Philippe De Smedt | Ghent University (original) (raw)

Papers by Philippe De Smedt

ABSTRACT Most geological and soil maps are not detailed enough to represent the high lateral and ... more ABSTRACT Most geological and soil maps are not detailed enough to represent the high lateral and vertical textural variability in the subsoil of coastal lowlands. Intensive sampling campaigns need to be carried out to quantify this variability. As an alternative, a proximal soil sensing procedure based on a single survey with an electromagnetic induction instrument was used to map a 6.5 ha Holocene tidal area in Belgium. We investigated the effectiveness of a multi-receiver apparent electrical conductivity (ECa) survey for mapping the trace of tidal paleochannels. From a limited number of augerings, a three-layered soil was observed composed of a clayey top layer, a clayey infilling of the tidal channel above a subsoil consisting of coarse sandy material. A fitting procedure allowed modelling the conductivities of both subsurface layers, after which the four simultaneous ECa measurements were combined to model the depth of the interfaces between the three layers. The predictions were validated by 16 depth observations along a 150 m transect. A correlation coefficient of 0.91, with an average error of 0.23 m, was found between the predicted and measured depths of the clay-sand interface. We concluded that the dense ECa measurements (2 by 2 m resolution) allowed reconstructing a precise three-dimensional representation of the tidal channels.

Soil Use and Management, 2014

ABSTRACT A key characteristic of flooded paddy fields is the plough pan. This is a sub-soil layer... more ABSTRACT A key characteristic of flooded paddy fields is the plough pan. This is a sub-soil layer of greater compaction and bulk density, which restricts water losses through percolation. However, the thickness of this compacted layer can be inconsistent, with consequences such as variable percolation and leaching losses of nutrients, which therefore requires precision management of soil water. Our objective was to evaluate a methodology to model the thickness of the compacted soil layer using a non-invasive electromagnetic induction sensor (EM38-MK2). A 2.7 ha alluvial non-saline paddy rice field was measured with a proximal soil sensing system using the EM38-MK2 and the apparent electrical conductivity (ECa) of the wet paddy soil was recorded at a high-resolution (1.0 × 0.5 m). Soil bulk density (n = 10) was measured using undisturbed soil cores, which covered locations with large and small ECa values. At the same locations (within 1 m2) the depth of the different soil layers was determined by penetrometer. Then a fitting procedure was used to model the ECa – depth response functions of the EM38-MK2, which involved solving a system of non-linear equations and a R2 value of 0.89 was found. These predictions were evaluated using independent observations (n = 18) where a Pearson correlation coefficient of 0.87 with an RMSEE value of 0.03 m was found. The ECa measurements allowed the detail estimation of the compacted layer thickness. The link between water percolation losses and thickness of the compacted layer was confirmed by independent observations with an inverse relationship having a Pearson correlation coefficient of 0.89. This rapid, non-invasive and cost-effective technique offers new opportunities to measure differences in the thickness of compacted layers in water-saturated soils. This has potential for site-specific soil management in paddy rice fields.

Environ. Sci.: Processes Impacts, 2015

In environmental assessments, the characterization of urban soils relies heavily on invasive inve... more In environmental assessments, the characterization of urban soils relies heavily on invasive investigation, which is often insufficient to capture their full spatial heterogeneity. Non-invasive geophysical techniques enable rapid collection of high-resolution data and provide a cost-effective alternative to investigate soil in a spatially comprehensive way. This paper presents the results of combining multi-receiver electromagnetic induction and stepped-frequency ground penetrating radar to characterize a former garage site contaminated with petroleum hydrocarbons. The sensor combination showed the ability to identify and accurately locate building remains and a high-density soil layer, thus demonstrating the high potential to investigate anthropogenic disturbances of physical nature. In addition, a correspondence was found between an area of lower electrical conductivity and elevated concentrations of petroleum hydrocarbons, suggesting the potential to detect specific chemical disturbances. We conclude that the sensor combination provides valuable information for preliminary assessment of urban soils.

