Balázs Székely

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Verified

Balázs verified their affiliation via an institutional email.

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• Dr. rer. nat. (PhD)
• Assoc. prof. (+ research) at Eötvös Loránd University

OPEN ACCESS: http://www.mdpi.com/2072-4292/5/6/2720 An active landslide in Doren, Austria, has been studied by multitemporal airborne and terrestrial laser scanning from 2003 to 2012. To evaluate the changes, we have determined the 3D motion using the range flow algorithm, an established method in computer vision, but not yet used for studying lan...

The horizontal variation and vertical layering of the vegetation are important properties of the canopy structure determining the habitat; three-dimensional (3D) distribution of objects (shrub layers, understory vegetation, etc.) is related to the environmental factors (e.g., illumination, visibility). It has been shown that gaps in forests, mosaic...

The morphological and compositional analysis of fossils provides essential knowledge about the classification and development of the species and about the environmental aspects during and after the life of the exemplar. We developed and applied a beyond-state-of-the-art combination of three-dimensional surface and volumetric digital imaging techniq...

Some previous studies have identified a number of features on Mars that are thought to be scoria cones. Since (terrestrial) scoria cones have special significance that they are monogenetic volcanoes, i.e. the volcanic edifice is created by a single eruptive event. The process usually produces fairly symmetrical cones, making them a target for morph...

This study uses Sentinel-3 SLSTR data to analyze short-term drought events between 2019 and 2021. It investigates the crucial role of vegetation cover, land surface temperature, and water vapor amount associated with drought over Kenya’s lower eastern counties. Therefore, three essential climate variables (ECVs) of interest were derived, namely Lan...

Lake Velence is a shallow soda lake in Hungary whose water budget is mainly driven by precipitation and evaporation. The lake has shown a deteriorating tendency recently, including extremely low lake levels and poor water quality, which indicates its vulnerability against changing climatic conditions. At the same time several water usage conflicts...

Groundwater resources in the Nairobi Aquifer Suite (NAS), Kenya, face significant problems largely due to rapid urbanization and the rising water demand. The depletion of groundwater resources at the local level could potentially extend to regional extents, and hence affect natural water flows. This therefore calls for the prediction of aquifer hyd...

LiDAR-based digital terrain models (DTMs) represent an advance in the investigation of small-scale geomorphological features, including dolines of karst terrains. Important issues in doline morphometry are (i) which statistical distributions best model the size distribution of doline morphometric parameters and (ii) how to characterize the volume o...

The extreme drought in Europe in 2022 also hit hard the Great Hungarian Plain. In this short overview article, we summarize the natural environmental conditions of the region and the impact of river control works on the water-retention capacity of the landscape. In this respect, we also review the impact of intensive agricultural cultivation on soi...

The standardized precipitation index (SPI) is a fundamental indicator of meteorological, hydrological, and agricultural droughts in the world. This study aims to evaluate different timescales, 3 months (SPI-3), 6 months (SPI-6), 9 months (SPI-9), and 12 months (SPI-12) indices from meteorological data in quantifying drought characterization in lowe...

Quality-controlled datasets are a foundation and a conduit for real results from anyset scientific objectives. The purpose of this paper was to emphasize the importance of qualitychecks and preparatory steps of any scientific data in the context of meteorological variablesand measurement. The motivation to make measurement was necessitated by a des...

Effective crop monitoring and accurate yield estimation are fundamental for informed decision-making in agricultural management. In this context, the present research focuses on estimating wheat yield in Nepal at the district level by combining Sentinel-3 SLSTR imagery with soil data and topographic features. Due to Nepal’s high-relief terrain, its...

Kenya has had five failed rain seasons for the last three years. In this context, there was a mass recurrent crop failure, death of livestock and wildlife, persistent water scarcity, and droughts of varying intensities. There have been a lot of challenges in assessing climate change and variability impacts in Kenya due to limited data sources. Furt...

Remote sensing offers the potential to provide up-to-date information on changes in forestry areas over large areas. Its application makes it possible to make assessments related to land use change. This research aims to assess whether land change using remote sensing can provide an efficient alternative, both in terms of cost and time, including i...

Meeting current needs without compromising future generations' ability to meet theirs is the only path toward achieving environmental sustainability. As the most valuable natural resource, soil faces global, regional, and local challenges, from quality degradation to mass losses brought on by salinization. These issues affect agricultural productiv...

