Investigating the erosion in the geomorphologic facies and its relationship with drainage density
حسن
احمدی
author
عطاءا...
کلارستاقی
author
ناصر
مشهدی
author
text
article
2009
per
Soil erosion prediction, qualitatively and quantitatively, is very important to watershed managers and decision-makers. In this paper BLM method is used to evaluate erosion qualitatively. Since BLM is also used in PSIAC and MPSIAC methods to evaluate eighth and ninth factors, using this method should be in combination with geomorphology methods. Also, relationship between erosion and drainage density was studied using regression analysis. Sarvelayat Drainage Basin is located on the north of Sabzevar-Mashhad road, with an area of about 35,300 hectares. Base maps of the slope, aspect, altitude, lithology were prepared and aerial photos were interpred, geomorphology facieses were developed. The results show a correspondence between of BLM and Geomorphology methods in studying geomorphology facieses. Furthermore, in the BLM method drainage pattern factor is very complicated to be ranked by experts. To remove this difficulty, in this paper, statistical test of relation between erosion and drainage density in geomorphology facieses was accomplished. The findings of the study indicate that there is a significant positive correlation (99%) between two variables.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27829_c411aadc26b3bbeb53283062752e84c9.pdf
The survey of avalanche- pron regions for determining the effective factors
نسیم
آرمان
author
علی
سلاجقه
author
text
article
2009
per
The word?AVALANCHE? means a suddenly and quick movement of a huge mass composed of different materials along with ice and snowmass, so that in mountains and snow areas of Iran like western hights of Kordestan, not only causes destruction landforming, gardens, erosion of soil, increasing of sediment, but also a lot of people are annually killed because of avalanches . In order to investigate the effective factors in generating avalanche and its relationship with erosion and sediment of the basin, this researche was conducted to find out the effect of parameters including topography, geology, geomorphology, climate, snow sample, pedology, plant cover, sediment and erosion with related maps. The parameters affecting avalanche were deivided into the fallowing categories which were studies using MSTAT-C software and the appropriate statistical tests were applied to data. The Results showed the important edaphical factors such as topography, pedology, plant cover, geomorphology, geology and climatological parameters such as snowfall depth (cm), wind velocity (m/s), total montly precipitation, maximum montly temperature, sunny hours, montly evaporation (mm). In case of topographic factors, passage area, general gradient and maximum high are the most effective factors respectively. In order to investigate the relationship between avalanche and erosion and topography on the basin, a T-test analysis was conducted and results showed that the occurance of avalanche is directly connected to the increase in the basin sediment.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27830_3c6eb51251ef5e1d40b2fe6ccf2ddc00.pdf
Preparing Digtal Maps of Some Soil Chemical Properties Using Satellite Data of landsat ETM+
مرتضی
اکبری
author
کوشیار
مختاری
author
سعید
پورمنافی
author
text
article
2009
per
The images taken by the TM Landsat 7 since September 2001 were used to prepare digital maps of certain soil chemical properties in northwestern Isfahan area. Geometric and Radiometric corrections were made on the images and then the images were recorded with 0.58 pixel accuracy. The images underwent processing, including image enhancement and PCA. Total 77 samples were collected randomly from the soil surface and analyzed in laboratory. Salinity, acidity, lime content and alkalinity were measured for each sample. Overlaying soil sample map on satellite image, the digital number (DN) of each sample point was extracted. Correlation and regression coefficients between DN and measured parameters were then estimated. The results showed no significant correlation between DN and Soil parameters. It was also showed that the correlation coefficients are higher for ETM+ 4, ETM+ 7 and ETM+ 1. It was clear that we cannot fit a regression model to the parameters that may be able to help us prepare soil map from satellite images. Therefore, it is suggested to use supervised classification methods to prepare soil maps.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27831_3e47bbecf570821799ab5b879fe92d4f.pdf
Simulation of runoff, sediment and soil erosion by EUROSEM model in Tange-Ravagh sub basin, South Karun watershed, Kohkeiluieh-Boyer Ahmad Province
احمد
جلالیان
author
محسن
حمیدپور
author
بهزاد
قربانی
author
شمسا...
