scholarly journals The influence of rural road development on forest extent changes over the three time periods: A case study of Chegeni region, Lorestan province

2018 ◽  
Vol 64 (No. 7) ◽  
pp. 313-318
Author(s):  
Motlaq Ayoob Rezaee ◽  
Parsakhoo Aidin ◽  
Adeli Kamran ◽  
Moayeri Mohamad Hadi
Keyword(s):  
Forest Cover ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Physical Parameters ◽  
Road Density ◽  
Forest Road ◽  
Settlement Development ◽  
The Road ◽  
Time Periods ◽  
Photo Mosaic

The objective of this study was to investigate the influence of the development of road quality (surfacing condition and road type) and road quantity (road density and distance to main road) on forest extent changes in a region in Zagros forests of Iran over the three time periods of 1960s, 2000s and 2010s. Ranks of 1 to 5 were assigned to road quality. Forest extent changes were analysed on digital aerial photo mosaic. The Spearman and Pearson correlation coefficients were used to test the relationship between the road parameters and forest extent changes. Results showed that rural-forest road network has more influence on settlement development. Forest extent was correlated negatively with the road quality. Moreover, there were more disturbances to native forests closer to roads. It was concluded that forest cover decrease was associated with physical parameters including access to roads, cultivation practices, road quality and settlement development.

scholarly journals Evaluating Banking Profit Performance in Ghana during and post Profit Decline: A five Step Du-Pont Approach

2015 ◽  
Vol 5 (2) ◽  
pp. 29-40 ◽  
Author(s):  
Baah Aye Kusi ◽  
Kwadjo Ansah-Adu ◽  
Albert Agyei
Keyword(s):  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Profit Margin ◽  
Foreign Banks ◽  
Ols Regression ◽  
Operating Profit ◽  
Asset Turnover ◽  
Profit Performance ◽  
Time Periods ◽  
Set Up

In this study we aimed at three objectives. First, identify and rank banks based on a composite score comprising of all five du-pont variables. Second, we identify variables in the five step du-pont set up that are most likely to influence bank ROE during and post profit declining periods. And third, we estimate a model to capture the variables that drive bank ROE during and post profit declining periods. We first establish from our rankings that, foreign banks in Ghana performed better during profit declining periods while the local banks performed better in post profit decline periods using the top ten banks as a benchmark in both periods. Employing Pearson correlation coefficients matrix, we recognized that operating profit margin, asset turnover and leverage were most likely to influence bank ROE in both time periods. We further employ OLS regression and find that bank ROE was impacted by operating profit margin and leverage during profit declining periods and post profit decline while tax effect added up in post profit declining periods.

DESIGNING AN OPTIMAL FOREST ROAD NETWORK BY CONSIDERATION OF ENVIRONMENTAL IMPACTS IN GIS OPTIMALIŲ MIŠKO KELIŲ TINKLO PROJEKTAVIMAS ĮVERTINUS POVEIKĮ APLINKAI GIS PROGRAMA / ПРОЕКТИРОВАНИЕ OПTИMAЛЬHOЙ CETИ ЛECHЫX ДOPOГ С УЧЕТОМ BOЗДEЙCTBИЯ HA OKPYЖAЮЩYЮ CPEДY, ОЦЕНЕННОГО С ИСПОЛЬЗОВАНИЕМ ГИС

2012 ◽  
Vol 20 (1) ◽  
pp. 58-66 ◽  
Author(s):  
Seyed Ataollah Hosseini ◽  
Mohammad Reza Mazrae ◽  
Majid Lotfalian ◽  
Aidin Parsakhoo
Keyword(s):  
Road Network ◽  
Negative Effects ◽  
Road Density ◽  
Forest Road ◽  
Road Verge ◽  
The Road ◽  
Road Planning ◽  
Golestan Province ◽  
Northern Forests ◽  
The Cost

