The geodiversity assessment is particularly important in the case of areas belonging to critical zones, especially in the mountain regions. Recognizing the parts of a territory that are the most diversified and vulnerable to changes is a crucial issue for management and planning of protected and conserved areas (PCAs). Karkonosze National Park (KNP) located in south-western Poland in the border area between Poland and the Czech Republic was chosen as a research area. KNP covers the northern slopes of the Karkonosze Mountains, the largest range of the Sudetes.

The geodiversity assessment based on spatial multicriteria analysis (S-MCA) with crowdsourced data was conducted. The geodiversity of KPN was evaluated with weighted linear combination (WLC) technique basis on selected criteria: 1) lithology, 2) relief energy, 3) geomorphology, 4) land use/land cover, 5) soils, 6) mesoclimate, and 7) hydrography. The assessment input data comprised of seven environmental factor ratings and weights were obtained from 57 Earth science researchers worldwide. These data served as the bases for a joint assessment of geodiversity and then spatially explicit global sensitivity analysis (GSA). The Monte Carlo simulation was used to sweep through criteria weight space, where weights are expressed using probability distributions. Multiple output suitability maps were generated and summarized using: an average suitability map, a standard deviation uncertainty map, and a number of sensitivity maps. The results helped to identify highly geodiverse areas that are burdened by high uncertainty and then to investigate which specific abiotic component contribute to the uncertainty the most. This could be valuable in monitoring and management of PCAs and significantly contribute to improving the existing results of geodiversity assessments and some savings resulting from field work.

In the case of the mountainous area - KNP, the geodiversity value is the most sensitive to the lithological and the geomorphological criteria map. None of the weightings proved influential, suggesting a high consensus in weighting the factors among the geo-questionnaire respondents. In the future, it is worth conducting further simulations, considering another S-MCA technique, such as Ordered Weighted Averaging (OWA).

How to cite: Najwer, A., Ligmann-Zielińska, A., Zwoliński, Z., and Jankowski, P.: Sensitivity analysis of criteria weights in geodiversity assessment of the Karkonosze National Park, Poland, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11910, https://doi.org/10.5194/egusphere-egu23-11910, 2023.

Managing a space and its resources is strictly related to the destination and human and/or ecological needs  that such resources should satisfy. Therefore, land planning might not only imply conservation perspectives but also the transformation, exploitation or even the destruction of such resources.

This is particularly true for some abiotic (lithified and unlithified resources, paleontological and mineral resources) and interfacial resources (soil resources), which are sometimes neglected by land planning processes that focus mainly on biotic resources or on biotic and abiotic water-related dynamics.

For such reasons, over the years, geodiversity assessment studies have been increasingly performed in different regions and at different spatial extents. Indeed, as operational concept, geodiversity implies a measurement and its application is narrowed to a given spatial area, allowing the identification of clusters for prioritization and planning purposes.

Nevertheless, previous geodiversity assessment studies suggested that the assessment of the variation—in number and types – of geodiversity entities  (i.e. geotaxa) cannot be, alone, always the only useful support for land planning and/or geoconservation perspectives, particularly when aggregating at larger spatial extents. Geodiversity research should imply as well the assessment of “geofunctionality”, defined as the contribution of geodiversity to socio-ecological functioning and, for instance, in terms of geo-ecosystem services, to human well-being. Indeed, an ecosystem service approach could provide more accurate information about the existence of provisioning, regulating, and cultural benefits supplied by underlying geodiversity processes and the corresponding demand for these services within the socio-ecological system.

The objective of this paper is to present a study involving the assessment of geo-ecosystem services supplied by geodiversity in French Guiana, an Overseas French Territory located in South America, between Suriname and Brazil. Provisioning (e.g. raw materials supply), regulating (e.g. natural habitat regulation) and cultural (e.g. geotourism and geoheritage) services were identified, assessed and mapped at the territory level using an indicator-based approach.

