Meghdad Jourgholami; Vahid Rizvandi; Baris Majnounian Garagiz
Abstract
Assessment and management of the environmental impacts of forest harvesting operations have become increasingly critical factors in practicing commercial forestry. This study investigated soil disturbance from a forest logging system operation on an 8-hectare mixed broadleaved stand in compartment no. ...
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Assessment and management of the environmental impacts of forest harvesting operations have become increasingly critical factors in practicing commercial forestry. This study investigated soil disturbance from a forest logging system operation on an 8-hectare mixed broadleaved stand in compartment no. 309 in Gorazbon district in Kheyrud educational and research forest. The objective of this study was to assess soil disturbance from ground-based skidding system operation contribute to statistically significant changes in bulk density and penetration resistance at various depths below the soil surface and changes in bulk density and penetration resistance related to different traffic intensities. A systematic predetermined grid that was laid out prior to harvesting to measure soil disturbance, and pre-and post soil disturbance were recorded by a visual assessment. Soil compaction and penetration resistance were measured by using a double sampling method consisting of a hammer driven hand corer and a hand-held soil penetrometer. Bulk density and soil strength measurements were taken at three depths: 10, 20 and 30 cm. Detrimental compaction was recorded for the soil bulk density results. Detrimental compaction was recorded for the soil penetrometer after medium and intense machine passes. Post-harvest detrimental soil disturbance wasn’t exceeded the USFS maximum allowable area that can be detrimentally impacted. Soil resistance results demonstrated no detrimental compaction in area to the skid trail center and wheel ruts.
Hamed Eskandari Damaneh; Gholamreza Zehtabian; Hassan Khosravi; Hossein Azarnivand; Aliakbar Barati
Abstract
The present research aims to assess climate change in the Minab plain and its effect on groundwater level variability in the future period. Climate change was explored by the climatic model CanESM2 using the SDSM4.2 software package, and the effect of climate change on groundwater resources was quantitatively ...
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The present research aims to assess climate change in the Minab plain and its effect on groundwater level variability in the future period. Climate change was explored by the climatic model CanESM2 using the SDSM4.2 software package, and the effect of climate change on groundwater resources was quantitatively modeled in the GMS10.0.5 software package under the emission scenarios of RCP2.6, RCP4.5, and RCP8.5. The results for the effect of climate change in the future period in the context of these scenarios showed that temperature will increase by 1.88ºC, 2.60ºC, and 4.28ºC and precipitation will decrease by 34.19%, 42.08%, and 59.43% versus the reference year, respectively. The results for the application of the climatic scenarios using the groundwater model revealed that due to the decline of precipitation in this period, mean groundwater level balance in the future periods leading to 2019, 2024, 2029, and 2035 versus the reference year (2003-2004) will be -13.99, -19.003, -22.70, and -25.61 m/yr in RCP2.6, -13.99, -18.95, -22.75, and -24.73 m/yr in RCP4.5, and -14.23, -19.22, -22.003, and -25.46 m/yr in RCP8.5, respectively. This shows that the drawdown will be being aggravated over time. Finally, this decline of precipitation and rise in temperature due to climate change and the subsequent increase in water abstraction for different uses will result in the growing depletion of the groundwater tables in Minab. So, it is recommended to planners and authorities to adopt strategies for adaptation to new climatic conditions and water scarcity and accommodate themselves with future conditions.
Ghasem Ali Dianati Tilaki; Ali Mohammadsharifi; Seyed Jalil Alavi
Abstract
The present study was conducted in the rangeland of Glandrood watershed in the province of Mazandaran. The objective of this study was to compare between the ecological amplitude of Festuca ovina L., and Poa bulbosa L., using the function HOF along the gradient of the environmental variables. For this ...