Symposium on the Application of Geophysics to Engineering and Environmental Problems 2014, 2014

Summary In the Roman town of Carnuntum 40 km south-east of Vienna (Austria) the unique discovery ... more Summary In the Roman town of Carnuntum 40 km south-east of Vienna (Austria) the unique discovery of a school of gladiators was made using a multi-disciplinary approach based on high-resolution near-surface geophysical prospection. The outstandingly well preserved architecture was revealed through non-invasive mapping using latest highly efficient multichannel ground penetrating radar systems. Foundations of a building complex including a circular training arena surrounded by wooden stands, the gladiator's living ...

Geoderma, 2015

ABSTRACT Different EMI inversion procedures were evaluated.•A 1D-laterally constrained and a non-... more ABSTRACT Different EMI inversion procedures were evaluated.•A 1D-laterally constrained and a non-constrained, robust 1D-inversion procedure were compared.•LIN approximations were compared with the full solution of the Maxwell's equations.•2D inversions of the EMI and ERT data were matched.•A robust calibration proved essential to attribute absolute values to the inversion results.

The area of Sandy Flanders, situated between the North Sea coast and the lower course of the Sche... more The area of Sandy Flanders, situated between the North Sea coast and the lower course of the Scheldt River in NW Belgium, is a relatively flat and low-lying area situated at the southern limit of the lowland cover sand region of the NW European plain. During the Late Pleniglacial and the Late Glacial, numerous, generally small but elongated sand dunes, shallow lakes and wet depressions were formed. During the last three decades intense archaeological prospection has taken place in this region, which is now one of the most intensively surveyed areas of NW Europe. This has led to the production of archaeological distribution maps, which show a distinct pattern regarding the temporal and spatial distribution of these archaeological sites. Some areas with a presumed high ecological value, such as the large but shallow Late Glacial fossil lake of the Moevaart Depressie (ca. 15km long and 2,5km wide), seem to have been attractive settlement locations in Prehistory, given the high amount of close-lying sites along its borders and on the cover sand ridge on its northern border. Habitation however seems to have ‘moved' in time, and is completely absent in Protohistory and even the Roman Period. During the Late Glacial and Holocene the landscape in the Belgian area of Sandy Flanders was subjected to major changes due to climatic fluctuations, and besides human factors, environmental conditions such as topography, soil, vegetation, but also hydrology and climate, may have influenced settlement conditions throughout time and played a role in this change in site location and the occupational history of the region. In this light an inter-disciplinary project 'Prehistoric settlement and land-use systems in Sandy Flanders (NW Belgium): a diachronic and geoarchaeological approach' (GOA project, UGent), involving archaeology, geography, palaeoecology, sedimentology and geophysical survey, has been undertaken. The study of both "empty" and densely inhabited areas is ongoing and aims at analyzing the settlement dynamics of the area of Sandy Flanders in terms of environmental potentials (theory of "wandering farmsteads") and the human impact ("enculturation") on the landscape. Likewise, we seek to investigate the reasons why other areas, which were inhabited in previous periods (e.g. the Moervaart area) were apparently not attractive anymore from the Metal Ages onwards. Indeed, to determine the suitability of a certain land type for a certain activity, it is necessary to understand the different types of land use (hunting-gathering, farming, …), the soil characteristics and the environment at different time intervals. During a large field campaign, a 70m long trench was dug through the deepest part of the former Moervaart lake, revealing alternating layers of (organic) lake marl and peat(y clay) indicating warmer/colder and drier/wetter phases. In addition, 15 mechanical corings have been made at four different locations within the depression, in large palaeochannels that cross the palaeolake, and on its borders. Both trench and corings were extensively sampled for palaeoenvironmental and sedimentological analyses and for OSL and 14C-dating. We present here the first results of the palaeoecological (mainly palynology, but also plant macroremains, charcoal, diatoms, ostracods, mollusks, beetles and Chironomideae) and sedimentological (water content, LOI, magnetic susceptibility, gamma-density) approaches, which provide new insights in the palaeolandscape evolution of this area during the Late Glacial and the early Holocene, in order to evaluate in detail how and to which degree this evolution determined the pre- and protohistoric occupation and exploitation within Sandy Flanders. Furthermore, significant emphasis is placed on the impact of prehistoric populations on both regional and local landscapes.