Difference maps were obtained in order to compare the relationship between the levels of the three geo-ecosystem services and a geodiversity index previously assessed in the region by past studies. As observed through the example of French Guiana, geodiversity and geofunctionality might not have always a systematic relationship and geodiversity assessment alone might mislead the development of pertinent sustainable strategies for urban, agricultural and mining planning.

However, these results raise some concerns related, first of all, on the lack of available data on the studied area (for example, soil-related data) which does not allow an exhaustive evaluation of geodiversity. Furthermore, it is essential to distinguish geofunctionality, as the capability of the territory to offer multiple services, from the actual contributions supplied by geodiversity processes and functions to human well-being.

How to cite: Scammacca, O., Fermet-Quinet, N., Bétard, F., Aertgeerts, G., Montagne, D., and Heuret, A.: The functional dimension of geodiversity: geo-ecosystem services assessment for sustainable land-planning in French Guiana, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2337, https://doi.org/10.5194/egusphere-egu23-2337, 2023.

Geodiversity aspect concentrates on recognition and description of different elements of the abiotic nature, which range remains the same throughout majority of researchers; it includes geology, geomorphology, hydrology, climate, human and biological heritage (ex. Cultural objects and Fossils). However, here we decided to explore the hydrological aspect more precisely, which always mentioned but rarely described and/or implemented into assessment. Hence, we decided to explore it and calculate as an additional value for qualitative-quantitative assessment of geodiversity for geosite recognition. The assessment has developed based on the global parameter simply recognizable for two main elements geology and geomorphology, with an aim to highlight places of interest to minimize the area of field observation. Meanwhile, all other elements of geodiversity have considered as additional processes and materials which are influencing geological formation, where hydrology is setting eminent position.

            For assessment of hydrology, we concentrated on two of the most common parameters, which can be easily calculated from standard SRTM data: Strahler order and watershed basin. Strahler order is demonstrated streams as branch hierarchy, where the sources are considered as first order and the main river is the last possible order. The evaluation system is directly connected to Strahler order as the larges stream is likely to carry the most diverse variety of rock samples transported from the high elevation source areas. Additionally, watershed area parameters have been used as overlapping layer for the geological model to demonstrate what kind of rock particles can be transported by the river system in particular water basin. Hence, this research explores influence of hydrological element on results of qualitative-quantitative assessment of geodiversity based on territory of Western Samoa, which includes Savaii and Upolu Islands dominated by Holocene shield volcanos and post/shield scoria cones.    

How to cite: Zakharovskyi, V. and Nemeth, K.: Influence of hydrological element on qualitative-quantitative assessment of geodiversity for geosite recognition based on Western Samoa, SW Pacific, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4718, https://doi.org/10.5194/egusphere-egu23-4718, 2023.

Within geodiversity assessment methods, the grid system is the most used approach to calculate a geodiversity index. Chosen for its simplicity and adjustment aptitude, it implies a fundamental and determinant decision, namely the selection of the cell size. This should comply with the inherent properties of the input datasets, being as well a function of the main goals of the analysis. This problematic has been studied by several authors, either by discussing and presenting analytical procedures, or by testing the effect of distinct cell sizes on their (modelling) analysis.

