Geodiversity and Geosystem Services of Drainage Basins: from Assessment to Enhancement
Geodiversity is a recent relevant topic among Geosciences, and characterizes drainage basins, which record information from a variety of components of the natural environment, relevant for the scientific assessment of both long-term evolutionary processes and interpretation of recent responses to climate change, as well as for the Nature-Human interactions. The establishment of a conceptual/methodological framework for multifactor/multidimensional approaches to Geodiversity of drainage basins is of relevant value for the enhancement of the related geosystem services.
From slope micro-catchments to large drainage systems, river basins are geosystems characterized by a high degree of individuality. Geodiversity assessment at various scales offers advanced knowledge on river catchment functioning by means of many conditioning factors, such as: geology, lithology, tectonics, geomorphology, energy and matter cycle, connectivity between slope and fluvial subsystems, soil, climate, land cover and land use etc. The variety of such environmental features controls the functional connectivity of river basins.
Since each catchment represents a different object, the assessment of geodiversity within river basins (i.e. intrinsic) appears as a complex analytical process of each element; at the same time, it drives the relationships between different basins (i.e. extrinsic geodiversity).
The key issue is the selection of criteria for assessing geodiversity considering the spatial, thematic and temporal resolutions. Another open problem is the assessment of services offered by geodiversity of drainage basins (i.e. geosystem services), particularly those in highly dynamic conditions due to present day climate change.
In this session, we aim to receive contributions on two closely-related concepts in a contemporary challenge for geoscientists. How can geodiversity and the related variable features limit the geosystem services? This question arises in present-day communities as the dilemma of using and exploiting river basin resources while preserving them for future generations. Different morphoclimatic conditions make great landscape, and in the specific drainage basins complexities and different possibilities of providing geosystem services emerges. These issues become particularly powerful in the era of the United Nations Sustainable Development Goals.
Arie Christoffel Seijmonsbergen and Matheus G.G. De Jong
Mountains provide a wide variety of services for their inhabitants, such as drinking water, energy and mineral resources, dairy farming and tourism. At the same time, mountains are globally recognized as dynamic, vulnerable, high geodiversity environments that deserve protection. The high geodiversity is due to the variety of geomorphological processes and their resulting landforms across time and space, in dependency of the geological substratum and changing climate. The processes which are active at present day are usually readily recognisable, those of the past often not. In order to continue to profit from geosystem services (in general: the services provided by the abiotic subsurface) in a sustainable way, it is imperative to study the pathways that led to the geomorphological diversity as we see now.
To do so, we analyzed a multi-scale geomorphological ArcGIS Pro geodatabase and developed a recoding scheme to semi-automatically relabel the legend units of the existing geomorphological maps in terms of past processes and landforms. This enabled us to quantify the geomorphological diversity change since the Late Glacial Maximum (LGM) by means of spatial analyses and zonal statistics supported by regional expert data of the deglaciation history.
Our study area is the municipality of Nenzing in Vorarlberg (Austria). It includes the Meng river catchment, a high alpine valley network in the Rätikon Mountains with elevations between 450 and 2850m. It is characterized by a wide variety of geomorphological environments, process groups and morphogenetic domains in which human activities and land use are restricted to forestry, cattle grazing and small scale regulated summer tourism. The area’s geomorphological diversity has documented scientific conservation value, such as pollen proxies and well-preserved ice-marginal landform sequences suitable for climate reconstructions, and also hosts geosites of outstanding educational and geoheritage value. Potential future developments in the area are the expansion of existing hydropower energy plants, the mining of ice-marginal gravel resources and the exploitation of groundwater aquifers, which all affect the geosystem services of the area itself and of adjacent areas.
The results of our analyses show that 1. geomorphological diversity has increased since the LGM, especially during and just after the Late Glacial period and likely due to the absence of a full vegetation cover; 2. landforms and deposits of the glacial environment have been degraded by or covered with deposits of the periglacial, fluvial, mass movement, organic and karst environments; and 3. human influence, notably in historic times, has added to and occasionally accelerated changes in geomorphological diversity by e.g. local mining activities, rerouting of waterways, deforestation leading to local landslides, construction of retaining walls and other natural hazard-reducing measures.
We conclude that knowledge of temporal geomorphological diversity change trajectories contributes to a better understanding and sustainable use of geosystem services. Furthermore, potential impacts from measures to unlock previously unused geosystem services can be interpreted in time and space.