Journal of Applied Geophysics, 2014

Geoderma, 2012

ABSTRACT Mobile multi-receiver electromagnetic induction sensors provide simultaneous readings of... more ABSTRACT Mobile multi-receiver electromagnetic induction sensors provide simultaneous readings of the apparent electrical conductivity (ECa) from overlapping soil volumes. Therefore, small contrasting features can be difficult to identify because they have a limited contribution to the bulk measurement, especially if they are present in the subsoil (i.e. beneath the topsoil). Integrating ECa data from simultaneous measurements with multiple coil configurations has the potential to elucidate the variability within the soil profile as it enables modelling the electrical conductivity (EC) for distinct depth intervals. Therefore, it was our objective to develop a methodology to enhance the delineation of contrasting subsoil features, such as in-filled gullies and archaeological features. We selected a 3.5 ha study site where contrasting features were expected. A three-layered build-up was taken as the initial EC-slicing model. After varying the interface depths, the shallowest and deepest EC-depth slice showed a clear minimum of their combined variances at interface depths of 0.36 m, which corresponded to the ploughing depth, and 0.86 m. This implies that the EC-depth slice in-between these depths, contained a demonstrably higher variability. A sub-area of 0.85 ha was completely excavated to a depth of 0.7 m, revealing the subsoil features and the host material. An automated edge detection algorithm showed that the EC-depth slice was superior to any individual ECa measurement for delineating the contrasting subsoil features. Therefore, we concluded that depth slicing by integrating simultaneous ECa signals from a multi-receiver EMI sensor clearly improved the identification of subsoil features.

NOTAE …, 2011

Meylemans, Erwin, Philippe De Smedt, Annelies Storme, Jan Bastiaens, Koen Deforce, Dries Desloove... more Meylemans, Erwin, Philippe De Smedt, Annelies Storme, Jan Bastiaens, Koen Deforce, Dries Desloover, and Marc Van Meirvenne. 2011. “A Multi-diciplinary Palaeoenvironmental Survey in the Western Moervaart-depression (East Flanders, B).” Notae Praehistoricae 31: 7–15. ... Meylemans, E., De Smedt, P., Storme, A., Bastiaens, J., Deforce, K., Desloover, D., &amp;amp;amp;amp;amp; Van Meirvenne, M. (2011). A multi-diciplinary palaeoenvironmental survey in the western Moervaart-depression (East Flanders, B). NOTAE PRAEHISTORICAE, 31, 7–15.

ABSTRACT Ground Penetrating Radar (GPR) reflections occur at sharp interfaces between contrasting... more ABSTRACT Ground Penetrating Radar (GPR) reflections occur at sharp interfaces between contrasting soil layers. Generally, the depth of the interface is expressed as the two-way travel time from the transmitting to the receiving antenna. Converting these travel times to depths requires knowledge of the propagation speed of the GPR wave in the soil.This velocity is influenced by the electric properties of the soil water content, mainly by the dielectric permittivity (ε). The soil electrical conductivity (σ), which also depends on the soil water content, can be accounted for by electromagnetic (EMI) induction prospecting. A procedure was proposed to thoroughly characterize a circular ditch system by inverting the apparent electrical conductivity (σa) measurements from a multi-receiver EMI instrument based on GPR profile data. A fitting procedure allowed to calibrate both the propagation speed of the GPR waves up to the interface between the ditch infilling and the underlying sand and the conductivities of both layers. Integrating the simultaneous EMI measurements and high-resolution GPR depth profiles and –slices improved the non-invasive dimensioning of the circular ditch system.