Being a key issue within geodiversity assessment methodologies, in this work an empirical methodology is presented to select the most appropriate cell size to assess the geodiversity of Portugal mainland. A direct quantitative method based on geodiversity indices was applied, using richness, and Simpsons’ and Shannon’s diversity and equity indices to geology (1:1000 000) and geomorphology (1:500 000) datasets of mainland Portugal, in a hexagonal analytical grid, through eight cell dimensions (1km, 2km, 5km, 10km, 15km, 20km, 25km and 30km). Several descriptive statistical parameters were analysed along the eight cell dimensions, for each map, with particular emphasis for dispersion statistical measures, namely quartile coefficient of dispersion, coefficient of variation, and skewness coefficient, range, Min, Max and IQR. The effect of cell size on the final maps of lithological and geomorphological diversity was also analysed, using the conventional representation of five classes (very high, high, medium, low and very low) based on the Jenks classification, by evaluating the area occupied per each class along the distinct cell sizes. The results from the analysis indicate that skewness coefficient, quartile coefficient of dispersion and coefficient of variation could be used as indicators of optimal cell size. All the performed analysis indicated the 5-10km dimension as the optimal cell size for the diversity and richness analysis, also considering the differences between both datasets, namely distinct scale, distinct polygon distribution area, distinct number of total features (categories). In general, the evenness and diversity indices seem to be more appropriated to be used as cell size indicators when applying statistic parameters, while richness seems to provide more clear results while using final maps and correspondent graphics that synthetize the area distribution per class. The empirical procedure here presented seems to be applicable to all type of scales and datasets.

How to cite: Lopes, C., Teixeira, Z., and Pereira, P.: Addressing cell size selection in geodiversity quantitative assessment procedures, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9821, https://doi.org/10.5194/egusphere-egu23-9821, 2023.

Recently, international focus on the United Nations Sustainable Development Goals has led to the proposal of Essential Geodiversity Variables (EGVs), a framework for geological (geodiversity) information, intended to stand alongside Essential Variables (EVs) already defined for Climate, Biodiversity and Oceans (limited to ocean physics, biochemistry, biology, and ecosystems). In Norway, the Nature Diversity Act, which acknowledges geological and landscape diversity alongside biodiversity, has helped establish geology as part of an essential foundation for knowledge-based management, on land, in the coastal zone and offshore. In keeping with this, geological mapping is a core component of two ongoing national multidisciplinary seabed mapping initiatives [MAREANO, Marine Base Maps for the Coastal Zone (pilot)].

Here we examine to what extent marine geological map products from the Geological Survey of Norway generated under these mapping initiatives fit within this EGV framework and how well it is suited to information on marine geodiversity. Further, we examine opportunities for highlighting quantitative geodiversity information through the development of non-traditional marine geological map products. We present some thematic examples at different spatial scales which explore the potential for delivering seabed geodiversity and related geological information more directly. It is important that such information is available in forms that are readily accessible and understandable to a wide range of end users who are largely non-geologists, and that it complements existing information used in coastal and offshore management.  

How to cite: Dolan, M. F. J., Bøe, R., and Bjarnadóttir, L. R.: Marine geological maps as essential seabed geodiversity information for sustainable management, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5129, https://doi.org/10.5194/egusphere-egu23-5129, 2023.

Monogenetic volcanic fields are group of short lived and small, typically mafic volcanoes that form clusters, alignments or distributed randomly over large territory. The geoheritage values of such volcanic fields are difficult to characterize due to the scale problem they pose within the commonly magnitudes larger regions than their footprints. Monogenetic volcanoes are defined by their simple geological architecture. Their geological and geomorphological diversity of them not detectable easily within the common spatial scale diversity estimates performed mostly with an aim to quickly identify geological and geomorphological diversity hotspots. Here we explore this paradox situation from three distinct, nearby large monogenetic volcanic fields – Harrat Rahat, Harrat Khaybar and Harrat Lunayyir - each considered to be an active volcanic system in the western Arabian Peninsula. Historic records documented 52 days eruption in 1256 CE nearby Madinah City at Harrat Rahat. Archaeological evidence (desert kites) and some direct radiometric dating indicate Holocene (< 5-ky) volcanism at Harat Khaybar. In contrast, Harrat Lunayyir experienced a failed eruption (e.g., magma has not reached the surface) in 2009. These young volcanic activities and proximity to large cities and infrastructure triggered an elevated effort to monitor volcanic hazards in the region. Geoheritage has recently been considered as an avenue toward developing resilient society against volcanic hazard. Geotourism has also been recently considered as a prime sector for investment for economic development especially in the volcanic fields of West Arabia. The rapid economic growth and the industrial need of raw materials put unprecedent pressure on the geoheritage of these volcanic fields threating the reduction of geodiversity of the region. Accurate method to estimate the geodiversity of these volcanic fields is in great need, however, to develop quantitative methods by using advanced GIS technologies is challenging. This is partially due to the nature of measuring geodiversity of volcanic fields and the quality and availability of accurate geological information capturing the volcanic geoheritage. Here we provide a qualitative approach first to define the volcanic geoheritage of these three volcanic fields applying the volcanic geology and associated facies mapping approach. Such method is promising as the arid climate and lack of vegetation-cover help to identify clearly the geoheritage of those regions fall beyond the volcanic edifices. This is particularly important in these fields where great variety of surface textures of pāhoehoe and ʻaʻā lavas as well as inter-edifice mixed arid terrestrial sedimentation occur. In addition, geological attributes of volcanic edifices such as geochemistry, petrological information and pyroclastic successions ordered in their volcanic hazard perspective been used to refine diversity elements. The utilization of remote sensing satellite data, high resolution terrain analysis methods and collating information on geoheritage elements such as archaeology, geocultural aspects and types of geotourism utilities are also considered. Combination of these data to the most up to date geological mapping information clearly showed the correlation of geodiversity with the maturity and longevity of volcanism of the studied volcanic field fields.

