The relationship of post-fire white ash cover to surface fuel consumption

2013 ◽  
Vol 22 (6) ◽  
pp. 780 ◽  
Author(s):  
Andrew T. Hudak ◽  
Roger D. Ottmar ◽  
Robert E. Vihnanek ◽  
Nolan W. Brewer ◽  
Alistair M. S. Smith ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Fire Severity ◽  
Mineral Soil ◽  
Field Measurements ◽  
Mixed Conifer ◽  
Complete Combustion ◽  
Surface Cover ◽  
White Ash ◽  
Before And After ◽  
Physically Based

White ash results from the complete combustion of surface fuels, making it a logically simple retrospective indicator of surface fuel consumption. However, the strength of this relationship has been neither tested nor adequately demonstrated with field measurements. We measured surface fuel loads and cover fractions of white ash and four other surface materials (green vegetation, brown non-photosynthetic vegetation, black char and mineral soil) immediately before and after eight prescribed fires in four disparate fuelbed types: boreal forest floor, mixed conifer woody slash, mixed conifer understorey and longleaf pine understorey. We hypothesised that increased white ash cover should correlate significantly to surface fuel consumption. To test this hypothesis, we correlated field measures of surface fuel consumption with field measures of surface cover change. Across all four fuelbed types, we found increased white ash cover to be the only measure of surface cover change that correlated significantly to surface fuel consumption, supporting our hypothesis. We conclude that white ash load calculated from immediate post-fire measurements of white ash cover, depth and density may provide an even more accurate proxy for surface fuel consumption, and furthermore a more physically based indicator of fire severity that could be incorporated into rapid response, retrospective wildfire assessments.

The effect of fire severity on ash, and plant and soil nutrient levels following experimental burning in a boreal mixedwood stand

1998 ◽  
Vol 78 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Mark Johnston ◽  
Julie Elliott
Keyword(s):  
Fuel Consumption ◽  
Forest Floor ◽  
Fire Ecology ◽  
Fire Severity ◽  
Mineral Soil ◽  
Rubus Idaeus ◽  
Nutrient Concentrations ◽  
Heat Output ◽  
Nutrient Inputs ◽  
Whole Tree

The Boreal Mixedwood Ecosystem Study near Thunder Bay, Ontario is a multi-disciplinary investigation of the impacts of harvesting and fire on the structure and function of a boreal mixed-wood ecosystem. The fire component comprises a set of treatments in which fire severity was manipulated by adjusting fuel loadings through a variety of harvesting techniques, and also included fire in standing timber. Intensive fuel sampling before and after the fire enabled detailed determinations of fuel consumption, heat output and forest floor reduction. Nutrient concentrations in ash, soil, and plant tissue following the fire were compared with fire severity in order to quantify potential nutrient inputs and their relationship to the amount of biomass consumed during the fire. Forest floor and woody fuel consumption varied significantly among treatments, with the most important factor being whether or not the stand had been harvested previous to the fire. The pH was highest and P concentrations among the lowest in the ash of unharvested blocks. Nutrient concentrations of the remaining forest floor and upper mineral soil were weakly related to the treatments. Forest floor P concentrations were highest on whole-tree harvested and lowest on uncut blocks. Whole-tree harvested blocks also had the highest pH values in forest floor and mineral soil. Concentrations of N, P, and Mg in the foliage of Populus tremuloides Michx. and Rubus idaeus L. were higher on unharvested burned than cut and burned plots, and were negatively correlated with the depth of forest floor reduction. These results indicate that fire severity plays a role in determining the extent of nutrient enrichment following fire, and may be important in influencing long-term site productivity. Key words: Fire severity, forest fire, nutrient cycles, soil chemistry, fire ecology

scholarly journals Blowing and drifting snow in Alpine terrain: numerical simulation and related field measurements

1998 ◽  
Vol 26 ◽  
pp. 174-178 ◽  
Author(s):  
Peter Gauer
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Three Dimensional ◽  
Field Measurements ◽  
Blowing Snow ◽  
Related Field ◽  
Drifting Snow ◽  
Physically Based ◽  
Snow Transport

A physically based numerical model of drifting and blowing snow in three-dimensional terrain is developed. The model includes snow transport by saltation and suspension. As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements.

