Transmission Line Corridor Research Articles

Vegetation composition along a New England transmission line corridor and its implications for other trophic levels

Transmission line corridors in forested landscapes provide important early successional habitats for a taxonomically rich array of native plant and animal life, including populations of rare species. We measured plant diversity and cover for 27 randomly selected paired powerline and woodland plots along a 140-km rights-of-way corridor that extended from northern Connecticut into southern New Hampshire. Mean plant richness was significantly higher in powerline plots (x¯=49.8 species) than in woodland plots (x¯=29.5 species). Powerline plots with the greatest richness were those that included a maintenance road or other areas of disturbed, open soil. Three hundred and twenty-six plant species were recorded in powerline plots, more than twice the number found in woodland plots (n=157). Powerline plots had higher invasive plant cover than the woodland plots, but non-native invasive species cover was low (<2%) in both powerline and woodland plots. Cover of clonal species was greater in the powerline plots (mean values of 12.0% ±1.2 vs. 4.0% ±0.6). Northern powerline plots in our study, maintained exclusively by mowing, had a higher proportion of tree cover than southern plots that were maintained by mowing plus spot-application of herbicides. No differences were found in the proportional cover of all woody plants, clonal species, or invasive species among the two management types. We include a discussion of host-specialized Lepidoptera, oligolectic bees, and other wildlife that are dependent on vegetation composition and structure found along transmission line corridors in the Northeast.

Influence of Icing to the Corona Loss Characteristics of the AC Power Transmission Lines

The transmission line corridor will inevitably cross the icing area in China. Icing will influence the corona characteristics of transmission lines. In order to deeply analyze the influence law of the icing to corona loss characteristics, an icing test platform that can be utilized to simulate icing conditions was built. Icing test was done in the corona cage of 1.8m×1.8m×4m. Through changing the conductivity of freezing water and the length of icicle, corona loss of the icing conductor was measured and the surface electric field was also simulated with the software ANSYS. The results show that the length of icicle is an important factor affecting the corona loss of the AC conductor and the conductivity of freezing water on that impact is not obvious. Owing to the icicles, the distortion of the conductor electric field is serious. With the increase of icicle length, conductor corona loss value increases significantly. When the length of icicle increases to about 18mm, the increase of the corona loss value is no longer obvious trending to be saturated . The simulation results coincided with the experimental results very well.

Study on Type Design of Multi-Circuit Transmission Line Tower

In China as the overhead transmission line corridor is less and less, multi-circuit transmission line tower application would become more common. In this paper the multi-circuit tower type design problem was analyzed and discussed, and put forward some ideas on how to solve these problems. To 330kV four-circuit tower type design as an example, the design steps, methods were described in detail, and gave three kinds of design schemes, finally, three kinds of tower characteristics are analyzed to draw valuable conclusions.

MODELO DE PROPENSÃO A OCUPAÇÕES IRREGULARES EM LINHAS DE TRANSMISSÃO DE ENERGIA ELÉTRICA

Power Line Transmissions Systems demand restrictions on the use of its adjacent areas due to it’s high voltage power cables. Despite the fact that many restrictions are imposed by law, there is a growing number of illegal occupation in those areas. Having in mind the purposes of monitoring and management of Transmission line corridors - adjacent areas to the transmission lines - georesources are efficient sources of territorial management and support to take decisions about a safe and lawful occupation. The present study helps to detect irregular occupations that have been occurring in a section of a transmission line located in Santa Catarina State. The corridor area, focus of this research managed by Eletrosul, is used here as a reference for a suggested principle of methodology in areas that attract new invasions. The appeal of that area was generated from the establishment of weights to the four variables considered crucial for occupation, as follow a) land use, b) neighborhood road, c) slope and d) proximity between towers. The final product is a map of propensity of invasion and allows preventive actions by Eletrosul, as well as to identify the local Transmission line corridor appointed with high propensity for invasion.

