TY - JOUR AU - Szabó, Loránd AU - Bertalan, László AU - Szabó, Gergely AU - Grigorszky, István AU - Somlyai, Imre AU - Dévai, György AU - Nagy, Sándor Alex AU - Holb, Imre AU - Szabó, Szilárd TI - Aquatic vegetation mapping with UAS-cameras considering phenotypes JF - ECOLOGICAL INFORMATICS J2 - ECOL INFORM PY - 2024 SN - 1574-9541 DO - 10.1016/j.ecoinf.2024.102624 UR - https://m2.mtmt.hu/api/publication/34839516 ID - 34839516 AB - Aquatic vegetation species at the genus level in an oxbow lake were identified in Hungary based on a multispectral Uncrewed Aerial System (UAS ) survey within an elongated oxbow lake area of the Tisza River under continental climate. Seven and 13 classes were discriminated using three different classification methods (Support Vector Machine [SVM], Random Forest [RF] , and Multivariate Adaptive Regression Splines [MARS]) using different input data in ten combinations: original spectral bands , spectral indices, Digital Surface Model (DSM) , and Haralick texture indices. We achieved a high (97.1%) overall accuracies (OAs) by applying the SVM classifier, but the RF performed only <1% worse, as it was represented in the first places of the classification rank before the MARS. The highest classification accuracies (>84% OA) were obtained using the most important variables derived by the Recursive Feature Elimination (RFE) method . The best classification required DSM as an input variable. The poorest classification performance belonged to the model that used only texture indices or spectral indices. On the class level, Stratoites aloides exhibit the lowest degree of separability compared to the other classes. Accordingly, we recommend using supplementary input data for the classifications beside s the original spectral bands, for example , DSM, spectral , and texture indices, as these variables significantly improve the classification accuracies in the proper combinations of the input variables . LA - English DB - MTMT ER - TY - CONF AU - Bertalan, László AU - Négyesi, Gábor AU - Szabó, Gergely AU - Túri, Zoltán AU - Szabó, Szilárd TI - Evaluating the efficacy of multitemporal TLS and UAS surveys for quantifying wind erosion magnitudes of sand dune topography T2 - EGU General Assembly 2024 : abstracts PB - European Geosciences Union (EGU) C1 - Wien PY - 2024 UR - https://m2.mtmt.hu/api/publication/34799801 ID - 34799801 LA - English DB - MTMT ER - TY - JOUR AU - de Oliveira-Júnior, José Francisco AU - Mendes, David AU - Szabó, Szilárd AU - Singh, Sudhir Kumar AU - Jamjareegulgarn, Punyawi AU - Cardoso, Kelvy Rosalvo Alencar AU - Bertalan, László AU - da Silva, Marcos Vinicius AU - da Rosa Ferraz Jardim, Alexandre Maniçoba AU - da Silva, Jhon Lennon Bezerra AU - Lyra, Gustavo Bastos AU - Abreu, Marcel Carvalho AU - Filho, Washington Luiz Félix Correia AU - de Sousa, Amaury AU - de Barros Santiago, Dimas AU - da Silva Santos, Iwldson Guilherme AU - Maksudovna, Vafaeva Khristina TI - Impact of the El Niño on Fire Dynamics on the African Continent JF - EARTH SYSTEMS AND ENVIRONMENT J2 - EARTH SYST ENVIRON VL - - PY - 2024 PG - 17 SN - 2509-9426 DO - 10.1007/s41748-023-00363-z UR - https://m2.mtmt.hu/api/publication/34476689 ID - 34476689 AB - Several studies investigated the occurrence of fires in Africa with numerical modeling or applied statistics; however, only a few studies focused on the influence of El Niño on the fire risk using a coupled model. The study aimed to assess the influence of El Niño on wildfire dynamics in Africa using the SPEEDY-HYCOM model. El Niño events in the Eastern Tropical Pacific were classified via sea surface temperature (SST) anomaly based on a predefined climatology between 1961 and 2020 for the entire time series of SST, obtaining linear anomalies. The time series of the SST anomalies was created for the region between 5° N and 5° S and 110° W and 170° W. The events were defined in three consecutive 3-month periods as weak, moderate, and strong El Niño conditions. The Meteorological Fire Danger Index (MFDI) was applied to detect fire hazards. The MFDI simulated by the SPEEDY-HYCOM model for three El Niño categories across different lagged months revealed relevant distinctions among the categories. In the case of ‘Weak’, the maximum variability of fire risk observed at time lags (0, -3, -6, and -9 months) was primarily in Congo, Gabon, and Madagascar. The ‘Moderate’ pattern had similar characteristics to ‘Weak’ except for the lag-6 months and its occurrence in the equatorial zone of Africa. ‘Strong’ showed a remarkable impact in East Africa, resulting in high fire risk, regardless of time lags. Precipitation and evaporation simulations (SPEEDY-HYCOM) indicated