scholarly journals Spatial interpolation and simulation of post-burn duff thickness after prescribed fire

1999 ◽  
Vol 9 (2) ◽  
pp. 137 ◽  
Author(s):  
P. R. Robichaud ◽  
S. M. Miller
Keyword(s):  
Spatial Patterns ◽  
Prescribed Fire ◽  
Field Studies ◽  
Timber Harvesting ◽  
Surface Model ◽  
Total Consumption ◽  
Trend Surface ◽  
Harvesting Techniques ◽  
A Site ◽  
Floor Material

Prescribed fire is used as a site treatment after timber harvesting. These fires result in spatial patterns with some portions consuming all of the forest floor material (duff) and others consuming little. Prior to the burn, spatial sampling of duff thickness and duff water content can be used to generate geostatistical spatial simulations of these characteristics. Results from field studies indicated that spatial patterns of duff characteristics occurred, and they were then modeled by kriging, simulation and a trend-surface modeling techniques. The higher elevations of the study unit burned more severely than the lower portion. This is believed to be due to the heat generated by the fire drying out the upper portions of the units, thus consuming more duff material and thinner pre-burn duff thickness due to ground-based harvesting techniques. Attempts to predict duff consumption and subsequent post-burn duff thickness were successful using a trend-surface model developed for this site and a general duff consumption model. Knowledge of spatial patterns of duff remaining may help land managers adjust prescriptions and alter ignition patterns to reduce areas where total consumption of duff might occur.

The Ecology and Management of Wood in World Rivers

2003 ◽  
Keyword(s):  
Spatial Patterns ◽  
General Framework ◽  
River System ◽  
Field Studies ◽  
Transport Processes ◽  
River Networks ◽  
Spatial And Temporal Patterns ◽  
History Of ◽  
World Rivers ◽  
Trapping Sites

<em>Abstract.</em>—A landscape perspective of wood in world rivers accounts for spatial and temporal patterns of sources of wood from streamside forests, processes of wood delivery to channels, transport of wood through river networks, and trapping sites of wood. Amounts of wood in a river system also depend on productivity of forests in source areas and decomposition rates. Collectively, these factors determine the amount and arrangement of individual pieces and accumulations of wood through a river network, which, in turn, affect ecological, geomorphic, social, and other features of rivers. Research to date deals with subsets of these components of wood in rivers, but there has been limited development of a general framework for wood in river networks. This chapter considers a framework for examining the arrangement of wood in river landscapes and how it may reflect the history of spatial patterns and timing of wood input and redistribution. Field studies provide examples of different spatial patterns and architectures of wood accumulations. Wood accumulations are shaped by input processes, trapping sites, and transport processes. Reaches in river networks may switch from wood patterns dominated by one set of controls to another because of gradual or abrupt input and redistribution. A framework for future studies and management includes interpretation of these different controls through time and over river networks.

scholarly journals Coastal Dune Vegetation Mapping Using a Multispectral Sensor Mounted on an UAS

2019 ◽  
Vol 11 (15) ◽  
pp. 1814 ◽  
Author(s):  
Suo ◽  
McGovern ◽  
Gilmer
Keyword(s):  
High Resolution ◽  
Data Processing ◽  
Spatial Patterns ◽  
Near Infrared ◽  
Environmental Changes ◽  
Vegetation Mapping ◽  
Coastal Dune ◽  
Sensor Data ◽  
Surface Model ◽  
Dune Vegetation

