scholarly journals Retroactive comparison of operator-designed and computer-generated skid-trail networks on steep terrain

2020 ◽  
Vol 29 (1) ◽  
pp. eSC01
Author(s):  
Marco Antonio Contreras ◽  
David L Parrott ◽  
Jeffrey W Stringer
Keyword(s):  
Cost Minimization ◽  
Timber Harvest ◽  
Timber Harvesting ◽  
Economic Benefits ◽  
Eastern Kentucky ◽  
Digital Elevation ◽  
Soil Disturbances ◽  
Steep Terrain ◽  
Elevation Model ◽  
The University

Aim of the study: Quantify potential economic benefits of implementing computer-generated skid-trail networks over the traditional operator-designed skid-trail networks on steep terrain ground-based forest operations.Area of study: A 132-ha harvest operation conducted at the University of Kentucky’s Robinson Forest in eastern Kentucky, USA.Materials and methods: We compared computer-generated skid-trail network with an operator-designed network for a 132-ha harvest. Using equipment mounted GPS data and a digital elevation model (DEM), we identified the original operator-designed skid-trail network. Pre-harvest conditions were replicated by re-contouring terrain slopes over skid-trails to simulate the natural topography and by spatially distributing the harvestable volume based on pre-harvest inventories and timber harvest records. An optimized skid-trail network was designed using these pre-harvest conditions and compared to the original, operator-designed network.Main results: The computer-generated network length was slightly longer than the operator-designed network (53.7 km vs. 51.7 km). This also resulted in a slightly longer average skidding distance (0.71 km vs. 0.66 km) and higher total harvesting costs (5.1 $ ton-1 vs. 4.8 $ ton-1).  However, skidding costs of the computer-generated network were slightly lower (4.2 $ ton-1 vs. 4.3 $ ton-1).  When comparing only major skid-trails, those with ≥ 20 machine passes, the computer-generated skid-trail network was 28% shorter than the operator network (9.4 km vs. 13.1 km). Research highlight: This assessment offers evidence that computer-generated networks could be used to generate efficient skid-trails, help determine skidding costs, and assess further potential economic and environmental benefits.Key words: timber harvesting; forest operations; network optimization; soil disturbances; cost minimization.

scholarly journals Weighted Visibility Classification and Seating Plan for the Aitken University Centre

2014 ◽  
Vol XL-2 ◽  
pp. 227-234
Author(s):  
T. Allison ◽  
D. Fraser ◽  
E. Stefanakis
Keyword(s):  
Web Application ◽  
Web Applications ◽  
Ice Surface ◽  
Price Levels ◽  
Digital Elevation ◽  
Information Products ◽  
Interactive Map ◽  
Elevation Model ◽  
The University

This paper describes the requirements for a weighted visibility classification of seats in the University of New Brunswick’s (UNB) Aitken University Centre (AUC). Price levels for seats are typically set for sections of seats based on promoter preferences. In a visibility classification, the digital elevation model (DEM) is created for the AUC and includes possible view obstructions. The view obstructions taken into account for this design were the penalty boxes, player bencher, and the rink boards. There were no other major obstructions in the AUC. The visibility calculations compute the number of visible pixels of the rink surface for each seat. It is expected that seats with a higher number of visible pixels will also have better visibility. The number of viewable pixels is weighted by distance to the center of ice surface to account for the preference of seats that are closer to the rink surface. This paper outlines the collection of data, weighted visibility classification method, and the development of information products. There are two main objectives of this weighted visibility classification and seating plan: (a) to demonstrate that a weighted visibility classification is a viable method to classify seats, and that this methodology could be used to set price levels for a venue and (b) create online web applications to suit the functionality for users and venue administrators. The user web application allows the user to pan, zoom and perform limited searches in the interactive map.

scholarly journals Evaluating digital terrain indices for soil wetness mapping – a Swedish case study