Classic scoria cone morphometric research began in the first half of the 20th century: field surveys and various resolution maps provided its basis. With the advent of new imaging technology, new processing tools were needed: nowadays, various analysis modules and plug-ins are becoming increasingly common in GIS software. The combination of digital...

Reference evapotranspiration (ET0) and real evapotranspiration (ET) are vital components in hydrological processes and climate-related studies. Understanding their variability in estimation is equally crucial for micro-meteorology and agricultural planning processes. The primary goal of this study was to analyze and compare estimates of (ET0) and (...

Morphometric studies of scoria cones have a long history in research. Their geometry and shape are believed to be related to evolution by erosion after their formation, and hence the morphometric parameters are supposed to be related with age. We analysed 501 scoria cones of four volcanic fields: San Francisco Volcanic Field (Arizona, USA), Chaîne...

Kenya is dominated by a rainfed agricultural economy. Recurrent droughts influence food security. Remotely sensed data can provide high-resolution results when coupled with a suitable machine learning algorithm. Sentinel-1 SAR and Sentinel-3 SLSTR sensors can provide the fundamental characteristics for actual evapotranspiration (AET) estimation. Th...

Soil health is a fundamental condition in ensuring sustainable agriculture and maintaining food security. Hence, soil protection against degradation and intensive use is crucial for local governments. Salinization depicts one of the most common land degradation forms, requiring continuous monitoring to control and prevent its risks. This study aims...

Drought is an extreme climate phenomenon that influences Earth’s water resources and energy balance. It affects hydrological cycle processes such as evapotranspiration, precipitation, surface runoff, condensation, and infiltration. Its extreme and severe occurrences threaten food security and drinking water availability for local populations worldw...

The world’s current task is to ensure food security for an ever-growing population of 7.674 billion in 2019. Soil degradation threatens sustainable agriculture in arid and semi-arid climates, where evaporation rates outweigh precipitation. Soluble salts concentrated in the subsoil under certain climatic conditions influence soil physicochemical pro...

As Hungary has the largest expanse of naturally salt-affected soils in Europe with a continuous decrease in groundwater levels due to climate change, the expansion of saline soils to the detriment of arable lands has become a potential risk that requires constant monitoring to sustain agricultural productivity and ensure food security. The study ai...

FREE ACCESS UNTIL August 2021: https://authors.elsevier.com/c/1dHoo3HcE1fbah ========================================================= Lake Balaton (Hungary), the largest lake in Central Europe, formed by the interplay of tectonic and external forces. Its shallow water and young soft sediments together allow to carry out ultra-high resolution r...

Scoria cones are favorite targets of morphometric research. However, in-depth, DTM-based studies have appeared only recently, and new methods are being developed. This study provides a classic evaluation of the cones of Chaîne des Puys (Auvergne, France) as well as introduces a more detailed and statistics-based set of properties. Beside the classi...

In December 2014 a catastrophic ice disturbance affected the forests of the Börzsöny Mts., Hungary. Planning salvage logging is an urgent task after such events. The use of Earth Observation (EO) data in near real-time could facilitate such planning at a critical time. However, conventional remote sensing studies apply data of passive multispectral...

Compared to Earth, the surface erosion activity of Mars is low, so Martian landscapes can survivefor long time, therefore Martian surface has been observed and analysed since the earliest timesof Mars research. Because the planet’s geological and mass wasting history can be studied withremote sensing, observations may provide deeper insight into th...

The aesthetic beauty of a landscape is an integral value reflected in artistic inspiration. Science, in contrast, tries to quantify the landscape using various methods. Of these, geodiversity indices have been found to be a useful approach, and this geomorphological diversity is characterized through derivatives made from digital terrain models (DT...

In 2020 we celebrate the 40 th anniversary of the seminal works of Wood (1980a,b) who was one of the first researchers who considered the shapes of volcanoes in a global point of view. These four decades have seen a number of new approaches that were made possible by the ever increasing computer power and the improvements in Digital Terrain Model (...

The Euphrates River is the main river running in Syria and the longest river in Western Asia and has three riparian countries, Iraq, Syria and Turkey. This research focuses on the Syrian part of the basin which makes 22% of total area of the basin. Analyzing and evaluating the morphometric parameters is very important for understanding the nature...

Purpose We conducted this project to develop a feasible method for mapping tropical peat lands of Bengkalis Island—as a test site—in Indonesia. Materials and methods The method based on limited availability of field measurements and a wide range of remotely sensed spatial datasets like radar elevation product, MODIS, and Landsat imageries. We appl...