Vegetation mapping, identifying the type and distribution of plant species, is important for analysing vegetation dynamics, quantifying spatial patterns of vegetation evolution, analysing the effects of environmental changes and predicting spatial patterns of species diversity. Such analysis can contribute to the development of targeted land management actions that maintain biodiversity and ecological functions. This paper presents a methodology for 3D vegetation mapping of a coastal dune complex using a multispectral camera mounted on an unmanned aerial system with particular reference to the Buckroney dune complex in Co. Wicklow, Ireland. Unmanned aerial systems (UAS), also known as unmanned aerial vehicles (UAV) or drones, have enabled high-resolution and high-accuracy ground-based data to be gathered quickly and easily on-site. The Sequoia multispectral sensor used in this study has green, red, red edge and near-infrared wavebands, and a regular camer with red, green and blue wavebands (RGB camera), to capture both visible and near-infrared (NIR) imagery of the land surface. The workflow of 3D vegetation mapping of the study site included establishing coordinated ground control points, planning the flight mission and camera parameters, acquiring the imagery, processing the image data and performing features classification. The data processing outcomes included an orthomosaic model, a 3D surface model and multispectral imagery of the study site, in the Irish Transverse Mercator (ITM) coordinate system. The planimetric resolution of the RGB sensor-based outcomes was 0.024 m while multispectral sensor-based outcomes had a planimetric resolution of 0.096 m. High-resolution vegetation mapping was successfully generated from these data processing outcomes. There were 235 sample areas (1 m × 1 m) used for the accuracy assessment of the classification of the vegetation mapping. Feature classification was conducted using nine different classification strategies to examine the efficiency of multispectral sensor data for vegetation and contiguous land cover mapping. The nine classification strategies included combinations of spectral bands and vegetation indices. Results show classification accuracies, based on the nine different classification strategies, ranging from 52% to 75%.

Application of 3 "S" Technologies in Information Extraction of Nuclear Leakage Accident

2013 ◽  
Vol 718-720 ◽  
pp. 2011-2014
Author(s):  
Dong Hui Zhang ◽  
Ying Jun Zhao ◽  
Chuan Zhang ◽  
Ning Bo Zhao ◽  
Dong Hua Lu
Keyword(s):  
Information Extraction ◽  
Spatial Dimension ◽  
Temporal Databases ◽  
Surface Model ◽  
Analysis Model ◽  
Temporal Dimension ◽  
Position Information ◽  
Trend Surface ◽  
3S Technology ◽  
Building Process

The paper analyzes the theories of nuclear leakage accident information extraction based on 3S technology, and studying roundly the building process of GIS spatial and temporal databases; the contents of RS images collection and the function of GPS geography position information. In addition, information extraction and analysis methods both on spatial dimension and temporal dimension are summarized. The spatial distribution and trend of radiation leak after the nuclear accident are simulated by trend surface model. Calculation and mapping shows the variation of the radiation value with time using time series analysis model.

scholarly journals The Effects of Selective Logging Behaviors on Forest Fragmentation and Recovery

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Xanic J. Rondon ◽  
Graeme S. Cumming ◽  
Rosa E. Cossío ◽  
Jane Southworth
Keyword(s):  
Forest Fragmentation ◽  
Spatial Patterns ◽  
Management Practices ◽  
Timber Harvesting ◽  
Selective Logging ◽  
Forest Landscape ◽  
Intermediate Scale ◽  
Scale Interactions ◽  
Predator Prey Model ◽  
Forest Resilience

To study the impacts of selective logging behaviors on a forest landscape, we developed an intermediate-scale spatial model to link cross-scale interactions of timber harvesting, a fine-scale human activity, with coarse-scale landscape impacts. We used the Lotka-Volterra predator-prey model with Holling’s functional response II to simulate selective logging, coupled with a cellular automaton model to simulate logger mobility and forest fragmentation. Three logging scenarios were simulated, each varying in timber harvesting preference and logger mobility. We quantified forest resilience by evaluating (1) the spatial patterns of forest fragmentation, (2) the time until the system crossed a threshold into a deforested state, and (3) recovery time. Our simulations showed that logging behaviors involving decisions made about harvesting timber and mobility can lead to different spatial patterns of forest fragmentation. They can, together with forest management practices, significantly delay or accelerate the transition of a forest landscape to a deforested state and its return to a recovered state. Intermediate-scale models emerge as useful tools for understanding cross-scale interactions between human activities and the spatial patterns that are created by anthropogenic land use.