Spatial variability in microclimate in a mixed-conifer forest before and after thinning and burning treatments

2010 ◽  
Vol 259 (5) ◽  
pp. 904-915 ◽  
Author(s):  
Siyan Ma ◽  
Amy Concilio ◽  
Brian Oakley ◽  
Malcolm North ◽  
Jiquan Chen
Keyword(s):  
Spatial Variability ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Mixed Conifer Forest ◽  
Before And After

scholarly journals Growth, Development and Ornamental Value of Miscanthus sinensis (Andersson) Species Depending on the Dose of Shrimp Biowaste

Agriculture ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 67
Author(s):  
Piotr Żurawik
Keyword(s):  
High Salinity ◽  
Mineral Soil ◽  
Growing Season ◽  
Miscanthus Sinensis ◽  
Alkaline Ph ◽  
Important Group ◽  
Planting Material ◽  
Miscanthus Giganteus ◽  
Before And After ◽  
Marine Products

Crustaceans, including shrimps, are an important group of marine products processed in over 50 countries around the world. It is one of the most profitable and fast-growing processing branches. About 30 to 40% of crustaceans are used immediately after fishing, while 60–70% are processed. This generates thousands of tons of waste, proper management of which becomes increasingly important. The study was conducted in the years 2015–2017. Planting material included rhizomes of Miscanthus sinensis and Miscanthus × giganteus. Shrimp shells, dried and fragmented into 2–3 mm long pieces, were added to the soil at a dose of 5%, 10% and 15%. Mineral soil without the dried waste served as control. pH and substrate salinity were determined both before and after the growing season, and vegetative and generative traits of the plants were assessed. Shrimp biowaste is rich in N, P, K, Ca and Mg, has alkaline pH and high salinity. Its effects on plants depend on its dose and plant species. Miscanthus sinensis turned out more sensitive to the substrate salinity but in both species shrimp biowaste improved their ornamental value. For Miscanthus sinensis the most beneficial dose was 5%, while for Miscanthus × giganteus it was 15%.

Labor Productivity and Managerial Efficiency against a Static Technology: The Pennsylvania Iron Industry, 1750–1800

1980 ◽  
Vol 40 (1) ◽  
pp. 129-136 ◽  
Author(s):  
Paul F. Paskoff
Keyword(s):  
Eighteenth Century ◽  
Fuel Consumption ◽  
Labor Productivity ◽  
Learning By Doing ◽  
Iron Industry ◽  
Managerial Efficiency ◽  
Before And After ◽  
Consumption Rates ◽  
The Face

An increase in labor productivity and a reduction of fuel consumption rates were two notable and closely related achievements of the management of Hopewell Forge, an ironworks in eighteenth-century Pennsylvania. Significantly, these economies were realized in the face of technological stasis through learning by doing. The analysis of this accomplishment is cast in the larger context of the performance of the iron industry before and after 1800.

scholarly journals FIELD MEASUREMENTS ON RUNWAY FRICTION DECAY RELATED TO RUBBER DEPOSITS

Transport ◽  
2016 ◽  
Vol 31 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Mario De Luca ◽  
Francesco Abbondati ◽  
Thomas J. Yager ◽  
Gianluca Dell’Acqua
Keyword(s):  
Functional Capacity ◽  
Field Measurements ◽  
Surface Characteristics ◽  
Air Traffic ◽  
Pavement Surface ◽  
Vulcanized Rubber ◽  
Before And After

Surfaces of airport pavements are subject to contamination that can be very dangerous for the movement of aircraft particularly on the runway. A recurrent problem is represented by the deposits of vulcanized rubber of aircraft tires in the touchdown area during landings and lesser during take-offs. This causes a loss of grip that compromises the safety of aircraft movements in take-off and landing operations. This study deals with the surface characteristics decay phenomenon related to contamination from rubber deposits. The experiment was conducted by correlating the pavement surface characteristics, as detected by Grip Tester, to air traffic before and after de-rubberizing operation and two models were constructed for the assessment of functional capacity of the runway before and after the operations de-rubberizing.