ایوبی
author
text
article
2009
per
To perform soil and water conservation programs in watersheds, a model is required to predict runoff, sediment and soil erosion spatially and temporally. This research was conducted in order to evaluate EUROSEM model in estimating runoff and soil loss in Tangh-Ravagh sub-basin of south Karun watershed. The study area covered 1 ha, was divided into nine units according to EUOSEM users guide manual. Soil and plant cover parameters and geometrical characteristics of the sub-basin were collected and measured, then parameterization, calibration and validation processes were done in 7 separate events. The calibration of hydrograph was performed by decreasing saturated hydraulic conductivity and capillary drive and increasing soil moisture. The calibration of sedigraph was done by decreasing detachability of soil particles and increasing Manninmg’s n and soil cohesion. Validation results showed that EUROSEM model provides a good simulation of the total runoff, total soil loss and peak runoff discharge, but it could not simulate well the time of runoff, time to peak discharge and the peak of sediment discharge. Comparisons of measured capillary drive and soil cohesion in the study area based on the values provided by EUROSEM manual, showed significant differences. Therefore, the tables are not recommended to be used in evaluating these parameters that should be adjusted locally.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27832_9669e71456f35efafc7e83a981025c38.pdf
Saline and alkaline soil mapping using ASTER data in the Qazvin plain
مارال
خدادادی
author
فریدون
سرمدیان
author
محمدصادق
عسکری
author
حسینقلی
رفاهی
author
علیاکبر
نوروزی
author
احمد
حیدری
author
text
article
2009
per
Salinity and alkalinity are two major phenomena leading to soil degradation in semiarid and arid areas. The main aim of this study was to evaluate the capability of ASTER data to provide soil salinity and alkalinity mapping in the selected parts of the Qazvin plain, which is known as an arid area. In this study, spectral classes were provided from sensed data, and with the help of field observation and soil analysis reorganized to have soil salinity and sodicity classes. Finally, soil salinity and sodicity maps were prepared. Soil sampling was implemented using stratified random sampling method, depending on landscape complexity and homogeneity, as well as on the representativity to ASTER data. Furthermore, at least one profile was studied in each soil map unit in order to examine subsoil salinity variation. Field samples from augur and profiles were analyzed in laboratory for Na+ , Ca2+ , Mg2+ cations, as well as soil texture , ECe and pH. We have analyzed additional data such as digital elevation model and slop that may improve the accuracy of classification. In addition, NDVI, SRVI, PVI, SAVI, SI, BI and NDSI indices, and PCA were analyzed. The results indicated that the combination of DEM with them ASTER bands would lead to highest accuracy. This study showed that thermal bands of ASTER increased the classification accuracy, and this illustrated its effective role to classify the soil salinity and sodicity. PCA had almost highest accuracy, among studied processing techniques. The indices had low accuracy in differentiating the saline soils. The optimum index factor had low overall accuracy. The sodicity map was less accurate as compared to the salinity map. The accuracy for moderate sodicity levels was less than the accuracy for low and high sodicity levels.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27833_f3a60e2356760e2929970584725cef5c.pdf
Simulation of SPI Time Series Stochastic Behavior by Using Markov Chain Model for Early Warning of Fars Province Drought
منصور
رجبی
author
حمیدرضا
مرادی
author
منوچهر
فرجزاده
author
جواد
بذرافشان
author
text
article
2009
per
The standard precipitation index (SPI) as a selected index was computed based on the same period in 32 years (1343-78) in the time scale of 12 months for 26 stations located inside and outside of Fars Province. In the next stage, drought severity data resulting from SPI method was combined with Markov chain, and a probability transition matrix and steady matrix of region were developed. Ultimately, region long term condition in terms of drought duration and severity was predicted for coming 10 years. The result showed that in probability transition matrix of drought, highest probability was observed in diagonal part of matrix indicating the stability of environmental condition. In probability steady matrix of drought, the percentage of the periods persisting fr long term is similar to the probabily shown by SPI, indicating Markov chine model capability of predicting draoughts and disemminating warnings in advance in Fars Province.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27834_fc8209bfd3405751c736c8bcc02bd9b9.pdf
Land use optimization for soil erosion decrease and income increase of watershed
محمد
شعبانی
author
حسن
احمدی
author
داوود
نیککامی
author
حسین
آذرنیوند
author
محسن
