The Experts below are selected from a list of 45006 Experts worldwide ranked by ideXlab platform
Mengchu Zhou - One of the best experts on this subject based on the ideXlab platform.
-
Bi-Objective Scheduling of Fire Engines for Fighting Forest Fires: New Optimization Approaches
2018Co-Authors: Peng Wu, Mengchu ZhouAbstract:It is challenging to perform emergency scheduling for fighting Forest Fires subject to limited rescue resources (i.e., vehicles with fire engines), since extinguishing each fire point should take into account multiple factors, such as the actual fire spreading speed, distance from fire engine depot to fire points, fire-fighting speed of fire engines, and the number of dispatched vehicles. This paper investigates a bi-objective rescue vehicle scheduling problem for multi-point Forest Fires, which aims to optimally dispatch a limited number of fire engines to extinguish Fires. The objectives are to minimize the total fire-extinguishing time and the number of dispatched fire engines. For this problem, we first develop an integer program that is an improved and simplified version of an existing one. After exploring some properties of the problem, we develop an exact dynamic programming algorithm and a fast greedy heuristic method. Computational results for a real-life instance, and benchmark and large-size randomly generated instances confirm the effectiveness and efficiency of the proposed model and algorithms. Besides, a bi-objective integer program is developed to address the multi-depot fire engine scheduling issue.
-
Dual-Objective Scheduling of Rescue Vehicles to Distinguish Forest Fires via Differential Evolution and Particle Swarm Optimization Combined Algorithm
2016Co-Authors: Guangdong Tian, Yaping Ren, Mengchu ZhouAbstract:It is complex and difficult to perform the emergency scheduling of Forest Fires in order to reduce the operational cost and improve the efficiency of extinguishing fire services. A new research issue arises when: 1) decision-makers want to minimize the number of rescue vehicles (or fire-fighting ones) while minimizing the extinguishing time; and 2) decision-makers prefer to complete this task given limited vehicle resources. To do so, this paper presents a novel multiobjective scheduling model to handle Forest Fires subject to limited rescue vehicle (fire engine) constraints, in which a fire-spread speed model is introduced into this problem to better describe practical Forestry fire. Moreover, a Multiobjective Hybrid Differential-Evolution Particle-Swarm-Optimization (MHDP) algorithm is proposed to create a set of Pareto solutions for this problem. This approach is applied to a real-world emergency scheduling problem of the Forest fire in Mt. Daxing'anling, China. Its effectiveness is verified by comparing it with a genetic algorithm and particle swarm optimization algorithm. Experimental results show that the proposed approach is able to quickly produce satisfactory Pareto solutions.
Mike D Flannigan - One of the best experts on this subject based on the ideXlab platform.
-
future emissions from canadian boreal Forest Fires
2009Co-Authors: Mike D Flannigan, Brian D Amiro, Alan S Cantin, W J De GrootAbstract:New estimates of greenhouse gas emissions from Canadian Forest Fires were calculated based on a revised model for fuel consumption, using both the fire fuel load and the Drought Code of the Canadia...
-
detecting the effect of climate change on canadian Forest Fires
2004Co-Authors: Nathan P Gillett, Andrew J Weaver, Francis W Zwiers, Mike D FlanniganAbstract:[1] The area burned by Forest Fires in Canada has increased over the past four decades, at the same time as summer season temperatures have warmed. Here we use output from a coupled climate model to demonstrate that human emissions of greenhouse gases and sulfate aerosol have made a detectable contribution to this warming. We further show that human-induced climate change has had a detectable influence on the area burned by Forest fire in Canada over recent decades. This increase in area burned is likely to have important implications for terrestrial emissions of carbon dioxide and for Forest ecosystems.
