Assessment of gaseous emissions and radiative forcing in Indian forest fires

This paper reports a study of the gaseous emissions from Indian forest fires from 2005 to 2016 and their potential impact on radiative forcing. Initially, forest burned area is quantified using MODIS-MCD45A1 data. Results showed that annual burned area of the study period ranges from 8439 km² to 25,442 km² and the maximum forest area is burned during February, March, and April in any year. Gaseous emissions are estimated using emission factors, the mass of fuel available for combustion, combustion factor, and burned area. CO₂, CO, and CH₄ are the major emissions during forest fires with an annual average of 105 × 10⁶ tonnes, 6 × 10⁶ tonnes, and 3.25 × 10⁵ tonnes, respectively. The average radiative forcing (RF) for CO₂, CH_4, and N₂O is estimated as 1.8 Wm^?2, 0.49 Wm^?2, and 0.177 Wm^?2, respectively. An important finding in the present study is the recurrence of forest fires during the pre-monsoon season.     

Forest fires in Portugal: how they happen and why they happen

Forest fires are recurrent phenomena in Southern European countries, due to the nature of Mediterranean forest and climatic characteristics. In Portugal, however, in the recent years, forest fires have become a public calamity and are now endangering the sustainability of the forest itself, as well as several derived economic activities. This paper reviews the past and current situation of forest fires in Portugal, analyses its main causes and consequences and derives recommendations to overcome this problem.     

The 2007 forest fires in the prefecture of Ilia: the views of citizens with regard to the actions taken before,during and after the fires

In 2007, the prefecture of Ilia, Peloponnese, Greece, was struck by very serious fires which were not only the result of extreme weather but also of human omissions and mistakes. This paper examines the views of the citizens of Ilia with regard to the actions of the Fire Department, the municipal authorities, the Forest Service, the citizens and the state, before, during and after the fires.     

Fire whirls in forest fires: An experimental analysis

This work presents a study on the formation of fire whirls with vertical axis on wildfires at laboratory scale. A particularity of the study is the use of typical forest fuels instead of fossil fuels as seen in some of previous studies on this topic. The forest fuels tested in the experiments were dead needles of Pinus pinaster, straw of Avena sativa, dead leaves of Eucalyptus globulus and a mix of shrubs mainly composed by heather (Erica australis) and gorse (Pterospartum tridentatum). The experimental results of the tests with and without forced flow inside a fire whirl generator were compared with tests in similar conditions out of the generator. It was possible to evaluate the effects of fuel bed size, bulk density and external vorticity on several parameters like flame height and diameter, mass decay and heat release rate. The results show that forced flow increases dramatically the burning rate and reduces the time needed to achieve a high rate of energy release. Comparison with results of other sources show that the flames that are generated in the present fire whirl generator are in a transition from fire whirl to pool fire regime and that it is possible to scale up some flow and thermal properties of field scale fire whirls and to derive predictive models on the basis of laboratory scale experiments.     

Estimating room temperatures from fires along walls and in corners

Determination of temperatures associated with room fires provides a means of assessing an important aspect of fire hazard: the likelihood of the occurrence of flashover. Layer temperatures in excess of 600°C have been associated with the occurrence of flashover. A data correlation has previously been presented to estimate layer temperatures for fires burning in the center of rooms. For fires in corners and along walls, restricted entrainment results in higher layer temperatures than predicted by the previous correlation. Modification factors for the previous correlation are developed to extend its applicability to wall and corner burning geometries. The present analysis suggests that a fire in a corner may cause flashover with only half the heat release rate necessary for a fire burning in the center of a room. Reference: Frederick Mowrer and Robert Williamson, Estimating Room Temperatures from Fires along Walls and in Corners,Fire Technology, Vol. 23, May 1987, pp. 133–145.     