محسنیساروی
author
text
article
2009
per
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27835_42257c49715f970cd85a50bee3433150.pdf
Study on Changes in Morphometric Characteristics of Bed Materials (Case study: Vaz Watershed, Mazandaran)
سیدحمیدرضا
صادقی
author
عبدالواحد
خالدیدرویشان
author
مهدی
وفاخواه
author
لیلا
غلامی
author
text
article
2009
per
Studying changes in morphometric characteristics of bed materials helps understand and manage hydrological processes governing a watershed system. The present study has been conducted in a 30-kilometer reach of Vaz River in Mazandaran Province to investigate changes in morphometric parameters of bed materials in downstream direction. To achieve the study’s purpose, seven cross sections were selected along the reach. The bed material were then sampled and associated morphometric parameters viz. mean, standard deviation, skewness, kurtosis, mode, , , , gravel, sand, mud, sediment texture, small, medium and large diameters, shape factor, nominal diameter, sphericity, roundness and width ratios were determined and corresponding changes were evaluated in downstream ward. The results of the study verified changes in morphometric characteristics. Besides that, it was understood that different natural reasons and anthropogenic activities have seriously affected the intensity and trend of the changes.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27836_1782807d8ee1ec4000615f0ae16274f4.pdf
Investigating the applicability of Neural Network method for estimating daily suspended sediment yield (Case study: Zard Drainage Basin, Khozestan Province)
سادات
فیضنیا
author
حسین
محمدعسگری
author
محمد
معظمی
author
text
article
2009
per
In this study, to drawn the model of daily suspended sediment yield, simultaneous water and sediment discharge data of Machine Hydrometric Station, which is located on Zard River, Ramhormoz, Iran, were used. For this purpose, after elimination of statistical deficiency and exclusion of deviated data, the data were divided into two parts: 80% of the data were allocated for training and the other 20% of data were used for the examination of neural network. After standardization of the data, by using training data series, neural network with back propagation error algorithm was developed. Furthermore, by using the training data series, regression equation was developed between water and sediment discharges. For evaluating these two methods, the examination data series and the statistical parameters of R2, MAE and RMS were used. The amounts of R2, MAE and RMS for the neural network method are as follows: R2=0.62, MAE=1854 and RMS=3184. The amounts of the mentioned parameters for estimation using regression equation are: R2=0.54, MAE=1934 and RMS=3251. The results have shown that the estimation of suspended sediment yield using neural network model is more accurate in comparison to the regression equation estimates. But for reaching an optimum model, the processes of the data preparation, network architecturing and network training should be performed carefully and accurately. It is concluded that for the estimation of river suspended sediment yield, this model should be considered and used.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27837_efff0d84126496fe8e9068e4e7123581.pdf
Evaluation of the quantitative effects of environmental parameters on occurance of gully erosion
قاسم
مرتضاییفریزهندی
author
حسن
احمدی
author
جمال
قدوسی
author
سادات
فیضنیا
author
محمد
جعفری
author
text
article
2009
per
This research was conducted in chap chap- Ghomish Abad sub-basin, Zanjanroud basin, located in northwest of Zanjan. 32 gullies in the central part of the region were selected and studied using historical data extracted from aerial photos in 1956,1967 and 2001, and sattelite images in 1990 and 1998 and field observations. The analysis of data related to topography, geology, soil, vegetation, cover, landuse, weather and climatology were obtained from questionaines, sattelite images and aerial photos. Then dataset were incorporated in GIS (ILWIS), R S. The results showed that the content of sodium enhances the dispersion of particles, especially clay particles, in the soil. Higher content of organic carbon stablizes soil particles and limits the gully expansion. The area of forehead catchment as well as daily rainfall (I>12.5mm & 0.5in) have significant relation with longitudinal development of gullies.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27838_363e49fda4436ef193d5bf57df3948c3.pdf
Evaluation of Performance of Empirical Models of Storm Events Sediment Yield of Drainage Basin and Introducing Calibration Coefficients
جواد
وروانی
author
سادات
فیضنیا
author
حسن
احمدی
author
محمد
جعفری
author
text
article
2009
per