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The present study was conducted in the rangeland of Glandrood watershed in the province of Mazandaran. The objective of this study was to compare between the ecological amplitude of Festuca ovina L., and Poa bulbosa L., using the function HOF along the gradient of the environmental variables. For this purpose 150 plots of 1m2 were established along the altitude gradient. The sampling method was randomized-systematic. In the area sampled, frequency of Festuca ovina and Poa bulbosa, altitude and slope were recorded. Soil samples were taken from 0-20 cm in each plot. In each sample, bulk density, pH, N, EC, organic matter, organic carbon, the percentage of sand, silt and clay were measured. In order to study the shape of response curve and the ecological optimum in relation to the mentioned variables, HOF function was used with binomial distribution function. The data were analyzed by R ver.3.0.2 software. The two species Festuca ovina and Poa bulbosa, mainly showed different ecological amplitude along the gradient environmental variables. The results showed that the ecological amplitude and optimum alonge altitude gradient for Festuca ovina has been recorded 2244-3037m and 3037m respectively for Poa bulbosa 2335-3037m and 2636 m respectively. Also the response curve of Poa bulbosato the altitude has unimodal and symmetric but for Festuca ovina was monotonically increasing trend. The response curve ofPoa bulbosato pH is monotonically decreasing but for Festuca ovina was unimodals symmetric.
Mohsen Armin; Sayed Alisaleh Velayatinejad; Vajihe Ghorbannia Kheybari; Fateme Taatpour; Morteza Behzadfar
Abstract
This research was conducted in two watersheds Dasht-e-Room in Boyerahmad county and Kareh in Dena county using IntErO model. After collecting basic information; the 26 input variables were extracted and calculated using topographic, pedologic, and geologic and land use maps and climatic data i. The results ...
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This research was conducted in two watersheds Dasht-e-Room in Boyerahmad county and Kareh in Dena county using IntErO model. After collecting basic information; the 26 input variables were extracted and calculated using topographic, pedologic, and geologic and land use maps and climatic data i. The results showed that the maximum outflow from the watersheds of Kareh and Dashtrom in 100 year return period are 235 and 179 cubic meters per second, respectively, In other words, the amount of runoff produced in the Kareh watershed is approximately 1.3 times the oufflow from the Dasht-e- room basin and the amount of soil erosion in Dasht-e-Room and Kare watersheds, 105162.22 and 71402.58 cubic meters per year, respectively. Considering sediment delivery ratio of 0.195 in Dasht-e-Room watershed and 0.487 in the Kareh watershed, the amount of soil eroded transferred to the outlet of the watersheds (sediment yield) is 20521.32 and 34800.46 cubic meters per year respectively. The erosion intensity coefficient in Dasht-e-Room watershed is 0.338 and as a result, based on the degree of erosion intensity of IntErO model, the erosion process intensity in this watershed is low and the dominant erosion of the region is deep. The erosion intensity coefficient in Kareh watershed is 0.403 and as a result, the erosion process intensity in this watershed is moderate and the dominant erosion of the region is superficial. The amount of sediment yield per unit area in Dasht-e-Room watershed is 133.53 and in the Kareh watershed it is 347 cubic meters per year.
Javad Daeizadeh; MAHSHID souri; Ehsan Zandi Isfahan; javad motamedi
Abstract
Total Petroleum Hydrocarbons are toxic and persistent pollutants that are considered as fundamental threat to the ecosystem. Phytoremediation, the use of plants for remediation of contaminated soils, is an effective and affordable way to reduce soil pollution. In this study, the potential phytoremediation ...
