Skip navigation.
Home
Enlightening Research

Geophysics

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

Soil Electrical Geophysics - public library @Zotero

Landviser maintains public library of publications related to "Soil Electrical Geophysics" on Zotero servers. You can view and browse that library below. PDFs of publications in public domain are attached to the respective listings in the library and are stored on this website. For most publications registration on Zotero or our website is not required, although we are strongly encourage you to register to gain access to all materials, receive timely updates and easily manage your own research library.

Using LandMapper to Monitor Soil Salinity and Mitigate Its Effects on Rice Production at US Gulf Coast

Landmapper - Portable and Scalable EC meterMost of the soils along US Gulf Coast are naturally slightly saline and some are waterlogged during much of the growing season. Naturally, those areas are used for rice production rotated with cattle grazing or hay growing. Soil salinity of those areas varies spatially and temporarily due to drought, hurricane-pushed sea water surges, micro-elevation within fields, variability of salinity levels in irrigation water. Monitoring soil and water salinity with conventional techniques of collecting soil samples by farmer and sending them to outside lab is costly and time-consuming. Such approach fails to provide timely advice to the farmer regarding crop selection pre-planting and mitigation inputs during the growing season. Several rice farms affected by Katrina and Ike hurricanes were monitored in 2006-2011 utilizing field soil EC meter, LandMapper ERM-02, consumer-grade GPS, and other common equipment available to a farmer. On six test fields EC values were recorded with LandMapper directly in the field at 30 locations in less than 45 min.

Cite this presentation:

Golovko, Larisa, and Anatoly Pozdnyakov. “Using LandMapper to Monitor Soil Salinity and Mitigate Its Effects on Rice Production at US Gulf Coast.” In Making Waves: Geophysical Innovations for a Thirsty World. Tucson  AZ: Environmental and Engineering Geophysical Society, 2012. http://www.landviser.net/webfm_send/94.SAGEEP 25 - 2012 - Tucson, AZ

Registered users can download full proceeding paper: 
 

Using LandMapper to Monitor Soil Salinity and Mitigate Its Effects on Rice Production at US Gulf Coast

Locations

Winnie, TX 29° 49' 12.7956" N, 94° 23' 2.6808" W
SAGEEP 2012 Tucson, AZ 32° 13' 18.2748" N, 110° 55' 35.3244" W

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

ELECTRICAL POTENTIAL (Self-Potential) MEASUREMENTS with LandMapper ERM-02

Self-potential map to detect directions of water fluxes, KievThe self-potential (SP) method was used by Fox as early as 1830 on sulphide veins in a Cornish mine, but the systematic use of the SP and electrical resistivity methods in conventional geophysics dates from about 1920 (Parasnis, 1997). The SP method is based on measuring the natural potential differences, which generally exist between any two points on the ground. These potentials are associated with electrical currents in the soil. Large potentials are generally observed over sulphide and graphite ore bodies, graphitic shale, magnetite, galena, and other electronically highly conducting minerals (usually negative). However, SP anomalies are greatly affected by local geological and topographical conditions. These effects are considered in exploration geophysics as “noise”. The electrical potential anomalies over the highly conducting rock are usually overcome these environmental “noise”, thus, the natural electrical potentials existing in soils are usually not considered in conventional geophysics.

LandMapper ERM-02, equipped with proper non-polarizing electrodes, can be used to measure such “noise” electrical potentials created in soils due to soil-forming process and water/ion movements. The electrical potentials in soils, clays, marls, and other water-saturated and unsaturated sediments can be explained by such phenomena as ionic layers, electro-filtration, pH differences, and electro-osmosis.

Another possible environmental and engineering application of self-potential method is to study subsurface water movement. Measurements of electro-filtration potentials or streaming potentials have been used in USSR to detect water leakage spots on the submerged slopes of earth dams (Semenov, 1980). The application of self-potential method to outline water fluxes in shallow subsurface of urban soils is described in (Pozdnyakova et al., 2001). The detail description of self-potential method procedure is provided in LandMapper manual.

Another important application of LandMapper ERM-02 is measuring electrical potentials between soils and plants. Electrical balance between soil and plants is important for plant health and electrical potential gradient governs water and nutrient uptake by plants. Monitoring of electrical potentials in plants and soils is a cutting-edge research topic in the leading scientific centers around the world.

Locations

Zamboanga 7° 1' 27.3612" N, 122° 11' 20.0544" E
Kiev-Pechersk Lavra Kiev 50° 24' 59.1768" N, 30° 33' 55.836" E

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
Syndicate content