Variable and dynamic nature of sediment transport by rivers and spatial and temporal variation of drainage basin sediment yield in general, especially during flood events, can lead to unreal and inaccurate judgments and faulty planning about erosion and sediment yield behavior of the drainage basin. Generally empirical models used to estimate the amount of sediment yield during flood events; however, there is little information on the accuracy and precision of such models. In this research, in order to evaluate the performance of the empirical models used to estimate the flood event sediment yield, at first the concurrent sediment and water discharge of some of the flood events (five events) were recorded on an hourly in the Poledouab hydrometric station located in Gharachay river of Markazi Province in a way that rising and falling limb of hydrographs included. Considering observed data of flood events sediment yield, the accuracy and precision of empirical model's estimations was investigated. The results show that there are two different kinds of estimation in the selected models. Some of them that overestimate the sediment yield include MUSLE model and its modifications, and those underestimating floods event sediment yield include sediment routing model and linear and mean class rating curves with bias correction factor of MVUE. Finally by considering observed value as a basis, the power of empirical equations calibrated for more accurate and precise estimation.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27839_e57b4216b6f4d7959efd31ecc27f9ae2.pdf
The Effects of Cutting Height on Growth of Old Saxaul (Haloxylon aphyllum) Afforestation in Yazd Province
ناصر
باغستانیمیبدی
author
text
article
2009
per
The determination of proper cutting height on old saxaul (Haloxylon aphyllum) trees is essential for sustainable development of afforestation in desert areas. In fact, the objective of this study was to determine the effect of different cutting levels on life period and growth of sexual trees. The study was carried out in obviously wilted planted saxaul forest, which is located in Ashkezar desert region of Yazd Province. Experiments were performed in a split-plot scheme with main-plots that had 250 and 125 trees per hectare whre sub-plots included three types of cutting heights of 10, 35 and 70 centimeter above ground surface, as well as the control sample (without cutting). Cutting was done on autumn 1994. The 6-year results (1994-2000) showed that the two mentioned densities had no significant effects on diameter and height growth (p?0.05). However, cutting levels had significant effects (p?0.01). The most foliage cover and other usable properties were attained with 35 centimeter cutting height above ground surface.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27840_1577fa610ab91efc088c4f673f502fe3.pdf
Effect of edaphical factors on oak sprouting ability
مهدی
پورهاشمی
author
محمدرضا
مرویمهاجر
author
قوامالدین
زاهدیامیری
author
محمود
زبیری
author
پریسا
پناهی
author
text
article
2009
per
This research was carried out in the Doveyse Forest with an area of 660 hectare, located in northern-east of Marivan city, Kurdistan Province, Iran. Totally 103 plots were designed using a systematic random rectangular grid with dimensions of 150m × 300m. Sprouting situation of oaks was studied in the plots. Based on plant ecological groups' map and physiographical factors, site homogeneous units were determined and soil samples were prepared from these units. The effect of the most important edaphical factors (totally 12 factors) were analyzed using PCA in the main aspects. The results showed that the most important factors affecting sprouting of oaks in north aspects are pH and electrical conductivity, and in south aspects PH and potassium content of soil are the factors that play a crucial role.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27841_9ecc2acb407f643700c3a7260332ca27.pdf
Evaluation of productivity, machine rate, and costs on TAF skidder (case study: In Kheyroudkenar Forest)
مقداد
جورغلامی
author
هوشنگ
سبحانی
author
وحید
اعتماد
author
text
article
2009
per
Transportation of wood from the cutting areas to the roadside imposes highest expenses in the whole logging operations. This research deals with this matter and studies the production and cost rates of TAF Skidder in cut-to-length system. The study was carried out in Kheyroudkenar Educational and Research Forest Station at Nowshahr, Iran. Using continuous time studies, the effective factors of skidding including winching distances, volume, slope, number of logs and tree species were identified and recorded. Overall, 46 turns were recorded on TAF, and the collected data were analyzed and skidding models were developed. The results showed that the production rates for TAF were 5.93 m³/hr (including delay times) and 8.33 m³/hr (no delays). Production costs were 74,861 and 53,279 Rials/m³, respectively. Studying the changes in each variable while the other variables kept fixed showed that, except the annual utilization of the cost of machinery produces a parablic function, factors have a positive linear relation with cost.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27842_66c77898fb5b1384671cb6fc92ee1ffd.pdf
Investication on the Capability of Landsat7 ETM+ data for Standing Volume Estimation of Beech Stands
