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EN
Landslides determine increases and decreases in specific soil compounds which is affecting soil fertility. The recovery of soil fertility is a long process and may be used as an indicator of the landslide age and can contribute to the management plan of the affected area. In order to add to data about soil properties affected by landslides, the current study focuses on a young and shallow landslide from the western part of the Transylvanian Depression. Soil samples were analysed from a physico-chemical point of view (pH, organic matter - OM, total organic carbon - TOC, major cations, and iron content) in two places, at between 0 and 60 cm depth (inside and outside the landslide). The results obtained showed lower values of pH inside the landslide, low values of TOC and rock fragments in both places studied (inside and outside the landslide) and no differences in soil texture between disturbed and undisturbed soil. The ammonium, magnesium and calcium content was higher outside the landslide, the sodium level was slightly higher outside the landslide, while the potassium concentration was higher inside the landslide. This study offers new data regarding recovery of soil fertility and highlights the importance of gaining knowledge on soil properties of relevance to future measures to increase the fertility of agricultural soils.
2
Content available Podatność osuwiskowa Polski
EN
Using the location data of landslides and information on geo-environmental conditions, the landslide susceptibility in Poland was calculated using statistical methods. It shows that 15% of the country’s area is susceptible to landslides. The greatest threats occur in the Carpathians and in many regions of the Sudetes, uplands and in the riverbanks. The most vulnerable areas are the slopes in the range of 9-30°, which are built by the flysch sediments in the faulted zones. The areas susceptible to landslides include over a million buildings and about 7,000 km of roads.
EN
The consideration was given to the geological and geomorphological factors of natural hazards in the Ukrainian Carpathians. Principal impact of rock lithology, geomorphological structure, underwater regime and seismic processes on the erosion, gravitational and water-gravitational processes formation was demonstrated. The research confirmed a special role of the tectonic factor and the presence of weak zones in the development of natural hazards. Weak zones are characterized by fracturing, brecciation, bedding of flysch deposits and contrast in permeability. The strength properties of rocks decrease drastically within such zones, and large-scale landslide formation processes occur, especially in the case of subparallel location of zones, relative to river valleys and slopes. The factors of hazardous geological processes were defined and classified using GIS analysis and the developed geological model. A conceptual model of landslide hazards in the area of Carpathian Mountains was developed. Weight coefficients of potentially landslide prone factors were determined from the on-site observations and archive data. An integral spatial map of landslide susceptibility was proposed. The results of this research were the basis of geological environment modeling for the assessment of hazardous geological processes impact on the functioning of infrastructure objects.
EN
Slope failures (SF) in mountainous terrain often occur during or after heavy rainstorms, resulting in the loss of life and damage to the natural and/or built environment. Assessing areas susceptible to SF is essential for land use planning in threatened areas. This article presents an didactic basedanalysis of the potential contribution to geo-spatial approaches for predicting SF qualitative exposure in mountainous environment. Its main aim is to assess the impact of the geologic, geomorphic, rainstorms, and anthropogenic factors in the initiation of SF in Zaarouria region. 219 events (1996–2016) were inventoried through images interpretation and field surveys and were compared to the physical parameters of the terrain to give a SF susceptibility index value using a simplified model. Vulnerability and risk maps are also established. The Standard deviation classification was used to delineate various susceptibility, vulnerability and risk zones, namely, nil, low, moderate and high. Field data on SF were employed to evaluate and validate the susceptibility zonation map. The results of this study demonstrate that SF are largely governed not only by geoenvironmental conditions but also by human activities, mainly roads and construction.