Planning of forest road network is the most important issue for sustainable management of northern forests in Iran. This study represented a technical method of forest road planning by using GIS (Geographic Information Systems) in Vatan forestry plan of Golestan province, Iran. The aim of this study was to find out options for the optimization of skid trail length and for decreasing the negative effects of redundant skid trail length. Results of this study showed that the total length of forest road and the road network density was 36745 m and 8.68 m ha−1, respectively. 54% of the area was covered by these roads. 98.06 km skid trail was planned from road verge into the forest interior. The density of this skidding trail was 23.17 m ha−1. The suggested road network length measured using GIS was 47.23 km. Road density was 10.87 m ha−1, with 79% coverage. Skid trail length was 81.04 km, and skid trail density was 19.15 m ha−1. On the basis of GIS measurements, the skid trails on new road network system had shorter length and more frequency. This causes to decrease the cost of primary transportation. Moreover, in this plan the roads with suitable coverage passed from stable slopes. Santrauka Miško kelių tinklo planavimas – viena svarstomų problemų, siekiant užtikrinti tvarią miškotvarkos sistemą šiaurinėje Irano dalyje esančiuose miškuose. Šiame straipsnyje pristatomas miško kelių planavimo techninis metodas, taikant GIS (geografinės informacinės sistemos) programą ir naudojant Vatan miško, Golestan provincijoje, Irane, planus. Šio tyrimo tikslas – išsiaiškinti galimybes, kaip optimizuoti miško keliukų ilgį ir sumažinti neigiamą poveikį miškui, mažinant perteklinį šių keliukų trasos ilgį. Pirminiai rezultatai parodė, kad bendras esamų kelių ilgis siekia 36 745 km, kelių tinklas aprėpė 54% visos tiriamosios teritorijos, tankis siekė 8,68 m ha−1, o optimalus miško kelių tinklas buvo rengiamas pagal esamą 98,06 km ilgio miško keliukų tinklą, kurio tankis – 23,17 m ha−1. Bendras siūlomo kelių tinklo ilgis siekia 47,23 km, tankumas – 10,87 m ha−1, jis aprėpia 79% teritorijos. Miško keliukų ilgis – 81,04 km, tankumas – 19,15 m·ha−1. Remiantis GIS matavimais, naujo miško keliukų tinklo keliukai buvo trumpesni, tačiau jų tinklas tankesnis. Dėl šios priežasties mažėja pirminės transporto išlaidos ir sukuriama optimali miško keliukų aprėptis, pagerinamas prieinamumas. Резюме Планирование сети лесных дорог является одним из важнейших вопросов при создании упорядоченной системылесохозяйствования в северной части Ирана. В статье представлен технический метод планирования лесохозяйственной деятельности (прокладки дорог) с использованием ГИС и плана леса Ватан в провинции Гулистан Ирана. Целью исследования было выяснить возможности оптимизации длины лесных дорог и уменьшениянегативных последствий их избыточной длины. Результаты исследования показали, что общая протяженность существующих лесных дорог составляет 36 745 км, сеть дорог охватывает 54% всей исследованной территории,ее плотность – 8,68 м га−1. Оптимальная сеть лесных дорог создавалась на основании имеющейся сети лесных дорог, протяженность которой 98,06 км, плотность – 23,17 м гa−1. Протяженность предлагаемой сети дорог составит 47,23 км, плотность – 10,87 м гa−1, она охватит 79% территории. Длина лесных дорог составит 81,04 км, а плотность – 19,15 м·гa−1. На основании измерений, проведенных с использованием ГИС, длина дорог лесной сети стала короче, а сеть более густой. В связи с этим снижаются первичные затраты на транспорт, охват леснымидорогами становится более оптимальным, увеличивается доступность.

scholarly journals Simulation of the effects of forest roads on stormflow generation using GIS and 2D vadose zone hydrological model

2017 ◽  
Vol 36 (1) ◽  
pp. 25-39 ◽  
Author(s):  
Tomáš Orfánus ◽  
Marián Jenčo ◽  
Juraj Bebej ◽  
Martin Benko
Keyword(s):  
Methodological Approach ◽  
Subsurface Water ◽  
Water Runoff ◽  
Runoff Generation ◽  
Road Density ◽  
Forest Roads ◽  
Forest Road ◽  
The Road ◽  
Road Surfaces ◽  
Infiltration Excess