2014 ◽  
Vol 18 (9) ◽  
pp. 3623-3634 ◽  
Author(s):  
A. M. Ågren ◽  
W. Lidberg ◽  
M. Strömgren ◽  
J. Ogilvie ◽  
P. A. Arp
Keyword(s):  
Surface Flow ◽  
Topographic Wetness Index ◽  
Water Index ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Soil Disturbances ◽  
Soil Wetness ◽  
Elevation Model ◽  
Terrain Indices

Abstract. Trafficking wet soils within and near stream and lake buffers can cause soil disturbances, i.e. rutting and compaction. This – in turn – can lead to increased surface flow, thereby facilitating the leaking of unwanted substances into downstream environments. Wet soils in mires, near streams and lakes have particularly low bearing capacity and are therefore more susceptible to rutting. It is therefore important to model and map the extent of these areas and associated wetness variations. This can now be done with adequate reliability using a high-resolution digital elevation model (DEM). In this article, we report on several digital terrain indices to predict soil wetness by wet-area locations. We varied the resolution of these indices to test what scale produces the best possible wet-areas mapping conformance. We found that topographic wetness index (TWI) and the newly developed cartographic depth-to-water index (DTW) were the best soil wetness predictors. While the TWI derivations were sensitive to scale, the DTW derivations were not and were therefore numerically robust. Since the DTW derivations vary by the area threshold for setting stream flow initiation, we found that the optimal threshold values for permanently wet areas varied by landform within the Krycklan watershed, e.g. 1–2 ha for till-derived landforms versus 8–16 ha for a coarse-textured alluvial floodplain.

Combined Filter Method Based on Terrain Factors

2014 ◽  
Vol 596 ◽  
pp. 342-345
Author(s):  
Man Yan ◽  
Yong Quan Liang
Keyword(s):  
Wiener Filter ◽  
Filter Method ◽  
Synthetic Aperture Radar Interferometry ◽  
Noise Filter ◽  
Interference Fringes ◽  
Digital Elevation ◽  
Filter Process ◽  
Steep Terrain ◽  
Elevation Model ◽  
Suppress Noise

Interferogram noise filter is one of the key technologies which use synthetic aperture radar interferometry phase to extract digital elevation model. However, the interference fringes’ details are often reduced when complex interferogram is filtered, and this leads to inaccurate phase unwrapping result, for this combined filter method based on terrain factors is proposed. Filter method can be selected through weight factor associated with the terrain slope in the filter process, and Wiener filter method is implemented in flat terrain area, frequency estimated filter method is achieved in steep terrain area. Then the new filter method is applied to deal with data where the region of Quebec, Canada. This proves that the new filter algorithm proposed in this paper can effectively suppress noise and better maintain stripe details.

scholarly journals Optimization of UAV Flight Missions in Steep Terrain

2020 ◽  
Vol 12 (8) ◽  
pp. 1293 ◽  
Author(s):  
Klemen Kozmus Trajkovski ◽  
Dejan Grigillo ◽  
Dušan Petrovič
Keyword(s):  
Digital Terrain Model ◽  
Ground Level ◽  
Optimal Method ◽  
Terrain Model ◽  
Digital Elevation ◽  
Terrain Following ◽  
Steep Terrain ◽  
Elevation Model ◽  
Uav Images ◽  
Oblique Images

Unmanned aerial vehicle (UAV) photogrammetry is one of the most effective methods for capturing a terrain in smaller areas. Capturing a steep terrain is more complex than capturing a flat terrain. To fly a mission in steep rugged terrain, a ground control station with a terrain following mode is required, and a quality digital elevation model (DEM) of the terrain is needed. The methods and results of capturing such terrain were analyzed as part of the Belca rockfall surveys. In addition to the national digital terrain model (NDTM), two customized DEMs were developed to optimize the photogrammetric survey of the steep terrain with oblique images. Flight heights and slant distances between camera projection centers and terrain are analyzed in the article. Some issues were identified and discussed, namely the vertical images in steep slopes and the steady decrease of UAV heights above ground level (AGL) with the increase of height above take-off (ATO) at 6%-8% rate. To compensate for the latter issue, the custom DEMs and NDTM were tilted. Based on our experience, the proposed optimal method for capturing the steep terrain is a combination of vertical and oblique UAV images.

