A comparison of thermocouples and temperature paints to monitor spatial and temporal characteristics of landscape-scale prescribed fires

2004 ◽  
Vol 13 (3) ◽  
pp. 311 ◽  
Author(s):  
Louis R. Iverson ◽  
Daniel A. Yaussy ◽  
Joanne Rebbeck ◽  
Todd F. Hutchinson ◽  
Robert P. Long ◽  
...  
Keyword(s):  
Grid Point ◽  
Heat Index ◽  
Maximum Temperature ◽  
Fire Intensity ◽  
Temperature Sensitive ◽  
Burned Areas ◽  
Rate Of Spread ◽  
Maximum Temperatures ◽  
Highly Correlated ◽  
Fire Characteristics

A method to better monitor landscape-level fire characteristics is presented. Three study areas in southern Ohio oak-hickory (Quercus-Carya) forests were established with four treatment areas of ~20 ha each: control (C), burn only (B), thin only (T) or thin plus burn (TB). Two independent measures useful for qualitatively characterising fire intensity were established on a 50-m grid, resulting in over 120 sampling locations at each site, in the burned areas: aluminum tags painted with temperature-sensitive paints, and logger-probe units that logged probe temperature every 2 s during burns. Fires were conducted in spring 2001. The logger-probe units allowed five measures qualitatively related to fire intensity or timing to be calculated at each grid point: maximum probe temperature; duration of probe temperature above 30°C; a heat index, defined as the summed temperatures above 30°C; time of maximum temperature; and estimated rate of spread. Maximum temperatures recorded by the two measuring systems were highly correlated (r2 = 0.83). Relative to painted tags, logger-probe units provide information useful for assessing some other components of fire behaviour. The temporal recording of temperatures allowed us to prepare a web-based simulation of the fires. Heat index and rate of spread estimates provided additional fire information. The TB units consistently burned cooler than the B units, perhaps because of uncured slash and a disrupted fuel bed in those units.

Fire effects on seed relaease and the emergence and establishment of seedlings in Banksia ericifolia. L.f

1981 ◽  
Vol 29 (5) ◽  
pp. 521 ◽  
Author(s):  
RA Bradstock ◽  
PJ Myerscough
Keyword(s):  
Seed Bank ◽  
Seedling Emergence ◽  
Fire Regimes ◽  
Fire Effects ◽  
Maximum Temperature ◽  
Fire Intensity ◽  
Fire Temperature ◽  
Banksia Ericifolia ◽  
Maximum Temperatures ◽  
The Relationship

Fire intensity and seasonality affected the release of seed in Banksia ericifolia L.f, and the post-fire emergence of seedlings. Mean maximum temperatures recorded in a heathland burn in May 1977 at heights of 0.5, 2 and 3 m were about 400, 275 and 175°C respectively. Variability in maximum temperature was dependent on the age and position of B. ericifolia stands. Release of seed held on B. ericifolia bushes increased significantly after fire. The proportion of seed released on unburnt controls stayed constant. Seeds were released earlier and quicker from cones exposed to high fire temperature maxima than from those exposed to low fire temperature maxima. Up to 80% of the seed bank was released 95 days after the fire. A greater proportion of the seed bank emerged and established as seedlings 5 months after the fire in May than after a fire the previous February. Seedling emergence and mortality were broadly related to rainfall over this period. The relationship between various fire regimes and abundance in B. ericifolia populations is discussed.

Soil temperatures during and following low-intensity prescribed burning in a Eucalyptus pauciflora forest

Soil Research ◽  
1986 ◽  
Vol 24 (1) ◽  
pp. 33 ◽  
Author(s):  
RJ Raison ◽  
PV Woods ◽  
BF Jakobsen ◽  
GAV Bary
Keyword(s):  
Organic Matter ◽  
Prescribed Burning ◽  
Organic Matter Content ◽  
Heat Content ◽  
Soil Surface ◽  
Maximum Temperature ◽  
Fire Intensity ◽  
Daily Maximum ◽  
Low Intensity ◽  
Maximum Temperatures