Abstract There was a destructive flood on Gidra river on June induced by 104-mm rainfall during 3 h on 7 June 2011. The total flood discharge was estimated to be 531,000 m3. The upper part of the Gidra river catchment is forested by more than 95%, but the forest floor has been disrupted to a large extent by intensive logging activities in the basin. Forest road density is up to 10 km/km2 in the catchment. The field inspections in the catchments revealed that approximately 25% of forest roads have been deepened down to the less permeable subsoil directly during their construction or by subsequent traffic and soil erosion. Forest roads affect runoff generation via two mechanisms: (1) generation of infiltration-excess runoff on road surfaces and (2) capturing of hillslope surface and subsurface water by road incisions. Infiltration-excess water runoff from all compacted surfaces was estimated to be about 54,000 m3 by simply multiplying the compacted area by the difference between the precipitation and infiltration. More challenging was to quantify the transformation of hillslope water to the road-surface runoff. We have suggested the methodological approach that combines the GIS analyses of the terrain with mathematical simulations of the subsurface water exfiltration from hillslopes to the road surfaces using HYDRUS 2D model. Simulations based on the variability of slope inclinations and slope lengths within catchment revealed that drainage of the upward hillslopes by forest roads and deeper logging lines increased the forest road runoff by another 6,000-15,000 m3 of water.

scholarly journals  Effects of roads on understory plant communities in a broadleaved forest in Hyrcanian zone

2012 ◽  
Vol 58 (No. 10) ◽  
pp. 446-455 ◽  
Author(s):  
M. Lotfalian ◽  
N. Riahifar ◽  
A. Fallah ◽  
S.M. Hodjati
Keyword(s):  
Tree Species ◽  
Ground Cover ◽  
Physical Parameters ◽  
Herbaceous Plant ◽  
Forest Road ◽  
Road Verge ◽  
Biological Communities ◽  
The Road ◽  
Understory Plant ◽  
Set Up

This study was conducted to assess the effect of forest road as a corridor on local biodiversity. For this purpose, 10 segments in a 10 year-old road were selected in Neka-Zalemrood forest in Hyrcanian zone. At each of the segments, we established two 100-m transects perpendicular to the road centre line, within which we sampled three macroplots of an area 400 m<sup>2</sup>. In each macroplot, nine quadrant microplots 2 &times; 2 m in size were set up for regenerated tree species and herbaceous plant survey. Chemical and physical parameters of soil were measured in laboratory. Results indicated that thirty-six herbaceous species and 13 regenerated tree species were recorded within the area of 100 m from the road verge. At the different distances from the road verge and both down and up-slope, the ground cover of Carex sylvatica and Rubus caesius L. as well as regeneration density of Carpinus betulus L. were higher compared to other species. Menhenick, Margalef, Shannon and Simpson indices were higher at the distance of 0&ndash;20 m than at the distances of 40&ndash;60 m and 80&ndash;100 m. Camargo and Smith-Wilson indices decreased when increasing distance to the road. These results are expected to provide critical information for decision makers and land managers for managing plant species and maintaining the integrity of biological communities. &nbsp;

scholarly journals Calculating the correction factor of skidding distance based on forest road network

2011 ◽  
Vol 57 (No. 11) ◽  
pp. 467-471 ◽  
Author(s):  
M. Lotfalian ◽  
E.H. Zadeh ◽  
S.A. Hosseini
Keyword(s):  
Correction Factor ◽  
Road Network ◽  
Road Density ◽  
Forest Road ◽  
The Road ◽  
Topographical Map ◽  
Arc Gis ◽  
The Mean ◽  
Gis Software