-
direct carbon emissions from canadian Forest Fires 1959 1999
2001Co-Authors: Brian D Amiro, Mike D Flannigan, B M Wotton, B J Stocks, David L Martell, J B Todd, K A Logan, J A Mason, Kelvin HirschAbstract:Direct emissions of carbon from Canadian Forest Fires were estimated for all Canada and for each ecozone for the period 1959-1999. The estimates were based on a data base of large Fires for the country and calculations of fuel consumption for each fire using the Canadian Forest Fire Behaviour Prediction System. This technique used the fire locations and start dates to estimate prevailing fire weather and fuel type for each of about 11 000 Fires. An aver - age of 2◊1 0 6 ha·year -1 was burned in this period, varying from 0.3 ◊ 10 6 ha in 1978 to 7.5 ◊ 10 6 ha in 1989. Ecozones of the boreal and taiga areas experienced the greatest area burned, releasing most of the carbon (C). The mean area-weighted fuel consumption for all Fires was 2.6 kg dry fuel·m -2 (1.3 kg C·m -2 ), but ecozones vary from 1.8 to 3.9 kg dry fuel·m -2 . The mean annual estimate of direct carbon emissions was 2 7±6T gC·year -1 . Individual years ranged from 3 to 115 Tg C·year -1 . These direct fire emissions represent about 18% of the current carbon dioxide emis- sions from the Canadian energy sector, on average, but vary from 2 to 75% among years. Post-fire effects cause an ad- ditional loss of carbon and changes to the Forest sink condition. Resume : Les emissions directes de carbone provenant des feux dans les forets canadiennes ont ete estimees pour l'ensemble du Canada et pour chacune des ecozones pendant la periode de 1959 a 1999. Les estimes s'appuient sur une base de donnees sur les feux importants survenus au pays et sur des calculs de consommation de combustibles pour chaque feu a l'aide du Systeme canadien de prediction du comportement des feux de foret. Cette technique utilise la loca- lisation et la date de debut des feux pour estimer les conditions meteorologiques qui prevalaient au moment du feu et le type de combustibles pour chacun des quelques 11 000 feux. Pendant cette periode ,2◊1 0 6 ha par annee en moyenne ont brule, allant de 0,3 ◊ 10 6 ha en 1978 a 7,5 ◊ 10 6 ha en 1989. Les plus grandes superficies brulees se retrouvent dans les
-
climate change and Forest Fires
2000Co-Authors: Mike D Flannigan, Brian J. Stocks, B M WottonAbstract:This paper addresses the impacts of climate change on Forest Fires and describes how this, in turn, will impact on the Forests of the United States. In addition to reviewing existing studies on climate change and Forest Fires we have used two transient general circulation models (GCMs), namely the Hadley Centre and the Canadian GCMs, to estimate fire season severity in the middle of the next century. Ratios of 2 x CO2 seasonal severity rating (SSR) over present day SSR were calculated for the means and maximums for North America. The results suggest that the SSR will increase by 10-50% over most of North America; although, there are regions of little change or where the SSR may decrease by the middle of the next century. Increased SSRs should translate into increased Forest fire activity. Thus, Forest Fires could be viewed as an agent of change for US Forests as the fire regime will respond rapidly to climate warming. This change in the fire regime has the potential to overshadow the direct effects of climate change on species distribution and migration.
Brian J. Stocks - One of the best experts on this subject based on the ideXlab platform.
-
Spatial patterns of Forest Fires in Canada, 1980-1999
2006Co-Authors: Marc-andré Parisien, Vernon S. Peters, Yonghe Wang, John M. Little, Erin M. Bosch, Brian J. StocksAbstract:The present study characterized the spatial patterns of Forest Fires in 10 fire-dominated ecozones of Canada by using a database of mapped Fires ≥200 ha from 1980 to 1999 (n = 5533 Fires). Spatial metrics were used individually to compare measures of fire size, shape (eccentricity and complexity), clustering, and geographic orientation among ecozones and were used concurrently in a multivariate analysis. In addition, a set of factors that influence the fire regime at the ecozone level – topography, climate, fuels, and anthropogenic factors – was compared with the metric outputs. We found significant differences in all spatial metrics among ecozones. The multivariate analysis showed that the Montane Cordillera ecozone, which covers most of British Columbia, had the most distinctive Fires: its Fires were smaller, less complex, and had a more regular distribution. The fire regime descriptors of ecozones were useful to interpret the spatial variation of some spatial metrics, such as fire size, eccentricity, and clustering, but provided little insight into the mechanisms of patterns of fire complexity, which were shown to be sensitive to data quality. Our results provide additional information about the creation of spatially heterogeneous landscapes. Furthermore, they illustrate the potential use of spatial metrics for a more detailed characterization of fire regimes and provide novel information for ecosystems-based land management.