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Total Petroleum Hydrocarbons are toxic and persistent pollutants that are considered as fundamental threat to the ecosystem. Phytoremediation, the use of plants for remediation of contaminated soils, is an effective and affordable way to reduce soil pollution. In this study, the potential phytoremediation of pasture plants i.e. Agropyron intermedium and Dactylisglomerata in soil contaminated with crude oil of different concentrations (20, 30, 40 and 50 percent) was scrutinized for 120 days under greenhouse condition. At the end of the study, changes in biological factors (shoot height, shoot dry weight and root dry weight) of each species and changes in petroleum hydrocarbons of soil were measured and results were analyzed using SPSS software. The process of decay kinetics curve of petroleum percent was used to calculate the time it takes for decomposition of petroleum hydrocarbons. Results showed that three main features of biological factors of both studied species in different treatments were significantly different compared to control group. Analysis of changes in petroleum hydrocarbons indicated that Agropyronintermedium reduced 79.81 percent of oil in the treatment of 20% and reduced 58.54 percent of oil in the treatment of 50%. Therefore, it has higher phytoremediation ability in comparison with Dactylisglomerata. The results of the analysis of petroleum in soil samples, fitted with zero-order kinetic model showed that the first order kinetic model is the best model for simulating the trend of changes of Petroleum hydrocarbon of the soil
Hamide Afkhami; mohammad dastorani; farzaneh fotouhi firuzabadi
Abstract
Due to the nature of the sediment data, selection of appropriate methods for processing the data before entering them to the artificial intelligence models can enhance the reliability of simulations results. In this study, the effects of sediment data processing procedures on ANN and ANFIS models outputs ...
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Due to the nature of the sediment data, selection of appropriate methods for processing the data before entering them to the artificial intelligence models can enhance the reliability of simulations results. In this study, the effects of sediment data processing procedures on ANN and ANFIS models outputs in 7 Dez Basin stations were evaluated. Accordingly, three scenarios were considered: In the first scenario, original data was used without exerting any processing technique; in the second scenario, the data was normalized; and in the third scenario, logarithm of data were used according to logarithmic distribution governing. The simulation results showed that using data logarithm leads to higher performance and lower error, especially in stations where the best fit probability distribution is one of the log family distributions. Finally, among applied models, ANFIS showed the best performance with coefficient efficiency of 0.95 and RMSE of 5.4, MSE of 1.4 and ME of 0.42 in Biatoon gauging station and using the third scenario.
Hojatollah Jalilian; Ghobad Rostamizad; Saleh Arkhi
Abstract
The necessity of using discharge data in hydrological designs and regional programming is an unavoidable matter. Unfortunately, malfunctioning of observation instruments, natural disasters and other problems sometimes result in incomplete or missing data. Having of data related to time series is necessary ...
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The necessity of using discharge data in hydrological designs and regional programming is an unavoidable matter. Unfortunately, malfunctioning of observation instruments, natural disasters and other problems sometimes result in incomplete or missing data. Having of data related to time series is necessary for every investigation about hydrometeorology. Thus missing data should be estimated in a proper way. There are different methods for generation of missing data which estimates the data with regard to particular parameters. In this study, we have used four methods including linear regression, multiple regression, Longbein method and Thomas-Fiering method for reconstruction of hydrometric data including monthly and annual discharge, sediment and water quality data. Results showed that among various methods, in 192 cases of reconstruction of monthly average discharge of 17 stations, Longbein and multiple regression methods in 33% and 27% of the cases have provided the best results, respectively. Two-variable regression in 8 of 17 stations had the best answer and it is suitable for estimating of annual average discharge. Also results indicated that we cannot use of relation between discharge-water quality and discharge-sediment to reconstruct data using above mentioned methods in the Sefidroud basin.
M.A Zare Chahouki; A Zare Chahouki; M Zare Ernani
Volume 63, Issue 3 , December 2010, , Pages 331-340
Abstract
The objective of this research was to study the relationships between edaphic and topographic factors with distribution of plant species. For this purpose, current study was conducted in Eshtehard rangelands of Tehran province. The sampling method was randomized–systematic and in each sampling unit, ...
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The objective of this research was to study the relationships between edaphic and topographic factors with distribution of plant species. For this purpose, current study was conducted in Eshtehard rangelands of Tehran province. The sampling method was randomized–systematic and in each sampling unit, three parallel transects with 750 m length containing 45 quadrates (according to vegetation variations) were established. Quadrate size was determined for each vegetation type using the minimal area; hence suitable quadrate size for different species was determined 1*2m (2 m2). Soil samples from the beginning and end of each transect at two depths 0-30 and 30-80 cm were taken and the measured soil properties included gravel, texture, organic matter, lime, pH and electrical conductivity. To analyze the environmental data, PCA was considered. The results indicated that gravel, texture, EC and lime play the main role in the distribution of plant species.
saeid barkhori; rasol mahdavi; gholamreza zehtabian; hamid gholami
Abstract
The overuse of fossil fuels, population growth and other factors have caused evident changes in the Earth climate. In this study, HadCM3 model was used to evaluate changes in the variables of precipitation, minimum and maximum temperatures at Jiroft plain in future periods. Afterward, climatic variables ...
