scholarly journals Near- and Middle-Infrared Monitoring of Burned Areas from Space

Author(s):  
Carlos C. DaCamara ◽  
Renata Libonati ◽  
Miguel M. Pinto ◽  
Alexandra Hurduc

Author(s):  
Д.В. Гусев

Естественное возобновление является важным фактором формирования насаждений, особенно главных лесообразующих пород. Растительное сообщество становится жизнестойким при условии способности восстановить численность популяций заменой погибших экземпляров новыми. Было выяснено в каком количестве происходит естественное возобновление сосны на гарях по сравнению с граничащими участками, не пройденными пожарами, взятые в качестве контроля. Район исследований относится к южной подзоне тайги на территории Ленинградской области в Кировском и Лужском лесничествах. Объектом исследований стали сосновые насаждения, где работы проводились в летний период с 2013 по 2015 год. Всего подобрано 36 участков (включая контроль) размером не более 0,3 га. Учет подроста проводился на учетных площадках. Каждая учетная площадка закладывалась при помощи шеста длиной 178,5 см. Площадь круговых площадок составляла 10 м2, они расположены последовательно друг за другом с непосредственным примыканием. На каждой площадке проводили перечет подроста и делили его по высоте на три категории крупности: мелкий до 0,5 м, средний – 0,6–1,5 м и крупный – более 1,5 м. А также естественное возобновление на участках делили по густоте – на три категории: редкий – до 2 тыс., средней густоты – 2–8 тыс., густой – более 8 тыс. растений на 1 га; по распределению по площади – на три категории в зависимости от встречаемости. Анализ послепожарного возобновления в сосняках показал, что на пробных площадях наблюдается отличное возобновление подроста сосны и обилие на площади, все это связано с уничтожением лесной подстилки, увеличением минерализации почвы что, в конечном счете, положительно влияет на естественное лесовосстановление, о чем свидетельствует появление всходов, а также лучше становится гидрологический режим почвы. Благодаря этому происходит хорошее восстановление. Количество благонадежного подроста составляет от 3,5 до 11,9 тыс. шт./га и его достаточно для естественного восстановления ценопопуляции после пожара. Подтверждена зависимость количество самосева и толщины лесной подстилки. Прогретая после пожара, богатая минеральными веществами почва благоприятна для появления всходов и самосева древесных растений. Natural regeneration is an important factor in the formation of plantations, especially the main forest-forming species. Plant community becomes viable, provided the ability to recover populations, replacement of lost copies new. Find out how much happens in a natural pine regeneration in burned areas compared to adjacent areas not affected by fires, are taken as a control. The study area belongs to the subzone of southern taiga on the territory of Leningrad region, the Kirov and Luga districts. The object of research became pine plantations where the work was carried out in year period from 2013 to 2015. Just picked up 36 stations (including the control) no larger than 0.3 hectares. accounting for the undergrowth was conducted on index sites. Each user platform was laid with a pole length of 178.5 cm the area of the circular pads was 10 m2, they are located successively one after another with a direct connection. At each site conducted the translation of the undergrowth and it was divided in height into three categories of size: small up to 0.5 m, average 0.6 to 1.5 meters and large – more than 1.5 meters. And natural regeneration on plots divided by the density for three categories: rare – up to 2 thousand, medium density – 2 to 8 thousand, thick – more than 8 thousand plants per 1 ha; on the distribution of the area – into three categories depending on the occurrence. Analysis of post-fire regeneration in pine forests showed that the sample areas there is a great renewal of undergrowth of pine and the abundance on the square, all this is due to the destruction of forest litter, increasing salinity of the soil which, ultimately, has a positive effect on natural regeneration, as evidenced by the appearance of seedlings, as well as better hydrological regime of the soil. Which a good recovery. The number of reliable undergrowth is from 3.5 to 11.9 thousand PCs/ha, enough for natural regeneration of seedlings after the fire. Confirmed the dependence of the number of self-seeding and thickness of forest litter. After the fire-warmed, mineral-rich soil is favorable for emergence and self-seeding of woody plants.



Author(s):  
Cesario Vincenzo Angelino ◽  
Luca Cicala ◽  
Sara Parrilli ◽  
Nicomino Fiscante ◽  
Silvia Liberata Ullo


2021 ◽  
Vol 13 (8) ◽  
pp. 1509
Author(s):  
Xikun Hu ◽  
Yifang Ban ◽  
Andrea Nascetti

Accurate burned area information is needed to assess the impacts of wildfires on people, communities, and natural ecosystems. Various burned area detection methods have been developed using satellite remote sensing measurements with wide coverage and frequent revisits. Our study aims to expound on the capability of deep learning (DL) models for automatically mapping burned areas from uni-temporal multispectral imagery. Specifically, several semantic segmentation network architectures, i.e., U-Net, HRNet, Fast-SCNN, and DeepLabv3+, and machine learning (ML) algorithms were applied to Sentinel-2 imagery and Landsat-8 imagery in three wildfire sites in two different local climate zones. The validation results show that the DL algorithms outperform the ML methods in two of the three cases with the compact burned scars, while ML methods seem to be more suitable for mapping dispersed burn in boreal forests. Using Sentinel-2 images, U-Net and HRNet exhibit comparatively identical performance with higher kappa (around 0.9) in one heterogeneous Mediterranean fire site in Greece; Fast-SCNN performs better than others with kappa over 0.79 in one compact boreal forest fire with various burn severity in Sweden. Furthermore, directly transferring the trained models to corresponding Landsat-8 data, HRNet dominates in the three test sites among DL models and can preserve the high accuracy. The results demonstrated that DL models can make full use of contextual information and capture spatial details in multiple scales from fire-sensitive spectral bands to map burned areas. Using only a post-fire image, the DL methods not only provide automatic, accurate, and bias-free large-scale mapping option with cross-sensor applicability, but also have potential to be used for onboard processing in the next Earth observation satellites.