Temperatures at the soil surface and at several soil depths were measured during, and at intervals, for 33 months after a low-intensity prescribed burn in a subalpine Eucalyptus pauciflora forest. The high organic matter content, low bulk density, and low moisture content of the surface soil caused steep soil temperature gradients to be generated during the fire. Mean maximum temperatures during the fire were 600 � 50, 450 � 52, 54 � 5 and 42 � 5�C in the litter and at 0, 2 and 5 cm soil depths respectively. The highest temperatures recorded at 0, 2 and 5 cm depths were 703, 94 and 44�C. Temperatures exceeding 200�C, which result in volatilization of N from soil organic matter, were estimated to have occurred in the upper 3 mm of the soil. Byram fire intensity tended to be negatively correlated with the maximum temperature measured at the soil surface, but was not correlated with the amount of heat absorbed by black cans (thermal integrators) or the increase in the heat content of the soil. After the burn, the mean daily maximum temperatures in the soil were markedly higher on burnt than on unburnt sites. For example, soon after burning increases were 6, 10, 4 and 4�C at 0, 2, 5 and 10 cm depths, respectively, during a 5-day summer period. Mean daily minimum temperatures on recently burnt plots were similar to or slightly lower than those on unburnt areas. Average day-time temperature in recently burnt forest in summer was elevated by up to 8 and 4�C at 0 and 10 cm soil depths.

Indices of fire characteristics in sandstone heath near Sydney, Australia

1999 ◽  
Vol 9 (2) ◽  
pp. 145 ◽  
Author(s):  
Sandra Whight ◽  
Ross Bradstock
Keyword(s):  
Relative Sensitivity ◽  
Fire Intensity ◽  
Rate Of Spread ◽  
Heathland Vegetation ◽  
And Performance ◽  
Fire Characteristics ◽  
Sydney Australia

The relative sensitivity and performance of post-hocindices of fire characteristics were examined in a heathland area burnt in1994. Sites burnt at differing times before 1994 were selected andqualitatively allocated to classes of high and low crown damage. Subsequentmeasures were made of height of consumption of crowns, length of the deadportion of Xanthorrhoea resinifera leaves, and minimumtip diameters of burnt branches of the shrubs,Banksia oblongifolia andBanksia ericifolia. Results indicated that significantdifferences in mean, minimum tip diameter corresponded to contrasting classesof crown damage (larger mean tip diameters in high crown damage sites). Meanminimum branch tip diameter in B. oblongifolia was notsignificantly correlated with fuel age but significant correlations were foundwith estimates of rate of spread and Byram fire intensity at the study sites.The minimum branch tip diameter method has potential for further developmentand use as an indicator of fire intensity in heathland vegetation.

Winter grazing can reduce wildfire size, intensity and behaviour in a shrub-grassland

2016 ◽  
Vol 25 (2) ◽  
pp. 191 ◽  
Author(s):  
Kirk W. Davies ◽  
Chad S. Boyd ◽  
Jon D. Bates ◽  
April Hulet
Keyword(s):  
Climate Change ◽  
Bos Taurus ◽  
Flame Height ◽  
Maximum Temperature ◽  
Fire Intensity ◽  
Climate Change Effects ◽  
Area Burned ◽  
Rate Of Spread ◽  
Winter Grazing ◽  
Dormant Season

An increase in mega-fires and wildfires is a global issue that is expected to become worse with climate change. Fuel treatments are often recommended to moderate behaviour and decrease severity of wildfires; however, the extensive nature of rangelands limits the use of many treatments. Dormant-season grazing has been suggested as a rangeland fuel treatment, but its effects on fire characteristics are generally unknown. We investigated the influence of dormant-season (winter) grazing by cattle (Bos taurus) on fuel characteristics, fire behaviour and area burned in Wyoming big sagebrush (Artemisia tridentata subsp. wyomingensis) shrub-grassland communities in south-eastern Oregon, USA. Winter grazing was applied for 5 years before burning and compared with ungrazed areas. Winter grazing decreased fine fuels and increased fine fuel moisture, which reduced flame height and depth, rate of spread and area burned. Winter-grazed areas also had lower maximum temperature and heat loading during fires than ungrazed areas, and thereby decreased risk of fire-induced mortality of important herbaceous functional groups. These results suggest that winter grazing may be a fuel management treatment that can be applied across vast shrub-grasslands to decrease wildfire risk and fire intensity to mediate climate change effects on wildfire activity.

Beyond “fire temperatures”: calibrating thermocouple probes and modeling their response to surface fires in hardwood fuels

2008 ◽  
Vol 38 (5) ◽  
pp. 1008-1020 ◽  
Author(s):  
Anthony S. Bova ◽  
Matthew B. Dickinson
Keyword(s):  
Fire Behavior ◽  
Calibration Method ◽  
Temperature Sensitive ◽  
Reporting Standard ◽  
Surface Fires ◽  
Standard Fire ◽  
Point Estimates ◽  
Measurement Devices ◽  
Maximum Temperatures ◽  
Fire Characteristics

The maximum temperatures of thermocouples, temperature-sensitive paints, and calorimeters exposed to flames in wildland fires are often called “fire temperatures” but are determined as much by the properties and deployment of the measurement devices as by the fires themselves. Rather than report device temperatures that are not generally comparable among studies, we show that maximum and time-integrated temperatures of relatively thick (4.8 mm diameter) type-K thermocouple probes (TCPs) can be calibrated to estimate fuel consumption and fire line intensity in surface fires. Although reporting standard fire characteristics is an improvement over reporting device temperatures, TCPs are not ideal instruments for monitoring surface fires, because they provide only point estimates of fire behavior and must be calibrated for different fire environments, TCP characteristics, and deployments. To illustrate how TCPs respond to fires and to point the way towards a more general calibration method, we report results from a numerical model that accurately simulated TCP response to a spreading surface fire.