Over the past decades it has become more and more common that digital terrain models (DTMs) of different landforms are studied using GIS tools in addition to field surveys. With the development of data acquisition in-strumentation, we can get more accurate and realistic representation of the surface in increasing resolution using different measurem...

A great number of fossils are collected systematically in the public collections, museums all around the world, by storing, systematizing and maintaining these invaluable objects of cultural heritage. Beside of their aesthetic and educational value most of these artefacts are suitable to scientific studies applying non-destructive scientific analyt...

Germanium (Ge) is widespread in the earth crust. As a cognate element to silicon (Si), Ge shows very similar chemical characteristics. Recent use of Ge/Si to trace Si cycles and changes in weathering over time, growing demand for Ge as raw material and consequently an increasing interest in Ge phytomining have contributed to a growing interest in t...

Digital terrain models (DTMs) are used in geomorphometry. Coupled with field validation, their use makes the studies more comprehensive, and opens the way towards automation. DTMs are influenced by the acquisition technology, accuracy, and resolution and questions arise about whether results depend on the type of DTMs. To study this, we have chosen...

Shell beds represent a useful source of information on various physical processes that cause the depositional condition. We present an automated method to calculate the 3D orientations of a large number of elongate and platy objects (fossilized oyster shells) on a sedimentary bedding plane, developed to support the interpretation of possible deposi...

GrainAutLine is an interdisciplinary microscopy image analysis tool with domain specific smart functions to partially automate the processing of marble thin section images. It allows the user to create a clean grain boundary image which is a starting point of several archaeometric and geologic analyses. The semi-automatic tools minimize the need fo...

It is a commonplace to state that the amount of available geoscientific data exploding unprecedentedly. As the observation platforms and sensors are being developed with rapid pace and the sampling rate multiplies almost yearly, beside the amount, the quality of these data is also improving: precision, data density are increasing, too. Besides terr...

Since the early 2000s, the DTMs have been increasingly used for morphometric studies, especially in volcanolog-ical research. The most common volcanic edifices for GIS analysis are the monogenetic scoria cones, because they are relatively symmetrical forms. With high-resolution LiDAR data we studied cone parameters, such as aspect, area, cone and c...

Geomorphometric and traditional GIS methods are widely used for studying volcanic forms, e.g. cinder (scoria) cones, which have usually symmetric shapes, but they can be asymmetrical, as well. Their asymmetry may stem of volcanogenic processes or result of erosional processes. Studying asymmetry one can imply to the denudation, denudation rate, and...

Currently the application of high density LiDAR data in forestry mostly concentrates on biomass calculation or classification of the forest into single tree species. However, in ecological point of view the LiDAR data can be a suitable dataset to analyse the forest at community level. In this study we investigated how to extract ecological informat...

The world's largest fossil oyster reef, formed by the giant oyster Crassostrea gryphoides and located in Stetten (north of Vienna, Austria), is studied in this article. Digital documentation of the unique geological site is provided by terrestrial laser scanning (TLS) at the millimeter scale. Obtaining meaningful results is not merely a matter of d...

Doline morphometry has always been in the focus of karst geomorphological research. Recently, digital terrain model (DTM) based methods became widespread in the study of dolines. Today, LiDAR datasets provide high resolution DTMs, and automated doline recognition algorithms have been developed. In this paper, we test different datasets and a doline...

We present the first GIS database as an interface of a digital oyster reef and managing tool for a protected natural heritage site. The state of the art in 3D digitizing, data processing, and visualization technologies allows mapping of the world’s largest fossil oyster reef in order to support paleontological investigations of the about 16.5 milli...

The purpose of this study is to illustrate the potential of 3D laser scanning technology in the context of paleontology. This is demonstrated by addressing a particular research question, the extraction of fossilized oyster shell central lines, in a dataset collected from the world's largest fossilized oyster reef whose age is 16.500.000 years. Las...

Photogrammetry provides a powerful tool to digitally document protected, inaccessible, and rare fossils. This saves manpower in relation to current documentation practice and makes the fragile specimens more available for paleontological analysis and public education. In this study, high resolution orthophoto (0.5 mm) and digital surface models (1...