-
climate change and Forest Fires
2000Co-Authors: Mike D Flannigan, Brian J. Stocks, B M WottonAbstract:This paper addresses the impacts of climate change on Forest Fires and describes how this, in turn, will impact on the Forests of the United States. In addition to reviewing existing studies on climate change and Forest Fires we have used two transient general circulation models (GCMs), namely the Hadley Centre and the Canadian GCMs, to estimate fire season severity in the middle of the next century. Ratios of 2 x CO2 seasonal severity rating (SSR) over present day SSR were calculated for the means and maximums for North America. The results suggest that the SSR will increase by 10-50% over most of North America; although, there are regions of little change or where the SSR may decrease by the middle of the next century. Increased SSRs should translate into increased Forest fire activity. Thus, Forest Fires could be viewed as an agent of change for US Forests as the fire regime will respond rapidly to climate warming. This change in the fire regime has the potential to overshadow the direct effects of climate change on species distribution and migration.
Y H Zhang - One of the best experts on this subject based on the ideXlab platform.
-
boreal Forest Fires burn less intensely in russia than in north america
2004Co-Authors: Martin J Wooster, Y H ZhangAbstract:[1] Around 5–20 million hectares of boreal Forest burns annually, mainly in Russia and North America. However, there are reports of significant differences in predominant fire type between these regions, which may have major implications for overall emissions of carbon, gases and aerosols. We examine boreal Forest fire intensities via MODIS observations of fire radiative energy release rate. Results support the contention of a consistent difference in fire intensity and mean fuel consumption in Russia and North America, due to differences in dominant fire type. North American Fires have higher mean intensities, increasing in proportion to percentage tree cover, characteristics indicating likely crown fire dominance. Russian Fires have lower mean intensities, independent of percentage tree cover, characteristics more indicative of surface fire activity. Per unit area burnt, the results suggest Russian Fires may burn less fuel and emit fewer products to the atmosphere than do those in North America. INDEX TERMS: 1615 Global Change: Biogeochemical processes (4805); 1640 Global Change: Remote sensing; 1694 Global Change: Instruments and techniques; 0315 Atmospheric Composition and Structure: Biosphere/atmosphere interactions. Citation: Wooster, M. J., and Y. H. Zhang (2004), Boreal Forest Fires burn less intensely in Russia than in North America, Geophys. Res. Lett., 31, L20505, doi:10.1029/2004GL020805.
Margit Schwikowski - One of the best experts on this subject based on the ideXlab platform.
-
an ice core based history of siberian Forest Fires since ad 1250
2011Co-Authors: Anja Eichler, Willy Tinner, Sabina Brutsch, Susanne Olivier, Tatyana Papina, Margit SchwikowskiAbstract:Abstract Forest Fires play a key role in the global carbon cycle and thus, can affect regional and global climate. Although Fires in extended areas of Russian boreal Forests have a considerable influence on atmospheric greenhouse gas and soot concentrations, estimates of their impact on climate are hampered by a lack of data on the history of Forest Fires. Especially regions with strong continental climate are of high importance due to an intensified development of wildFires. In this study we reconstruct the fire history of Southern Siberia during the past 750 years using ice-core based nitrate, potassium, and charcoal concentration records from Belukha glacier in the continental Siberian Altai. A period of exceptionally high Forest-fire activity was observed between AD 1600 and 1680, following an extremely dry period AD 1540–1600. Ice-core pollen data suggest distinct Forest diebacks and the expansion of steppe in response to dry climatic conditions. Coherence with a paleoenvironmental record from the 200 km distant Siberian lake Teletskoye shows that the vegetational shift AD 1540–1680, the increase in fire activity AD 1600–1680, and the subsequent recovery of Forests AD 1700 were of regional significance. Dead biomass accumulation in response to drought and high temperatures around AD 1600 probably triggered maximum Forest-fire activity AD 1600–1680. The extreme dry period in the 16th century was also observed at other sites in Central Asia and is possibly associated with a persistent positive mode of the Pacific Decadal Oscillation (PDO). No significant increase in biomass burning occurred in the Altai region during the last 300 years, despite strongly increasing temperatures and human activities. Our results imply that precipitation changes controlled fire-regime and vegetation shifts in the Altai region during the past 750 years. We conclude that high sensitivity of ecosystems to occasional decadal-scale drought events may trigger unprecedented environmental reorganizations under global-warming conditions.