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The overuse of fossil fuels, population growth and other factors have caused evident changes in the Earth climate. In this study, HadCM3 model was used to evaluate changes in the variables of precipitation, minimum and maximum temperatures at Jiroft plain in future periods. Afterward, climatic variables was simulated by the LARS-WG model in the periods of 2011-2030 (horizon 2020) and 2046-2065 (horizon 2055) under three scenarios of A1B, A2 and B1. The results showed that the highest amounts of minimum and maximum temperatures will occur based on three scenarios A1B, A2 and B1 in the horizon of 2055. By comparing the average of the monthly minimum and maximum temperatures in the base period (1989-2010) and future periods (under the scenarios of A1B, A2 and B1), the average temperature will increase in the most months of the year. During the scenarios of A1B, A2 and B1, the most annual precipitation will occur in the horizon of 2020. The average amounts of monthly precipitation will increase in the months of January, August, September, October, November and December and will decrease in the other months. Comparing long-term annual precipitation shows that the lowest amount of precipitation will happen under the scenario of B1 and during the period of 2046 to 2065. However, the most precipitation will happen under the scenario of A1B and during the 2011-2030 period.
Samaneh Razavizadeh; Ali Salajegheh; Shahram Khalighi Sigaroudi; Mohammad Jafari
Abstract
Land use change is one of the main factors in the process of changing the regime of flood in watersheds. Taleghan watershed has been subjected to many land use changes over years, which probably effects on flood characteristics of Taleghan River. In present study the effects of land use change on some ...
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Land use change is one of the main factors in the process of changing the regime of flood in watersheds. Taleghan watershed has been subjected to many land use changes over years, which probably effects on flood characteristics of Taleghan River. In present study the effects of land use change on some parameters including peak flow, volume and flood base time, in part of Taleghan basin, was investigated by using Geographical Information System (GIS) and HEC-HMS model. Land use maps of 1987 and 2002 were prepared and integrated with soil hydrological groups and pasture conditions maps in GIS with the aim of providing of CN map. Then by using curve number and SCS unit hydrograph in sub basins and also Muskingum routing method, HEC-HMS model was calibrated and validated, for 10 incident rainfall - runoff views. Results of the simulation showed that due to the changes in land use (the reduction in the level of agricultural lands and increases in pasture areas), peak flow and flood volume in 2002 than in 1987 showed the average reduction of 46% and 34%, respectively. The evaluation of base time of flood showed no change in the parameter in flood hydrograph at the study period. On the whole the results showed that the trend of land use changes have the positive effect on reducing flood productions in study area.
ali dastranj; ahmad nohegar; Arash Malekian; Hamid gholami
Abstract
Abstract Vulnerability assessment and vulnerability mapping, is an important strategy to management of karst water resources. Due to the geomorphology of karst developed in karst aquifers and other natural conditions Azhvan-Bisotun area, Emissions are rapidly and widely. The aim of this study is mapping ...
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Abstract Vulnerability assessment and vulnerability mapping, is an important strategy to management of karst water resources. Due to the geomorphology of karst developed in karst aquifers and other natural conditions Azhvan-Bisotun area, Emissions are rapidly and widely. The aim of this study is mapping vulnerability Azhvan-Bisotun karst aquifer in Kermanshah province against surface contamination by using COP model. According to the aforementioned approach, the COP method considers three factors to assess the resource vulnerability: Overlying layers (O), Concentration of flow (C) and Precipitation regime (P). The results show that the vulnerability of the area between zero and 4.5, respectively, at the end of the five-class very high, high, medium, low and very low were classified. In general, the total area calculated parameters C, P and O have the most significant role in the vulnerability zone. The results demonstrate that COP is a useful method to assess the vulnerability of the test sites under consideration.