How to cite: Nemeth, K. and Moufti, M. R.: Conceptual framework of geoheritage and geodiversity of large monogenetic volcanic fields: from qualitative to quantitative assessments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5457, https://doi.org/10.5194/egusphere-egu23-5457, 2023.

Abstract

The aims of this study is to demonstrate the adaptation of geopark concept for the geo-tourism and geodiversity at Penghu Marine Geopark.

By adopting the idea of geopark from the UNESCO, Taiwan revised the Cultural heritage preservation law to add geopark concept in 2016. Penghu Archipelago was designed as marine geopark since 2020. By law, it is a way toward to local sustainable development.

To promote geo-tourism, the Penghu National Scenic Area Administration, as management agency of geopark, is trying to introduce landscape explanation software and to improve the knowledge of local community associations, tour guides and volunteers. The goals are to transform the Penghu Islands into a high-quality geopark and ensure sustainability.

This paper tries to discuss what is the way for local geo-tourism. Penghu Marine Geopark is a typical example. The methodology used in this paper are:

• To review the natural background and potential hazards of the environment. Because of tropical marine environment, Penghu owns unique basaltic landscape and a kind of geodiversity. However, it is important to find a way for landscape conservation, to prevent and reduce the impact of natural hazards, such as coastal erosion and landslide.
• To promote local community to enhance the capability of promoting geo-product. Penghu is famous for its marine environment and good quality fish product. It is an important natural resource for whole community.

This paper tries to demonstrate:

• How Penghu islands adapt winter monsoon and summer tropical cyclone. During extreme weather condition, the needs for water resources, electricity and food will be the first priority.
• Coastal erosion is another issue. To reduce the impact of coastal hazards, how local people and government try to introduce such concepts through environmental education to raise the capability of resilience.
• For water resources, desalination facilities are getting more and more important engineering for the Penghu islands. It is a necessary to prepare such engineering works in advance. Local geo-tourism can only achieve after the problems are solved. For local sustainable development, it will need technical support including water, energy and food resources. It is also need to reduce the damage from the impact of climate change and natural hazards to meet the SDGs goals.

How to cite: Lin, J.-C.: Geo-tourism and Geodiversity of geoparks – a demonstration at Penghu Marine Geopark, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4019, https://doi.org/10.5194/egusphere-egu23-4019, 2023.

In the last decade, GIS programs allowed to focus on the dissemination of international, national, and municipal data making them available for consultation or for download and future processing by the population. Several geoportals can be used to share the information, as Internet-based geospatial resources, allowing users to discover, view and access geospatial information and services provided by a wide range of organisations. From this data there are unlimited options for analysis by users, including students and teachers, such as making maps, 3D models and other applications.