that El Niño categories in Africa need particular attention in the central, southern, and southeastern regions emphasizing the significance of lag-0 and lag-6 (evaporation) as well as lag-0, lag-6, and lag-9 (precipitation). The SPEEDY-HYCOM coupled model in conjunction with the MFDI was efficient in assessing climate variabilities in Africa during El Niño events. This model allows the analysis and prediction of wildfire risks based on El Niño events, providing crucial information for wildfire management and prevention. Its simulations uncover significant variations in risks among different El Niño categories and lagged months, contributing to the understanding and mitigation of this environmental challenge. LA - English DB - MTMT ER - TY - CHAP AU - N., Antić AU - M., Kašanin-Grubin AU - Bertalan, László AU - V., Gajić AU - L., Kaluđerović AU - N., Mijatović AU - B., Jovančićević ED - Željko, Jaćimović ED - Miljan, Bigović ED - Milica Kosović, Perutović TI - How Bad Volcano-Clastic Badlands Actually Are? T2 - 23rd European Meeting on Environmental Chemistry, EMEC23, Book of abstracts PB - Chemical Society of Montenegro CY - Podgorica PY - 2023 SP - 22 UR - https://m2.mtmt.hu/api/publication/34735335 ID - 34735335 LA - English DB - MTMT ER - TY - CONF AU - Antić, Nevena AU - Bertalan, László AU - Stefanović, Milica AU - Kašanin-Grubin, Milica TI - Badlands involcano-clastic rocks: examplesfrom Serbia and Hungary T2 - EUGEO PY - 2023 UR - https://m2.mtmt.hu/api/publication/34524988 ID - 34524988 AB - Badlands can develop under different climatic conditions ranging from arid to humid on materials that have a specific combination of physico-chemical properties depending on their mineralogical composition. Mostly these materials are fine-grained terrigenous, lacustrine or marine sediments of different age. However, badlands can also form in volcano-clasitc materials, and Cappadocia badlands in Turkey is the most prominent example. Less known in the literature are two sites also developed in this type of sediments: Đavolja Varoš, on Radan Moutain in SE Serbia and the Kazár badlands in NW Hungary. The Đavolja Varoš badlands, 0.7 km2 in size is formed by the intensive development of rills and gullies on slopes built from thick volcano-clastic material. The initial relief is reduced only to sharp ridges between adjacent gullies. This badland is developed in dacito-andesitic poorly-consolidated poorly-sorted tuffs. The weathering processes are intense and governed by high intensity precipitation and prolonged drying periods. The reddish earth pyramids built of these erodible materials are protected by the cap rock. Loss of balance and fall of the protective cap rock accelerates the erosion. The smaller Kazár badlands covering the area of 1ha are developed in rhyolitic poorly-consolidated highly porous tuffs. Rills and gullies are the dominant geomorphic processes and the weathering is dominated by freeze-thaw processes. At the Kazár badlands earth pyramids are not protected with the cap rock and weathering, disintegration and sheet wash erosion intensively shape the landscape. Although the materials differ slightly in composition, both being poorly sorted, clay-size rich materials make them sensitive to erosion, proving once more the importance of material composition, in this case namely grain size including sorting and mineralogical composition, for badlands development and future evolution. LA - English DB - MTMT ER - TY - CHAP AU - Szabó, Loránd AU - Bertalan, László AU - Szabó, Gergely AU - Szabó, Szilárd ED - Abriha-Molnár, Vanda Éva TI - Holtágak UAV-alapú felmérésének lehetőségei multispektrális kamera alkalmazásával T2 - Az elmélet és gyakorlat találkozása a térinformatikában XIV. : Theory meets practice in GIS PB - Debreceni Egyetemi Kiadó CY - Debrecen SN - 9789636150846 PY - 2023 SP - 269 EP - 273 PG - 5 UR - https://m2.mtmt.hu/api/publication/34023203 ID - 34023203 AB - This study discusses the importance of wetland habitats in maintaining hydrological cycles, providing ecological value, and serving as a natural habitat for endangered species. These habitats include oxbow lakes, which are formed by river bends and serve as unique habitats for various plant and animal species. The distribution of these species may depend on direct contact with the river and seasonal flooding events. Oxbow lakes are sensitive to environmental factors, including sedimentation and human activities, which can affect their lifespan and contribute to eutrophication. Remote sensing is a useful tool for studying these habitats, as they can be difficult to access for field surveys. However, existing satellite data may not have high