Fire ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 26
Author(s):  
Casey Teske ◽  
Melanie K. Vanderhoof ◽  
Todd J. Hawbaker ◽  
Joe Noble ◽  
John Kevin Hiers

Development of comprehensive spatially explicit fire occurrence data remains one of the most critical needs for fire managers globally, and especially for conservation across the southeastern United States. Not only are many endangered species and ecosystems in that region reliant on frequent fire, but fire risk analysis, prescribed fire planning, and fire behavior modeling are sensitive to fire history due to the long growing season and high vegetation productivity. Spatial data that map burned areas over time provide critical information for evaluating management successes. However, existing fire data have undocumented shortcomings that limit their use when detailing the effectiveness of fire management at state and regional scales. Here, we assessed information in existing fire datasets for Florida and the Landsat Burned Area products based on input from the fire management community. We considered the potential of different datasets to track the spatial extents of fires and derive fire history metrics (e.g., time since last burn, fire frequency, and seasonality). We found that burned areas generated by applying a 90% threshold to the Landsat burn probability product matched patterns recorded and observed by fire managers at three pilot areas. We then created fire history metrics for the entire state from the modified Landsat Burned Area product. Finally, to show their potential application for conservation management, we compared fire history metrics across ownerships for natural pinelands, where prescribed fire is frequently applied. Implications of this effort include increased awareness around conservation and fire management planning efforts and an extension of derivative products regionally or globally.



Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1761
Author(s):  
Izabela Rutkowska ◽  
Jakub Marchewka ◽  
Piotr Jeleń ◽  
Mateusz Odziomek ◽  
Mateusz Korpyś ◽  
...  

Aluminum oxide is one of the most commonly used materials in the industry. It is used in the field of catalysis, refractories, and optics. Despite the fact that there are many techniques available, there is still a great challenge in obtaining a material with desired and designed properties. Nevertheless, there is a great flexibility in making customized alumina materials with desired physicochemical properties synthesized by sol–gel methods. This work consists in characterizing the physicochemical properties of sol–gel synthesized aluminum oxide using different sol–gel preparation routes. Three different sols were obtained by using organic precursors and underwent thermal treatment. The structure (Middle Infrared Spectroscopy, Diffused Reflectance Infrared Spectroscopy, X-ray Diffraction, Magic Angle Spinning Nuclear Magnetic Resonance) and microstructure (Scanning Electron Microscopy with Electron Dispersive Spectroscopy) tests of the materials were carried out. The specific surface area was determined by using the Brunauer–Emmett–Teller (BET) method. Thermal analysis was performed for all the powders, in order to analyze the specific temperature of materials transformation.



2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Víctor Fernández-García ◽  
Elena Marcos ◽  
Sara Huerta ◽  
Leonor Calvo

Abstract Background Wildfires are one of the major environmental concerns in Mediterranean ecosystems. Thus, many studies have addressed wildfire impacts on soil and vegetation in Mediterranean forests, but the linkages between these ecosystem compartments after fire are not well understood. The aim of this work is to analyze soil-vegetation relationships in Mediterranean burned forests as well as the consistency of these relationships among forests with different environmental conditions, at different times after fire, and among vegetation with different functional traits. Results Our results indicate that study site conditions play an important role in mediating soil-vegetation relationships. Likewise, we found that the nature of soil-vegetation relationships may vary over time as fire effects are less dominant in both ecosystem compartments. Despite this, we detected several common soil-vegetation relationships among study sites and times after fire. For instance, our results revealed that available P content and stoichiometry (C:P and N:P) were closely linked to vegetation growth, and particularly to the growth of trees. We found that enzymatic activities and microbial biomass were inversely related to vegetation growth rates, whereas the specific activities of soil enzymes were higher in the areas with more vegetation height and cover. Likewise, our results suggest that resprouters may influence soil properties more than seeders, the growth of seeders being more dependent on soil status. Conclusions We provide pioneer insights into how vegetation is influenced by soil, and vice-versa, in Mediterranean burned areas. Our results reflect variability in soil-vegetation relationships among study sites and time after fire, but consistent patterns between soil properties and vegetation were also detected. Our research is highly relevant to advance in forest science and could be useful to achieve efficient post-fire management.



1988 ◽  
Author(s):  
David W. Hafemeister


1996 ◽  
Vol 17 (9) ◽  
pp. 1727-1734 ◽  
Author(s):  
V. K. DADHWAL ◽  
J. S. PARIHAR ◽  
T. T. MEDHAVY ◽  
D. S. RUHAL ◽  
S. D. JARWAL ◽  
...  


Author(s):  
Leonardo A. Hardtke ◽  
Paula D. Blanco ◽  
Héctor F.del Valle ◽  
Graciela I. Metternicht ◽  
Walter F. Sione


1999 ◽  
Vol 427-428 ◽  
pp. 184-189 ◽  
Author(s):  
F. Maroun ◽  
F. Ozanam ◽  
J.-N. Chazalviel


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