Hossein Eslami; Ali Salajagheh; Shahram Khalighi sigaroudi; hasan Ahmadi; Shamsollah Ayoubi
Abstract
Rainfall erosivity is the ability of rainfall to detach the soil particles. This study was conducted to evaluate spatial variability of rainfall erosivity indices in Khouzestan Province. The point data of indices (EI30, AIm, KE>1 and Onchev indices) in 74 stations were used to generate spatial erosivity ...
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Rainfall erosivity is the ability of rainfall to detach the soil particles. This study was conducted to evaluate spatial variability of rainfall erosivity indices in Khouzestan Province. The point data of indices (EI30, AIm, KE>1 and Onchev indices) in 74 stations were used to generate spatial erosivity maps through deterministic and geostatistical interpolation methods (Radial Basis Functions, Inverse Distance Weighted, Kriging and Cokriging). Results indicate that cokriging have least error and most correlation with determining coefficient of 0.89, 0.89, 0.48 and 0.49 for EI30, AIm, KE>1 and Onchev indices. Based on the correlation relationships between the basins specific sediment yield (in basins dominating the sedimentation stations) and mean indices of EI30, AIm, KE>1 and Onchev, EI30 index with correlation coefficient of 0.98 (P<0.01) is selected as the appropriate rainfall erosivity index. Based on the prepared map on the basis of Cokriging method with secondary variable of maximum mean monthly rainfall, the east and northeastern regions presented the highest values of EI30 index, while the southern and western regions showed the lowest values of EI30 index. The annual rainfall erosivity (EI30) ranged from 404 to 3064 Mj.mm.ha-1.h-1.y-1.
M. Jankju; F. Noedoost
Abstract
Ecological studies on range plants enhance our knowledge on the rangeland ecosystems which are useful for their planning and management. By doing field and laboratory experiments during 2008-2009, ecological conditions were studied in the main habitats of Z. atriplicoides in the rural and winter ...
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Ecological studies on range plants enhance our knowledge on the rangeland ecosystems which are useful for their planning and management. By doing field and laboratory experiments during 2008-2009, ecological conditions were studied in the main habitats of Z. atriplicoides in the rural and winter rangelands of Northern Khorasan province (NKP). Forage quality was also studied at different phonological stages. According to the results, Z. atriplicoides grows in the habitats with mean annual rainfall ranging from 260-380 mm, temperature 8-16 ºC, and altitude 680-1200 meter a.s.l. Topography was as plains and rolling lands, with geologic formations being conglomerate, marl, shale and sandstone. Soil texture was silty loam, weak alkaline, and poor in phosphorus and nitrogen. Vegetative growth and flowering stages were simultaneously occurred at early April till early June, but seed ripening and shedding happened at late June-mid August. Toward the end of growing season, ADF and NDF increased while crude protein decreased, which led to a gradual decrease in forage quality. Ability for growing in different habitats – from cold dry to warm humid- and having protein content and metabolic energy higher than the critical level for rangeland livestock are the relative advantages, whereas significant leaf reduction in response to drought and heat stresses, inability for growing in saline lands and low palatability and preference values are the major disadvantage for Z. atriplicoides in the rangeland of Iran. The most suitable time for livestock grazing and seed collection of Z. atriplicoides in the NKP are May-June and July, respectively.
Shahram Khalighi Sigarodi; Mohammad Rostami Khalaj; Mohammad Mahdavi; Ali Salajegheh
Abstract
Large impervious surfaces and man-made waterways are the characteristic of urban area. Increasing urbanization and rapid growth of cities in recent decades towards the upstream watershed, has been severely affected on rainfall-runoff processes in urban area. Therefore, to computer models in order to ...