Indicators and framework for assessing sustainable infrastructure

Much of the focus on sustainable infrastructure has concentrated on buildings and construction processes. To advance this thinking for other civil infrastructure systems (CIS), this paper outlines a framework that uses a set of proposed indicators to measure the sustainability of chosen infrastructure options and help select the preferred alternative in a multiobjective decision approach. Physically implementing "sustainable infrastructure" involves three life stages for any project: preproject planning, project implementation, and ongoing operations. It is critical to evaluate the sustainability of chosen options in each of these life stages. This research develops two categories of indicators, mandatory screening indicators (MSI) and judgment indicators (JI), and a multilayer approach for incorporating these indicators. A normalization procedure has been adapted to work within the framework to help compare alternatives across a range of indicators and different orders of data magnitude. A hypothetical example using a transmission line corridor is presented to illustrate how the framework can be applied.Key words: indicators, infrastructure, sustainable, environment, decision making, alternatives.

Tracing overhead transmission line corridors with regard to environmental and spatial qualities

Tracing overhead transmission line corridors with regard to environmental and spatial qualities

An integro-differential equation technique for the computation of radiated EMI due to corona on HV power transmission lines

This work presents a novel technique for the computation of radiated electromagnetic interference (EMI) levels due to corona on high-voltage (HV) transmission lines. The EMI levels computed using the present technique for various HV transmission lines from around the world matches well with the experimentally measured values, thus validating the present technique. Using the technique developed, the influence of transmission line length, distance of observation point from the line, conductor diameter as well as the transmission line configuration on the radiated EM field has been studied. It is seen that for observation points which are close to the transmission line corridor, the total radiated electric field remains almost constant for line lengths above 1500 m. For observation points which are far away, a longer length of the line needs to be considered for computation of the total electric field. In the study, it is seen that the transmission line conductor height and line configuration have marginal influence on the radiated electric field.

Study of population exposure to magnetic fields due to secondary utilization of transmission line corridors

A program of secondary utilization of transmission line corridors for recreational, commercial, educational and industrial activities has been in existence at Hydro-Quebec for several years. In the context of studies indicating a possible link between exposure, educational and industrial activities has been in existence at Hydro-Quebec for several years. In the context of studies indicating a possible link between exposure to power frequency magnetic fields and human health, a study has been carried out to determine the exposure of people involved in the different types of secondary-utilization activities in and near transmission line corridors. Results of this study are presented in this paper.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Nesting by Raptors and Common Ravens on Electrical Transmission Line Towers

Raptors and common ravens (Corvus corax) (hereafter called ravens) began nesting on towers along a 596-km segment of a 500-kV transmission line in southern Idaho and Oregon within 1 year of its construction. We began monitoring these nesting populations in 1981 to assess the effectiveness of artificial structures in attracting nesting raptors and to provide guidelines for enhancing raptor nesting opportunities on transmission lines. Within 10 years, 133 pairs of raptors and ravens were nesting along the 500-kV line. Rapid colonization of towers along the line probably was due to lack of other nesting substrate in the transmission line corridor, and the proximity of existing nesting populations in the nearby Snake River Canyon

A case study on the effects of a transmission-line corridor on Sika deer habitat use at the foothills of Mt Goyo, northern Honshu, Japan: S. Takatsuki, Ecological Research, 7(2), 1992, pp 141–146

A case study on the effects of a transmission-line corridor on Sika deer habitat use at the foothills of Mt Goyo, northern Honshu, Japan: S. Takatsuki, Ecological Research, 7(2), 1992, pp 141–146

Transmission Line, Railroad and Pipeline Common Corridor Study

The sharing of common corridors by electric power transmission lines, pipelines and rail-road facilities is becoming more commonplace. However, such corridor sharing can result in undesired coupling of electromagnetic energy from the power lines to the paralleling facilities. The principal concerns are with respect to both personnel safety and equipment operational compatibility. Induced interfering voltages and currents can result from either magnetic or electrostatic induction from the power line circuits. The induction can occur during either the normal steady-state operation of the power system or during a fault. The situations that give rise to problems, as well as the candidate mitigation measures, depend on the susceptibilities, the excitation parameters and the interaction between the electromagnetically coupled components of the common corridor. This paper presents the results of a recently completed study of a utility common corridor in southern Arizona. A detailed analysis of the voltages and currents induced into the pipeline and rail facilities was performed using a computer program developed during the study. Alternate forms of mitigation were investigated to ensure personnel safety and operational compatibility where likely problems were predicted.

