LIST OF FIGURES

Fig. 1. Scheme of self-potential method with (a) fixed-base, (b) gradient, and (c) combined techniques. Crosses indicate leading (measuring) electrode locations and circles show trailing (base) electrode locations

Fig. 2. Scheme of the four-electrode laboratory conductivity cell. Electrical field lines are shown with thin straight lines (uniform electrical field

Fig. 3. Scheme of the four-electrode method. Electrical field lines are shown with thin curvilinear lines (non-uniform electrical field)

Fig. 4. Photograph of equipment for SP, EP, VES, and ET used in this study: (1) multifunctional voltmeter and auto-canceler with polarization compensation, (2) ammeter, (3) electrode array

Fig. 5. Scheme of the vertical electrical sounding (VES) device: (1) voltmeter and auto-canceller, (2) ammeter and commutator for electrodes AB and MN, (3) netted wires for different distances among electrodes AB and MN, and (4) electrodes

Fig. 6. Example of VES data assessment and calculation on Excel 97 spreadsheet

Fig. 7. Scheme of electrode array for electrical tomography

Fig. 8. Scheme of the non-contact electromagnetic profiling (NEP): (1) receiver-register block, (2) receiving antenna, (3) cord, (4 and 6) radiating antennas, (5) generator of electromagnetic waves, (7) detector for measuring the distance, and (8) cord for measuring the distance

Fig. 9. Photograph of NEP equipment: (1) receiver-register block, (2) receiving antenna, (3) cord, (4 and 6) radiating antennas, (5) generator of electromagnetic waves, (7) detector for measuring the distance, and (8) cord for measuring the distance

CHAPTER III

Fig. 10. Experimental relationships between electrical resistivity and bulk density. Sample 2 (20-30 cm) of sedge-mossy peat soil with different (1.08, 1.07, 0.8, and 0.52 g g^-1) water contents

Fig. 11. Experimental relationships between electrical resistivity and soil volumetric water content. Data recalculated and combined from different water contents for the soil samples from (a) 10-20 cm, (b) 20-30 cm, (c) 40-50 cm, and (d) 50-70 cm layers

Fig. 12. A piece-wise linear relationship between the natural logarithm of water content and electrical resistivity

Fig. 13. The illustration to Voronin’s theory. Curves are the water retention functions for different soils, such as solid line for A horizon of Mollisol, dashed line for B1 horizon of Mollisol, open circles for A horizon of Spodosol, closed circles for E horizon of Spodosol, dotted-dashed line for C1 of Aridosol. Straight lines show the boundaries between different water ranges based on Eq. [44], [45], [47], and [48] (Voronin, 1986

Fig.14. An example of experimental relationship between electrical resistivity and water content of a peat soil

Fig.15. An example of the linearized relationship between electrical resistivity and water content

Fig. 16. Relationships between electrical potential and exchange cations in Alfisols

CHAPTER IV

Fig. 24. Distributions of the density of mobile electrical charges and electrical parameters in soil profiles belonging to (a) the first and third cases and (b) the second case. Solid lines represent the density of electrical charges and dashed lines show the electrical parameters distributions

Fig. 25. Distributions of the density of mobile electrical charges and electrical parameters illustrating (a) enrichment and (b) depletion of topsoil with electrical charges. Solid lines represent the density of electrical charges and dashed lines show the electrical parameters distributions

Fig. 26. The electrical potential distribution in profiles of (a) and (b) Typic Haplocryalf, (c) Umbric Glossocryalf, (d) Mollic Glossocryalf, (e) Mollic Haplocryalf, and (f) typical water content distribution for these Cryalfs

Fig. 27. Deep profile of electrical potential in Typic Haplocryalf

Fig. 28. Distributions of electrical potential in a 20-m transect on Typic Ferrudalf under coniferous forest measured at depths: (a) 5 cm, (b) 15 cm, (c) 25 cm, (d) 35 cm, (e) 45 cm, and (f) iso-potential in the whole transect

Fig. 29. Electrical resistivity distributions in (a) Arenic Glossudalf on sandy loam parent material and (b) Haplic Glossudalf on clay loam measured in soil pits with four-electrode probe. The mean values with error bars are shown for (a) 23-25 and (b) 28-32 measurements on the particular depths of soils under native coniferous-deciduous forest in "Chashnikovo", Moscow area, Russia

Fig. 30. Profile distributions of electrical resistivity in (a) Arenic Glossudalf on sandy loam parent material and (b) Haplic Glossudalf on clay-loam measured with VES method. The mean values with error bars are shown for (a) 11 and (b) 20 VES profiles measured within 3x15 m area on soils under native coniferous-deciduous forest in "Chashnikovo", Moscow area, Russia

Fig. 31. Distributions of electrical potential in (a) Mollic Haplocryalf, (b) Oxyaquic Haplocryalf, and (c) Aquic Haplocryalf. Measurements are conducted in Central Forest Reserve of Russia, Tver’ area

