Optimales Layout einer Walderschliessung

2016 ◽  
Vol 167 (5) ◽  
pp. 294-301
Author(s):  
Leo Bont

Optimal layout of a forest road network The road network is the backbone of forest management. When creating or redesigning a forest road network, one important question is how to shape the layout, this means to fix the spatial arrangement and the dimensioning standard of the roads. We consider two kinds of layout problems. First, new forest road network in an area without any such development yet, and second, redesign of existing road network for actual requirements. For each problem situation, we will present a method that allows to detect automatically the optimal road and harvesting layout. The method aims to identify a road network that concurrently minimizes the harvesting cost, the road network cost (construction and maintenance) and the hauling cost over the entire life cycle. Ecological issues can be considered as well. The method will be presented and discussed with the help of two case studies. The main benefit of the application of optimization tools consists in an objective-based planning, which allows to check and compare different scenarios and objectives within a short time. The responses coming from the case study regions were highly positive: practitioners suggest to make those methods a standard practice and to further develop the prototype to a user-friendly expert software.

2020 ◽  
Vol 156 ◽  
pp. 04001
Author(s):  
Titi Kurniati ◽  
Adrial Sy ◽  
Purnawan Purnawan

Padang city, which is located on the western coast of Sumatra, has the potential to experience a powerful earthquake and thus generate tsunami. After the earthquake, with or without a tsunami warning, the society is required to evacuate. Because of the short time, vertical evacuation is the best alternative for the safety of society. Evacuation on foot to the temporary rescue building (Temporary Evacuation Shelter, TES) is more advisable than evacuation using motorized vehicles that tends to cause congestion. Temporary evacuation maps and potential shelters in Padang have been established by BPBD (Disaster Management Agency). In the Padang Barat sub-district, there are 13 potential shelters. This study aims to determine the level of accessibility to potential shelters based on travel time and road width parameters. In determining accessibility, the study area is divided into 50x50m size grids. The travel time is determined based on the distance from the center of the grid to the nearest TES through the road network. The limitation of evacuation time is 10 minutes. The results of data analyzing showed that among the 4358 grids which were occupied by society, there were 2272 grids (52.1%) which have low accessibility (based on travel time) and 30% has a low level of accessibility based on travel time and width road parameter.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Tinggui Chen ◽  
Shiwen Wu ◽  
Jianjun Yang ◽  
Guodong Cong ◽  
Gongfa Li

It is common that many roads in disaster areas are damaged and obstructed after sudden-onset disasters. The phenomenon often comes with escalated traffic deterioration that raises the time and cost of emergency supply scheduling. Fortunately, repairing road network will shorten the time of in-transit distribution. In this paper, according to the characteristics of emergency supplies distribution, an emergency supply scheduling model based on multiple warehouses and stricken locations is constructed to deal with the failure of part of road networks in the early postdisaster phase. The detailed process is as follows. When part of the road networks fail, we firstly determine whether to repair the damaged road networks, and then a model of reliable emergency supply scheduling based on bi-level programming is proposed. Subsequently, an improved artificial bee colony algorithm is presented to solve the problem mentioned above. Finally, through a case study, the effectiveness and efficiency of the proposed model and algorithm are verified.


2011 ◽  
Vol 97-98 ◽  
pp. 512-517
Author(s):  
Wen Jie Zou ◽  
Jian Cheng Weng ◽  
Jian Rong ◽  
Wei Zhou

In order to improve the reliability of urban road network operation evaluation, the road network regional Partition methods were launched in this paper. The geographic grid was introduced first, and a 4-level road network model was defined. Then, the spatial analysis based urban road network division method was proposed by analyzing the characteristics of road network operation. This method can reflect the influence between adjacent regional units, and improve the reliability of urban road network division. Finally, this research took a certain area in Beijing as a case study, and divided the road network as several regional units. Macroscopic evaluation result shows that it is effective for scientifically describing the road network operation status.


Author(s):  
Monika Siejka ◽  
Monika Mika

The development of the communication systems determines the economic level of the country. In Poland, despite the successive investments in this area, it is still not enough beneficial solutions to the road network and international calls. The problem of the acquisition of property for public roads on both the valuation principles and the way of obtaining land for these purposes is constantly modified. These changes are intended to simplify the procedures, which have a significant impact on shortening of the investment process. The current provisions of law give the possibility of the start of road investment before a property owner receives compensation for land taken for this purpose. This situation requires an inventory of component parts of the property for the purposes of their valuation. The paper presents the methodology of inventory the real estate components for the needs of their valuation using modern measurement techniques GNSS and GIS.


2012 ◽  
Vol 51 (No. 1) ◽  
pp. 37-46 ◽  
Author(s):  
J. Dobiáš

The forest road network influences surface runoff of uninfiltrated precipitation water on forest lands, mainly in hilly and mountainous areas. This water flows onto the road crown in unpaved forest roads that do not have any ditches. Dragging of extracted logs causes mechanical damage to the crown of unpaved forest road, and tracks after tractor wheels and furrows after dragged logs originate. Flowing water is accumulated in these depressions and the water stream causes erosion. The method for evaluation of conditions for the origination and degree of this erosion damage consists in the calculation of tangential stresses near the bottom at various depths of water and various gradients of road. Limit gradients of road for the origination of greater or smaller damage by erosion for the subsoil grain of various sizes are determined by a comparison of calculated tangential stresses with critical tangential stresses. Rates of discharge were calculated for the particular models of damage.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Md. Shohel Reza Amin ◽  
Umma Tamima ◽  
Luis Amador Jimenez

This study demonstrates through a case study that detailed analyses, even after the construction of a project, are feasible using current technologies and available data. A case study of highway 25 is used to illustrate the method and verify the levels of air contaminants from additionally induced traffic during and after the construction of highway. Natural traffic growth was removed from the effect of observed gas emissions by comparing observed levels on other further locations in the same metropolitan area. This study estimates air pollution from the additional traffic during and after the construction of A-25 extension project. NO2 levels were spatially interpolated during peak and off-peak hour traffic and traffic density simulated on the road network for four scenarios. Comparing the four scenarios, it was found that levels of NO2 concentrations were reduced at neighbor areas due to less traffic during the construction period. Levels of NO2 after the construction were higher than those in 2008. The simulated traffic density for four scenarios revealed that traffic density was significantly increased on both arterial and access roads within the close vicinity of the extension project during and after its construction.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yangfan Zhou ◽  
Shunping Jia ◽  
Baohua Mao ◽  
Tin Kin Ho ◽  
Wei Wei

Modern trams are developing fast because of their characteristics like medium capability and energy saving. Exclusive way is always set in practice to avoid interruption from general vehicles, while trams have to stop at intersections frequently due to signal rules in the road network. Therefore, signal optimization has great effects on operational efficiency of trams system. In this paper, an arterial signal coordination optimization model is proposed for trams progression based on the Asymmetrical Multi-BAND (AM-BAND) method. The AM-BAND is modified from the following aspects. Firstly, BAM-BAND is developed by supplementing active bandwidth constraints to AM-BAND. Assisted by the IBM ILOG CPLEX Optimization Studio, two arterial signals plans with eight intersections are achieved from AM-BAND and BAM-BAND for comparison. Secondly, based on the modified BAM-BAND, a BAM-TRAMBAND model is presented, which incorporates three constraints regarding tram operations, including dwell time at stations, active signal priority, and minimum bandwidth value. The case study and VISSIM simulation results show that travel times of trams decrease with signal plan from BAM-TRAMBAND comparing with the original signal plan. Moreover, traffic performance indicators such as stops and delay are improved significantly.


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