scholarly journals Variations in Subpixel Fire Properties with Season and Land Cover in Southern Africa

2010 ◽  
Vol 14 (6) ◽  
pp. 1-29 ◽  
Author(s):  
Ted C. Eckmann ◽  
Christopher J. Still ◽  
Dar A. Roberts ◽  
Joel C. Michaelsen
Keyword(s):  
Remote Sensing ◽  
Land Cover ◽  
Southern Africa ◽  
Ecological Impacts ◽  
Fire Season ◽  
Remotely Sensed Data ◽  
Radiative Power ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Fire Properties ◽  
Aerosol Emissions

Abstract Some of the most widely used datasets for monitoring the world’s fires come from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors aboard NASA’s Terra and Aqua satellites. For virtually all remote sensing systems, including MODIS, pixels that contain fires comprise a mix of burning and nonburning components, each with sizes and temperatures that vary between pixels. Current remote sensing products provide little information about these subpixel components, severely limiting estimates of the gas and aerosol emissions and ecological impacts from the world’s fires. This study shows how multiple endmember spectral mixture analysis (MESMA) can estimate subpixel fire sizes and temperatures from MODIS and can overcome many limitations of existing methods for characterizing fire intensities from remotely sensed data, such as the fire radiative power (FRP) approach. This study used MESMA to estimate subpixel fire sizes and temperatures for MODIS scenes in southern Africa, analyzed how these sizes and temperatures varied with season and land cover, and compared these to analyses made with FRP. This study could be the first to analyze fire sizes and temperatures on a spatial scale as large as a MODIS scene and a temporal scale as large as a full fire season. The variations in MESMA estimates of fire temperature with season and land cover were more consistent than the FRP estimates. Based on these findings, MESMA appears to be more effective than FRP at capturing some variations in fire temperatures, which strongly influence the gas and aerosol emissions from fires, along with their effects on ecosystems.

scholarly journals ASSESSING LAND COVER CHANGES CAUSED BY GRANITE QUARRYING USING REMOTE SENSING

2017 ◽  
Vol XLII-3/W2 ◽  
pp. 119-124 ◽  
Author(s):  
R. S. Moeletsi ◽  
S. G. Tesfamichael
Keyword(s):  
South Africa ◽  
Remote Sensing ◽  
Land Cover ◽  
Surface Mining ◽  
Google Earth ◽  
Land Cover Changes ◽  
Dimension Stone ◽  
Remotely Sensed Data ◽  
Landsat Images ◽  
Granite Quarries

Dimension stone quarrying in the area between Rustenburg and Brits in the North West Province of South Africa has been in existence for over 70 decades. The unique characteristics of the granite deposits in South Africa resulted in making the country a global producer of the granite rocks. This led to intensified quarrying activities between Rustenburg and Brits town. However, this surface mining method, has a potential to impact the environment in a negative way causing loss in vegetation, depletion of natural resources, loss of scenic beauty and contamination of surface water resources. To assess the land cover changes caused by granite quarrying activities, remotely sensed data in the form of Landsat images between 1998 and 2015 were used. Supervised classification was used to create maps. Accuracy assessment using Google Earth<sup>TM</sup> as a reference data yielded an overall accuracy of 78&amp;thinsp;%. The post classification change detection method was used to assess land cover changes within the granite quarries. Granite quarries increased by 1174.86 ha while formation of quarry lakes increased to 5.3 ha over the 17-year period. Vegetation cover decreased by 1308 ha in area while 18.3 ha bare land was lost during the same period. This study demonstrated the utility of remote sensing to detect changes in land cover within granite quarries.

Application of Remote Sensing and GIS to Detect Land Use and Land Cover Changes in Jos East Local Government Area, Plateau State, Nigeria.

2021 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
Solomon Wuyep zitta
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Land Cover ◽  
Agricultural Land ◽  
Digital Camera ◽  
Land Cover Changes ◽  
Remotely Sensed Data ◽  
Plateau State ◽  
Ground Truthing ◽  
Land Management System