EN
This paper presents a GIS-based method for landslide susceptibility (LS) assessment using slope-movement inventory and field data. The study has been carried out along A1-Highway (A1-H) in Hanif region as this road section is threated by several types of mass wasting. This hilly zone is known by their landslides sensitive terrains in the North of Algeria. The terrain data are collected from a Géologic map, satellite imageries, digital elevation model, rainfall data, field suveys and ancillary data. In this paper Frequency Ratios (FR) based on bivariate statistical method are evaluated by comparing the observed landslides to their controlling factors. The product of the linear summation of the FR values was a landslide susceptibility index (LSI) map. It was categorized using the natural breaks classification method. The resultant LS zonation map delineates the area into five hierarchic zones. The results confirms that the angle of the slope, plays the most role in wasting especially in road sides. The LS can be used for preliminary land use planning and hazard mitigation purpose. By means of this map the current route of the A1-H can be improved to cross less susceptibles zones.
EN
The paper presents a statistical approach to landslide susceptibility modelling using the GIS-based spatial data analysis. The area of investigation is an urban district in which the activation of mass movements is of interest to both the local population and the authorities. The analyzes were carried out on the basis of the “Map of landslides and risk areas for the city of Gdansk” drawn in 2011. The research took into account the geological, geomorphological, hydrological, hydrogeological and anthropogenic conditions. Eleven landslide influencing factors were considered in the analyses. The landslide susceptibility map was evaluated by the landslides index method. The obtained results show that the most susceptible to landslides are slopes of angle between 10–29° and areas located at a distance of 50 m from watercourses and reservoirs. The presence of silty sands, silts and clays along a lithological layer and the N, NWand NE aspect of a slope are also of great significance. The final map presents the areas with the greatest probability of mass movement occurrence.
PL
W pracy przedstawiono ilościową ocenę zagrożenia osuwiskowego i związanego z nim ryzyka w testowym rejonie Karpat fliszowych (okolice Szymbarku w Beskidzie Niskim). Wykorzystano równanie Varnesa i schemat metodyczny, pokazujący etapy takiej oceny: od inwentaryzacji osuwisk, przez wyznaczenie podatności na osuwanie i zagrożenia, aż po oszacowanie ryzyka na badanym obszarze. W ten sposób po raz pierwszy w polskiej literaturze dokonano oceny ryzyka osuwiskowego w sposób kompleksowy. Do wyznaczenia podatności na osuwanie i zagrożenia wykorzystano techniki GIS i metodę ELR (Empirical Likelihood Ratio) należącą do klasy funkcji sprzyjania (Favouribility Function). Przeprowadzone modelowanie wykazało przydatność zastosowanych metod do przewidywania zagrożeń w skali obszaru badań (modelowanie w dużej skali – 1:10 0000). Wrażliwość (vulnerability) osza­­cowano na podstawie wskaźnika odnoszącego koszt napraw do kosztów odtworzenia obiektu. Z kompilacji map zagrożenia i potencjalnych strat powstała mapa ryzyka osuwiskowego dla obszaru badań. Przeprowadzona analiza strat i korzyści w przypadku zagrożenia osuwiskowego wykazała duży (nawet 20%) udział strat pośrednich w stosunku do strat bezpośrednich. Wynika z tego, że straty pośrednie nie mogą być pomijane przy oszacowaniu ryzyka osuwiskowego i powinny by uwzględniane w planowaniu przestrzennym.
EN
The paper presents quantitative estimation of landslide hazard and risk in the test area located in the Polish Flysch Carpathians (surrounding of Szymbark, Beskid Niski Mts.). The adopted approach is enrooted in Varnes equation and, thus, problem solving is tackled with a stepwise strategy comprising landslide inventory, susceptibility and hazard modelling, and assessment of related risk in the studied area. Under such framework the landslide risk has been evaluated comprehensively for the first time in Poland. Drawing upon GIS capabilities, landslide susceptibility and hazard were modelled using ELR (Empirical Likelihood Ratio) function, belonging to Favourability Functions. The performed multivariate statistical modelling turned to be useful for predicting landslide hazard in the test area (large scale modelling - i.e. 1:10 000). Vulnerability was estimated by relating costs of repairs to costs of analysed objects at risk. The developed landslide risk map is the outcome of compiling the landslide hazard map with the map of potential losses. Moreover, the performed cost-benefit analysis showed that indirect losses are significant (up to 20%) when compared to direct ones. Therefore, the indirect losses may not be neglected and have to be taken under consideration in spatial planning and landscape management.