The Algarvensis aUGGp is relying on this technology for various purposes ranging from scientific site assessment and categorization, to educational and touristic engagement.

Here, we present examples of practical applications based on GIS information, such as storymaps, digital terrain models in 3D and touristic maps.

Storymaps are based on web applications that allow to tell a story in a dynamic way combining geographical maps with text and other multimedia contents. These applications are increasingly used in scientific dissemination, as well as educational tool within a wide range of themes. They have thus also great potential to enable the awareness about the geoparks and the geosites values to all the public in an interactive and appealing way as well as to support stakeholders and policy makers’ action and management decisions for conservation. Digital educational resource can also be used to explore the geosite during the pedestrian trails, but also as a virtual field trip in a classroom context, for instance. This study had the support of national funds through Fundação para a Ciência e Tecnologia (FCT), under the project LA/P/0069/2020 granted to the Associate Laboratory ARNET and UID/00350/2020 CIMA, as well as from the Municipalities of Loulé, Silves and Albufeira.

How to cite: Veiga-Pires, C., Oliveira, S., Pereira, L., and Moura, D.: Engaging for geosite awareness based on GIS information, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14013, https://doi.org/10.5194/egusphere-egu23-14013, 2023.

The notion of geoheritage counts numerous attempts of definition in literature, all based on the value that a given element of the environment has for humanity. The major differences concern the values that allow an element of geodiversity to be considered as geoheritage. In particular, the values that every author lists are different from the values of the other authors. In particular, only some values are shared by all the authors (namely Scientific, Educational, Cultural and Aesthetic values), while others are only partially shared (e.g., the Recreational or the Economic values). Our work aims at representing these differences in the definition of geoheritage, starting from a formal representation of the elements of geodiversity, useful for both geosites recognition and geoparks management.

The first  phase in the organisation of the information that is necessary for describing the elements of geodiversity is supported by ontological and semantic study, to prove the coherence of the conceptual model. The “elements of geodiversity” and the “elements of geoheritage” are encoded into classes of an ontology for the description of geoheritage, and several properties describe the elements populating both the classes, also underlying their relations. In this phase, the use of the ontology supports  the design of a coherent structure to prevent ambiguity and vagueness in the definitions. Moreover, since some of the elements of geodiversity are geologic features, we can lean on ontologies for geosciences, in which these elements are already encoded and unambiguously described.

The second phase  is the transformation of the conceptual base into a user-friendly tool, through the support of the Omeka-s Content Management System, that provides tools for the creation of compilation masks that gosites/geopark operators can use to fill a database for the description of elements of geodiversity and geoheritage.

Such an organisation of data can support the consistency of the representation of the data and easy further comparison and consultation of information. This brings to higher transparency in the identification of elements of geoheritage,, a relevant information for the proper management of geoparks or other protected areas. Last but not least, such structured data management can be helpful in the valuation of the changes in time of the condition of the evaluated elements of geodiversity, and consequently, of the global evaluated area (such as a geopark).

How to cite: Mantovani, A., Guerini, M., Khoso, R. B., Giardino, M., and Lombardo, V.: Encoding of geodiversity and geoheritage: towards consistency of representation and comparability of descriptions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12797, https://doi.org/10.5194/egusphere-egu23-12797, 2023.

Biodiversity is of fundamental importance for ecosystem functioning as it provides goods and services essential to life on earth, serving human and societal needs (WHO). The positive relationship between ecosystem functioning and biodiversity shows how important biodiversity is to sustainably maintain key ecosystem functions and associated services (Benkwitt et al., 2020). One of the most important tools to protect diversity species is to preserve geodiversity, e.g., geodiversity or diversity of materials, landscape forms and processes, that supports the diversity of habitats (Beier et al., 2015). In particular, rivers are a source of geodiversity and key components of the hydrological cycle in circumpolar regions. They are considered dynamic hotspots that convey freshwater, heat, and terrigenous materials (sediment, nutrients, and carbon) that regulate the biological productivity of terrestrial and marine ecosystems (Feng et al., 2021).