enough spatial resolution for detailed mapping of smaller oxbow lakes, necessitating the use of aerial or unmanned aerial vehicle (UAV) surveys. UAVs offer a more cost-effective and efficient alternative to traditional aircraft surveys, with the potential to capture high-resolution data over smaller areas. We introduced a case study and conducted a UAV survey of the Rakamazi Nagy-morotva oxbow lake. Our goal was to identify the aquatic vegetation on genus-level in a study area using a multispectral UAV camera. Based on our research, we recommend using additional input datasets, such as digital surface models, spectral and texture indices, in addition to spectral bands for classification, as the appropriate combinations of these input variables can significantly improve classification accuracy. LA - Hungarian DB - MTMT ER - TY - CONF AU - Bertalan, László AU - Pataki, Angelika AU - Nagy, Loránd Attila AU - Négyesi, Gábor AU - Szabó, Szilárd TI - Multi-temporal UAS surveys for reconstructing soil water content of ploughland plots through multispectral and thermal infrared imagery T2 - EGU General Assembly 2023: Abstracts PB - European Geosciences Union (EGU) C1 - München PY - 2023 DO - 10.5194/egusphere-egu23-11235 UR - https://m2.mtmt.hu/api/publication/33678059 ID - 33678059 LA - English DB - MTMT ER - TY - JOUR AU - Kenyeres, Zoltán AU - Bauer, Norbert AU - Bertalan, László AU - Szabó, Gergely AU - Márkus, András AU - Sáringer-Kenyeres, Tamás AU - Szabó, Szilárd TI - Cost-benefit analysis of remote sensing data types for mapping mosquito breeding sites JF - SPATIAL INFORMATION RESEARCH J2 - SPAT INF RES VL - 31 PY - 2023 IS - 2 SP - 419 EP - 428 PG - 10 SN - 2366-3286 DO - 10.1007/s41324-023-00511-7 UR - https://m2.mtmt.hu/api/publication/33657250 ID - 33657250 AB - Environmentally friendly biological mosquito control by Bacillus thuringiensis var. israelensis formulations needs appropriate breeding maps. The mapping accuracy depends on the quality of the used remote sensing data. Further, the mapping is expected to be cost-efective. Our aim was to study the efect of the quality of various remote sensing data on the applicability of the maps. We depicted larval habitats by manual interpretation in Quantum GIS 3.16.1 software using remote sensing data of SENTINEL, Google Earth, commercial geoTIFF RGB orthophoto, individual unoccupied aerial systems (UAS) RGB, and multispectral mosaics. Based on our results, after classifcation of the target area by sorting, mixed-use of remote sensing data is required to achieve a highly cost-efcient mapping: RGB aerial photographs with 0.5 m per pixel resolution can be used efciently in areas dominated by grassland habitats, while forest areas need customised footage taken by UAS or drones during the foliage-free period (15 cm per pixel resolution, multispectral technique). Our cost-beneft analysis showed that the aim-optimised method could reduce investment to 6-8% and the cost of data collection to 20-50% of the highest budget. This result is signifcant for all participants of biological mosquito control. LA - English DB - MTMT ER - TY - CHAP AU - Bertalan, László AU - Anette, Eltner AU - Ian, Maddock AU - Alonso, Pizarro ED - Manfreda, Salvatore ED - Ben Dor, Eyal TI - Monitoring river channel dynamics by Unmanned Aerial Systems T2 - Unmanned Aerial Systems for Monitoring Soil, Vegetation, and Riverine Environments PB - Elsevier CY - Amsterdam SN - 9780323852838 T3 - Earth Observation PY - 2023 SP - 271 EP - 292 PG - 22 DO - 10.1016/B978-0-323-85283-8.00004-7 UR - https://m2.mtmt.hu/api/publication/33624764 ID - 33624764 LA - English DB - MTMT ER - TY - CHAP AU - Nagy, Loránd Attila AU - Szabó, Gergely AU - Bertalan, László ED - Abriha-Molnár, Vanda Éva TI - Eltérő módon történő UAV-felvételezésből származó fotogrammetriai modellek összehasonlító pontosság-vizsgálata T2 - Az elmélet és gyakorlat találkozása a térinformatikában XIII. PB - Debreceni Egyetemi Kiadó CY - Debrecen SN - 9789636150396 PY - 2022 SP - 233 EP - 238 PG - 6 UR - https://m2.mtmt.hu/api/publication/33572859 ID - 33572859 AB - UAV-based data collection and modelling is becoming increasingly important nowadays. The accuracy of the method is influenced by several factors, but mainly the camera properties, including its tilt angle. The aim of this research was to analyse how different flight paths and camera angles affect the accuracy of the resulting digital surface models and orthophoto-mosaics in urban area mapping. The results show that the oblique mode does not increase the accuracy, but overall, the double grid flight path resulted higher horizontal and vertical accuracy. LA - Hungarian DB - MTMT ER -