models of subsurface resistivity or IP!
For Windows XP/Vista/7  (available for 32- and 64-bit PCs.)

3D surveys for pole-pole, pole-dipole, dipole-dipole, rectangular, trapezoid, Wenner, Wenner-Schlumberger,and non-conventional arrays.

Now available as a combined package together with RES2DINV, the 2D Resistivity & IP inversion program.
Supports exact and approximate least-squares optimisation methods
Supports smooth and sharp constrasts inversions
Supports up to 5041 electrodes and 67500 data points on computers with 1GB RAM
Supports trapezoidal survey grids
Supports parallel calculations on Pentium 4 (and compatible) based computers
Multi-core support with RES3DINVx32, 128GB memory support with RES3DINVx64

Syndicate content