However, Arctic and Antarctic regions (circumpolar regions) are one of the most threatened ecosystems by climate warming. In land examples of climate change impacts in circumpolar regions are a reduction in snow cover (Dankers and Christensen, 2005), earlier snowmelt (Tan et al., 2011), increased water fluxes (Feng et al., 2021), or modifications in the frequency of extreme runoff events (Svetlana et al., 2017). These changes modify the hydrological cycle and have subsequent impacts on drainage networks, undoubtedly affecting the diversity of river processes and landforms.

Thus, in this work we aim to explore river morphological diversity in a Sub-Arctic catchment, the Tana River, the biggest catchment in Fennoscandia draining to the Barents Sea. Tana is a transboundary river between Finland and Norway and of special importance to local socio-economic activities, biological diversity and, e.g., Atlantic salmon preservation. Therefore, a better understanding of the processes that shape river diversity in the present and in the past, to predict future consequences of climate warming is of crucial importance. In order to tackle this, we tested a bottom-up method to characterize fluviodiversity (the diversity of river landforms). This was performed by i) a systematic extraction of local characteristics of the river network (channel slope, width and confinement, morphological pattern, and geomorphic activity) at different scales, ii) an objective determination of river diversity by applying a K-means clustering algorithm and iii) a validation of results with field visits and aerial photo interpretation.

This test showed promising results and indicated that machine learning algorithms such as K-means can successfully classify representative river types. Interestingly, the validation of the results also showed that assessing fluviodiversity of circumpolar regions requires additional understanding of the past landscape evolution to be able to identify present fluvial forms. This is mainly because these areas are usually affected by glacial retreat and land uplift combined with a fast change in runoff, and therefore geomorphic activity. Thus, future research needs to include additional parameters reflecting such post-glacial processes, to further understand past, present and future of fluviodiversity which can provide better insights to adapt to and mitigate the effects of climate change in circumpolar regions.

How to cite: Calle, M., Gonzales-Inca, C., Blåfield, L., Nylén, T., and Alho, P.: Fluviodiversity and Climate Change in Circumpolar regions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6082, https://doi.org/10.5194/egusphere-egu23-6082, 2023.

The DPSIR (Drivers, Pressures, State, Impact, Response) framework is a widely utilized tool for analyzing the relationship between human activities and their impacts on the environment (O’Neill et al., 2002). In this study, we applied the DPSIR framework to examine the loss of geodiversity and degradation of geosystem services in the Monte Rosa (North Western Italian Alps, Sesia Val Grande UNESCO Global Geopark).

Using the DPSIR framework, we identified both the human and climatic drivers of change in geodiversity and geosystem services in the mountain areas, including glaciers, permafrost, temperature, precipitation, rivers and torrents. These drivers exert various pressures on the environment, including, the more frequent extreme events by rainfall, permafrost degradation, fluvial processes, glacial processes and glacial shrinkage. To accurately measure the drivers and pressures that are influencing mountain system, we compiled a list of data, sources, techniques and tools that are appropriate for this purpose. We assessed the current state of geodiversity and geosystem services in the area and evaluated the impacts of these pressures. Our results showed that the available services can be dilapidated overtime due to the active influence of these drivers of change.

Our study demonstrates the utility of the DPSIR framework for understanding the complex interactions between human activities, climate change and the environment, and for identifying strategies for conserving and preserving geodiversity and geosystem services. The findings of this research can inform decision-making and policy development at the local, regional, and national levels, with the ultimate goal of mitigating the negative impacts of human and climatic activities on the environment.

Keywords: DPSIR, geosystem services, geodiversity

References: O'Neill, R. V., Krumhardt, K. M., & Brauman, K. A. (2002). The DPSIR framework. Environmental Science & Policy, 5(5), 347-359.