How to cite:
Seijmonsbergen, A. C. and De Jong, M. G. G.: Understanding alpine geosystem services from a geomorphological diversity perspective, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9351, https://doi.org/10.5194/egusphere-egu22-9351, 2022.
The characterization of geoheritage has a relevant role in the discussion of geoethics. What is geoheritage and what element of geoheritage should we conserve for the future generations? According to many authors, geoheritage are those parts of geodiversity that are relevant for human kind and are worthy to be included into geoconservation programs. The relevance of geodiversity is often expressed in literature through the use of lists of values that, according to the author who publishes it, make a geologic feature/a geodiversity element as part of geoheritage.
Several authors proposed their lists of values. However, these lists present some differences: someone includes values that are not considered by other authors, or expresses them with different words. The consequence is that some elements of geodiversity, or, more in general, some geologic features could be considered as geoheritage only if a given list is taken into account. This situation may bring ambiguity when it comes to decide whether a feature is geoheritage, and can consequently bring to choose an inadequate strategy for geoconservation. For example, an underestimated feature will not be included into geoconservation programs, and an inappropriate use could ruin it. Viceversa, an overestimated feature can be overprotected, resulting in an obstacle for the local economy.
This contribution aims to present, as an example, the differences between some of these lists of values. The core of the presentation is a table that highlights which of the values are the same and what are the differences (missing or differently expressed values). This is a step of a wider research, whose goal is to identify a method to limit ambiguities in the definition of geoheritage features, in order to support geopark and geosite’s stakeholders in the management of their territories and in the transparency of their decisions.
How to cite:
Mantovani, A., Giardino, M., and Lombardo, V.: Values of geodiversity: a geoheritage oriented comparison, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11338, https://doi.org/10.5194/egusphere-egu22-11338, 2022.
Studies on geodiversity have been gaining prominent interest among the geoscientific community over the last decades. As operational concept, geodiversity implies a measurement and its application narrowed to a given spatial area. However, such concept is often integrated to support planning perspectives that focus mostly on geoconservation, neglecting other activities that might transform, destroy or exploit georesources. Furthermore, diversity alone might not account for the actual pivotal role that abiotic and interfacial components play in socio-ecological systems and their functioning.
In a first part, the present research reviews the geodiversity concept, integrated within a framework towards its operationalization for territorial management. Geodiversity is defined as the range of abiotic and interfacial resources – lithodiversity, superficial diversity, hydrodiversity, pedodiversity, geomorphodiversity, mineral diversity, paleodiversity and climate diversity – of a given area, including their constitution, assemblages, structures, properties and contributions to socio-geo-ecological systems. Geodiversity is therefore considered both in its typological and functional diversity, the latter one being related to the geo-ecosystem services (GES) that geodiversity provides to society. The characterization of geodiversity is completed with the identification of the anthropogenic drivers linked to land-planning strategies (e.g. urban projects, mining activities, agricultural practices) and that might affect, positively or negatively, GES supply.
The second part, aims at confirming the necessity of an operational framework through the assessment of geodiversity and its spatial patterns on the French Guiana case-study, an Oversea French territory located in South America, within the Guiana Shield. Almost entirely covered by the Amazon rainforest ecosystem of exceptional biodiversity, French Guiana is considered as an international conservation and land-planning challenge which faces multiple issues (e.g. urban, agricultural and industrial growth, forest management and gold mining planning). However, French Guiana geodiversity and its management are not properly acknowledged by land-planning strategies.
The assessment of geodiversity of French Guiana was performed through the creation of a 10x10 km grid in a GIS environment. Lithodiversity and superficial diversity, hydrodiversity, geomorphodiversity and mineral diversity sub-indices were assessed based on the number of entities within each grid-cell. The four sub-indices were summed to obtain a geodiversity index. Local Moran’s I was then used to identify geodiversity hotspots and coldspots.
Geodiversity hotspots were found mainly along the gold-bearing greenstone belts crossing French Guiana. However – despite the fact that further data must be integrated for soil and paleontological resources that are still little known at the scale of the whole territory – some areas showing low geodiversity are known to display important points of geological interest (from a geoheritage perspective). Therefore, this research allows to review a more comprehensive definition of geodiversity and to highlight the necessity of standardized datasets and classification methods to assess all geodiversity components. The assessment of diversity alone is not enough for geoconservation nor broader land-planning perspectives. It is pivotal to account for the contribution of geodiversity to the functioning of a given area and its interaction with anthropic activities. Geofunctionality can be assessed through proper datasets identifying and quantifying GES flows (i.e. supply-demand), for instance, through Essential Geodiversity Variables.