&nbsp; Average skidding distance for forest stands is an important parameter for the determination of the optimum road density and spacing. In this research the real mean skidding distance and theoretical mean skidding distance were measured to calculate the correction factor of skidding distance for Chafrood forest in Hyrcanian zone. The length and azimuth of skid trails from road and depot junction to forest interior were measured. Moreover, the position of skid trail was recorded by GPS. These skid trails with a buffer of 140 m were designed on a topographical map using Arc GIS software. Results indicated that the road spacing of 500 m in the study area resulted in a theoretical mean skidding distance of 125 m. For a real mean skidding distance of 525.9 m and for the mean slope of 40%, the correction factor was estimated to be 4.2.

scholarly journals SEDIMENTOS PROVENIENTES DE ESTRADAS DE USO FLORESTAL EM CONDIÇÃO DE RELEVO ONDULADO A FORTEMENTE ONDULADO

FLORESTA ◽  
2010 ◽  
Vol 40 (1) ◽  
Author(s):  
Carla Maria Camargo Corrêa ◽  
Renato Antônio Dedecek ◽  
Gláucio Roloff
Keyword(s):  
Forest Certification ◽  
Road Density ◽  
Forest Roads ◽  
Forest Road ◽  
The Road ◽  
Conservation Measure ◽  
Conservation Measures ◽  
One Year ◽  
In Fire ◽  
Soil Losses

Avaliaram-se, por um ano, as perdas de solos por enxurrada, em trechos de estradas secundárias e aceiros e a contribuição das áreas adjacentes, para estimar as perdas de solo em função da precipitação acumulada. Três tratamentos foram estabelecidos: num deles adotou-se medida de conservação, com implantação de barreiras de contenção de enxurrada a cada 50 m associadas a valas para deposição de sedimentos, adentrando nos talhões; os outros tratamentos compreendem trechos de estrada sem conservação e aceiros. Constataram-se os seguintes valores de perda de solo: 5,2 t.km-1 para o tratamento sem conservação, 4,1 t.km-1 em estradas com conservação e 1,4 t.km-1 em aceiros, totalizando 10,7 t.km-1 de perdas de solo acumulado no período. As medidas de conservação adotadas pela empresa reduziram as perdas de solo em 11,9% nas Unidades de Manejo Florestal Ruthes e Leonel, em Itaiópolis (SC). A densidade de estradas apresentou-se dentro do limite máximo recomendado para efeito de certificação florestal (59,92 m.ha-1). Associado às condições de perfil longitudinal, sistema de drenagem e revestimento do leito estradal, aponta-se a necessidade de melhor dimensionamento das medidas de conservação e manutenção mais frequente. O controle da precipitação apresentou-se estatisticamente confiável na estimativa de perda de solo por erosão nas estradas avaliadas. Palavra chave: Erosão hídrica; estrada florestal; perdas de solo; Pinus sp.   Abstract Sediments proceeding from forest roads in wavy to strong waved relief conditions. For one year were evaluated, the soil losses by runoff proceeding to parts of fire breaks and secondary roads with it’s respectively contribution areas, for estimative equations for soil losses in function of the accumulated precipitation. Tree treatments were established: roads with conservation measure, using water bars for control the runoff equidistant in 50 meters, associated with drain into the stands; roads without conservation and fire breaks. The soil losses as follow: 5,2 t.km-1 for roads without conservation measure, 4.1 t.km-1 in roads with conservation measure and 1,4 t.km-1 in fire breaks, totalizing 10,7 t.km-1 soil losses in the period. The conservation measures adopted had reduced the soil losses in 11,9% in the Forest Management Units Ruthes and Leonel - Itaiopolis / SC. The road density with 59,92 m.ha-1 just about the maximum limit recommended for forest certification. Associated to the longitudinal profile conditions, draining system and covering of the stream bed road, had pointed with respect to the necessity of better sizing of the conservation measures and more frequent maintenance. The control of precipitation was presented confidence statistical information for estimative the soil losses procceding from erosive process in the evaluated forest roads. Keywords: Hydric erosion; forest road; soil loss and Pinus sp.  