European Journal of Soil Science, 2013

Archaeological practice within the European context of heritage management is facing huge challen... more Archaeological practice within the European context of heritage management is facing huge challenges in ways of recording and reproduction of ex-situ preserved sites. As a consequence of the Valletta-treaty, numbers of archived images and drawings of excavated structures as prime sources of past human activity, are exponentially growing. Contrarily to portable remains however, their future study and revision is biased by the two-dimensional character of the recorded data, rendering difficult their future reconstruction for new study or public dissemination. A more realistic three-dimensional (3D) way of recording and archiving should be pursued. In this paper the possibilities for 3D registration of archaeological features are examined in a computer vision-based approach using the PhotoScan software package (Agisoft LCC). It proved to be a scientific and cost-effective improvement compared to traditional documentation methods. Advantages can be found in the high accuracy and straightforwardness of the methodology. The extraction of an orthophoto or a Digital Terrain Model from the 3D model makes it feasible to integrate detailed and accurate information into the digital archaeological excavation plan. The visual character of 3D surface modeling offers enhanced output-possibilities allowing a better documentation of in-situ structures for future research and a higher public participation and awareness for the archaeological heritage.

Journal of Archaeological Science

Archaeological research at Stonehenge (UK) is increasingly aimed at understanding the dynamic of ... more Archaeological research at Stonehenge (UK) is increasingly aimed at understanding the dynamic of the wider archaeological landscape. Through the application of state-of-the-art geophysical techniques, unprecedented insight is being gathered into the buried archaeological features of the area. However, applied survey techniques have rarely targeted natural soil variation, and the detailed knowledge of the palaeotopography is consequently less complete. In addition, metallic topsoil debris, scattered over different parts of the Stonehenge landscape, often impacts the interpretation of geophysical datasets. The research presented here demonstrates how a single multi-receiver electromagnetic induction (EMI) survey, conducted over a 22 ha area within the Stonehenge landscape, offers detailed insight into natural and anthropogenic soil variation at Stonehenge. The soil variations that were detected through recording the electrical and magnetic soil variability, shed light on the genesis of the landscape, and allow for a better definition of potential palaeoenvironmental and archaeological sampling locations. Based on the multi-layered dataset, a procedure was developed to remove the influence of topsoil metal from the survey data, which enabled a more straightforward identification of the detected archaeology. The results provide a robust basis for further geoarchaeological research, while potential to differentiate between modern soil disturbances and the underlying sub-surface variations can help in solving conservation and management issues. Through expanding this approach over the wider area, we aim at a fuller understanding of the human-landscape interactions that have shaped the Stonehenge landscape.

Today, most surveys in archaeogeophysical prospection use magnetic properties to detect archaeolo... more Today, most surveys in archaeogeophysical prospection use magnetic properties to detect archaeological features. Such magnetic surveys are usually conducted with magnetometers and, to a lesser extent, with magnetic susceptibility meters and electromagnetic induction (EMI) sensors. Although the latter are the only instruments that allow mapping of multiple physical soil properties simultaneously, EMI remains the odd-one-out in archaeogeophysical prospection. Nevertheless, by simultaneously recording the electric and magnetic soil variability, EMI survey can be beneficial in early archaeological evaluation stages, because detailed pedological and archaeological information is gathered at the same time. Furthermore, by using multi-receiver EMI instruments vertical soil variation also can be integrated into the survey. However, although the potential of EMI for mapping electric soil variations is well known from advances in soil science, magnetic susceptibility measurements have been investigated less. Here we show the potential of a multi-receiver EMI survey to detect weak magnetic anomalies by measuring the apparent magnetic susceptibility (κa) of multiple soil volumes at a test site. The shallow κa data were compared with topsoil susceptibility measurements using a magnetic susceptibility loop sensor survey, and with magnetic susceptibility profiling using a probe sensor for evaluating the deeper κa-data. Further comparisons were made between these datasets and aerial photography and field walking data.We found that the multiple EMI κa measurements allowed for a straightforward discrimination of the natural and anthropogenic magnetic variations of shallow and deeper soil volumes, and allowed visualizing weak magnetic anomalies.