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Large impervious surfaces and man-made waterways are the characteristic of urban area. Increasing urbanization and rapid growth of cities in recent decades towards the upstream watershed, has been severely affected on rainfall-runoff processes in urban area. Therefore, to computer models in order to illustrate these processes the proper design or assessment of urban drainage systems has special attention. The purpose of this study is simulation and validation the volume of runoff and calibrated SWMM model in small urban area. Required parameters of the model using land use maps, DEM of study area, and field inspection were calculated. For calibration and validation process model, corresponding to three event rainfall runoff measured at the output of the basin and was compared with runoff simulated by the model. The results showed there is good agreement between simulated and observed runoff discharge and depth. There is a little difference between simulated and observed for runoff rate but this difference is more than acceptable value (NS>0.5). NS value for the first, second and third event is the, 0.69, 0.85 and 0.52 respectively. This performance represents that the SWMM model is effective in the study area and this model can be used for in appropriate designs, and evaluate network systems in urban drainage.
Ghodrat Alah Heydari; Hamid Reza Saeidi Goraghani
Abstract
Assessment of diversity and species richness in the understanding of ecosystem functions, protect and preserve genetic resources, evaluation and control of environmental change and the success or failure will help natural resource management programs. Arbitrary banning livestock grazing program and one ...
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Assessment of diversity and species richness in the understanding of ecosystem functions, protect and preserve genetic resources, evaluation and control of environmental change and the success or failure will help natural resource management programs. Arbitrary banning livestock grazing program and one of the most common and perhaps the most degraded pastures and reduced the diversity and species richness. Given the importance of livestock grazing on vegetation change in the qualitative and quantitative research to study the effect of the three grazed sites Reference area, Key area and Critical area on the diversity and richness species with different plant forms in southern slopes of Damavand mountain Summer Rangeland. Each unit, sampling was conducted along three transects 150 meters. Along each transect 15 plots with a scale and located within 10 meters of each plot type and number of plant species and the percentage and number of notes they were based. Numerical indicators to assess the diversity and richness of species diversity indices and using software Past Simpson, Shannon - Weiner index was calculated enrichment Menhnyk and Margalof. Data analyses was performed in SPSS18 software and compare the various indices of diversity and richness between regions with different intensities grazing Duncan's multiple range tests was performed.
Masoomeh Abbasi Khalaki; Mohammad Jafary; Ali Tavili; mehdi moameri
Abstract
To find the effect of Atriplex canescens on soil chemical properties, two adjacent areas, each with and area of 1 ha, were selected in Hossein Abad Hapeshloo Shahryar. In one area it was planted Atriplex canescens in 2003 while the later one without Atriplex canescens was considered as control area. ...
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To find the effect of Atriplex canescens on soil chemical properties, two adjacent areas, each with and area of 1 ha, were selected in Hossein Abad Hapeshloo Shahryar. In one area it was planted Atriplex canescens in 2003 while the later one without Atriplex canescens was considered as control area. To sample soil, random- systematic method was used along 3 transects with a length of 100 m. In planting site transects were established perpendicularly on furrows were while in control site they were established parallel. Along each transect, 3 profiles were dug in initiate, medium and end points of each transect under shrubs and samples were taken from two depths (0- 30 cm and > 30 cm). Then, soil characteristics including texture, pH, Ec, Lime (CaCo3), ESP, organic mater (OM) and elements of Na, K, Ca, Mg and N were measured in laboratory. The results of this study showed that pH and Mg were significantly reduced in planting site compared of control. In addition, Na, Mg, Lime and Ca were significantly increased in planting site in comparison to control.
Leila Zandi; Reza Erfanzadeh; Hamid Joneidi-Jafari
Abstract
This study aimed to determine the effect of land use changes from rangeland to horti-agricultural lands on the most important qualitative characteristics of soil such as total soil carbon and particulate organic matter, in Salavatabad region, Sanandaj. In the present study, one rangeland, two cultivated ...