This study examines the potentials of Remote Sensing techniques and GIS in land resources management with particular reference to detect land use and land cover changes in Jos East L.G.A, between 1995 to 2015. In this study, administrative maps, remotely sensed data (Landsat and Nigeriasat-1 satellite imageries) and GIS techniques were used in the image analysis. All these were done using Ilwis 3.3 Academic, ERDAS 9.3, IDIRISI 17.0 and ArcGIS 10.1. Digital camera was also used for ground truthing. The results were presented using classified imageries. Between the years 1995 to 2015, there was consistent change in the land use land cover of Jos east with different LULC categories. Throughout the study years, vegetation was observed to have the highest percentage of the total land coverage with 57544.28 ha (63%) in 1995, decreasing to 50322.96 ha (50%) in 2005, and 34969.95 (39%) in the year 2015. While agricultural/farm land was gradually increasing throughout the study period with 21271.05 ha (23%) in 1995, 27017.37 ha (27%) in 2005 and 25406.19 ha (28%) in 2015. Findings also showed that build-up-areas/settlement development increased consistently from 1451.97ha (2%) in 1995, 3290.49 ha (3%) in 2005 to 5817.96 (6%) in 2015. It was concluded that agriculture in the study area is increasing while large areas of vegetation is drastically reducing and being converted to farmlands and settlements. It is recommended that government should put up a reliable land management system in form of restrictions on premature conversion of agricultural land, there should be policies that control threat to the vegetation cover. Government should take cognizance of the land use and land cover at a regular interval to ascertain the changes that are taking place in the study area.

Remote sensing of burned areas in tropical savannas

2003 ◽  
Vol 12 (4) ◽  
pp. 259 ◽  
Author(s):  
José M. C. Pereira
Keyword(s):  
Remote Sensing ◽  
Canopy Cover ◽  
Stand Density ◽  
Fire Season ◽  
Burned Area ◽  
Tropical Savannas ◽  
Remotely Sensed Data ◽  
Area Index ◽  
Major Satellite ◽  
Burned Areas

Problematic aspects of fire in tropical savannas are reviewed, from the standpoint of their impact on the detection and mapping of burned areas using remotely sensed data. Those aspects include: the heterogeneity of savanna—resulting in heterogeneity of fire-induced spectral changes; fine fuels and low fuel loadings—resulting in short persistence of the char residue signal; tropical cloudiness—which makes multitemporal image compositing important; the frequent presence of extensive smoke aerosol layers during the fire season—which may obscure fire signals; and the potential problem of detecting burns in the understory of woody savannas with widely variable tree stand density, canopy cover and leaf area index. Finally, the capabilities and limitations of major satellite remote sensing systems for pan-tropical burned area mapping are addressed, considering the spatial, spectral, temporal and radiometric characteristics of the instruments.

Is burn severity related to fire intensity? Observations from landscape scale remote sensing

2013 ◽  
Vol 22 (7) ◽  
pp. 910 ◽  
Author(s):  
Heather Heward ◽  
Alistair M. S. Smith ◽  
David P. Roy ◽  
Wade T. Tinkham ◽  
Chad M. Hoffman ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Spatial Scales ◽  
Burn Severity ◽  
Radiative Energy ◽  
Fire Intensity ◽  
Ecological Change ◽  
Fire Event ◽  
Radiative Power ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Normalized Burn Ratio

Biomass burning by wildland fires has significant ecological, social and economic impacts. Satellite remote sensing provides direct measurements of radiative energy released by the fire (i.e. fire intensity) and surrogate measures of ecological change due to the fire (i.e. fire or burn severity). Despite anecdotal observations causally linking fire intensity with severity, the nature of any relationship has not been examined over extended spatial scales. We compare fire intensities defined by Moderate Resolution Imaging Spectroradiometer Fire Radiative Power (MODIS FRP) products with Landsat-derived spectral burn severity indices for 16 fires across a vegetation structure continuum in the western United States. Per-pixel comparison of MODIS FRP data within individual fires with burn severity indices is not reliable because of known satellite temporal and spatial FRP undersampling. Across the fires, 69% of the variation in relative differenced normalized burn ratio was explained by the 90th percentile of MODIS FRP. Therefore, distributional MODIS FRP measures (median and 90th-percentile FRP) derived from multiple MODIS overpasses of the actively burning fire event may be used to predict potential long-term negative ecological effects for individual fires.

scholarly journals Vertical distribution of aerosols over the Maritime Continent during El Niño

2018 ◽  
Vol 18 (10) ◽  
pp. 7095-7108 ◽  
Author(s):  
Jason Blake Cohen ◽  
Daniel Hui Loong Ng ◽  
Alan Wei Lun Lim ◽  
Xin Rong Chua
Keyword(s):  
Vertical Distribution ◽  
El Niño ◽  
El Nino ◽  
Fire Season ◽  
Free Troposphere ◽  
Fire Plume ◽  
Radiative Power ◽  
Fire Properties ◽  
Aerosol Plume ◽  
Fire Radiative Power