EN
This paper describes a new methodology for assessing landslide susceptibility from temporal land-use change using integrated earth observation (EO) and a GIS. Ground surface change data using LANDSAT and INSAR (permanent scatterer, PS) are used in a physically based geotechnical model which firstly defines initial susceptibility to landslides through geological and geomorphological background data or field study. Secondly it provides the impacts of change in terms of positive or negative effects on limit equilibrium factors of safety (FS) and thirdly the potential outcome of changes at a FS of 1.0 in terms of slope deformation. Application of the model in the Caramanico area using EO data from 1987 to 2000 is described and interpretative and image processing procedural difficulties are discussed. In this study only surface changes from vegetation to artificial structures could be reliably used in the model. Nevertheless preliminary results show promise, suggesting there may be some spatial relationships between areas of historic surface change and deformation recorded by GPS and PS in the urban area.
PL
W artykule przedstawiono nową metodę oceny podatności osuwisk na okresowe zmiany użytkowania terenu. W badaniach wykorzystano zintegrowane obserwacje satelitarne oraz technikę GIS. Na podstawie informacji o zmianach powierzchni Ziemi, uzyskanych z satelitów LANDSAT i INSAR, opracowano model geotechniczny, który, po pierwsze, na podstawie danych geologicznych i geomorfologicznych lub też bezpośrednich badań terenowych, określa podatność terenu na powstawanie osuwisk, po drugie, wskazuje wpływ zmian na granice równowagi czynników bezpieczeństwa (FS), a po trzecie, przedstawia potencjalny efekt zmian na deformację zboczy przy współczynniku FS = 1.0. Opisano też wykorzystanie tego modelu w rejonie Caramanico (Włochy) z uwzględnieniem obserwacji satelitarnych z lat 1987-2000. Przedyskutowano trudności pojawiające się w trakcie obróbki danych satelitarnych i podczas ich interpretacji. Okazało się, że w opracowaniu dotyczącym rejonu Caramanico można wykorzystać jedynie dane dotyczące zmian powierzchniowych, związanych z zamianą terenów pokrytych roślinnością na tereny zabudowane. Niemniej, wstępne wyniki wspomnianych badań sugerują, że mogą istnieć przestrzenne związki istniejących uprzednio zmian powierzchni z deformacjami obszarów zurbanizowanych, odnotowanymi przez pomiary GPS oraz przez satelitarne pomiary radarowe PS.
EN
This study focuses on one of the most complex petrographic and structural relief units in Romania, affected by significant earthquakes and uplift neotectonic movements, i.e. the Subcarpathian region. The Subcarpathians represent a highly fragmented hilly area subject to various mass movements and erosion processes, frequently affecting settlements, transport infrastructure and environmental values. The paper aims to present a landslide exposure assessment conducted for this region, following three main stages which are addressed in the context of present environmental conditions and their possible future changes: landslide susceptibility, landslide hazard and the exposure of elements at risk. It also intends to address and discuss the associated specific contexts, problems and challenges. By integrating selected landslide hazard scenarios, computed under different precipitation and seismic conditions, and key data on elements at risk (i.e. built-up areas, arable lands, permanent crops and major protected areas) into GIS spatial and statistical analyses, potential current and future landslide risk areas are outlined. Results are quantified at the Local Administrative Unit (LAU; towns and communes) level. The output maps reveal significant regional differences in landslide susceptibility and hazard according to the specific predisposing and triggering factors considered, as well as spatial variations in the landslide exposure in relation to specific land-uses and protected areas in the region. The present study contributes to increasing knowledge on landslide susceptibility, hazard, and exposure in the area and provides a ground for further related investigations. In addition, because of its predictive character, this study may constitute a useful tool for policy makers supporting decisions with regard to where future priorities should be focused.
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