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This study aimed to determine the effect of land use changes from rangeland to horti-agricultural lands on the most important qualitative characteristics of soil such as total soil carbon and particulate organic matter, in Salavatabad region, Sanandaj. In the present study, one rangeland, two cultivated pea lands, two cultivated wheat lands and two gardens were selected in growth season in the end of spring, 2014. Forty two soil samples were taken randomly and systematically from the study region. Then, soil micro- and macro aggregates were separated using 0.25 mm and 2 mm sieves. Total soil carbon and particulate organic matter of soil samples were measured in the laboratory. The results showed that land use changes from rangeland to horti-agriculture significantly decreased total carbon and particulate organic matter in micro-aggregates. While total carbon and particulate organic matter in macro-aggregates was not changed by land use changes from rangeland to horticultural land. We suggested that if rangeland will be converted into agricultural land, horticultural land is the best for land use changes.
Peyman Amin; Mohammad raza ekhtesasi
Abstract
In the last two decades, the land subsidence, especially in fine-grain plains, cracks emerged in YazdArdakan plain, it is called soil crack. One of the important assumptions in relation to emergence of this phenomenon, withdrawal of water from underground aquifers and decrease the hydro dynamic pressure ...
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In the last two decades, the land subsidence, especially in fine-grain plains, cracks emerged in YazdArdakan plain, it is called soil crack. One of the important assumptions in relation to emergence of this phenomenon, withdrawal of water from underground aquifers and decrease the hydro dynamic pressure and dense sediment. This phenomenon happens in fine-grained sediment and caused damage to building structures, roads, masts. the case study is clay plain lands without desert pavement in East of Yazd. For sampling, 12 samples were taken from three points were selected which one of them in the vicinity of crack and two other points were within 100 meters of side of crack in each point, four profiles were drilled from zero to 120 cm depth. On samples some experiments such as the indicators of changing bulk modulus were measured in different moistures in galvanized metal cube boxes with dimensions of 20 cm, some experiments were done such as Atterberg limit tests, divergence and failure limit. The results showed that liquid limit of the crack’s territory is near to 29 percent and moisture limit of crack is close to 4 percent. the most vertical and horizontal shrinkage in crack soils were 11 and 6 percent respectively. In other words, in per meter depth of sediment, 11 cm subsidence in areas with moisture less than 4 percent is not unexpected. With regard to the specific circumstances of the area, is proposed structural projects, gas lines, water pipes and bridges is not done in these areas.
reza hamed moghadam salari; Abbas Ali Ghezelsofloo; milad Iranshahy
Abstract
The purpose of this study is to investigate the potential of some plants for Phytoremediation of soil contaminated with lead, zinc, cadmium and copper. To do this, four plant species of Achillea millefolium, Agropyron elongatum, Bouteloua dactyloides and Artemisia sieberi were cultivated and plant samples ...
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The purpose of this study is to investigate the potential of some plants for Phytoremediation of soil contaminated with lead, zinc, cadmium and copper. To do this, four plant species of Achillea millefolium, Agropyron elongatum, Bouteloua dactyloides and Artemisia sieberi were cultivated and plant samples were irrigated with refinery wastewater. The results showed that in terms of plants, Bouteloua dactyloides, Artemisia sieberi and Achillea millefolium are good transfer of metals to their aerial parts which is suitable for plant extraction (the most important technique of Phytoremediation). Agropyron elongatum mostly accumulates copper and lead metals in the root. This is a proper feature of phytostabilization. Also the capability of these four plants species for Phytoremediation is as follows: Bouteloua dactyloides> of Achillea millefolium> Artemisia sieberi = Agropyron elongatum. Bouteloua dactyloides is proper for Phytoremediation of all heavy metals. For Bouteloua dactyloides, plant transfer factor (TF) in metals: zinc, copper, lead and cadmium is 1.17 and 1.9, 1.12 and 1.41, respectively, and bio concentration factor (BCF) for that in these metals are 1.77 and 1.22, 0.95 and 1.37, respectively. Since Bouteloua dactyloides has high tolerance to drought and high temperatures and is also suitable for lawn making, it is suggested that this type of species is used for Phytoremediation of soils contaminated with heavy metals in polluted areas as well as lawn making so that in addition to soil cleansing from heavy metals and being proper with native climates in many parts of Iran and having low irrigation requirements.