How to cite: Khoso, R. B., Guerini, M., Giardino, M., Viani, C., and Acquaotta, F.: Human and natural influences impacting the Geodiversity and Geosystem services in mountain regions: An application of DPSIR framework, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13022, https://doi.org/10.5194/egusphere-egu23-13022, 2023.

The rapid evolution of the landscape in the Arctic observed over many years is of concern from a climate perspective, but also regarding emerging natural hazards. Part of this evolution involves soil deformation which, by redistributing soil and organic matter, is impacting the soil carbon cycle. The variety and complexity of the mechanisms controlling soil movement is a significant source of uncertainty in estimating current and future soil carbon storage and fluxes. A better understanding of the soil deformation triggers and kinematics will allow us to better understand their impact on climate change.

In this study, we investigate soil deformations and their controls in a discontinuous Arctic permafrost environment using a dense, low-cost sensor network providing depth-resolved deformation and temperature measurements to depths up to 1.8 m (Wielandt et al., 2022). The sensor network was deployed at 59 locations across a 2 km² watershed located near Nome, AK. The deformation and temperature were monitored with a high resolution from May 2022 to September 2022. During this period, the watershed experienced air temperatures exceeding 0°C and numerous rain events, leading to critical conditions for soil deformation. During the monitoring period, displacements of a few millimeters to tens of centimeters were recorded to depths up to 1.8 m. These displacements showed different spatio-temporal patterns that vary as a function of the topographic position, the subsurface structure and the thermal and hydrological states. While some locations showed a clear relationship between seasonal thaw depth and soil deformation, other locations remained either stable or deformed mostly in response to rainfall events. A detailed analysis of the data allowed us to highlight the different factors controlling the deformation (e.g. slope aspect, permafrost depth, bedrock depth, soil moisture, etc.). We were thus able to characterize the impact of each factor on the evolution of the morphology of the watershed. This study provides a better understanding of the mechanisms controlling hillslope deformation and their possible impact on the soil carbon distribution and the hazard they may represent.

Wielandt, S., Uhlemann, S., Fiolleau, S., Dafflon, B., 2022. Low-Power, Flexible Sensor Arrays with Solderless Board-to-Board Connectors for Monitoring Soil Deformation and Temperature. Sensors 22, 2814. https://doi.org/10.3390/s22072814

How to cite: Fiolleau, S., Uhlemann, S., Wielandt, S., Shirley, I., Wang, C., Rowland, J., Thaler, E., and Dafflon, B.: Understanding hillslope deformation mechanisms in permafrost environments using a dense sensor network., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8883, https://doi.org/10.5194/egusphere-egu23-8883, 2023.

Deep subsurface weathering has traditionally been measured by quantifying variations in weathered material properties through cores and boreholes. However, cores collected from the subsurface necessarily sample a minimal fraction of the subsurface. On the other hand, geophysical surveys can be used to obtain a representative perspective of the subsurface. To better understand the near-surface weathered layers, the paper presents an application of rock physics modelling with the help of field-based seismic refraction measurement. We acquired seismic refraction data in hillslope using 4.5 Hz natural frequency geophone with 5-meter geophone spacing. We estimated the subsurface compressional (P) wave velocity (VP) structure and mapped the seismic profile. The profile demonstrated saprolite thickness varying from 1 to 2 meters. To better identify the weathered layers (saprolite) in this section, we predicted porosity using the velocity-porosity relationship model. The porosity estimated through the model was validated by the porosity of the sample extracted from boreholes. This study shows how low-cost techniques can provide useful information about near-surface complexity. Therefore, from this study, it was concluded that proper identification of near-surface layers requires a combination of complementary field-based measurement and precise lab-based rock physics measurement. 

How to cite: Pal, A. K. and Nair, A. M.: Near-surface characterisation of weathered layer-using application of rock physics modelling in seismic measurement, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12793, https://doi.org/10.5194/egusphere-egu23-12793, 2023.