A web-based landslide susceptibility map for Attica Region in Greece
Figure 1: Rockfall at Galani spring near the village of Agia Pelagia (Eastern side of Kithira Island, Greece). The photo has been taken by UAV (February 2019).
I would like to present a recent fulfilled EU co-funded research project, named DIAS*. This research has generated a 1:100,000 regional scale landslide inventory map for the Attica Region of Greece which is the basic platform for the construction of susceptibility, hazard and risk map analysis for different areas of the entire county. In accordance with extreme rainfall episodes that have taken place more frequently over the last years in the Attica Region as well as the existence of mega-fires that arise due to the climate crisis in the Mediterranean region, this research can facilitate the role of Civil Protection Authorities, by providing inputs for prevention and preparedness.
Figure 2: Map from Copernicus emergency management service regarding two disastrous mega-fires that happened in the Attica Region in the summer of 2018.
The outcome of the DIAS project is accessible to the public, through a web-based platform using open-source GIS software so as to aid awareness of landslides among different stakeholders (e.g. landslide experts, government agencies, planners, citizens), and acquire an explanation about the interaction of cascading events such as (flash) floods, earthquakes, fires and landslides in daily life. In the following link, http://dias-proj.civil.duth.gr/mapstore/#/context/Dias_Landslides/40, anyone can view DIAS spatial distribution of over 200 slope failures (e.g. rockfalls, falls, slides) based on published and unpublished information, field observations and remote sensing techniques.
The identified slope failures were included in the ArcGIS database as: 1) spatial data (mapped as points) and 2) tabular (descriptive) data in text or numeric form, stored in rows and columns in a database and linked to spatial data (Burns and Madin, 2009). In addition, the following information per slope failure is presented based on Working Party on World Landslide Inventory (1990) findings:
(i) geographic details: prefecture, municipality, locality,
(ii) geological formation, lithological composition,
(iii) mass movement date – field survey date,
(iv) type of movement, (v) triggering factor,
(vi) landslide causes.
The landslide susceptibility map produced is shown in Figure 3, where:
(a) slope failures are presented as points, assigning a unique identifier and a number of attributes to each landslide,
(b) active faults are presented as lines and
(c) landslide susceptibility categorization has been completed according to the findings of Tavoularis et al. (2021).
Figure 3: Excerpt from the landslide WebGIS platform for Attica Region, Greece.
This region with a size of approximately 3,800 km2 was selected for the following reasons:
- in this region, many cases of slope failures** have been reported
- the Attica region contains almost half of the Greek population, more than 60% of the industrial production in Greece and high-value properties and infrastructure. For this reason, mapping areas prone to slope failure helps public authorities associated with public works in taking mitigation measures against the increase of risk in potentially dangerous areas, leading to losses of life and investments in such a densely populated county.
- taking into account that in the next five to ten years, very important civil engineering projects are to be constructed in Attica county, the existence of a regional-scale landslide susceptibility map could be a very useful tool for supporting decisions in order to prevent the positioning of high-value constructions in unsuitable locations.
In order to achieve this, a database of slope failures triggered in the Attica Region from 1961 to 2020 was developed and a semi-quantitative heuristic methodology called Rock Engineering System (RES) was applied through an interaction matrix, where ten parameters, selected as controlling factors for the landslide occurrence, were statistically correlated with the spatial distribution of slope failures. The generated model was validated by using historical landslide data, field-verified slope failures and a methodology developed by the Oregon Department of Geology and Mineral Industries, showing a satisfactory correlation between the expected and existing landslide susceptibility level. The intention is that the database should be updated constantly. For further reading about this research, please visit the following hyperlink: https://doi.org/10.3390/land10020148.
Figure 4: Interaction between landslide inventory, susceptibility, hazard, and risk data through the use of Rock Engineering System methodology.
*: DIAS is the acronym for Landslide Risk Resilliece (in Greek: Διαχείριση της κατολισθητικής διακινδύνευσης στην Περιφέρεια Αττικής)
**: Characteristic slope failures from this research can be found on the Safe Greece 2020 online conference presentation which took place on 14-16 October 2020 in Athens:
This research is co-financed by Greece and the European Union (European Social Fund – ESF) through the Operational Program “Human Resources Development, Education and Lifelong Learning 2014-2020” in the context of the project “Landslide Risk Resilience of Attica region” MIS (5050327).
Burns, W., Madin, I. 2009. Protocol for inventory mapping of landslide deposits from light detection and ranging (LiDAR) imagery. Special paper 42, Oregon Department of Geology and Mineral Industries.
Hudson, J. Rock Engineering Systems: Theory and Practice, 1st ed.; Ellis Horwood Limited: Chichester, West Sussex, UK, 1992. pp. 1–185.
Tavoularis, N.; Koumantakis, I.; Rozos, D.; Koukis, G. 2017. Landslide susceptibility mapping using Rock Engineering System approach and GIS technique: An example from southwest Arcadia, Greece. Eur. Geol. J. 2017, 44, 19–27. Available online: https://eurogeologists.eu/tavoularis-landslide-susceptibility-mapping-using-rock-engineering-system-approach-gis-technique-example-southwest-arcadia-greece/.
Tavoularis, N.; Argyrakis, P.; Papathanassiou, G.; Ganas, A. 2020. Towards the development of an updated GIS-based landslide hazard map in Attica region, Greece; DIAS project. In Proceedings of the Safe Greece 2020 7th International Conference on Civil Protection & New Technologies, 14–16 October 2020.
Tavoularis, N., Papathanassiou, G., Ganas, A. Argyrakis, P. 2021. Development of the Landslide Susceptibility Map of Attica Region, Greece, Based on the Method of Rock Engineering System. Land 2021, 10, 148. https://doi.org/10.3390/land10020148.
Dr. Nikolaos Tavoularis holds a PhD (2017) in Engineering Geology from National Technical University of Athens (School of Mining Engineering, Department of Geological Sciences). He is an experienced Geologist with a demonstrated history of working in the civil engineering industry for various major projects in Greece. He has received (2020) an Excellence Fellowship by EU about a post doc research related to Landslide Risk Assessment. From 2016 up to date, he is working for civil engineering projects in the Region of Attica, the biggest regional government administration in Greece. He is a member of the International Association of Engineering Geologists (IAEG).
This research project was fulfilled with the cooperation of George Papathanasiou (Associate Professor of Democritus University of Thrace, Greece, Athanasios Ganas (Researcher at National Observatory of Athens, Institute of Geodynamics) and Panagiotis Argyrakis (Researcher from Peloponnese University)
This article has been edited by Ruth Bektas.
Disclaimer: This article expresses the personal opinions of the author. These opinions may not reflect the official position of the European Federation of Geologists (EFG).