Browsing by Author "Emir T."

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Impacts of Small-Scale Mechanized Logging Equipment on Soil Compaction in Forests
(2020-09-01) Varol T.; Emir T.; Akgul M.; Ozel H.B.; Acar H.H.; Cetin M.
The present study focuses on assessing the effects of different numbers of skidders on soil compaction. To assess the skidding effects, four-wheeled small-scale logging equipment attached to an ATV (Automated Transfer Vehicle) was used. Skidding operations were carried out on undistributed forest corridor (20 × 3 m).To measure soil compaction, 11 measurement lines were used, spaced at 2-m intervals. A total of 33 measurement points were used to measure soil compaction. Soil compaction values were measured for different soil depths with 5 cm intervals in the 0–40 cm range as MpA. The results were evaluated for the skidding zone and the wheel zone. Prior to skidding, soil compactions at 0 cm (top soil) is almost 2.5–3 times lower than those at the other depths. The p values indicate that the numbers of passes and the compaction values belong to nonidentical groups. The Bonferroni method was used to determine whether the compaction values are similar. The Dunn test results demonstrate that there were statistically significant differences between the mean values of the number of passes up to the 60th pass. However, there are no statistically significant differences between the means of the compaction values occurring between 60 and 80 and 100 and 120 passes. Generally, soil compaction is expressed as an increase in the soil bulk density. Soil bulk density and soil porosity are negatively correlated. It was found that for each of the zones, soil compaction values between the depths of 15 cm and 40 cm are approximately 4 times higher than at the 0 cm soil depth. Soil compaction values increased 3 times at the depths of between 0 cm and 5 cm. The average soil compactions values in the skidding zone are approximately 1.5 times higher than those at the wheel zones at the depth greater than 5 cm. The use of different skid trails will decrease soil compaction of the forest stand, provide uniformity of soil compactions in forest stand.
Prediction of soil-bearing capacity on forest roads by statistical approaches
(2021-08-01) Varol T.; Ozel H.B.; Ertugrul M.; Emir T.; Tunay M.; Cetin M.; Sevik H.
The soil-bearing capacity is one of the important criteria in dimensioning the superstructure. In Turkey, predictability of California Bearing Ratio values, which may be used in the planning and dimensioning of forest roads, of which about 26% lacks the superstructure, by using soil mechanical properties (cost and time efficient parameters that are easier to determine) is investigated. Simple linear regression, multiple linear regression, artificial neural networks and adaptive network–based fuzzy inference system methods were utilized. Two hundred sixty-four California Bearing Ratio values obtained from the project carried out on the forest roads of Bartin Forest Operation Directorate were used in both the production of training-test data and the creation of models. Statistical performance of the models was assessed by means of parameters such as root-mean-square error, mean absolute error and R2. The obtained results show that the bearing capacity values predicted by artificial neural networks and adaptive network based fuzzy inference system models display significantly better performance than the simple linear regression and multiple linear regression models. While the highest prediction capacity belongs to adaptive network based fuzzy inference system (0.969–0.991), it is followed by artificial neural networks (R2 = 0.796–0.974), multiple linear regression (R2 = 0.796) and simple linear regression (R2 = 0.554). What makes the algorithms superior than the traditional statistical models is the fact that they have many processing neurons, each with local connections, and thus have higher error tolerance. On the other hand, for the forest and rural roads, which play an important role in rural development of the forest peasants, to be able to operate all-seasons, superstructure should be immediately built in order to minimize the wear on the roads.
The effects of rill erosion on unpaved forest road
(2019-01-01) Varol T.; Ertuğrul M.; Özel H.B.; Emir T.; Çetin M.
This research aims to investigate the degree of rill erosion and its relationship with the factors effective on rill volume on unpaved forest roads in Bartın Province in Turkey. For this purpose, measurements were made at 380 sample locations on different regions of the forest roads in Arıt and Hasankadı sub-districts. The measurements were performed on 4 years old unpaved forest roads. Among the road surface (RS), road cut (RC), sidecast fill (SCF) and skid trail (ST) road sections, RS and ST ranked as the first two sections with the highest segment length. Segment length is characterized as the most effective field factor on erosion, which further increased the rill volume by the combined effect of increasing slope, in this research. According to the stepwise (forward-backward) regression analysis results, inclusion of both segment length and slope parameters in the RS, SCF and RC equations supports this finding. The correlation of all road sections (RS, SCF, RC, ST) with the segment length are 0.84, 0.63, 0.75 and 0.83, respectively, and the correlation with the slope are 0.55, 0.73, 0.57 and 0.64, respectively. As a result of the slope-based categorization of the relationship between segment lengths and rill volume for the road sections, R 2 values were found to increase up to 0.88 for RS, 0.78 for SCF, 0,94 for RC and 0.88 for ST. The rill volume at short and steep roads can be lower than the rill volume at long and low-slope roads. Therefore, we calculated the rill volumes per unit road segment area. As a result of application of equations based on shear stress and stream power sediment transport capacity theory, RMSE values with very low mean error were obtained. In further related studies, drainage areas in addition to segment lengths and slope should also be taken into account to determine the positive and negative effects in evaluation of rill erosion amounts. Also, similar studies should be performed on other basins having a larger number of unpaved forest roads as a means to extend the applicability of the obtained findings.