Sustainable management of forest resources can only be achieved through a well-organized road network. Road upgrading is a major forest engineering task on an existing road to ensure it is capable of timber harvest or forest fire protection. The purpose of this operation is to bring a currently substandard road up to full standard. Forest road managers considering the technical, economic, and environmental factors that affect forest road not only when they plan forest roads but also when they are going to upgrade them. This paper describes the methodology of decision making when you have limited resources to upgrade the forest road network and you have to prioritize the forest roads that are going to be upgraded. In a Mediterranean island, the timber harvest is not a reason to upgrade a forest road but the fire protection and the growth of tourists that visits a forest ecosystem is. When technical and economic factors are identical the prioritization of forest road upgrade is based on the environmental factors and to the environmental impact assessment (EIA) of each forest road that needs an upgrade. With this work, we suggest that the forest road managers should consider upgrading the forest network based on environmental prioritization in areas with the same characteristics.
Forest roads are necessary to provide access to the forest for general management, maintenance, timber extraction and recreation. Forest roads is a costly investment made by the forest owner and the proper design and planning will reduce its maintenance cost. Following economic and environmental considerations, the designer will prepare tentative or provisional road location lines on a map which he will then inspect on the ground. The designer may have to amend the route before a final selection of the chosen location. Except for the road location line, the designer will consider and propose the construction of forest technical work along the road. Usually, the technical works are proposed after the inspection of the ground or after the construction of the forest road, in this study and with the use spatial analysis of high accuracy DEM we find the slopes that need to be stabilized with a retaining wall in a forest road network that is used already. With this methodology, the forest manager can analyse the needs for forest technical works like a retaining wall of all the forest network and after he can go for ground inspection to the specific areas. The forest manager can alter the spatial criteria from the office and run different scenarios with knowing the locations that will need slope stabilization with a retaining wall. With this preliminary spatial analysis, the forest manager will be more accurate to the economic cost of each forest road maintenance without a costly field survey of all the forest network.
Digital Elevation Models (DEMs) have become a widely used tool and product in the last 20 years. They provide a snapshot of the landscape and landscape features while also providing elevation values. They have allowed us to better visualize and interrogate topographic features. A landscape feature is a road and the location of the road is the “foundation” of any road. A road constructed in a poor location can fail and cause serious environmental damage, as well as add financial strain from continuous and costly maintenance problems. The forest managers know that forest roads must be inspected regularly and maintained as necessary to minimize erosion of the road surface, otherwise, they will require costly repairs. Forest roads represent a significant investment by forest owners and as such, this investment must be preserved. Nowadays forest managers expect the field survey also use DEM and orthophotos datasets to better understand the condition of the road network and to set maintenance and upgrade priorities. In this study, we validate several DEMs and we compare them to the measurements of a detailed road surveying with geodesic GPS. The aim is to use DEMs to spot troubles in the forest road network and relieve the forest owner from the cost of periodic field survey of the forest roads.
KEYWORDS: Mining, Unmanned aerial vehicles, Image processing, Photogrammetry, Forestry, Data processing, Data modeling, Global Positioning System, Data acquisition, Agriculture
Main subject of this paper is to investigate and evaluate methodologies for photogrammetric applications in geosciences, theoretically and practically, mainly focusing on systematic monitoring of surface mining areas. Its objective is to develop a technique adaptable to the particular characteristics of each application in order to efficiently meet the criteria of short time and low cost, but also of the required high frequency of application, as well as those of accuracy of the end products. Several methods for surface monitoring in mines have been developed. In particular, key aspects of the whole process to be studied in detail are, the following: a) Regarding data collection, UAVs with integrated RGB cameras will be used for data capture, b) Careful flight planning and geometric configuration of image acquisition, depending on the morphology of the object of interest and accuracy requirements will be under consideration, c) SfM applications and the bundle adjustment method with self-calibration will be used in order to process the collected data, d) GCPs (ground control points), check points and GPS/IMU information will be used for evaluating the results and e) Volume calculation differences between areas of interest will be practically evaluated. The main need for aerial mapping applications in mines environment besides accuracy standards, cost minimization and speed of work is of course public safety and prevent the loss of life.
KEYWORDS: Roads, Geographic information systems, Forestry, Raster graphics, Environmental management, Remote sensing, Data modeling, Databases, Environmental sensing, Global Positioning System
Forest roads are mentioned as necessary and functional structures in forest lands which supply access of forestry workers, machines and others for management, afforestation, harvesting, transportation, protection, recreation, hunting activities and wildlife safely and efficiently during the year. Forest roads is a type of low-volume roads (Defined as roads with traffic volumes of no more than 400 vehicles per day, they have enormous impacts on economies, communication, and social interaction). Effective road drainage is crucial to protect the road prism from damage and to keep the road surface stable for the road quality. The quality of the road is very substantial for forestry activities and it has been a major problem for Greek forestry sector. The most effective method for controlling erosion on forest roads is to keep water from accumulating on and running down the road surface. Water should be diverted from the road surface and dispersed into vegetation and ground litter with cross culverts, rolling dips, diversion ditches and water bars. The creation of standards for drainage systems is one of the most important technical developments in forest road construction. Mapping of the locations in the forest road network in which a technician is required to safely drain rainwater. In the present study, sample points of locations were taken using global positioning system (GPS) for the determination of culverts and then remote sensing and GIS were used for a map creation. The goal is to provide a simple road structure of adequate strength to support heavy vehicle traffic and provide drainage structures to pass water at its normal level through the road corridor.
Topographical information is fundamental to many geospatial related information and applications on Earth. Remote sensing satellites have the advantage in such fields because they are capable of global observation and repeatedly. One of the newest free of charge global digital surface model (DSM) is ALOS World 3D 30m mesh (AW3D30) and it is provided by Japan Aerospace Exploration Agency (JAXA). The AW3D30 version 1 released on May 2016 and on March 2017 the newer version 1.1 released with changes in specific areas. In Greece, the National Trigonometric Network established by the Hellenic Military Geographic Service (HMGS), the network includes 26,739 trigonometric control points but are not systematically maintained and many do not exist anymore. The trigonometric control points located in areas without vegetation, so the vegetation height does not influence the comparison. This paper calculates the vertical difference of the AW3D30 DSM and the trigonometric survey points of 1st, 2nd, 3rd, and 4th order. Also, a map identifying the areas with low and high height difference is presented.
In this study, we compare ALOS World 3D 30m mesh (AW3D30) which is provided free by Japan Aerospace Exploration Agency (JAXA), European Digital Elevation Model (EUDEM) which is provided free by European Environment Agency (EEA) and the DEM created from digitized contours from the 1/50.000 topographic maps of Hellenic Military Geographic Service (HMGS). The vegetation height of a forest environment affects the elevation data of AW3D30 and EU-DEM, with that in mind, we choose to compare the elevation data in forest fire break lines. The two DSMs, AW3D30 and EU-DEM v1.1 published in 2016 and the spatial resolution is 30m for AW3D30 and 25m for EU-DEM. For the DEM we created from the topographic maps we used 20m-pixel size. The statistical parameters of the three DEMs have examined in 149 forest fire break lines of total length 187,955.8 km. The study area is located in Chalkidiki a part of the Region of Central Macedonia in Northern Greece.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.