رمضانعلی
خرمی
author
علیاصغر
درویشصفت
author
منوچهر
نمیرانیان
author
text
article
2009
per
In order to investigate the capability of Landsat7 ETM+ data to estimate standing volume of pure beech stands, the data of this sensor dated June 2001 were used. This study was carried out in Farim forests in an area measuring over 2,000 ha. Orthorectification of image was performed using ephemeris data, GCPs and a precise DEM, and its result was verified using roads vector layer. In order to study the relationship between standing volume and multispectral satellite data, ninety five 60m×60m sample plots were selectively established in the forest. Sampling was performed in pure beech stands located on the north-facing slopes. In each plot, DBHs greater than 12.5 cm were measured and the standing volume of trees were determined based on a local tarif table. The position of each plot was also recorded by GPS and a digital map of the sample plots was prepared using these positions. Digital numbers related to each plot were extracted from spectral bands. The resulting RMS error of orthorectification was 0.85 pixel. Desired coincidence between the roads layer of digital topographic maps and the rectified image indicated high precision of the orthorectification. Based on Pearson’s correlation coefficient, data in NIR band and NIR fused with Pan showed the highest correlation, with the standing volume with correlation coefficients of -0.70 and -0.72, respectively. In regression analysis, for infrared band, the highest correlation coefficient with standing volume in simple linear and binominal models were obtained -0.74 and -0.76, respectively, and for fused band 4, these coefficients were -0.77 and -0.80, respectively.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27843_a5a14780d6bad0e96358732ab9d10ecc.pdf
Optimization of Proden's Six Tree Sampling Method
آرزو
سلطانی
author
محمود
زبیری
author
منوچهر
نمیرانیان
author
text
article
2009
per
follows: basal area (m2/ha) and density (number per hectare).We used data related to six tree sampling method practiced in Pattom section in kheyroud kenar forest. We analyzed three hypotheses:
A. Plot radius equals to the distance between the center plot and nth tree plus half of the nth tree diameter.
B. Plot radius equals to the distance between center plot and nth tree plus the nth tree diameter.
C. Plot radius equals to the distance between center plot and nth tree plus the nth tree diameter and half of the distance between nth tree and (n+1)th tree.
We used these hypotheses and calculated basal area and density for each plot. Then we calculated density and basal area for all forest with weighted mean, arithmetic mean and corrected mean with bias correcting factor. We used Wilcoxon and t tests to compare the result of n-tree sampling method with true values. As a result, weighted mean and second hypothesis are suitable for estimating basal area. However for density, corrected mean and third hypothesizes are better. When the number of trees in a sample plot increases the precision of sampling method increases too. The results of n-tree sampling method are not significantly different from each other.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27844_9f2b4dcff9697a17869fec159ba3df08.pdf
Initial results of some characteristics in Fagus orientalis seedling as affected by canopy density, after soil scarification and seed sowing
مسعود
طبری
author
محمدرضا
پورمجیدیان
author
پیام
فیاض
author
text
article
2009
per
Some characteristics of oriental beech (Fagus orientalis Lipsky) seedling were compared in three different beech stands with canopy densities of 15% (open), 55% (semi-closed) and 85% (closed), located in north of Iran (h=1400 m a.s.l.). In the center of each stand, following the elimination of herbal vegetation and shrubs, a soil scarification, together with beech seed sowing, was performed in four plots of 100 × 100 cm. The results of the first growing season demonstrated that seed germination rate did not differ with increased canopy density. Survival and shoot growth rates in seedlings were smaller in open canopy; however, no statistical difference in these characteristics was found between closed canopy and semi-closed canopy. Foliage discoloration elevated as canopy opening increased. It can be concluded that at early felling, creating the stands with canopy density ~ 40-60% is more suitable for growth, establishment and vitality quality in beech seedlings preceded by seed sowing following soil scarification.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27845_3ac705969d048f6068394cc226834ee4.pdf
Investigation on the Spatial Pattern of Trees in Zagros Forests
سیدیوسف
عرفانیفرد
author
جهانگیر
فقهی
author
محمود
زبیری
author
منوچهر
نمیرانیان
author
text
article
2009
per
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27846_f3546b7fed1d08c5fe9907f10f3c9d3b.pdf
Economic Evaluation of Natural Lands in ٍSub-Urban Area
سیدرشید فلاح
شمسی
author
ارسطو
سعید
author
هوشنگ
سبحانی
author
علیاصغر
درویشصفت
author