Fig. 32. Electrical resistivity distribution measured on soil sequence with (a) VES in 5-m interval. Profiles of electrical resistivity measured in (1) Mollic Haplocryalf, (2) Oxyaquic Haplocryalf, and (3) Argic Cryaquoll with (b) four-electrode probe in soil pits and (c) VES in Central Forest Reserve of Russia, Tver’ area

Fig. 33. Profile distributions of electrical resistivity measured with VES on cultivated Histosols in Yachroma valley: (1) Limnic Haplosaprists, (2) Fluvaquentic Haplosaptists, and (3) Typic Luvihemist on [a], [b], [c], and [d]. Typic Haplohemist (1) without application of fertilizers and (2) with 3-year application of N₉₀P₁₂₀K₁₂₀ each year are on [e]. Sapric Haplohemrist (1) cultivated under perennial grasses and (2) drained but uncultivated under native deciduous forest are on [f]

Fig. 34. Distributions of (a) soils and (b and c) electrical resistivity in soil catena across the Klyazma valley, "Chashnikovo", Moscow area, Russia. VES on Typic Ferrudalf formed on layered sandy-loam outwash (1) cultivated and (2) under native coniferous forest; (3) Typic Fraglossudalf; (4) Aquic Ferrudalf on clay-loam glacial till; (5) Oxyaquic Haploudalf; (6) Limnic Haplosaprists; Sapric Haplohemrist (7) non-cultivated and (8) cultivated; (9) Aeric Humaquept

Fig. 35. Distributions of electrical resistivity measured with four-electrode probe along the soil profiles of (a) Typic Ferrudalf, Moscow area; (b) Typic Kandiudalf, Tula area; (c) Mollic Hapludalf, Kursk area; (d) Typic Argialboll, Kursk area; (e) Typic Calciudoll, Har’kov area; (f) Xeric Calcigypsid, Herson area

Fig. 36. Electrical parameters in Mollisols catena: (1) Typic Hapludoll; (2) Cumulic Hapludoll; (3) Aquic Cumulic Haploudoll. Central Chernozem Reserve of Russia, Kursk area

Fig. 37. Distributions of (a) electrical potential and (b) water content in profiles of (1) Typic Haplocalcid and (2) Typic Natrargid

Fig. 38. Distributions of electrical potential in 20-m transect measured with 10 cm interval on complex of Sodic Haplocalcid and Typic Natrargid (highlighted on the scale in black). Electrical potentials are measured on (a) 2 cm, (b) 5 cm, (c) 15 cm, (d) and 25 cm depths. Iso-potential contours are on (e)

Fig. 39. Average electrical resistivity distributions measured with VES in (a) Dzanibek Research Center, Crimea in profiles of (1) Typic Haplosalid, n=8 and (2) Typic Natrargid, n=12; and in (b) Don valley near Tambov in profiles of (1) non-saline Calciudoll, n=8 and (2) saline Calciudolls, n=12

CHAPTER V

Fig. 40. The geomorphology profile across the Yachroma valley, CPBRS Field 8. Profiles of electrical resistivity are measured with four-electrode probe in soil pits

Fig. 41. Distributions of soil properties (water content, ash content, bulk density, and electrical resistivity) measured in soil pits along the transect in Field 8, CPBRS. Line markers with numbers indicate locations of soil pits

Fig. 42. NEP profiles of experimental fields 1, 3, and 4, CPBRS. (A) distance between antennas 9 m (profiling depth about 1.2 m) and (B) distance between antennas 16 m (profiling depth about 2.2 m)

Fig. 43. Scheme map of experimental fields 1, 2, 3, 4, and 5, CPBRS developed with NEP method and recommended agricultural usage

Fig. 44. Determination of drying depth on the cultivated Hemic Haplosaprist with VES method

Fig. 45. An example of estimating peat soil depth with VES method

Fig. 46. Tabola experimental fields of RIIVP: (light blue) medium-saline Vertic Humaquept, (blue) low-saline Vertic Humaquept, (red) non-saline Cumulic Humaquept, (green) non-saline Typic Humaquept, (yellow) low-saline Cumulic Humaquept, (navy) open water. Numbers indicate the locations of VES and soil sampling. Arrows show the directions of NEP

Fig. 47. Gandurino experimental fields of RIIVP: (orange) Vertic Halaquept, (brown) Typic Halaquept, (light blue) medium-saline Vertic Humaquept, (blue) medium-saline Typic Humaquept, (green) Salidic Sulfaquept, and (navy) open water. Numbers indicate the locations of VES and soil sampling. Arrow shows the direction of NEP

Fig. 48. Electrical resistivity distributions in Halaquaept profiles indicating the groundwater depths

Fig. 49. The relationship between the electrical resistivity measured in situ by VES method and the total salt content in soils of delta Volga, Russia

