Skip navigation.
Home
Enlightening Research

ER

Electrical resistivity, the inverse of conductivity. Ohm m is SI unit of measure. ER=1/EC

Applications of LandMapper handheld for near-surface soil surveys and beyond

LandMapper - fast, portable, versatile, affordableOn-the-go sensors, designed to measure soil electrical resistivity (ER) or electrical conductivity (EC) are vital for faster non-destructive soil mapping in precision agriculture, civil and environmental engineering, archaeology and other near-surface applications. Compared with electromagnetic methods and ground penetrating radar, methods of EC/ER measured with direct current and four-electrode probe have fewer limitations and were successfully applied on clayish and saline soils as well as on highly resistive stony and sandy soils. However, commercially available contact devices, which utilize a four-electrode principle, are bulky, very expensive, and can be used only on fallow fields. Multi-electrode ER-imaging systems applied in deep geophysical explorations are heavy, cumbersome and their use is usually cost-prohibited in many near-surface applications, such as forestry, archaeology, environmental site assessment and cleanup, and in agricultural surveys on farms growing perennial horticultural crops, vegetables, or turf-grass. In such applications there is a need for accurate, portable, low-cost device to quickly check resistivity of the ground on-a-spot, especially on the sites non-accessible with heavy machinery.

Four-electrode principle of EC/ER measurements

Our equipment utilizes well-known four-electrode principle to measure electrical resistivity or conductivity (Fig).

Locations

Jonesboro, AR 35° 50' 32.2692" N, 90° 42' 15.4044" W
Krasnoyarsk 56° 0' 38.8404" N, 92° 51' 9.99" E

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

LandMapper ERM-01 - simple handheld resistivity meter

Throw away your augers and soil samplers! Well, not quite... LandMapper® ERM-01 is new non invasive device, which will help you to map land parcels with contrasting soil properties within the fields quickly, non destructivelyand cost-efficiently.

Landmapper is an excellent tool for soil mapping required for environmental consulting, golf courses maintenance, construction services, farm management, new land development, and real-estate planning. It is a must have tool for forensic and archaeological investigators, even for serious treasure hunters. Using this non invasive device prior to soil sampling you can significantly reduce the amount of samples required and precisely design a sampling plan based on the site spatial variability.

LandMapper® ERM-01 measures electrical resistivity or conductivity of soils and related media for express non invasive mapping and monitoring of agricultural fields as well as construction and remediation sites. In a typical setting, a four-electrode probe is placed on the surface and an electrical resistivity value is read from the digital display. The device measures electrical resistivity in a surface layer of the depth from 2 cm down to 20 m, which is set by varying the size of a four-electrode probe. Measurements are based on well-known four-electrode principle, which allows to avoid influence of electrode contact potential on measured electrical conductivity or resistivity of the media and obtain accurate readings.  The field tests were performed by our customers in USA, Russia, China, Canada, Sweden, France, Germany, Iraq, Dubai, Brazil, Panama and many others.

RES2DINV - 2D Geophysical Inversion Software for Resistivity and Induced Polarization data

Supports on land, underwater and cross-borehole surveysRES2DINV with topography

Supports the Wenner (alpha,beta,gamma), Wenner-Schlumberger, pole-pole, pole-dipole, inline dipole-dipole, equatorial dipole-dipole, gradient and non-conventional arrays. 
Supports exact and approximate least-squares optimisation methods 
Supports smooth and sharp constrasts inversions 
Supports up to 16000 electrodes and 21000 data points on computers with 1GB RAM 
Seamless inversion of very long survey lines using sparse inversion techniques 
(RES2DINV only license includes limited used of RES3DINV 3D inversion program)

RES2DINV software is designed to interpolate and interpret field data of electrical geophysical prospecting (2D sounding) of electrical resistivity (conductivity) and induced polarization. The inversion of the resistivity and IP data is conducted by least-square method involving finite-element and finite-difference methods. The software can handle data from any electrode array, including Wenner (a, b, g), dipole-dipole, inline pole-dipole, pole-pole, Wenner-Schlumberger, equatorial pole-dipole and non-conventional arrays. Interpolate data from land, under water, and cross-borehole surveys. Easy data conversion from the most popular geophysical instruments including ABEM  Lund, Syskal, AGI, PASI, IRIS, SCITREX, etc.

Locations

Geotomo Software penang 5° 15' 47.6424" N, 100° 29' 4.6428" E
Landviser, LLC 29° 32' 17.2716" N, 95° 4' 28.9776" W

Electrical Geophysical Methods to Evaluate Soil Pollution from Gas and Oil Mining

transect across bitumen polluted soil and brune collectorElectrical geophysical methods were successfully used for exploration of gas and oil fields (Kalenev, 1970). However, the methods are not widely used for estimation of the soil pollution with petroleum products (Znamensky, 1980; Pozdnyakov et al., 1996a). The possibility of using the methods of electrical resistivity to evaluate the places of petroleum pollution or natural petroleum and gas deposits is based on highly different resistivities of soil and petroleum products. Petroleum and various products of petroleum manufacture, such as oil, gasoline, bitumen, and kerosene have very high electrical resistivity compared with soils. Electrical resistivity of petroleum varies from 104 to 1019 ohm m (Fedinsky, 1967), whereas resistivity of petroleum-saturated sand is much lower (2200 ohm m) (Znamensky, 1980), but is still higher than that of any non-polluted soil.

Soil pollution by the products of gas and petroleum mining was studied near Urengoi in northwest Siberia, Russia. The virgin soils, Glacic and Aquic Haplorthels, were extremely polluted with various by-products of petroleum extraction and manufacturing, such as bitumen, gasoline, kerosene, and mining brine solutions. The study area was thoroughly investigated with four-electrode profiling on 1.2-m array and vertical electrical sounding.

Location

Urengoj 65° 57' 27" N, 78° 23' 4.2" E

Electrical Geophysical Methods in Agriculture

Agriculture: a budding field in geophysicsMapping alluvial soils of humid areas with electrical geophysical methods: We tested the electrical geophysical methods of non-contact electrical profiling (NEP) and electrical profiling (EP) for mapping peat and mineral alluvial soils formed in the glacial valley of Yachroma river. More >>

Vertical Electrical Sounding to detect groundwater levels in arid areas: The approximate location of the groundwater table was estimated by a visual inspection of the VES curve. The AB/2 value with the sharp change to the low resistivity (3-20 ohm m) was selected from each VES profile...More >>

Evaluation of stone contents in soils with electrical geophysical methods to aid orchard planning: Geophysical methods of electrical resistivity, such as VES and four-electrode profiling provided the information about spatial distributions of stones in skeletal soils.  High resistivity will indicate the presence of stones in soil profiles. More >>

Application of the geophysical methods of electrical resistivity in precision farming:  One of the challenges facing the adoption of precision agriculture technology is the identification of productivity-related variability of soil properties accurately and cost-effectively. More >>

Syndicate content