There is a tank hewn into coastal Pleistocene limestone near Diu city on the Saurashtra Peninsula of western India. Site survey and a review of similar structures worldwide provide evidence that this tank could have been used for holding fish or Murex snails. The approximately 5 × 5 m tank is connected to the sea by a 1-m-deep canal; today it would...

Today one of the biggest challenges in forestry application of ALS LiDAR data is to classify different tree species. Selecting training areas or finding the optimal algorithm is important, but determining the optimal number of classes (which species are possible to separate) is also important but only a few papers aim to solve this issue. The CCDA...

Mobile Laser Scanning (MLS) is an evolving operational measurement technique for urban environment providing large amounts of high resolution information about trees, street features, pole-like objects on the street sides or near to motorways. In this study we investigate a robust segmentation method to extract the individual trees automatically in...

Airborne Laser Scanning (ALS) is a widely used technology for forestry classification applications. However, single tree detection and species classification from low density ALS point cloud is limited in a dense forest region. In this study we investigate the division of a forest into homogenous groups at stand level. The study area is located in...

The world's largest fossilized oyster reef is located in Stetten, Lower Austria excavated during field campaigns of the Natural History Museum Vienna between 2005 and 2008. It is studied in paleontology to learn about change in climate from past events. In order to support this study, a laser scanning and photogrammetric campaign was organized in 2...

Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery, including, among others, geology, dentistry, neurology. Its application in ecology was suggested more than 20 years ago. The main problem of its a...

Scoria cones are often studied using geomorphometric and traditional GIS methods, e.g. aspect, slope his-tograms, area, cone height/width ratio. In order to enhance the non-symmetric shape components in contrast to the conical forms, we used a new approach in our research: the polar coordinate transformation (PCT) introduced by Székely & Karátson (...

Geomorphometric analysis of the scoria cones of the San Francisco Volcanic Field using polar coordinate transformation

A field experiment was conducted to investigate the uptake of Ge and selected REEs in functional groups of selected crop species. Five species belonging to the functional group of grasses (Hordeum vulgare, Zea mays, Avena sativa, Panicum miliaceum and Phalaris arundinacea) and four species from the group of herbs (Lupinus albus, Lupinus angustifoli...

The rich echinoid fauna of the Badenian (Middle Miocene) from Budapest (Hungary) is well known for more than one hundred years. Along the road cuts and due to the construction of large buildings from 1960 to 2011, new Badenian outcrops with rich and well preserved echinoids were found in the city. Thus the main aim of this study was to revise histo...

Hungary is situated in the crossroad of several large-scale infrastructural pathways like transnational pipelines and transcontinental motorways. At the same time the country is rich in known and potential archaeological sites. Archaeological prediction techniques aided by remote sensing are intended to help increase preparedness for archaeological...

Centrally symmetric landform elements are very common features on the surface of the planet Mars. The most conspicuous ones of them are the impact craters of various size. However, a closer look on these features reveals that they show often asymmetric patterns as well. These are partially related to the geometry of the trajectory of the impacting...

This study aims to investigate how intercropping of oat (Avena sativa L.) with white lupin (Lupinus albus L.) affect the mobile fractions of trace metals (Fe, Mn, Pb, Cd, Th, U, Sc, La, Nd, Ge) in soil solution. Oat and white lupin were cultivated in monocultures and mixed cultures with differing oat/white lupin-ratios (11 % and 33 % lupin, respect...

The world's largest fossil oyster reef, formed by the giant oyster Crassostrea gryphoides and located in Stetten (north of Vienna, Austria) is studied in this article. Digital documentation of the unique geological site is provided by terrestrial laser scanning (TLS) at the millimeter scale. Obtaining meaningful results is not merely a matter of da...

We present the largest GIS-based data set of a single shell bed, comprising more than 10,280 manually outlined objects. The data are derived from a digital surface model based on high-resolution terrestrial laser scanning (TLS) and orthophotos obtained by photogrammetric survey, with a sampling distance of 1 mm and 0.5mm, respectively. The shell be...

Shell beds are frequently discussed as indicators for tsunamites. Studies on coastal tsunami versus storm deposits suggest that wedge-like bed-load dominated deposits are more typical for storms, whereas sheet-like, suspended-load dominated deposits with mudclasts point to tsunamis. Cooccurrence of shells from spatially distinctly separate environm...

Extracting the grain boundaries from marble thin sections is an important starting point for many material analysis applications. It is used for example to calculate the maximum grain sizes which has a long tradition in marble provenancing. Earlier, MGS was estimated with the naked eye, later, thin sections were used. After these, more sophisticate...