Time-dependent smoke yield and mass loss of pool fires in a reduced-scale mechanically ventilated compartment

Technical and pure grades of the combustibles heptane and dodecane were used in a series of small-scale fire tests conducted in a 1 m³ compartment that was mechanically ventilated at 5 and 8 air changes per hour (ACH). Combustible mass loss rates, soot mass concentrations, soot size distributions, several gas species concentrations, and compartment temperatures were measured during the fire. Results for the two pure-grade hydrocarbons were compared with results obtained for their respective technical grades. Technical-grade dodecane produced the highest soot emissions; pure n-heptane produced the lowest. Soot size distributions of all four combustibles attained a steady profile whose modal diameter was about 200 nm. Underventilated fires showed higher carbon monoxide yields than soot yields. Both compartment ventilation rates produced similar results, although the fire self-extinguished earlier for 5 ACH.     

Effects of soil conservation measures in a partially vegetated area after forest fires

After forest fires on the east coast of Korea in 2000, some burnt areas were left untreated. Although 80% of the area was reasonably revegetated within 3 months, about 20% of the area was partially vegetated, mainly due to a low density of sprouters and poor growing conditions (eroded soil and steep slopes). Three years after the fires, the effect of soil conservation measures, such as mulching with wood chips, seeding with native plant species and log erosion barriers (LEBs), on runoff and soil erosion were examined using runoff plots. Wood chip mulching greatly reduced runoff and sediment yields and these effects were consistent regardless of the volume of rainfall. Neither seeding nor LEBs reduced runoff and sediment yields. No positive or negative effects of mulching, seeding or LEBs on ground vegetation cover were observed. The ineffectiveness of seeding and LEBs may have been due to the steep slope, the failure of germination and establishment of seeded plants, and the small diameter of logs. Treating hill slopes with mulch should be considered where post-fire regeneration is slow and there is an absence of organic material such as litter.     

Relationship between construction characteristics and carbon emissions from urban household operational energy usage

Carbon emitted from urban metabolism constitutes a substantial proportion of the anthropogenic greenhouse gas emission, which is at least partially responsible for the recent global warming. Part of the urban carbon emission comes from residential energy consumption. Given the ongoing rapid urbanization and strict emission-reduction requirement, understanding the urban home energy usage carbon emission (UHEUCE) is of great importance to optimize the sustainability of social and economic developments in China. For this reason, a survey has been conducted to exam the condition of home energy usage in Xiamen Island, SE China. This study was based on 340 valid responses and a general linear model for univariate method. The analysis showed (1) among the residential building characteristics, window thermal insulation has the greatest effect on UHEUCE. (2) Construction age and wall thermal insulation could also influence UHEUCE in areas where summer is hot and winter is warm. The better heat prohibiting effect of external wall and window, as well as the newer construction, the more UHEUCE can be generated. The survey provided helpful first-hand data for design and planning on urban energy saving, emission reduction, and for relevant scientific researches.     

2019 年世界代表性国家和地区森林火灾发生概况分析

森林火灾突发性强、破坏性大,一旦失去控制,处置救助十分困难,被称为世界性难题。2019 年全球气候异常,高温、干旱、大风等极端天气增加,多地爆发大规模森林火灾。笔者综述2019 年具有代表性的国家、地区森林火灾发生情况和特点并分析其背后相关的自然因素和社会因素,以期对我国森林防灭火工作有所借鉴。     

CO2, CO, and Hg emissions from the Truman Shepherd and Ruth Mullins coal fires, eastern Kentucky, USA

Carbon dioxide (CO₂), carbon monoxide (CO), and mercury (Hg) emissions were quantified for two eastern Kentucky coal-seam fires, the Truman Shepherd fire in Floyd County and the Ruth Mullins fire in Perry County. This study is one of the first to estimate gas emissions from coal fires using field measurements at gas vents. The Truman Shepherd fire emissions are nearly 1400 t CO₂/yr and 16 kg Hg/yr resulting from a coal combustion rate of 450-550 t/yr. The sum of CO₂ emissions from seven vents at the Ruth Mullins fire is 726 ± 72 t/yr, suggesting that the fire is consuming about 250-280 t coal/yr. Total Ruth Mullins fire CO and Hg emissions are estimated at 21 ± 1.8 t/yr and > 840 ± 170 g/yr, respectively. The CO₂ emissions are environmentally significant, but low compared to coal-fired power plants; for example, 3.9 × 10⁶ t CO₂/yr for a 514-MW boiler in Kentucky. Using simple calculations, CO₂ and Hg emissions from coal-fires in the U.S. are estimated at 1.4 × 10⁷-2.9 × 10⁸ t/yr and 0.58-11.5 t/yr, respectively. This initial work indicates that coal fires may be an important source of CO₂, CO, Hg and other atmospheric constituents.     