scholarly journals MAPPING THE USABILITY AND QUALITY OF BICYCLE PATHS USING A TERRAIN-INCLINATION-BASED CLASSIFICATION, STUDY CASE: DARCY RIBEIRO CAMPUS, UNIVERSITY OF BRASÍLIA, BRAZIL

2020 ◽  
Vol XLII-3/W12-2020 ◽  
pp. 87-90
Author(s):  
A. J. d. Siqueira ◽  
P. M. d. Almo ◽  
R. E. Cicerelli ◽  
R. F. C. Machado ◽  
T. Almeida
Keyword(s):  
Rectangular Grid ◽  
Traffic Jam ◽  
Digital Elevation ◽  
Medium Range ◽  
Study Case ◽  
Process Of Urbanization ◽  
Elevation Model ◽  
Almost All ◽  
The University

Abstract. Over the last decades, Brazilian cities have gone through a rapid process of urbanization. Population growth has brought the need for new technological and construction developments such as highways and housing centers. One of the most important factors related to this growth has to do with the capacity of locomotion, which is done especially by car. In Brasilia there is a large volume of cars circulating, which causes noise, air pollution, difficulty of locomotion during rush hours generated by traffic jam and stress that affects drivers and the general population. The bike stands out in this context because it is a vehicle considered clean for not polluting the environment and it is easily accessible to almost all social classes, being ideal for short to medium range routes. The University of Brasilia (UnB) has a considerable number of cyclists. The University has several bike lanes that have been built to connect the various departments along the campus. In this context, the purpose of this work is the elaboration of a slope map made from a Digital Elevation Model (DEM) to classify the bike lanes as critical or not. The DEM was made from a rectangular grid by the Anudem method and a final map in the 1 : 10000 scale was generated. The proportion of green areas and lampposts that cover the bike lanes on campus was also analyzed. The results characterize the bike lanes as non-critical in relation to the inclination, whereas the relation of number of lampposts as well as the vegetation that cover the area to the number of bike racks on campus was considered low.

scholarly journals Evaluating digital terrain indices for soil wetness mapping – a Swedish case study

2014 ◽  
Vol 11 (4) ◽  
pp. 4103-4129 ◽  
Author(s):  
A. M. Ågren ◽  
W. Lidberg ◽  
M. Strömgren ◽  
J. Ogilvie ◽  
P. A. Arp
Keyword(s):  
Surface Flow ◽  
Topographic Wetness Index ◽  
Water Index ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Soil Disturbances ◽  
Soil Wetness ◽  
Elevation Model ◽  
Terrain Indices

Abstract. Driving with forestry machines on wet soils within and near stream and lake buffers can cause soil disturbances, i.e. rutting and compaction. This – in turn – can lead to increased surface flow, thereby facilitating the leaking of unwanted substances into downstream environments. Wet soils in mires, near streams and lakes have particularly low bearing capacity and are more susceptible to rutting. It is important to model and map the extent of these areas and associated wetness variations. This can be done with adequate reliability using high resolution digital elevation model (DEM). In this article, we report on several digital terrain indices to predict soil wetness by wet-area locations. We varied the resolution of these indices to test what scale produces the best possible wet-areas mapping conformance. We found that topographic wetness index (TWI) and the newly developed cartographic depth-to-water index (DTW) were the best soil wetness predictors. While the TWI derivations were sensitive to scale, the DTW derivations were not and were therefore numerically fairly robust. Since the DTW derivations vary by the area threshold used for setting stream flow initiation we found that the optimal threshold values varied by landform, e.g., 1–2 ha for till-derived landforms vs. 8 –16 ha for a coarse-textured alluvial floodplain.

scholarly journals Possibilities for forest development in a zone of controlled inundation in Kruibeke (Eastern Flanders) by means of a geographical information system