How to cite:
Scammacca, O., Bétard, F., Heuret, A., Aertgeerts, G., and Montagne, D.: Geodiversity assessment of French Guiana: the need to integrate geodiversity within land-planning , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12641, https://doi.org/10.5194/egusphere-egu22-12641, 2022.
Arxan-Chaihe Volcanic Field (ACVF) is southwest of the Great Xing'an Range in Inner Mongolia, NE, China. This is a typical monogenetic volcanic field formed in the Pleistocene with its latest activity in a fissure eruption about 2000 years ago. The volcanic elements are the main attraction of two geoparks (Arxan and Zalantun), including fissure-aligned spatter/scoria cones and occasional maar volcanoes. Besides the young volcanic features, the region is dominated by eroded and structurally dissected exhumed Mesozoic basement rocks, such as granites and metamorphosed sedimentary rocks. The main geoeducation, geotouristic and geoconservation activities are centred along with the recent basaltic volcanic features, while the older rocks receive little or no attention so far within the conceptual framework of the geoparks. The geodiversity estimate of the ACVF is clearly incomplete. Here we present the first geodiversity estimate of the region applying the method outlined recently in Zakharovskyi & Németh (2021), combining the geomorphological and geological elements into a grading system weighting their rarity, significance, and uniqueness. To outline the geomorphological diversity, the geomorphon concept was used alongside watershed analysis of the theoretical fluvial network of the region aided by the localisation of volcanic geomorphology elements. For the geological diversity estimates, the available geological maps, field surveys and volcano geology classification were utilised. The boundaries of geoparks enclose a region of diverse geomorphological structures presented by mountain ranges, valleys, and hills with an altitude between 500 and 1700 m above sea level. Lakes are either lava-ponded lakes or crater lakes. The fluvial system contains four main rivers and their side streams located mostly in the east part of the region. Geology and geomorphology are the core parameters that generally represent geodiversity. Qualitative-quantitative assessment methods highlight the most valuable geodiversity parameters of the region, which can become potential geosites. Several methods were applied through the GIS tool using QGIS freeware. The analyses contain the distinguishing rock types, geomorphology, streams, slopes, and terrain forms (geomorphons). By calculation of those parameters, the values of geodiversity were calculated. In addition, the spatial variation of geochemistry data was entered into the GIS system to delineate geochemical patterns within the volcanic field as an additional attribute to recognise the internal diversity of the eruptive products. Our study concluded that the recent volcanic features indeed bear high geodiversity and elevated geoheritage values. However, the uplifted and structurally complicated old terrains with mature fluvial networks provide high geomorphological diversity to the region, therefore keeping the overall geodiversity score high regardless of the relatively uniform geological assets. Well-selected geosites from those regions would serve important geotouristic and geoeducation goals and should be included in the geoconservation strategy of the region.
Zakharovskyi, V.; Németh, K. Quantitative-Qualitative Method for Quick Assessment of Geodiversity. Land 2021, 10, 946. https://doi.org/10.3390/land10090946
How to cite:
Li, B., Zakharovskyi, V., and Németh, K.: Geodiversity estimate of a region hosting an intracontinental monogenetic volcanic field in the territory of the Arxan UNESCO Global Geopark and Zalantun Autonomous Geopark, NE China, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3241, https://doi.org/10.5194/egusphere-egu22-3241, 2022.
The term geodiversity was proposed in the 1990s, however there is still a noticeable lack of established conceptual and methodological framework for geodiversity assessment. In its absence, various geodiversity assessment methods have been proposed. They can be categorized, based on data sources, into direct and indirect, and based on the assessment procedure into qualitative, quantitative, and mixed (qualitative-quantitative). Each of these categories introduces an ambiguity by relying on expert judgment or interpreted geodata rather than on direct measurement. Despite the impressive number of different terrain-specific studies, there has been a conspicuous absence of comparative studies testing the efficacy of geodiversity assessment methods across different types of terrain characterized by differences in morphology, morphogenesis, and relief energy.