Developing Operational and Safety Guidelines for School Sites in Texas

2005 ◽  
Vol 1922 (1) ◽  
pp. 90-97
Author(s):  
Scott A. Cooner
Keyword(s):  
Field Studies ◽  
Advisory Panel ◽  
Department Of Transportation ◽  
School Site ◽  
Texas Department ◽  
District Personnel ◽  
Site Access ◽  
School Sites ◽  
Site Planning ◽  
A Site

The objective of a two-year study was to recommend school site planning guidelines for transportation-related elements such as site selection, general site requirements and design, bus operations, parent drop-off and pickup zones, driveways, turn lanes, signing and marking, parking, and pedestrian and bicycle access. The research team based these guidelines on a comprehensive review of existing guidelines and the results of field studies at school sites in Texas. Examples are provided of good practices and of practices to avoid for three of the more prominent guidelines. The guidelines are focused on transportation design, operations, and safety within school sites—with a particular focus on the parent drop-off and pickup zones. A site plan review checklist based on the 21 consensus guidelines approved by the project advisory panel is provided. Texas Department of Transportation engineers, field crews, architects, and school district personnel can use this checklist to coordinate efforts and improve the safety and efficiency of school site access and traffic flow.

Glyphosate-Resistant Horseweed (Conyza canadensis) Growth, Seed Production, and Interference in Cotton

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 346-350 ◽  
Author(s):  
Lawrence E. Steckel ◽  
C. Owen Gwathmey
Keyword(s):  
Seed Production ◽  
Yield Loss ◽  
Maximum Yield ◽  
Field Studies ◽  
Lint Yield ◽  
Growth Stages ◽  
Conyza Canadensis ◽  
Cotton Lint ◽  
Cotton Lint Yield ◽  
A Site

Field studies were conducted to examine both density and duration of glyphosate-resistant (GR) horseweed interference in cotton. Two studies, one examining the effect of horseweed density and a second the duration of horseweed interference, were conducted on a site with a natural population of horseweed that were treated with glyphosate at 0.84 kg ae ha−1prior to planting and at the 2nd and 4th cotton node growth stages. GR horseweed density effect on cotton height, maturity, and lint yield was determined at horseweed densities of 0, 5, 10, 15, 20, and 25 plants m−2. Duration of horseweed interference was evaluated when 20 horseweed m−2were allowed to interfere with cotton from emergence to 2nd node, 6th node, 10th node, 12th node, and 1st bloom stage of cotton. The maximum cotton lint yield loss (46%) occurred when horseweed was allowed to compete with cotton from emergence to maturity at the two highest densities (20 and 25 horseweed m−2). When the data were fit to the Cousens model the estimateda(maximum yield loss) andi(yield loss per unit density as density approaches zero) were 53 ± 7.3 and 2.8 ± 0.6 SE, respectively. In both years of the study, horseweed interference from emergence to the 2nd cotton node did not reduce cotton lint yields. In 2006, cotton lint yield loss was 28% compared to 39% in 2005 when horseweed interfered with cotton from emergence until the 6th cotton node. Cotton lint yield loss was 37 and 44% when horseweed competed to the 8th cotton node in 2005 and 2006, respectively. Maximum horseweed seed production was 134,000 to 148,000 seeds m−2.

Trend surface analysis of spatial patterns of tree size, microsite effects, and competitive stress

1986 ◽  
Vol 16 (2) ◽  
pp. 279-282 ◽  
Author(s):  
A. J. Thomson
Keyword(s):  
Surface Analysis ◽  
Spatial Patterns ◽  
Three Dimensional ◽  
Tree Size ◽  
Dimensional Representation ◽  
Trend Surface Analysis ◽  
Individual Tree ◽  
Spatial Trend ◽  
Trend Surface ◽  
Three Dimensional Representation

Trend surface analysis was used to determine the spatial patterns of tree size, competitive stress, and effects of microsite on growth. A three-dimensional representation of the trend surface facilitated interpretation. Gradients of competitive stress depended on the competition index used. Microsite effects have a spatial trend and individual tree genetic effects are represented by the residuals from this trend.

scholarly journals A Confirmatory Snowfall Enhancement Project in the Snowy Mountains of Australia. Part I: Project Design and Response Variables