In Madagascar, soil erosion is significant even when it is compared to world averages. A resulting special geomorphic feature is a form of gully erosion known as lavaka that appears in the highlands of the country. Lavakization (the generation and development of these features) is due to rather unique multifactorial environmental conditions. Among...

In recent studies root-soil interactions of white lupine (Lupinus albus L.) have drawn special attention to researchers due to its particularly high potential to increase bioavailability of phosphorous (P) and trace nutrients in soils. In mixed cultures, white lupine has the ability to mobilize P and trace nutrients in soil in excess of its own nee...

Nitrogen (N) fertilization is necessary for growth and development of plants but it may also causes an increased metal uptake by plants due to changes of physiochemical properties of the elements in soil. The research in phytoremediation and phytomining conducted so far has revealed that the effect of nitrogen fertilizers initially depends on the f...

Concentrations of Germanium (Ge) and Rare Earth Elements in soils are estimated at 1.5 mg kg-1 (Ge), 25 mg kg-1 (La) and 20 mg kg-1 (Nd), which are only roughly smaller than concentrations of Pb and Zn. Germanium and rare earth elements are thus not rare but widely dispersed in soils and therefore up to date, only a few minable deposits are availab...

The central area of the Pannonian basin encompasses mostly low-relief areas. Its south-western part, the southern Transdanubian hilly areas have characteristic NNW-SSE directional pattern. One of the largest valleys is a conspicuously straight valley section of the River Sárvíz between Székesfehérvár and Szekszárd. The river collects the waters of...

In this contribution we present a semi-automated method for reconstructing the brittle deformation field of an excavated Miocene oyster reef, in Stetten, Korneuburg Basin, Lower Austria. Oyster shells up to 80 cm in size were scattered in a shallow estuarine bay forming a continuous and almost isochronous layer as a consequence of a catastrophic ev...

The aim of the study was to investigate the effects of different forms of N-fertilization (NH4SO4, Mg(NO3)2, NH4NO3) on the metalaccumulation in reed canary grass.

Predstavljena je uporaba geomorfometričnih analiz (pri uporabi digitalnega modela reliefa – DMR) planeta Marsa. Osredotočili smo se na odkrivanje vršajev. Razvili smo metodi progresivno Boolovo prekrivanje in ISOcluster, in sicer v smislu posebne geomorfometrije, torej izključno za čim natančnejše odkrivanje vršajev na tem notranjem kamnitem planet...

The study area is situated between the uplifting Alps and the subsiding Little Hungarian Plain, between 16°–17° E and 47°–47.5° N. The differential vertical motion implies neotectonic activity and some associated geomorphologic features (e.g. wind gaps, small streams in large valleys, etc.) may be observed as a result of drainage reorganization. Af...

The spatial context of the vegetation, especially its horizontal variation and vertical layering is an important property of the canopy structure. Many influencing factors that determines the natural, semi-natural or non-natural habitat are related to the two-dimensional (2D) or three-dimensional (3D) distribution of objects: shrub layers, understo...

Terrestrial talus slopes are a common feature of mountainous environments. Their geomorphic form is determined by their being constituted of scree, or similar loose and often poorly sorted material. Martian talus slopes are governed by the different nature of the Martian environment, namely: weaker gravity, the wide availability of loose material,...

The description and evaluation of geological, sedimentary and paleontological features in the field is often rather subjective. Many conclusions are based on view measurements on subjectively chosen elements, thought to be representative for the entire setting. One method to overcome this problem is the data acquisition by terrestrial laser scannin...

The study of land degradation in Madagascar is very important due to severe gully formation termed as lavakization. Lavakas are very abundant in the island and therefore have been subject of many studies in the past 60 years. Nevertheless many questions still remain concerning their formation and development. The aim of this study was to assemble a...

In Madagascar, land degradation is significant, resulting in special gullies termed as lavakas. Lavakization (the generation and development of these features) is due to the combination of many environmental factors, such as geological, soil compositional, anthropogenic factors, etc. Among these the spatial and temporal distribution of precipitatio...

The Western Pannonian Alpine Foothills, the transition zone of the Eastern Alpine Foreland and the Pannonian Basin, is an area of differential uplift: it is bordered by the exhuming Rechnitz window in NW and the subsiding Little Hungarian Plain in the E. The eastern part of the area exhibits a great number of very flat, slightly tilted surface sub...