THE TEMPERATURES OF SURFACE FIRES IN JACK PINE BARREN: I. THE VARIATION IN TEMPERATURE WITH TIME

1966 ◽  
Vol 44 (10) ◽  
pp. 1285-1292 ◽  
Author(s):  
David W. Smith ◽  
John H. Sparling
Keyword(s):  
Jack Pine ◽  
Maximum Temperature ◽  
Surface Fires ◽  
Mean Temperature ◽  
The Mean ◽  
Maximum Temperatures

The temperatures of 18 fires in an open jack pine barren near Timmins, Ontario, have been recorded. The maximum temperature recorded was 545 °C, although in other determinations fire temperatures in excess of 1000 °C were reached. The mean temperature of all fires was 340.6 ± 133.2 °C. Three fires at 230, 345, and 545 °C were considered in detail.The maximum temperature of a fire was normally recorded at heights of 5 cm or 10 cm above the surface. Maximum temperatures of hotter fires usually occurred at greater heights than cooler ones. Duration and the temperature ("intensity") of the fire are important aspects of fire studies.

Fuel and fire characteristics in savanna - woodland of West Africa in relation to grazing and dominant grass type

2007 ◽  
Vol 16 (5) ◽  
pp. 531 ◽  
Author(s):  
Patrice Savadogo ◽  
Didier Zida ◽  
Louis Sawadogo ◽  
Daniel Tiveau ◽  
Mulualem Tigabu ◽  
...  
Keyword(s):  
Prescribed Burning ◽  
Management Tool ◽  
Fuel Load ◽  
Maximum Temperature ◽  
Fire Intensity ◽  
Fire Behaviour ◽  
Savanna Woodland ◽  
Vegetation Height ◽  
Average Maximum ◽  
Dominant Grass

Fuel characteristics, fire behaviour and temperature were studied in relation to grazing, dominant grass type and wind direction in West African savanna–woodland by lighting 32 prescribed early fires. Grazing significantly reduced the vegetation height, total fuel load, and dead and live fuel fractions whereas plots dominated by perennial grasses had higher values for vegetation height, total fuel load and the quantity of live fuel load. Although fire intensity remained insensitive (P > 0.05) to any of these factors, fuel consumption was significantly (P = 0.021) reduced by grazing, rate of spread was faster in head fire (P = 0.012), and flame length was shorter in head fire than back fire (P = 0.044). The average maximum temperature was higher (P < 0.05) on non-grazed plots, on plots dominated by annual grasses, on plots subjected to head fire, and at the soil surface. Lethal temperature residence time showed a nearly similar trend to fire temperature. Wind speed and total fuel load were best predictors of fire behaviour parameters (R2 ranging from 0.557 to 0.862). It can be concluded that grazing could be used as a management tool to modify fire behaviour, back fire should be carried out during prescribed burning to lower fire severity, and the fire behaviour models can be employed to guide prescribed early fire in the study area.

Calorimetric determination of the effect of additives on cement hydration process

2013 ◽  
Vol 67 (2) ◽  
Author(s):  
Pavel Šiler ◽  
Josef Krátký ◽  
Iva Kolářová ◽  
Jaromír Havlica ◽  
Jiří Brandštetr
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Maximum Temperature ◽  
Granulated Blast Furnace Slag ◽  
Mineral Components ◽  
Maximum Temperatures ◽  
The Impact ◽  
Furnace Slag ◽  
Calorimetric Determination

AbstractPossibilities of a multicell isoperibolic-semiadiabatic calorimeter application for the measurement of hydration heat and maximum temperature reached in mixtures of various compositions during their setting and early stages of hardening are presented. Measurements were aimed to determine the impact of selected components’ content on the course of ordinary Portland cement (OPC) hydration. The following components were selected for the determination of the hydration behaviour in mixtures: very finely ground granulated blast furnace slag (GBFS), silica fume (microsilica, SF), finely ground quartz sand (FGQ), and calcined bauxite (CB). A commercial polycarboxylate type superplasticizer was also added to the selected mixtures. All maximum temperatures measured for selected mineral components were lower than that reached for cement. The maximum temperature increased with the decreasing amount of components in the mixture for all components except for silica fume. For all components, except for CB, the values of total released heat were higher than those for pure Portland cement samples.