Image-based 3D modeling has already proven its value for the recording of excavations, however un... more Image-based 3D modeling has already proven its value for the recording of excavations, however until now its application has remained rather small-scale. We have examined the possibilities and limitations of image-based 3D modeling in the recording of an entire excavation, and its impact on the workflow of the excavation process and the post-excavation processing. Our results suggest that image-based 3D modeling can be an excellent and suitable method for the recording, documentation and visualization of the excavated archaeological heritage. It offers great possibilities for increasing the quality of the archived archaeological excavation record. The high-resolution geometric information allows a straightforward quantification of the data. However it also brings along new challenges, including a change in the workflow of the excavation and the post-excavation process. Although there are limitations, these are greatly surpassed by the possibilities of the method. We believe that image-based 3D modeling can cause a(n) (r)evolution in archaeological excavation practice.

Studies of past human-landscape interactions rely upon the integration of archaeological, biologi... more Studies of past human-landscape interactions rely upon the integration of archaeological, biological and geological information within their geographical context. However, detecting the often ephemeral traces of human activities at a landscape scale remains difficult with conventional archaeological field survey. Geophysical methods offer a solution by bridging the gap between point finds and the surrounding landscape, but these surveys often solely target archaeological features. Here we show how simultaneous mapping of multiple physical soil properties with a high resolution multi-receiver electromagnetic induction (EMI) survey permits a reconstruction of the three-dimensional layout and pedological setting of a medieval reclaimed landscape in Flanders (Belgium). Combined with limited and directed excavations, the results offer a unique insight into the way such marginal landscapes were reclaimed and occupied during the Middle Ages. This approach provides a robust foundation for unravelling complex historical landscapes and will enhance our understanding of past human-landscape interactions.

Soil Use and Management, 2014

Environ. Sci.: Processes Impacts, 2015

Symposium on the Application of Geophysics to Engineering and Environmental Problems 2014, 2014

Geoderma, 2015

Journal of Applied Geophysics, 2014

Geoderma, 2012

NOTAE …, 2011

European Journal of Soil Science, 2013

Journal of Archaeological Science

Archaeological distribution patterns are often biased by cultural and environmental processes. Th... more Archaeological distribution patterns are often biased by cultural and environmental processes. These processes influence the preservation of archaeological phenomena in the landscape. Their impact starts when the site and structures are left or abandoned or objects are deposited or disposed of. However, in archaeological landscape research, these processes are seldom incorporated. Therefore, the potential impact of both environmental and cultural processes on the preservation of archaeological phenomena needs to be understood and their influence on the observed archaeological site distribution patterns needs to be measured. Furthermore the history, intensity and methodology of the archaeological research in the region influence the known archaeological distribution pattern and therefore an understanding of the archaeological practice in the region is necessary in the study of the past landscapes of that region. This paper presents a case study on the distribution pattern of Bronze Age barrows in the highly urbanised landscape of north-western Belgium. By integrating natural, cultural and archaeological processes in archaeological landscape research, the completeness and reliability of the archaeological dataset can be estimated. Efforts to estimate completeness and reliability of any dataset should be an integral part of every archaeological landscape research project, especially as biases or hiatuses in datasets can lead to serious misinterpretations or circular reasoning. Furthermore, knowledge of the biography of landscapes is not only important in the study and understanding of past archaeological landscapes, but also in the preservation of these landscapes and our ability to incorporate hidden past landscapes into the actual sustainable management of its cultural–historical heritage.