scholarly journals Biomass burning fuel consumption dynamics in the tropics and subtropics assessed from satellite

2016 ◽  
Vol 13 (12) ◽  
pp. 3717-3734 ◽  
Author(s):  
Niels Andela ◽  
Guido R. van der Werf ◽  
Johannes W. Kaiser ◽  
Thijs T. van Leeuwen ◽  
Martin J. Wooster ◽  
...  
Keyword(s):  
South America ◽  
Fuel Consumption ◽  
Spatial Patterns ◽  
Field Measurements ◽  
Sub Saharan Africa ◽  
Burned Area ◽  
Return Periods ◽  
Sub Saharan ◽  
In Fire ◽  
Consumption Dynamics

Abstract. Landscape fires occur on a large scale in (sub)tropical savannas and grasslands, affecting ecosystem dynamics, regional air quality and concentrations of atmospheric trace gasses. Fuel consumption per unit of area burned is an important but poorly constrained parameter in fire emission modelling. We combined satellite-derived burned area with fire radiative power (FRP) data to derive fuel consumption estimates for land cover types with low tree cover in South America, Sub-Saharan Africa, and Australia. We developed a new approach to estimate fuel consumption, based on FRP data from the polar-orbiting Moderate Resolution Imaging Spectroradiometer (MODIS) and the geostationary Spinning Enhanced Visible and Infrared Imager (SEVIRI) in combination with MODIS burned-area estimates. The fuel consumption estimates based on the geostationary and polar-orbiting instruments showed good agreement in terms of spatial patterns. We used field measurements of fuel consumption to constrain our results, but the large variation in fuel consumption in both space and time complicated this comparison and absolute fuel consumption estimates remained more uncertain. Spatial patterns in fuel consumption could be partly explained by vegetation productivity and fire return periods. In South America, most fires occurred in savannas with relatively long fire return periods, resulting in comparatively high fuel consumption as opposed to the more frequently burning savannas in Sub-Saharan Africa. Strikingly, we found the infrequently burning interior of Australia to have higher fuel consumption than the more productive but frequently burning savannas in northern Australia. Vegetation type also played an important role in explaining the distribution of fuel consumption, by affecting both fuel build-up rates and fire return periods. Hummock grasslands, which were responsible for a large share of Australian biomass burning, showed larger fuel build-up rates than equally productive grasslands in Africa, although this effect might have been partially driven by the presence of grazers in Africa or differences in landscape management. Finally, land management in the form of deforestation and agriculture also considerably affected fuel consumption regionally. We conclude that combining FRP and burned-area estimates, calibrated against field measurements, is a promising approach in deriving quantitative estimates of fuel consumption. Satellite-derived fuel consumption estimates may both challenge our current understanding of spatiotemporal fuel consumption dynamics and serve as reference datasets to improve biogeochemical modelling approaches. Future field studies especially designed to validate satellite-based products, or airborne remote sensing, may further improve confidence in the absolute fuel consumption estimates which are quickly becoming the weakest link in fire emission estimates.

Landscape-scale effects of fire severity on mixed-conifer and red fir forest structure in Yosemite National Park

2013 ◽  
Vol 287 ◽  
pp. 17-31 ◽  
Author(s):  
Van R. Kane ◽  
James A. Lutz ◽  
Susan L. Roberts ◽  
Douglas F. Smith ◽  
Robert J. McGaughey ◽  
...  
Keyword(s):  
Forest Structure ◽  
National Park ◽  
Scale Effects ◽  
Fire Severity ◽  
Landscape Scale ◽  
Yosemite National Park ◽  
Mixed Conifer

scholarly journals Global fire emissions estimates during 1997–2015

2017 ◽  
Author(s):  
Guido R. van der Werf ◽  
James T. Randerson ◽  
Louis Giglio ◽  
Thijs T. van Leeuwen ◽  
Yang Chen ◽  
...  
Keyword(s):  
North America ◽  
Fuel Consumption ◽  
Fire Severity ◽  
Emission Factors ◽  
Trace Gas ◽  
Burned Area ◽  
Biogeochemical Model ◽  
Fire Dynamics ◽  
Fire Emissions ◽  
Aerosol Emissions