新时期我国森林航空消防发展现状及对策研究

文章从新时期我国森林航空消防发展面临的困境和问题入手,就森林航空消防建设发展形势进行了系统分析,在此基础上,提出了指挥领导、力量编成、装备配备、保障基础等方面的具体对策,进而为我国森林航空消防事业科学发展提供参考。     

水泥行业碳达峰形势分析和建议

我国的水泥及熟料产量和销量连续多年位居世界第一.水泥行业是CO2排放重点行业,也是建材行业的碳排放大户."双碳"目标背景下,水泥行业面临严峻挑战,同时也迎来了新的机遇,对水泥行业高质量、可持续发展起到了推动作用.     

Clean-energy policies and electricity sector carbon emissions in the U.S. states

State governments in the United States have enacted various clean-energy policies to decarbonize electric utilities, diversify energy supplies, and stimulate economic development. With a panel data set for 48 continental states from 1990 to 2008, fixed-effect panel regressions are estimated to test the impacts of clean-energy policies on total carbon emissions, electricity consumption, and carbon intensity. The results indicate that supply-side policy tools, such as RPS and EERS, are negatively correlated with carbon intensity in the electricity sector. More aggressive policies are needed to reduce total carbon emissions.     

Sustainable forest management in the developing world: Science challenges and contributions

Forests are a global resource and important issues dealing with their use and maintenance cannot be effectively dealt with in an insular fashion. Global participation is mandatory, if these resources are to be sustained and equitably utilized. The seriousness and urgency of most of the forestry and environmental problems are linked to the inability or means of developing countries to provide appropriate scientific and technical knowledge, effective policy, regulations and planning frameworks to deal with the problems. To fully understand and appreciate the challenges to forest science, it is useful to establish an appropriate background against which they should be viewed, and suggest how to improve our capability to deliver knowledge for a sustainable future. There are three keys to making this a reality: information, innovation, and implementation — all derived from human resources.     

Application of System Dynamics model as decision making tool in urban planning process toward stabilizing carbon dioxide emissions from cities

In spite of the fact that cities are the main sources of CO₂ emissions, presently there are still no specific measures directly addressing the global warming issue in the urban planning process in Malaysia. The present study thus aims to shed new light in the urban planning sector in Malaysia by adopting System Dynamics Model as one of the decision making tools in the urban planning process, with specific considerations on the future CO₂ emission trends. This paper presented projections of future CO₂ emission trends based on the case of Iskandar Development Region of Malaysia, under various options of urban policies, using the System Dynamics Model. The projections demonstrated the capability of the said model in serving as a decision making tool in the urban planning process, with specific reference to CO₂ emissions from cities. Recommendations have been made on the possible approach of adopting the model in the process of Structure Plan study. If the current model was successfully adopted in the urban planning process in Malaysia, it will mark the first step for Malaysia in taking specific considerations on the issues of CO₂ emissions and global warming in the urban planning process.     

Assessing the probability of carbon and greenhouse gas benefit from the management of peat soils

This study proposes a method for assessing the probability that land management interventions will lead to an improvement in the carbon sink represented by peat soils. The method is able to: combine studies of different carbon uptake and release pathways in order to assess changes on the overall carbon or greenhouse gas budget; calculate the probability of the management or restoration leading to an improvement in the budget; calculate the uncertainty in that probability estimate; estimate the equivalent number of complete budgets available from the combination of the literature; test the difference in the outcome of different land management interventions; and provide a method for updating the predicted probabilities as new studies become available. Using this methodology, this study considered the impact of: afforestation, managed burning, drainage, drain-blocking, grazing removal; and revegetation, on the carbon budget of peat soils in the UK. The study showed that afforestation, drain-blocking, revegetation, grazing removal and cessation of managed burning would bring a carbon benefit, whereas deforestation, managed burning and drainage would bring a disbenefit.The predicted probabilities of a benefit are often equivocal as each management type or restoration often leads to increase in uptake in one pathway while increasing losses in another.     