Abstract. The vertical distribution of aerosols over Southeast Asia, a critical factor impacting aerosol lifetime, radiative forcing, and precipitation, is examined for the 2006 post El Niño fire burning season. Combining these measurements with remotely sensed land, fire, and meteorological measurements, and fire plume modeling, we have reconfirmed that fire radiative power (FRP) is underestimated over Southeast Asia by MODIS measurements. These results are derived using a significantly different approach from other previously attempted approaches found in the literature. The horizontally constrained Maritime Continent's fire plume median height, using the maximum variance of satellite observed aerosol optical depth as the spatial and temporal constraint, is found to be 2.04 ± 1.52 km during the entirety of the 2006 El Niño fire season, and 2.19±1.50 km for October 2006. This is 0.83 km (0.98 km) higher than random sampling and all other past studies. Additionally, it is determined that 61 (+6–10) % of the bottom of the smoke plume and 83 (+8–11) % of the median of the smoke plume is in the free troposphere during the October maximum; while 49 (+7–9) % and 75 (+12–12) % of the total aerosol plume and the median of the aerosol plume, are correspondingly found in the free troposphere during the entire fire season. This vastly different vertical distribution will have impacts on aerosol lifetime and dispersal. Application of a simple plume rise model using measurements of fire properties underestimates the median plume height by 0.26 km over the entire fire season and 0.34 km over the maximum fire period. It is noted that the model underestimation over the bottom portions of the plume are much larger. The center of the plume can be reproduced when fire radiative power is increased by 20 % (with other parts of the plume ranging from an increase of 0 to 60 % depending on the portion of the plume and the length of the fire season considered). However, to reduce the biases found, improvements including fire properties under cloudy conditions, representation of small-scale convection, and inclusion of aerosol direct and semi-direct effects are required.

scholarly journals Application of GIS and Remote Sensing Technique to Change Detection in Land Use/Land Cover Mapping of Igbokoda, Ondo State, Nigeria

1970 ◽  
Vol 3 (1) ◽  
Author(s):  
James R. Adewumi ◽  
James K. Akomolafe ◽  
Fidelis O. Ajibade ◽  
Blessing B. Fabeku
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Land Cover ◽  
Change Detection ◽  
Rapid Change ◽  
Land Use Land Cover ◽  
Remotely Sensed Data ◽  
Landsat Images ◽  
Annual Increment ◽  
Rapid Urbanization

This paper aims at establishing changes in land use and land cover in Igbokoda municipality using Geographic Information System and remote sensing techniques. Three satellite images for three different epochs 1986, 1999 and 2013 were used to produce a land use/land cover map classification for Igbokoda. In determining the extent of land use/land cover changes in the township from 1986 through 1999 to 2013, Landsat images of the town were downloaded from the United State Geological Survey online archive. The images were analyzed using change detection technique (NDVI differencing) along with SRTM 90m DEM of the study area to generate the extent of the changes that have occurred. Ground trotting was carried out to ascertain the accuracy of data and the major changes in the land use/land cover. Results show that vegetation has decreased from 75.04% in 1986 to 46.81% in 2013 which was due to increase in population and rapid urbanization. In 1996 the Built-up area covers 19.6321 km2 of the study area but has increased rapidly to 39.1505 km2 in the year 1999 with an average annual increment of 2.025Km2/year. By the year 2013, the built-up area has increased to 64.1520Km2. Also in the same vein, the bare surface area which was 13.28029km2 in 1986 was increased to 39.6053 and 50.240Km2 in 1999 and 2013 respectively. On the contrary, the vegetated area of Igbokoda reduced from 196.3046Km2 in 1999 to 122.4680Km2 in 2013. This study has demonstrated that remotely sensed data and GIS based approach is timely and cost effective than the conventional method of analysis, classification of land use pattern effective for planning and management. It further shows that If the rapid change in land use is not properly manage, the situation poses a serious threat to Igbokoda town by increasing surface runoff and susceptibility to flooding.

Remote sensing and GIS integration for land cover analysis, a case study: Bozcaada Island

2005 ◽  
Vol 51 (11) ◽  
pp. 239-244 ◽  
Author(s):  
F. Bektas ◽  
C. Goksel
Keyword(s):  
Remote Sensing ◽  
Information System ◽  
Geographic Information System ◽  
Land Cover ◽  
Land Cover Change ◽  
Geographic Information ◽  
Remotely Sensed Data ◽  
Change Analysis ◽  
Processing Techniques

In this study, remote sensing and geographic information system (GIS) techniques were used in order to accomplish land cover change of Bozcaada Island, Turkey, by using multitemporal Landsat Thematic Mapper data. Digital image processing techniques were conducted for the processes of image enhancement, manipulation, registration and classification for land cover change analysis. The land cover changes between two different dates were visualized and analyzed by using Geographic Information System techniques. The results showed that remotely sensed data and GIS are effective and powerful tools for carrying out changes on land cover of the island and monitoring of its impact on the environment.