احمد
فرجیدانا
author
text
article
2009
per
In this research, the main objective was an economic appraisal of the lands allocated for tourism in the study area. The study has been done for “Babak Fort” Park, which is about 4.5 ha in the countryside region of Kaleibar, Eastern Azerbaijan. All information about the visitors was collected using questionnaires including questions that aimed at characterizing travel-cost components. Travel-Cost Analysis (TCA) has been used to estimate economic land value of the park area. First of all, the surrounding region of the park has been divided into concentric sub-regions according to the travel departures and travel costs. Demand function of the visitor’s has been estimated on the basis of the cost of travel and the number of visitors per 100 thousands of residents from each sub-region. Then expected number of visitors has been estimated, using the function of the visitor’s demand and establishing an assumed entrance fee. Demand function of the park has been estimated, using different amount of the assumed entrance fees and the expected number of visitors for the visitors both on weekends and the visitors of historic events. Total economic land value of the park has been estimated by calculating integral of the demand function. Estimating expected net income per (ha) and expected net income per each million Rls. investment, tourism has been compared with other land uses of the region. The comparison indicates that the park area and tourism gain more annual net income per (ha) rather than other land uses. Nevertheless, the private sector has a slight inclination toward the investment of financial resources in developing tourist facilities. This can be attributed to the private sector’s limited resources and the high investment required for park management. Therefore, managing the park by public sector has become inevitable.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27847_5663c7ff92cb9847f81c2c22ef3b61c8.pdf
Application of Transect sampling in Khalkhal protected forests
یونس
نوکی
author
محمود
زبیری
author
جهانگیر
فقهی
author
text
article
2009
per
This study was conducted to determine and introduce an optimised method in terms of precision fcost or inventory of protected forests. In this research, transect method based on distances between trees and transect method based on probability theory were selected to be compared. The parameters for evaluation were number per hectare, crown cover and basel area (suitable parameter for this type of forests). To achieve this , an inventory grid with dimensions of 100*100m including 48 transects with length of 40m was designed. To compare the result of inventory methods with real population statistical parameters %100 inventory applied in 49.53 ha. The results showed that the population mean was similar to the sampling method of transect with distance between trees regarding all parameters. The t test revealed there is no significance difference between %100 inventory and the method of transect with distance between trees. K. S test revealed there is no significance difference between the distrbution of trees per hectare crown cover and basel area class with %100 inventories. Thus, the method of transect based on distancee between tree is a sutiable method in terms of precision.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27848_50bbd66896d13085499cf2062b04c54e.pdf
Study of Cost Production of Felling using Chainsaw in
مهرداد
نیکوی
author
هوشنگ
سبحانی
author
باریس
مجنونیان
author
محمدرضا
مرویمهاجر
author
جهانگیر
فقهی
author
text
article
2009
per
Manual felling by chainsaw is one of the logging components which is directly related to human labor performance. It is important because it has to be carried out only in winter. To evaluate the current felling system in Asalem forest and possibility of finding better techniques and cutting team organization. To carry out the study, parcels 318, 319, 321, 322, 365 and 367 of Naav watershed were selected in order to collect the necessary information. The elemental factors of the cutting cycle were identified and 131cycles were recorded. Effective factors such as tree diameter at cutting stump height, travel distance between cut trees, longitudinal and side slope were recorded. Based on data analyzed and the statistical model developed the following results were obtained:
The best model of cutting time is a function of independent variables such as the tree diameter at cutting stump height, travel distance between cutting trees, and the longitudinal slope independent variables. The validity of the model was examined and was verified at 95%. The number of cut trees per hour (production rate) with and without delay time was 10 and 13 and the production cost 23,343 and 18,424 Rials respectively. The study of change in each variable on cutting times and respected costs displayed direct linear changes. The delay times had the highest rank after making under cut and back cut.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27849_61dbd0ca8091c97757ef68176b1802e1.pdf