Fig. 50. NEP of non-saline Typic Humaquept on the field with VES 5, Tabola area. (A) distance between antennas 9 m (profiling depth about 1.2 m) and (B) distance between antennas 16 m (profiling depth about 2.2 m)

Fig. 51. NEP of non-saline Typic Humaquept on the field with VES 9, Tabola area, indicating the change in electrical resistivity due to sprinkler irrigation. Distance between antennas 9 m (profiling depth about 1.2 m)

Fig. 52. NEP of low-saline Cumulic Humaquept on the field with VES 10, Tabola area, indicating the change in electrical resistivity with rising groundwater:(A) distance between antennas 9 m (profiling depth about 1.2 m) and (B) distance between antennas 16 m (profiling depth about 2.2 m)

Fig. 53. NEP of Vertic Halaquept on the field of Gandurino: (A) distance between antennas 9 m (profiling depth about 1.2 m) and (B) distance between antennas 16 m (profiling depth about 2.2 m)

Fig. 54. Spatial location of the (a) total 898 and randomly selected (b) 700, (c) 200, and (d) 100 data points of SAR

Fig. 55. Sample variogram (dots) and model (solid line) of the (a) total 898 and (b) 100 randomly selected SAR data

Fig. 56. Relative improvement (+) or reduction (-) of estimation accuracy based on (a) mean kriging variance, (b) mean squared error, and (c) correlation of estimated and actual values for kriging (circles) and cokriging (squares) using randomly selected data sets of SAR, compared with kriging using the total SAR data

Fig. 57. Contour maps of SAR estimated by (a) kriging with 898 SAR data, (b) cokriging with 200 SAR and 898 in-situ EC data, (c) kriging with 200 SAR data, and (d) cokriging with 100 SAR and 898 in-situ EC data

Fig. 58. Relative sampling cost and relative improvement of prediction accuracy based on mean kriging variance, mean squared error, and correlation between estimated and actual values for cokriging using various reduced SAR data sets and 898 EC data compared with kriging using the 898 SAR data

Fig. 59. Soil and electrical profiles of Vertic Palexerolls formed on stony carbonated clay and under-laid by limestone

Fig. 60. Some profile distributions of electrical resistivity measured by VES method in stony soils of Crimea Peninsula, Ukraine

Fig. 61. The relationship between the electrical resistivity measured in situ by VES method and the volumetric stone content

CHAPTER VI

Fig. 62. Scheme of the investigated area within Patriarch garden, Kiev, Ukraine: the numbers in circles show VES locations, lines are routes for EP investigation (Route 1 from VES 1 to VES 21 and Route 2 from VES 27 to VES 21), and the darken place near the church is a concrete wall

Fig. 63. Scheme of the investigated area in Astrakhan’, Russia: the numbers show VES locations; arrows indicate the NEP routes, and black circle represents Dramatic Theater with active drainage

Fig. 64. Typical distribution of electrical resistivity within soil profile measured by VES in Patriarch garden, Kiev, Ukraine

Fig. 65. Result of the SP measurements within Patriarch garden, Kiev, Ukraine. The curves are iso-potential lines. The numbers and letters indicate fluxes, zones of infiltration and saturation

Fig. 66. Electrical resistivity distributions within soil profile measured by VES in Astrakhan’, Russia

Fig. 67. Profiles of electrical resistivity measured by the NEP along the slope in Astrakhan’, Russia: profiling with (A) 9-m distance between antennas and (B) 16-m distance between antennas. Vertical lines show location of crossroads, (!) indicates local increase of resistivity near the Dramatic Theater, and (!!) indicates increase of resistivity at the crossroads in the low part of the hill

Fig. 68. Electrical profiling with four-electrode probe on a transect in area polluted with petroleum products and mining solutions. Measuring interval 1 m. Urengoi area, northwest Siberia

Fig. 69. Non-contact electromagnetic profiling through the areas polluted with salty mining solutions used during petroleum and gas mining. Urengoi area, northwest Siberia

Fig. 70. Profile distributions of electrical resistivity measured by VES method in soils of northwest Siberia polluted by petroleum and gas mining: (a) non-polluted Gelisols, (b) soil near the stream with mining solution discharge, (c) soil polluted with bitumen, (d) soil in a brine collector

Fig. 71. Spatial variability of electrical resistivity over the disturbed Typic Cryboralf. Rectangular boxes (0.5x1.0 m) with numbers indicate the locations of ER measurements; numbers are the values of electrical resistivity (ohm m), and the shaded rectangle outlines the known location of former (5-year old) soil pit

Fig. 72. Graph representation of summary statistics of bulk electrical resistivity measured (1) on control and (1a) over former soil pit on Cumulic Cryboralf, plowland; (2) on control and (2a) over former soil pit on Typic Cryboralf, coniferous-deciduous forest; (3) on control and (3a) over former soil pit on Sapric Haplohemist, grassland; and (4) on control and (4a) over former soil pit on Typic Cryboralf, grassland. All soil pits are about 2-month age

LIST OF TABLES