Abstract. Climate, land use, and other anthropogenic and natural drivers have the potential to influence fire dynamics in many regions. To develop a mechanistic understanding of the changing role of these drivers and their impact on atmospheric composition, long term fire records are needed that fuse information from different satellite and in-situ data streams. Here we describe the fourth version of the Global Fire Emissions Database (GFED) and quantify global fire emissions patterns during 1997–2015. The modeling system, based on the Carnegie-Ames-Stanford-Approach (CASA) biogeochemical model, has several modifications from the previous version and uses higher quality input datasets. Significant upgrades include: 1) new burned area estimates with contributions from small fires, 2) a revised fuel consumption parameterization optimized using field observations, 3) modifications that improve the representation of fuel consumption in frequently burning landscapes, and 4) fire severity estimates that better represent continental differences in burning processes across boreal regions of North America and Eurasia. The new version has a higher spatial resolution (0.25°) and uses a different set of emission factors that separately resolves trace gas and aerosol emissions from temperate and boreal forest ecosystems. Global mean carbon emissions using the burned area dataset with small fires (GFED4s) were 2.2 x 1015 grams carbon per year (Pg C yr-1) during 1997–2015, with a maximum in 1997 (3.0 Pg C yr-1) and minimum in 2013 (1.8 Pg C yr-1). These estimates were 11 % higher than our previous estimates (GFED3) during 1997–2011, when the two datasets overlapped. This increase was the result of a substantial increase in burned area (37 %), mostly due to the inclusion of small fires, and a modest decrease in mean fuel consumption (–19 %) to better match estimates from field studies, primarily in savannas and grasslands. For trace gas and aerosol emissions, differences between GFED4s and GFED3 were often larger due to the use of revised emission factors. If small fire burned area was excluded (GFED4 without the "s" for small fires), average emissions were 1.5 Pg C yr-1. The addition of small fires had the largest impact on emissions in temperate North America, Central America, Europe, and temperate Asia. Our improved dataset provides an internally consistent set of burned area and emissions that may contribute to a better understanding of multi-decadal changes in fire dynamics and their impact on the Earth System. GFED data is available from http://www.globalfiredata.org.

scholarly journals Experimental and field verifications of radial gates as flow measurement structures

2021 ◽  
Author(s):  
Hossein Khalili Shayan ◽  
Javad Farhoudi ◽  
Alireza Vatankhah
Keyword(s):  
Field Measurements ◽  
The United States ◽  
Data Series ◽  
Flow Conditions ◽  
Flow Limit ◽  
Before And After ◽  
Energy And Momentum ◽  
Extensive Experimental Data ◽  
Radial Gate ◽  
Discharge Curves

Abstract Radial gates are common structures in irrigation projects. This paper presents some theoretical-based equations for explicit estimation of the discharge from the radial gate under free and submerged flow conditions using Energy and Momentum (E-M) principles. The proposed equations were calibrated using extensive experimental data collected from the literature and this study for three types of radial gates under free and submerged flow conditions. The submergence threshold of radial gates is concluded, based on the concepts of hydraulic jump and the intersection of free and submerged head-discharge curves. The results indicated that the error in estimating the discharge increases under transition ( − 2.5 ≤ Sr% ≤ + 2.5), gate lip (1 < y0/w ≤ 2), and high submerged (yt/y0 ≥ 0.95) flow conditions. However, in these flow limit conditions, the discharge error can be considerably decreased by adjusting the tailwater depth to flow depth just after the gate and using the energy equation for the sections before and after the gate. The efficiency of the proposed methods was evaluated based on the data series from field measurements of radial gates in 29 check structures at irrigation canals in the United States and Iran. The results showed that the discharge could be estimated using the proposed equations in field conditions with acceptable accuracy.

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