scholarly journals Application of Remote Sensing and GIS for Monitoring and Evaluation of the Reforestation Activities in Kupang district of East Nusa Tenggara

2004 ◽  
Vol 12 (1) ◽  
Author(s):  
Irmadi Nahib ◽  
Jaya Wijaya
Keyword(s):  
Remote Sensing ◽  
Information System ◽  
Forest Management ◽  
Land Cover ◽  
Management Strategy ◽  
Monitoring And Evaluation ◽  
Remotely Sensed ◽  
Remote Sensing And Gis ◽  
Remotely Sensed Data ◽  
Analyse Data

To support reforestation activities, spatially forestry data are inexorably needed to support the activities. By using multi –temporally data, reforestation activities an be identified and detected. To accomplish the purpose, this research uses Landsat TM data aquired in 1990 and 1995. Remotely sensed data and Geographyc Information System (GIS) are methods that can be applied to gather, monitor as well as analyse data swiftly and accurately. This research uses remotely sensed data to collect land cover features in given area. Geographyc information System is used to capture and to analyse reforestation data. The expected is GIS based forest management strategy making.

scholarly journals DINÂMICA NO USO E COBERTURA DA TERRA NA REGIÃO DO MATOPIBA ENTRE 2000 E 2016

Nativa ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 547
Author(s):  
Eraldo Aparecido Trondoli Matricardi ◽  
Thais Jacob Mendes ◽  
Eder Miguel Pereira ◽  
Pedro Guilherme De Andrade Vasconcelos ◽  
Humberto Ângelo ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Land Cover ◽  
Riparian Forest ◽  
Landsat Imagery ◽  
Sustainable Use ◽  
Remotely Sensed Data ◽  
Land Occupation ◽  
Study Region ◽  
Study Results

O processo de ocupação das terras do Cerrado brasileiro tem impactado severamente sua paisagem natural nas últimas décadas. No presente estudo estimou-se as mudanças no uso e cobertura da terra ocorridas entre 2000 e 2016 na região do MATOPIBA usando dados e técnicas de sensoriamento remoto. Estimou-se também as áreas de agricultura irrigada e as alterações no uso e cobertura da terra ocorridas dentro de áreas protegidas na região de estudo. Nove classes de uso e cobertura de terra (corpos de água, cerrado denso, cerrado aberto, floresta ciliar, agricultura, campos irrigados, sombra, campos queimados e solo exposto) foram detectadas usando imagens de satélite e a técnica de classificação da máxima verossimilhança. Com base nos resultados desta pesquisa, observou-se o aumento 40,9% de campos agrícolas e solos expostos entre 2000 e 2016 na área de estudo. As áreas de agricultura irrigada aumentaram aproximadamente 154% (102.000 hectares) no mesmo período. Embora os diferentes tipos de antropização de áreas naturais tenham sido observados em toda a área de estudo, o maior aumento ocorreu na porção sul, onde as terras mais aptas para agricultura mecanizada estão mais concentradas. A antropização também aumentou dentro das terras protegidas de uso sustentável, onde as atividades de conservação deveriam ser prioritariamente implementadas na região de estudo, tais como a criação de corredores ecológicos e políticas públicas, visando o uso sustentável de seus recursos naturais.Palavras-chave: desmatamento; Cerrado; sensoriamento remoto. LAND USE AND LAND COVER DYNAMIC IN THE MATOPIBA REGION BETWEEN 2000 AND 2016 ABSTRACT: The land occupation process in the Brazilian Cerrado has severely impacted its natural landscape in the last decades. In this study, we estimated the land use and land cover changes occurred in the MATOPIBA region between 2000 and 2016 by using remotely sensed data and techniques. We also estimated the irrigated fields and deforested lands occurred within protected areas in the study region. Nine land use and land cover classes (water bodies, dense cerrado, open cerrado, riparian forest, agriculture, irrigated fields, shade, burned fields, and exposed soil) were detected by using Landsat imagery and by applying the Maximum Likelihood remote sensing technique. Based on our study results, we observed an increase of 40,9% agricultural fields and exposed soils during between 2000 and 2016 in the study region. Irrigated fields increased approximately 154% (102,000 ha) during the studied period. Although different types of anthropization were observed throughout the study area, the major increasing change was observed within the southern portion, where the most suitable agricultural lands are concentrated. The anthropization also increased within protected lands of sustainable use, where conservation activities should be prioritarily enforced in the study region, such as the creation of ecological corridors and public policies aiming sustainable use of its natural resources.Keywords: deforestation; Cerrado; remote Sensing.

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