Reliability of the Minimum Masking Level as Outcome Variable in Tinnitus Clinical Research

2020 ◽  
Vol 29 (3) ◽  
pp. 429-435
Author(s):  
Patricia C. Mancini ◽  
Richard S. Tyler ◽  
Hyung Jin Jun ◽  
Tang-Chuan Wang ◽  
Helena Ji ◽  
...  
Keyword(s):  
Standard Deviation ◽  
High Frequency ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Outcome Variable ◽  
Reliable Estimate ◽  
Moderate Correlation ◽  
Trained Subjects ◽  
The Relationship ◽  
Minimum Intensity

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.

Comparative Responses to Squats Completed with Free Weights and an Exoskeleton

2020 ◽  
Vol 4 (1) ◽  
pp. 51-63
Author(s):  
Peter Neuhaus ◽  
Chris Jumonville ◽  
Rachel A. Perry ◽  
Roman Edwards ◽  
Jake L. Martin ◽  
...  
Keyword(s):  
Data Collection ◽  
Female Athletes ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Actual Data ◽  
Limited Data ◽  
Comparative Similarity ◽  
Insufficient Amount ◽  
Force Data ◽  
Familiarization Session

AbstractTo assess the comparative similarity of squat data collected as they wore a robotic exoskeleton, female athletes (n=14) did two exercise bouts spaced 14 days apart. Data from their exoskeleton workout was compared to a session they did with free weights. Each squat workout entailed a four-set, four-repetition paradigm with 60-second rest periods. Sets for each workout involved progressively heavier (22.5, 34, 45.5, 57 kg) loads. The same physiological, perceptual, and exercise performance dependent variables were measured and collected from both workouts. Per dependent variable, Pearson correlation coefficients, t-tests, and Cohen's d effect size compared the degree of similarity between values obtained from the exoskeleton and free weight workouts. Results show peak O2, heart rate, and peak force data produced the least variability. In contrast, far more inter-workout variability was noted for peak velocity, peak power, and electromyography (EMG) values. Overall, an insufficient amount of comparative similarity exists for data collected from both workouts. Due to the limited data similarity, the exoskeleton does not exhibit an acceptable degree of validity. Likely the cause for the limited similarity was due to the brief amount of familiarization subjects had to the exoskeleton prior to actual data collection. A familiarization session that accustomed subjects to squats done with the exoskeleton prior to actual data collection may have considerably improved the validity of data obtained from that device.

Leader-Member Exchange (LMX) Impact on Work-Home Interference in a South African Commuter Transport Engineering Company

2019 ◽  
Vol 43 ◽  
Author(s):  
Jan Christoff Visagie ◽  
Michael M. Jones ◽  
Herman L. Linde
Keyword(s):  
South African ◽  
Structural Equation ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Leader Member Exchange ◽  
Negative Consequences ◽  
Dyadic Relationship ◽  
Cross Sectional ◽  
Engineering Company ◽  
Member Exchange

The South African workplace is confronted with many leadership challenges, specifically those relating to the employment relationship between subordinates and their supervisors. A high-quality relationship is essential, considering the work-family spillovers employees experience. Limited research has been conducted on the potential positive and negative consequences of the leader-member exchange (LMX) dyadic relationship. In this study, we used a cross-sectional research design, and drew an employee sample (N = 120) from a commuter transport engineering company. A five-point Likert scale was employed and statistical analyses were carried out using the SAS statistical program. We calculated Pearson correlation coefficients and used structural equation modelling to test the proposed conceptual model to indicate possible correlations between the different variables. The main finding of the study was that the nature of the LMX relationship quality in the relevant company appeared to be high and positively related to work-home enrichment but negatively related to work-home conflict and role overload. The article concludes by making a number of suggestions to respond to challenges.

Optimales Layout einer Walderschliessung

2016 ◽  
Vol 167 (5) ◽  
pp. 294-301
Author(s):  
Leo Bont
Keyword(s):  
Road Network ◽  
Spatial Arrangement ◽  
Problem Situation ◽  
Optimal Layout ◽  
Forest Road ◽  
The Road ◽  
Network Cost ◽  
User Friendly ◽  
Short Time

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.

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