Flavius Sîrbu

Prof. Flavius Sîrbu

ICAM, West University of Timişoara, Timişoara, Timiş, Romania
orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 May 2022 in Scientific Data
Verified
Journal Article
Open access
PDF file
MLMyroslava Lesiv
Myroslava Lesiv
Dmitry SchepaschenkoDmitry Schepaschenko
Dmitry Schepaschenko
MBMarcel Buchhorn
Marcel Buchhorn
Linda SeeLinda See
Linda See
MDMartina Dürauer
Martina Dürauer
SFSteffen Fritz
Steffen Fritz
Spatially explicit information on forest management at a global scale is critical for understanding the status of forests, for planning sustainable forest management and restoration, and conservation activities. Here, we produce the first reference data set and a prototype of a globally consistent forest management map with high spatial detail on the most prevalent forest management classes such as intact forests, managed forests with natural regeneration, planted forests, plantation forest (rotation up to 15 years), oil palm plantations, and agroforestry. We developed the reference dataset of 226 K unique locations through a series of expert and crowdsourcing campaigns using Geo-Wiki (https://www.geo-wiki.org/). We then combined the reference samples with time series from PROBA-V satellite imagery to create a global wall-to-wall map of forest management at a 100 m resolution for the year 2015, with forest management class accuracies ranging from 58% to 80%. The reference data set and the map present the status of forest ecosystems and can be used for investigating the value of forests for species, ecosystems and their services.

1 April 2022 in Scientific Data
Verified
Journal Article
Open access
PDF file
JBJuan Carlos Laso Bayas
Juan Carlos Laso Bayas
Linda SeeLinda See
Linda See
IGIvelina Georgieva
Ivelina Georgieva
Dmitry SchepaschenkoDmitry Schepaschenko
Dmitry Schepaschenko
ODOlga Danylo
Olga Danylo
SFSteffen Fritz
Steffen Fritz
During December 2020, a crowdsourcing campaign to understand what has been driving tropical forest loss during the past decade was undertaken. For 2 weeks, 58 participants from several countries reviewed almost 115 K unique locations in the tropics, identifying drivers of forest loss (derived from the Global Forest Watch map) between 2008 and 2019. Previous studies have produced global maps of drivers of forest loss, but the current campaign increased the resolution and the sample size across the tropics to provide a more accurate mapping of crucial factors leading to forest loss. The data were collected using the Geo-Wiki platform (www.geo-wiki.org) where the participants were asked to select the predominant and secondary forest loss drivers amongst a list of potential factors indicating evidence of visible human impact such as roads, trails, or buildings. The data described here are openly available and can be employed to produce updated maps of tropical drivers of forest loss, which in turn can be used to support policy makers in their decision-making and inform the public.

1 November 2015 in Cold Regions Science and Technology
Verified
Journal Article
Closed access
AOAlexandru Onaca
Alexandru Onaca
AAAdrian Cristian Ardelean
Adrian Cristian Ardelean
PUPetru Urdea
Petru Urdea
FAFlorina Ardelean
Florina Ardelean
FSFlavius Sîrbu
Flavius Sîrbu

13 June 2019 in Progress in Earth and Planetary Science
Verified
Journal Article
Open access
PDF file
FSFlavius Sîrbu
Flavius Sîrbu
LDLucian Dragut
Lucian Dragut
Takashi OguchiTakashi Oguchi
Takashi Oguchi
YHYuichi S. Hayakawa
Yuichi S. Hayakawa
MMMihai Micu
Mihai Micu
As geomorphological processes operate at various spatial scales, their morphological expressions, i.e., land-surface variables (LSVs) should be scaled accordingly. Most approaches on landslide susceptibility modeling and landslide detection have been performed based on arbitrarily scaled LSVs. We propose a methodology to improve automated landslide detection by fitting each LSV to its optimal scale. We test our approach on two landslide inventories, with different landslide morphology. First, we derive seven LSVs from a DEM in a standard 3 × 3 moving window. Then, we rescale each LSV using focal mean statistics in increasingly larger moving windows until the optimal scale is found, i.e., scale at which logistic regression shows the best fit between the existence of landslide scarps and individual LSVs. The LSVs at the optimal scale are used as input data in a random forest (RF) model. In order to calculate the effect of scaling predictors on the accuracy of the model, we compare the results, using the area under the curve (AUC), against the results from an RF model with unscaled LSVs as input data. The results show (i) that different LSVs have different optimal scales, and (ii) the multi-scale approach improved the models significantly, from AUC = 0.73 to 0.80 for the first study area and from AUC = 0.59 to 0.73 for the second study area. Based on these results, we conclude that a multi-scale approach should be considered when automated models are used in order to detect landslides, in complex terrain settings.

1 February 2020 in CATENA
Verified
Journal Article
Closed access
AOAlexandru Onaca
Alexandru Onaca
FAFlorina Ardelean
Florina Ardelean
AAAdrian Ardelean
Adrian Ardelean
BMBrigitte Magori
Brigitte Magori
FSFlavius Sîrbu
Flavius Sîrbu
EGEmil Gachev
Emil Gachev

28 June 2024 in Permafrost and Periglacial Processes
Verified
Journal Article
Open access
RPRăzvan Popescu
Răzvan Popescu
SFSimon Filhol
Simon Filhol
BEBernd Etzelmüller
Bernd Etzelmüller
MVMirela Vasile
Mirela Vasile
APAlin Pleșoianu
Alin Pleșoianu
Simon GascoinSimon Gascoin
Simon Gascoin
Computer modeling of sporadic and isolated patches of mountain permafrost distribution is difficult to implement without overestimating it. The main challenge is to determine the very areas where the criteria for permafrost maintenance are met. This paper aims to modeling the permafrost distribution in the Southern Carpathians (SC), a typical marginal periglacial mountain range. For this purpose, a collection of 883 bottom temperature of late winter snow cover (BTS) points was used as a proxy for permafrost presence or absence in order to train several machine learning models. The performances of each model were evaluated with AUC with varying between 0.99 for Maxent and 0.74 for K‐nearest neighbors and most models (five) exhibiting values between 0.82 and 0.86. Other tests such as confusion matrices, sensitivity analyses, data shuffling, and data size reduction tests indicated that Maxent, AdaBoost, and support vector machine offered the best results while logistic regression, neural network, and gradient boosting exhibited rather poor permafrost distributions. The final ensemble median model indicated a total permafrost area of 19.2 km 2 occupying 1%–9% of the alpine area of the studied massifs. NDVI proved crucial for permafrost prediction because it allows delimiting the debris surfaces where permafrost is probable.