2011 ◽  
Vol 50 (7) ◽  
pp. 1432-1447 ◽  
Author(s):  
Michael J. Manton ◽  
Loredana Warren ◽  
Suzanne L. Kenyon ◽  
Andrew D. Peace ◽  
Shane P. Bilish ◽  
...  
Keyword(s):  
Supercooled Liquid ◽  
Field Studies ◽  
Control Area ◽  
Target Area ◽  
Fixed Target ◽  
Southeastern Australia ◽  
Seeding Material ◽  
Static Seeding ◽  
A Site ◽  
Precipitation Enhancement

AbstractThe Snowy Precipitation Enhancement Research Project (SPERP) was undertaken from May 2005 to June 2009 in the Snowy Mountains of southeastern Australia with the aim of enhancing snowfall in westerly flows associated with winter cold fronts. Building on earlier field studies in the region, SPERP was developed as a confirmatory experiment of glaciogenic static seeding using a silver-chloroiodide material dispersed from ground-based generators. Seeding of 5-h experimental units (EUs) was randomized with a seeding ratio of 2:1. A total of 107 EUs were undertaken at suitable times, based on surface and upper-air observations. Indium (III) oxide was released during all EUs for comparison of indium and silver concentrations in snow in seeded and unseeded EUs to test the targeting of seeding material. A network of gauges was deployed at 44 sites across the region to detect whether precipitation was enhanced in a fixed target area of 832 km2, using observations from a fixed control area to estimate the natural precipitation in the target. Additional measurements included integrated supercooled liquid water at a site in the target area and upper-air data from a site upwind of the target.

scholarly journals VEGETATION MAPPING OF A COASTAL DUNE COMPLEX USING MULTISPECTRAL IMAGERY ACQUIRED FROM AN UNMANNED AERIAL SYSTEM

2018 ◽  
Vol XLII-1 ◽  
pp. 421-427
Author(s):  
C. Suo ◽  
E. McGovern ◽  
A. Gilmer
Keyword(s):  
High Resolution ◽  
Spatial Patterns ◽  
High Accuracy ◽  
Vegetation Mapping ◽  
Coastal Dune ◽  
Sensor Data ◽  
Surface Model ◽  
Unmanned Aerial System ◽  
Management Actions ◽  
Multispectral Camera

<p><strong>Abstract.</strong> Vegetation mapping, identifying the distribution of plant species, is important for analysing vegetation dynamics, quantifying spatial patterns of vegetation evolution, analysing the effects of environment changes on vegetation, and predicting spatial patterns of species diversity. Such analysis can contribute to the development of targeted land management actions that maintain biodiversity and ecological functions. This paper represents a methodology for 3D vegetation mapping of a coastal dune complex using a multispectral camera mounted on an Unmanned Aerial System (UAS) with particular reference to the Buckroney dune complex in Co. Wicklow, Ireland. UAS, also known as Unmanned Aerial Vehicles (UAV’s) or drones, have enabled high-resolution and high-accuracy ground-based data to be gathered quickly and easily on-site. The Sequoia multispectral camera used in this study has green, red, red-edge and near infrared wavebands, and a normal RGB camera, to capture both visible and NIR images of the land surface. The workflow of 3D vegetation mapping of the study site included establishing ground control points, planning the flight mission and camera parameters, acquiring the imagery, processing the image data and performing features classification. The data processing outcomes include an orthomosiac model, a 3D surface model and multispectral images of the study site, in the Irish Transverse Mercator coordinate system, with a planimetric resolution of 0.024<span class="thinspace"></span>m and a georeferenced Root-Mean-Square (RMS) error of 0.111<span class="thinspace"></span>m. There were 235 sample area (1<span class="thinspace"></span>m<span class="thinspace"></span>&amp;times;<span class="thinspace"></span>1<span class="thinspace"></span>m) used for the accuracy assessment of the classification of the vegetation mapping. Feature classification was conducted using three different classification strategies to examine the efficiency of multispectral sensor data for vegetation mapping. Vegetation type classification accuracies ranged from 60<span class="thinspace"></span>% to 70<span class="thinspace"></span>%. This research illustrates the efficiency of data collection at Buckroney dune complex and the high-accuracy and high-resolution of the vegetation mapping of the site using a multispectral sensor mounted on UAS.</p>

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