1996 ◽  
Vol 61 ◽  
Author(s):  
L. Nachtergale ◽  
A. De Schrijver ◽  
P. Troch ◽  
N. Lust
Keyword(s):  
Environmental Changes ◽  
Geographical Information ◽  
Forest Types ◽  
Soil Drainage ◽  
Substrate Current ◽  
Digital Elevation ◽  
Preliminary Study ◽  
Elevation Model ◽  
Data Layers ◽  
The University

As an  area of 750 hectares is going to be constructed as a controlled inundation  zone of the river ScheIdt, a preliminary study of the environmental changes  and the possible shifts in forest types was done by the Laboratory of  Forestry and the Laboratory of Hydrology and Water Management, both of the  University of Ghent. Based on a digital elevation model and the relation  between water height in the river and the amount of water entering the area  for a given height of the dikes, for each place in the inundation zone the  frequency of inundation was determined.     These frequencies, in combination with the data layers soil texture, soil  drainage, substrate, current land use and historical vegetation data allowed  to determine the potentially natural vegetation according to Van Der Werf  (1991) and to do a prediction of the forest communities most likely to occur  now and for the inundation scenario. Because the very common use of poplar  cultivars, also the future possibilities of these trees were considered. As a  synthesis, a number of management suggestions could be worked out.

scholarly journals GIS Framework for Spatiotemporal Mapping of Urban Flooding

Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 77 ◽  
Author(s):  
Sayed Abedin ◽  
Haroon Stephen
Keyword(s):  
Spatiotemporal Mapping ◽  
Dem Resolution ◽  
News Reports ◽  
Digital Elevation ◽  
Parking Lot ◽  
Storm Drain ◽  
Elevation Model ◽  
Flood Dynamics ◽  
The University ◽  
Runoff Hydrographs

This research aims to develop a framework using the Geographic Information System (GIS) to perform modeling and mapping of flood spatiotemporal variation in urban micro-watersheds. The GIS-framework includes a workflow of several methods and processes including delineation of urban watershed, generation of runoff hydrographs, and time series mapping of inundation depths and flood extent. This framework is tested in areas previously known to have experienced flooding at the University of Nevada, Las Vegas main campus, including Black Parking Lot (Blacklot) and East Mall. Calibration is performed by varying Digital Elevation Model (DEM) resolution, rainfall temporal resolution, and clogging factor whereas validation is performed using flood information from news reports and photographs. The testing at the Blacklot site resulted in calibration at 5 m DEM resolution and clogging factor of 0.83. The flood model resulted in an error of 24% between the estimated (26 inches/66 cm) and actual (34 inches/86.36 cm) flood depths. The estimated flood extents are consistent with the reported conditions and observed watermarks in the area. The flood beginning time estimated from the model is also consistent with the news reports. The testing at East Mall site also shows consistent results. The GIS framework provides spatiotemporal maps of flood inundation for visualization of flood dynamics. This research provides insight into flood modeling and mapping for a storm drain inlet-based watershed.

MARS — Its Tenth Anniversary of Operation and its Future

1980 ◽  
Vol 19 (03) ◽  
pp. 125-132
Author(s):  
G. S. Lodwick ◽  
C. R. Wickizer ◽  
E. Dickhaus
Keyword(s):  
Conceptual Development ◽  
Administrative Support ◽  
Final Section ◽  
Economic Benefits ◽  
Hospital Environment ◽  
Computer Scientist ◽  
University Of Missouri ◽  
Complete Bibliography ◽  
The University ◽  
Economic Considerations

The Missouri Automated Radiology System recently passed its tenth year of clinical operation at the University of Missouri. This article presents the views of a radiologist who has been instrumental in the conceptual development and administrative support of MARS for most of this period, an economist who evaluated MARS from 1972 to 1974 as part of her doctoral dissertation, and a computer scientist who has worked for two years in the development of a Standard MUMPS version of MARS. The first section provides a historical perspective. The second deals with economic considerations of the present MARS system, and suggests those improvements which offer the greatest economic benefits. The final section discusses the new approaches employed in the latest version of MARS, as well as areas for further application in the overall radiology and hospital environment. A complete bibliography on MARS is provided for further reading.

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