Study and comparison of Woody Species Diversity in Maple Plantations in Mazandaran Wood and Paper Low Forests
لیلا
وطنی
author
مسلم
اکبرینیا
author
غلامعلی
جلالی
author
کامبیز
اسپهبدی
author
text
article
2009
per
This study aims to assign woody plants diversity in four fields of 15 years’ Maple plantation in Paeinband Mazandaran Forests developed by the Mazandaran Wood and Paper Industries. In each plantation, three 20*20 m plots were designed while a plot was chosen to serve as the control sample in the surrounding forest area. Species and number of woody plants has been counted in each plot, and diameter and height of generated species was measured up to 1.3 meters height. Species diversity was examined using Shannon Wiener function, and evenness and richness were measured using Simpson and Menhinic indexes. Almost 18 tree and shrub species were observed in mentioned fields in this study. Results of this study in Nodeh and Talookola illustrate that there is no significant difference about Shannon Wiener diversity function among planted maples in the selected areas and the naturally grown trees in the forest area. However, the results derived Afratakht and Pahnekola sites show among planted maples in the selected areas and the naturally grown trees in the forest area from the standpoint of Shannon Wiener diversity function. There is no significant difference about biodiversity indexes (evenness and richness) among planted maples in the selected areas and the naturally grown trees in the forest area.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27850_b7df24c0d075a91eebb2b8ae78e3023e.pdf
Photostabilization of CMP Bleached Pulp by Various Inhibitors
محمد
آزادفلاح
author
سیداحمد
میرشکرایی
author
احمد
جهانلتیباری
author
داود
پارساپژوه
author
text
article
2009
per
Photostabilization of Hardwood CMP pulp bleached with hydrogen peroxide in the presence of various additives including three ortho-hydroxy aromatic UV absorbers, hydroperoxide decomposer, hindered nitroxide and hindered phenolic antioxidant was studied. All treatments were applied as impregnation on the surface of CMP bleached testsheets. 2,4-dihydroxy benzophenone (DHB), Tinuvin 328 and Tinuvin 405 inhibited moderately light-induced yellowing of CMP bleached pulp. Hindered nitroxide (4-hydroxy TEMPO) and phenolic antioxidant (Irganox 1010) not only couldn’t stabilize CMP bleached pulp efficiently, but also intensified yellowing of the pulp. The hydroperoxide decomposer (Everfos 168) was also not found to be an effective inhibitor for CMP bleached pulp.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27851_6f866ffb42a414d98e50e77383009101.pdf
Assessment of Internal Trade of Iranian poplar Timber
علی
بیاتکشکولی
author
سعید
امیری
author
آرزو
سلطانی
author
مهدی
فائزیپور
author
کاظم
دوستحسینی
author
text
article
2009
per
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27852_34a0b807ace7fc1b32d546bd6aeab6bf.pdf
Effect of Heat Treatment Temperature and Log
عبدا...
حسینزاده
author
کاظم
دوستحسینی
author
علیاکبر
عنایتی
author
حبیبا...
خادمیاسلام
author
text
article
2009
per
In plywood industries, the transverse hygrothermal deformation of wood has an important role in log end checks extension. In this survey, the transverse deformation /of wood and log end checks of hornbeam have been studied. Twenty seven hornbeam (Carpinus betulus) trees in three diameter classes were cut down at “ Kheyroodkenar Forest” in Nowshahr. From each tree, one log and two disks from ends, were cut. By a specified method, the elastic and hygrothermal deformation of disks were measured. Furthermore, all log end checks were measured before and after heat treatment and data were statistically analyzed. The results shows that hygrothermal deformation does not follow any specific pattern and varies among diametric classes of hornbeam logs. Among the diametric classes, there were little changes in the longest check relative factor and log waste percent. As the heat treatment temperature increases the mean checks length, the longest check relative factor and log waste percent increases due to the increased hygrothermal and total deformations.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27853_9c7db9a9ad001a4cc13dafe3b70b8638.pdf
Study on Poly-Aromatic Hydrocarbons (PAH) in Recycling of creosote-treated Timbers. Part 1: Solvent extraction of creosote from creosote-treated solid wood
محسن
شیخالاسلامی
author
علینقی
کریمی
author
سیداحمد
میرشکرایی
author
علیاکبر
عنایتی
author
داود
پارساپژوه
author
text
article
2009
per