The complex debate on prehistoric settlement decisions is no longer tackled from a purely archaeo... more The complex debate on prehistoric settlement decisions is no longer tackled from a purely archaeological perspective but from a more landscape-oriented manner combined with archaeological evidence. Therefore, reconstruction of several components of the former landscape is needed. Here, we focus on the reconstruction of the groundwater table based on modeling. The depth of the phreatic aquifer influences, for example, soil formation processes and vegetation type. Furthermore, it directly influences settlement by the wetness of a site. Palaeogroundwater modeling of the phreatic aquifer was carried out to produce a series of full-coverage maps of the mean water table depth between 12.7 ka and the middle of the 20th century (1953) in Flanders, Belgium. The research focuses on the reconstruction of the input data and boundary conditions of the model and the model calibration. The model was calibrated for the 1924–1953 time period using drainage class maps. Archaeological site data and podzol occurrence data act as proxies for local drainage conditions over periods in the past. They also served as a control on the simulated phreatic palaeogroundwater levels. Model quality testing on an independent validation data set showed that the model predicts phreatic water table levels at the time of soil mapping well (mean error of 1.8 cm; root mean square error of 65.6 cm). Simulated hydrological conditions were in agreement with the occurrence of archaeological sites of Mesolithic to Roman age at 96% of the validation locations, and also with the occurrence of well-drained podzols at 97% of the validation locations.

As the application of ground-based frequency domain electromagnetic induction (FDEM) surveys is o... more As the application of ground-based frequency domain electromagnetic induction (FDEM) surveys is on the rise, so increases the need for processing strategies that allow exploiting the full potential of these often large survey datasets. While a common issue is the detection of baseline drift affecting FDEM measurements, the impact of residual corrugations present after initial drift removal is less documented. Comparable to the influence of baseline drift, this ‘micro-drift’ introduces aberrant data fluctuations through time, independent of the true subsurface variability. Here, we present a method to detect micro-drift in drift-corrected FDEM survey data, therefore allowing its removal. The core of the procedure lies in approaching survey datasets as a time series. Hereby, discrete multi-level wavelet decomposition is used to isolate micro-drift in FDEM data. Detected micro-drift is then excluded in subsequent signal reconstruction to produce a more accurate FDEM dataset. While independently executed from ancillary information, tie-line measurements are used to evaluate the reliability and pitfalls of the procedure. This demonstrates how data levelling without evaluation data can increase subjectivity of the procedure, and shows the flexibility and efficiency of the approach in detecting minute drift effects. We corroborated the method through its application on three experimental field datasets, consisting of both quadrature and in-phase measurements gathered with different FDEM instruments. Through a 1D assessment of micro-drift, we show how it impacts FDEM survey data, and how it can be identified and accounted for in straightforward processing steps.

Although the Belgian lowlands witnessed a dense rural occupation in Roman and especially in medie... more Although the Belgian lowlands witnessed a dense rural occupation in Roman and especially in medieval times, the exact nature of the settlement patterns, the farms and the interaction with the landscape is still poorly understood archaeologically, both scientifically and from a heritage curatorship point of view. Archaeogeophysical research has remained relatively limited in this area. However, other prospection techniques such as aerial photography provide ample evidence of historic rural settlement. The main aim of this research is to develop an efficient and integrated approach for the characterization of these rural landscapes, by combining and mutually evaluating data from geophysical methods including magnetometer, electromagnetic induction and ground-penetrating radar, aerial photography, fieldwalking, historic accounts and test-pitting.