Therefore, we have selected three different national parks represent different landscape types: mountains (Karkonosze National Park), uplands (Roztocze National Park), and lowlands (Wolin National Park). Input datasets included 1 m DEM and thematic map layers: lithological, geomorphological, hydrographical and soils features as well as CORINE Land Cover. The presentation reports on geodiversity assessments performed independently by experts and volunteers as crowdsourcing analytical data. A potential strength of the crowdsourcing approach over the expert-based approach is that the former minimizes subjectivism, which is a common critique of expert-based environmental valuation, including the subject of our research - geodiversity assessment. Using the DEM data and r.watershed tool, the 1-order catchments were delineated for the national parks (KNP 212, RNP 403, WNP 289) and used as spatial units for geodiversity assessment. The use of catchments instead of squares, grid cells or arbitrary polygons is a new approach in geodiversity assessments. The expert and volunteer assessment data sets were separately processed with two spatial multicriteria methods: Weighted Linear Combination (WLC) - also referred to as the global version of WLC, and Local Weighted Linear Combination (L-WLC) resulting in two geodiversity maps for each of the parks. More over we used two scenarios. Under the first scenario, called the expert-based scenario, an expert familiar with the study area or a group of experts classifies the individual abiotic components of geodiversity and assigns them weights instrumental for computing a geodiversity score. In the second scenario, called the crowdsource-based scenario, multiple individual ratings concerning the abiotic components of geodiversity and their weights are collected and aggregated to yield a corresponding geodiversity score. The maps were qualitatively evaluated for their efficacy of capturing spatial heterogeneity and differentiating between high and low geodiversity of specific areas within the national parks. The expert-based maps were compared with the volunteer-based maps using statistical measures of association and similarity: Spearman’s correlation coefficient, the Jaccard similarity index, also known as Tanimoto index, and the relative Manhattan similarity.
The results show that L-WLC is more suitable for geodiversity mapping of mountainous areas characterized by high morphogenetic and morphometric diversity whereas WLC yields better results in less diverse areas such as uplands and lowlands. The use of data originating from volunteer-based assessment requires meeting internal and external data quality standards and should be treated with caution.
How to cite:
Zwoliński, Z., Najwer, A., and Jankowski, P.: Geodiversity assessment with global and local S-MCA in different landscapes based on expert and crowdsourcing data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9007, https://doi.org/10.5194/egusphere-egu22-9007, 2022.
The current state of geodiversity estimates still lack of complete strategy of assessments in comparison with its analogue, biodiversity. This issue connects with the number of differences between these terminologies and existing form of their elements. However, the basic understanding of geodiversity, which common among most researchers, is the numeric representation of the variety of abiotic elements includes geology, geomorphology, hydrology, climate, soils and other features and processes influencing non-living nature. In this research, two main elements of geodiversity (geology and geomorphology) have been assessed with two different scale systems defined as “grid” and “non-grid”. “Grid” system based on cells with side size of 2.5 km, where each cell contains an arithmetic average value of geodiversity for each region throughout the area of research (Figure). Meanwhile, “non-grid” system assesses the areas bordered by different values of geodiversity, which shows number of shapes with sizes and forms delineated by geodiversity values on the model (Figure). Both scales were calculated by qualitative-quantitative methodology of assessment of geodiversity. The methodology based on 5-point evaluation system for geological and geomorphological elements calculated by arithmetic average equation, where places with high values can be considered as potential geosites, which should be studied in detail for future research. The two islands (Upolu and Savai’i) of Western Samoa have been selected for the research due to their relatively simple geological history based on an early growth of a basaltic shield volcano(s) covered by small scoria and spatter cones formed during the post-shield rejuvenated volcanism. Even though the region is in the tropical climate zone with high rainfall, its geology provides an even relief throughout the islands, with only few short immature fluvial networks. The multiple extensive lava sheets also acted as erosion-resistant substrate further forming fluvial networks of deep but narrow canyon-like stream valleys with numerous high waterfalls. These regions are recognizable by qualitative-quantitative methodology, but differently represented on the models with mentioned scale systems (“grid” and “non-grid”). For Samoa Islands, fluvial networks are important as they expose volcanic stratigraphy and forming rugged morphological elements on the surface. Their limited geometry commonly prevents them to be clearly visible on the “grid-based” system of geodiversity assessment. Meanwhile, “non-grid” system accurately outlines these regions as locations with high values (especially Upolu Island) (Figure). In result, “grid” and “non-grid” scale systems utilized by one qualitative-quantitative methodology demonstrate different pictures: “Grid” scale system of geodiversity estimates is more suitable for a quick first order assessment of geodiversity with big databases, while “non-grid” method fits better to outline exact location with high geodiversity in a large map scale, hence more useful to highlight valuable regions for geoconservation.
How to cite:
Zakharovskyi, V., Németh, K., and Li, B.: Comparison of grid and non-grid types of scaling for geodiversity assessment, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3204, https://doi.org/10.5194/egusphere-egu22-3204, 2022.
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