传统工艺与现代工艺相结合在治理森林公园地质灾害中的应用

国家森林公园属于生态文明建设的内容。在地形陡峭的公园里,如何解决公园内的地质灾害问题,确实考验着人们的智慧。上方山森林公园景区采取传统工艺与现代工艺相结合的方式,克服了公园里的运输和工期紧张的困难,有效地治理了公园内的地质灾害问题。     

不同结构类型建筑全生命周期碳排放比较

从可持续发展的战略考虑,选用对资源消耗尽可能少、对生态环境影响小、循环再利用率高的生态环境建筑材料,是21世纪发展新型建筑体系的大趋势。本文基于生命周期评价理论(LCA),建立建筑全生命周期碳排放的核算模型。同时,为探讨减少建筑碳排放的途径和合适结构类型、结构材料的选择,本文从重型结构(钢结构、钢筋混凝土结构)和轻型结构(木结构、轻钢结构)两种不同的结构类型及相应的结构材料入手,对其全生命周期的碳排放进行定量测算和对比分析。结果表明,每年单位建筑面积碳排放,轻型结构〈重型结构;木结构〈轻钢结构〈钢结构〈钢筋混凝土结构。     

Gross CO2 and CH4 emissions from the Nam Ngum and Nam Leuk sub-tropical reservoirs in Lao PDR

Gross CO₂ and CH₄ emissions (degassing and diffusion from the reservoir) and the carbon balance were assessed in 2009-2010 in two Southeast Asian sub-tropical reservoirs: the Nam Ngum and Nam Leuk Reservoirs (Lao PDR). These two reservoirs are within the same climatic area but differ mainly in age, size, residence time and initial biomass stock. The Nam Leuk Reservoir was impounded in 1999 after partial vegetation clearance and burning. However, GHG emissions are still significant 10 years after impoundment. CH₄ diffusive flux ranged from 0.8 (January 2010) to 11.9 mmol m^− 2 d^− 1 (April 2009) and CO₂ diffusive flux ranged from - 10.6 (October 2009) to 38.2 mmol m^− 2 d^− 1 (April 2009). These values are comparable to other tropical reservoirs. Moreover, degassing fluxes at the outlet of the powerhouse downstream of the turbines were very low. The tentative annual carbon balance calculation indicates that this reservoir was a carbon source with an annual carbon export (atmosphere + downstream river) of about 2.2 ± 1.0 GgC yr^− 1.The Nam Ngum Reservoir was impounded in 1971 without any significant biomass removal. Diffusive and degassing CO₂ and CH₄ fluxes were lower than for other tropical reservoirs. Particularly, CO₂ diffusive fluxes were always negative with values ranging from - 21.2 (April 2009) to - 2.7 mmol m⁻² d⁻¹ (January 2010). CH₄ diffusive flux ranged from 0.1 (October 2009) to 0.6 mmol m⁻² d⁻¹ (April 2009) and no degassing downstream of the turbines was measured. As a consequence of these low values, the reservoir was a carbon sink with an estimated annual uptake of - 53 ± 35 GgC yr⁻¹.     

Potential emissions reductions from the use of dual-combined heat and power systems in different climate conditions

In this paper, the potential carbon dioxide emissions (CDE) reduction from the use of a combined heat and power system with two power generation units (D-CHP) is examined for a restaurant building in nine different climate conditions. The performance of the D-CHP system is evaluated on the basis of CDE and operational cost savings. In addition, the results from the D-CHP optimised scheme are compared with the optimised results of a base-loaded CHP (BL-CHP) system and a CHP system operated following the electric load (CHP-FEL). Results show that the D-CHP system produces greater savings over BL-CHP and CHP-FEL for most of the locations examined, whether optimised based on CDE or based on cost. Moreover, the effect of the emissions and cost spark spreads for each location on the D-CHP system performance is analysed. Results indicate that higher spark spreads are shown to yield greater savings for all CHP configurations.