Understanding palaeotopographical variability forms the basis for understanding prehistoric socie... more Understanding palaeotopographical variability forms the basis for understanding prehistoric societies. Alluvial and lacustrine environments, in particular, are key areas with both a high archaeological and palaeoecological potential. However, the often deep stratification of these sites, the high water table and the complex sedimentological variations can hamper a detailed reconstruction of the spatial relationship between prehistoric settlement and their environment. Combining different remote and proximal sensing techniques and coring data, can offer detailed insight into such landscapes. More specifically, the integration of mobile geophysical methods allows the collection of unprecedented continuous information on large-scale palaeolandscape variability. In this study we present a combined approach in order to map and model prehistoric landscapes and river systems in and around a Late Glacial palaeolake in north-western Belgium. Based on filtered and unfiltered digital elevation models, a survey area of 60 ha was selected, in which detailed mobile multi-receiver electromagnetic induction survey was conducted. The results allowed for the delineation of palaeochannels in the area and enabled modelling the depth of these features in the survey area, providing insight into their flow characteristics. 14C sampling enabled the dating of the evolving river system to the transition between the Late Glacial and the Early Holocene. Through additional coring, this river system could be traced further through the palaeolake area. Based on these results a detailed reconstruction was made of the palaeotopography that harboured the Final Palaeolithic and Early Mesolithic occupation of the study site.► 60 ha were surveyed in a palaeolake with a multi-receiver EMI instrument. ► Geophysical data were combined with a DEM and borehole data. ► A depth model was composed of detected palaeochannels. ► Palaeoriver chronology was established using 14C dates. ► Data integration allowed a detailed reconstruction of the prehistoric landscape.

Today, most surveys in archaeogeophysical prospection usemagnetic properties to detect archaeolog... more Today, most surveys in archaeogeophysical prospection usemagnetic properties to detect archaeological features. Such
magnetic surveys are usually conducted with magnetometers and, to a lesser extent, with magnetic susceptibilitymeters
and electromagnetic induction (EMI) sensors. Although the latter are the only instruments that allow mapping multiple
physical soil properties simultaneously, EMI remains the odd-one-out in archaeogeophysical prospection. Nevertheless,
by simultaneously recording the electric andmagnetic soil variability, EMI survey can be beneficial in early archaeological
evaluation stages, because detailed pedological and archaeological information is gathered at the same time. Furthermore,
by usingmulti-receiver EMI instruments vertical soil variation also can be integrated into the survey. However, although the
potential of EMI for mapping electric soil variations is well known from advances in soil science, magnetic susceptibility
measurements have been investigated less. Here we show the potential of a multi-receiver EMI survey to detect weak
magnetic anomalies bymeasuring the apparentmagnetic susceptibility (κa) ofmultiple soil volumes at a test site. The shal-
low κa data were compared with topsoil susceptibility measurements using a magnetic susceptibility loop sensor survey,
and with magnetic susceptibility profiling using a probe sensor for evaluating the deeper κa-data. Further comparisons
weremade between these datasets and aerial photography and fieldwalking data.We found that themultiple EMI κa mea-
surements allowed for a straightforward discrimination of the natural and anthropogenicmagnetic variations of shallowand
deeper soil volumes, and allowed visualizing weak magnetic anomalies.

Full-coverage maps for several specific soil characteristics were produced at particular time-int... more Full-coverage maps for several specific soil characteristics were produced at particular time-intervals over a time span of 12,716 years for a 584 km2 large study area located in Belgium. The pedogenetic process model SoilGen2 was used to reconstruct the evolution of several soil variables at specific depths in the soil profile at various point locations (96 in total). The time span covered by the simulations encompassed the final part of the Younger Dryas and the Holocene up till the present. Time series on climate, organisms and groundwater table were reconstructed and supplied to the model as boundary conditions. Model quality optimization was performed by calibrating the solubility constant of calcite by a comparison of the simulated time necessary for decarbonization with literature values and evaluating the calibrated value over a wide range of precipitation surpluses representative for the regarded time period. The simulated final state was evaluated against measurements collected in a database representing the historic state of the soil at 1950. The simulated specific soil characteristics at the point locations were then used to produce full-coverage maps at the particular time-intervals by regression kriging. Such maps are believed to provide useful information for geoarcheological studies and archeological land evaluations.