Creosote-treated wood products can be considered as an important source of fiber in wood industries. Often it is necessary to extract the creosote as a byproduct to activate natural bonding in wood fibers like untreated wood or increasing the bonding capacity by adhesive substrates. In this research, woodchips obtained from Iranian beech (Fagus orientalis) railway-tie, solvent extracted by methanol, methylene chloride and petroleum ether during ten hours in boiling condition to leach out creosote from waste-treated wood. The extracted materials were measured after half an hour, one, two, four, seven and ten hours and compared with the initial quantity of creosote in the waste-treated wood. The results showed that half of all extractable creosote was leached out at the first hour of extraction period, and extending the process time over seven hours was no longer efficient. The maximum yield of creosote extraction from woodchips with mean dimensions of 22 ×18 ×4 mm was measured to be 51-67 percent by immersion method and selected solvents.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27854_e7f92c175606ffab3acedfcb38e97d2f.pdf
Determination of optimal steaming time and temperature of logs for veneer and plywood production
علیاکبر
عنایتی
author
مصطفی
شهریارپور
author
حسن
یوسفی
author
text
article
2009
per
In this study logs of alder, maple, beech, oak, ash, hornbeam and Elm logs were used.. The variable parameters were the diameter classes at two levels( 50-60 and 60-70 cm), the steaming temperature at three levels(50, 60and75?C ) for alder, maple and(60, 75, 90?C) for other wood species, the steaming time were at the diameter class of 50-60cm, 10, 15, 25 hours (for Maple , Alder), 55,65,75 hours (for Hornbeam) 45, 55, 65 hours (for other wood species) and at the diameter class 60-70 cm, 15, 25, 30 hours(for Maple , Alder)65,75,85 hours(for Hornbeam) 55, 65, 75hours(for other wood species ). Five replicates were made and in total of 630 logs were analyzed. Physical and mechanical characteristics such as moisture content (before and after the steaming), hardness, pith diameter (after peeling) and the layer quality of all the species were measured. The results showed that the optimal steaming time and temperature is different for different species for both diameter classes (50-60 cm and 60-70 cm).The optimal steaming conditions at both diameter classes (50-60 and 60-70 cm) for alder and maple species as well as for beech and elm species were similar where to those for ash, oak and hornbeam species that require unique steaming conditions.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27855_b3563f66840875378dad1c452aa55f62.pdf
Study on Poly-aromatic Hydrocarbons (PAH) in Recycling of Creosote-treated Timbers
علینقی
کریمی
author
محسن
شیخالاسلامی
author
سیداحمد
میرشکرایی
author
داود
پارساپژوه
author
علیاکبر
عنایتی
author
text
article
2009
per
Extraction of poly-aromatic hydrocarbons (PAH) from creosote-treated wood products by methanol, methylene chloride and petroleum ether was studied as a function of various times using liquid chromatography. The non-polarity of polycyclic aromatic hydrocarbons and the lack of chemical consistency between these compounds and wood ingredients are the reasons for the weak penetration of these agents into wood cell walls in which causing Main portion of accumulated compounds in the pores of the treated wood could be easily extracted by the organic solvents. Extracted creosote, after 1, 2, 4 and 7 hours solvent extraction, was analyzed by HPLC technique using reversed phase chromatography and concentration of a number of PAH were determined. The results showed that the main portion of PAH are leached out from waste treated-wood at the first hour of extraction process. Longer extraction time does not considerably enhance PAH extraction.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27856_b18516b30cf94d01089182a55deb9d9c.pdf
Evaluation of Paper Properties Obtained From Maple Juvenile Wood Through Kraft Pulping Process
رضا
نقدی
author
سیدضیاءالدین
حسینی
author
حسین
رسالتی
author
text
article
2009
per
To investigate the strength properties of handsheets made of kraft pulping process, the biometrical characteristics of maple fibers including length, width, and cell membrane thickness were measured. Average fiber length, width, and cell membrane thickness of maple in Shastcola area, Gorgan, were determined as 871.88, 22.35, and 1.99 µm, respectively. The age of Maple juvenile wood was estimated 13.5 years. After the determination and separation of juvenile wood, different pulp types were produced through kraft pulping process. Kraft cooks were treated under different conditions including time in two 120 and 180 minute levels and temperature in two 160 and 170 ?C levels with liquor to wood ratio of 5 to 1 in 3 repetitions. Pulp yields were between 45.47 and 41.26 percent. Kappa number in kraft pulps was minimum in the temperature of 170?C and cooking time of 180 minutes. Handsheets were made from pulp produced at base weight of 60 gr/m2. The strength properties of handsheets were assessed. and compared with the minimum strength of “IS” and “JIS” . The results indicate that all strength properties of kraft handsheets were higher than the minimum strength of “IS” and “JIS”. Hence, applying maple juvenile wood in pulp and paper industry using kraft process is recommended.
Iranian Journal of Natural Resources (Not Publish)
دانشکده منابع طبیعی
61
v.
1
no.
2009
https://ijnr.ut.ac.ir/article_27857_0e29389a73f8eecdd515ef801b5b7ad3.pdf