Transmission Line, Railroad and Pipeline Common Corridor Study

The sharing of common corridors by electric power transmission lines, pipelines and rail-road facilities is becoming more commonplace. However, such corridor sharing can result in undesired coupling of electromagnetic energy from the power lines to the paralleling facilities. The principal concerns are with respect to both personnel safety and equipment operational compatibility. Induced interfering voltages and currents can result from either magnetic or electrostatic induction from the power line circuits. The induction can occur during either the normal steady-state operation of the power system or during a fault. The situations that give rise to problems, as well as the candidate mitigation measures, depend on the susceptibilities, the excitation parameters and the interaction between the electromagnetically coupled components of the common corridor. This paper presents the results of a recently completed study of a utility common corridor in southern Arizona. A detailed analysis of the voltages and currents induced into the pipeline and rail facilities was performed using a computer program developed during the study. Alternate forms of mitigation were investigated to ensure personnel safety and operational compatibility where likely problems were predicted.

Predicting Avian Community Response to Lakeshore Cottage Development

Breeding songbird species were studied in both developed and undeveloped lakeshore habitats of central Ontario. Information is presented for managing lake shorelines for human recreational development without significant loss of wildlife values. The disturbed ground vegetation layer was significantly correlated with a number of habitat variables deemed important in describing avian habitats. Avian species were placed in one of three groups: the ovenbird (Seiurus aurocapillus), an example from the group found primarily in undeveloped habitats; the eastern phoebe (Sayornis phoebe), one of the group found in highly developed habitats; and the veery (Catharus fuscescens), from the group that was not significantly affected by development. These findings are presented in a simple model of breeding bird response to disturbance that can be used to assess the negative impact of cottage development. J. WILDL. MANAGE. 48(4):1239-1247 Human encroachment on undeveloped areas often impacts the plant and animal communities located there. Avian species respond as their breeding habitat is altered or destroyed. Neotropical migrants may be particularly affected by development because not only is their breeding habitat being altered, but wintering grounds are being converted to pasture and farmland (Terborgh 1974). In the last 50 years, many lakes in south-central Ontario have become popular for recreational activity. Cottages have been built along many lakeshores with associated roads and transmission line corridors nearby. Unlike successional sequences, cottage construction tends to impose permanent change in the vegetation and associated environment. Resource managers need information to predict how changes imposed by this development affect wildlife. Robertson and Flood (1980) found an increase in diversity of the songbird community along portions of cottage lakesh re in the nearby Rideau Lakes. Martin (1960) investigated changes in bird populations in relation to forest succession in the Algonquin Park area. James and Wamer (1982) and others have demonstrated that bird species diversity depends on vegetation structure and composition. The mportance of large blocks of unbroken for st was reviewed by Robbins (1979). We have added to these studies to provide resource managers with a tool to predict how future cottage development m y affect bird communities along lakeshores. Songbird populations are notoriously diffic lt to measure, and the populations themselves fluctuate widely. Preston (1960) noted that for 57 breeding species in Ohio, based on 10 years of survey data, nly a out half (28 species) bred every year. James and Wamer (1982) showed that study plots of less than 10 ha often have less than the total species breeding in an area. In our work, based on 2 years of data and small sample plots, we cannot hope to show the long-term comprehensive impact of cottage construction on songbird populations. However a general model of cottage development and the re'Present address: Ontario Ministry of Environment, Box 21, Dorset, Ontario POA 1EO, Canada. 2 Present address: Ontario Ministry of Natural Resources, Cochrane, Ontario, POL 1CO, Canada. J. Wildl. Manage. 48(4):1984 1239 This content downloaded from 157.55.39.70 on Tue, 06 Sep 2016 05:51:31 UTC All use subject to http://about.jstor.org/terms 1240 AVIAN COMMUNITY RESPONSE * Clark et al. suiting impact on the wildlife community is needed to provide planners with guidance in approving or disapproving plans for cottage subdivisions. A concurrent study described the habitat associations of 19 species of breeding birds at varying levels of cottage development and determined that tree density, shrub coverage, conifer composition, and canopy volume were important in describing the habitat associations (Clark et al. 1983). The purpose of this study was to develop a method to predict changes in avian species composition caused by cottage development that could be used to model the impact of habitat disturbance on wildlife commu-

Deer Use and Habitat Characteristics of Transmission-Line Corridors in a Douglas-Fir Forest

Odocoileus hemionus columbianus utilise, en hiver, les corridors des lignes de transmission, comme habitat plutot que la foret a Pseudotsuga, pres du lac Trinity, Californie

The Effect of Transmission-line Corridors on Bird Populations

The Effect of Transmission-line Corridors on Bird Populations