The ecology of immature phases of Trichostrongyle nematodes: II. The effect of climatic factors on the availability of the infective larvae of Trichostrongylus retortaeformis to the host

Parasitology ◽  
1948 ◽  
Vol 39 (1-2) ◽  
pp. 26-38 ◽  
Author(s):  
H. D. Crofton
Keyword(s):  
Climatic Factors ◽  
Faecal Pellet ◽  
Cold Weather ◽  
Maximum Temperature ◽  
Infective Stage ◽  
Faecal Pellets ◽  
Infective Larvae ◽  
High Death ◽  
Maximum Temperatures ◽  
Rate Of Evaporation

1. Eggs and larvae of Trichostrongylus retortaeformis were used.2. The rate of hatching of eggs was shown to be mainly related to temperature. From November to March, when maximum temperatures were below 50° F., there was no hatching. When maximum temperatures of 50–55° F. occurred eggs hatched on or before the fifteenth day, but never during the first 8 days. Eggs hatched in 8 days or less when maximum temperatures of 60–80° F. occurred.3. When the rate of evaporation in the air was high, eggs still hatched and reached the infective stage, the grass blades reducing the rate of loss of moisture from the faecal pellet. Laboratory experiments show that eggs may not develop to the infective stage if the faecal pellets are on a grassless portion of the pasture. This is most likely to occur when the rate of evaporation is high and the temperature low.4. Hatching may be delayed by cold conditions, but some eggs remain viable for long periods and they hatch when the temperature rises. Eggs passed by the host in the autumn can survive a cold winter and hatch in the spring, but eggs passed during the coldest period die.5. During periods when the maximum temperature never exceeded 55° F., little or no migration of larvae occurred. When temperatures rose above 55° F. the number of larvae migrating increased; but rise of temperature was associated with increase in the rate of evaporation. High rates of evaporation reduced the number of larvae migrating on the grass blades.6. Some infective larvae died soon after exposure on grass plots, but a small number survived long periods. In cold weather some larvae were still alive after 20 weeks. A high death-rate occurred in warm weather. A large proportion of the larvae died during periods in which the rate of evaporation was high; in one of these periods 95% of the larvae were dead at the end of 4 weeks' exposure.7. The number of larvae on grass blades of a pasture was shown to be dependent, at any time, upon the climate at that time, and upon past conditions which had influenced hatching and survival:

scholarly journals Extreme heat in India and anthropogenic climate change

2018 ◽  
Vol 18 (1) ◽  
pp. 365-381 ◽  
Author(s):  
Geert Jan van Oldenborgh ◽  
Sjoukje Philip ◽  
Sarah Kew ◽  
Michiel van Weele ◽  
Peter Uhe ◽  
...  
Keyword(s):  
Air Pollution ◽  
Global Warming ◽  
Health Effects ◽  
Climate Models ◽  
Decadal Variability ◽  
Heat Waves ◽  
Health Impact ◽  
Heat Index ◽  
Maximum Temperature ◽  
Surface Cooling

Abstract. On 19 May 2016 the afternoon temperature reached 51.0 °C in Phalodi in the northwest of India – a new record for the highest observed maximum temperature in India. The previous year, a widely reported very lethal heat wave occurred in the southeast, in Andhra Pradesh and Telangana, killing thousands of people. In both cases it was widely assumed that the probability and severity of heat waves in India are increasing due to global warming, as they do in other parts of the world. However, we do not find positive trends in the highest maximum temperature of the year in most of India since the 1970s (except spurious trends due to missing data). Decadal variability cannot explain this, but both increased air pollution with aerosols blocking sunlight and increased irrigation leading to evaporative cooling have counteracted the effect of greenhouse gases up to now. Current climate models do not represent these processes well and hence cannot be used to attribute heat waves in this area. The health effects of heat are often described better by a combination of temperature and humidity, such as a heat index or wet bulb temperature. Due to the increase in humidity from irrigation and higher sea surface temperatures (SSTs), these indices have increased over the last decades even when extreme temperatures have not. The extreme air pollution also exacerbates the health impacts of heat. From these factors it follows that, from a health impact point of view, the severity of heat waves has increased in India. For the next decades we expect the trend due to global warming to continue but the surface cooling effect of aerosols to diminish as air quality controls are implemented. The expansion of irrigation will likely continue, though at a slower pace, mitigating this trend somewhat. Humidity will probably continue to rise. The combination will result in a strong rise in the temperature of heat waves. The high humidity will make health effects worse, whereas decreased air pollution would decrease the impacts.

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