Jahanbakhsh Teymuri Majnabadi; Parvin Ramak; vahid karimian
Abstract
The present research aims to investigate the effect of temporal succession on the biological operation of planting Haloxylon persicum on the functional characteristics of rangelands in Khaf County. Three rangelands in which H. persicum planting operations were performed at different ages of 10, 20 and ...
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The present research aims to investigate the effect of temporal succession on the biological operation of planting Haloxylon persicum on the functional characteristics of rangelands in Khaf County. Three rangelands in which H. persicum planting operations were performed at different ages of 10, 20 and 30 years, and the control area were selected. Sampling along 3 transects of 100 meters, located 10 meters apart, were measured and analyzed for each area and a total of 12 transects. Using the function analysis method, three characteristics of stability, infiltration and nutrient cycle were measured using 11 soil surface indexes. The results showed that there is a significant difference between the succession times for biological restoration from the functional point of view (P <0.01). The highest degree of stability and infiltration is related to the H. persicum range of 30 years old and the smallest of it belongs to the control area. There is a significant difference between the biological regeneration time of H. persicum planting and the control area in terms of nutrient cycle index (P <0.01). The highest levels of nutrients are related to the 30-year-old H. persicum, 20-year-old H. persicum, 10-year-old H. persicum, and the control area. In general, the results of the present study indicate positive biologic effects on the characteristics of the rangeland function, and these positive effects are evident in increasing the functional indexes over time.
Mohammad Reza Ekhtesasi; Fateme Hazirei
Abstract
Mulching is one of the methods of sand movement control to prepare condition for permanent fixation. Oil mulches have been used in Iran. Because of high cost and negative environmental impacts of oil mulches, changes in mulches type and mulching methods is vital. Therefore, for the first time in Iran, ...
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Mulching is one of the methods of sand movement control to prepare condition for permanent fixation. Oil mulches have been used in Iran. Because of high cost and negative environmental impacts of oil mulches, changes in mulches type and mulching methods is vital. Therefore, for the first time in Iran, different combinations of cement and lime were examined as stabilizer. Sandy soil from the Yazd-Ardakan plain is used as bed treatment and Portland cement were used as the mulch in this research. The treatments were prepared using different ratios of the above mentioned materials. One liter of water was added to each mulch combinations and were sprinkled on the plot of 100 cm (length) × 30 cm (width) ×4 cm (height) sands. A completely randomized design is used as research plan with three repeating. Physical parameters, such as thickness, compressive strength, which are created by mulches, and wind erodibility of the treatments were measured. The measured data were analyzed using SPSS statistical software. Results show that by increasing the amount of cement, soil crust resistance increases. The combination mulch of cement 400 gr, sand 800 gr, and lime 10 gr is selected as the best treatment, because it can be prepare optimum physical conditions for sand dune fixation. In addition, the cost of field cement mulching estimated 30% lower than oil mulching.
asgar hosseinzadeh; Ghodratolah Heidari; Hosein Barani; Hasan Zali; Ehsan Zandi Esfahan
Abstract
Nomadic migration has been a way of living in Iran from ancient times. Although this way of life has changed in different periods, the intensity of these changes has an origin in social, political and security issues in addition to livestock and rangelands. The population of the study area is 70 and ...
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Nomadic migration has been a way of living in Iran from ancient times. Although this way of life has changed in different periods, the intensity of these changes has an origin in social, political and security issues in addition to livestock and rangelands. The population of the study area is 70 and a number of 58 people were selected using Cochran formula. In the present study, questionnaires were used and data collection was performed using interview. To measure social integration, five factors were used which were included in the questionnaire including customary rights, within group-trust, tribal and local trust, confidence and awareness of the projects provided by the government, and legal protection. Cronbach's Alpha coefficient for the social integration was calculated to be 0.88 and the correlation between social integration and the factors including beneficiaries’ literacy, the history of exploitation, annual income from animal husbandry and the number of livestock was analyzed through Pearson test using SPSS software. It was revealed that there was a direct and significant relationship between social integration and annual revenue of animal husbandry and the history of exploitation while social integration had a significant inverse relationship with the number of livestock, indicating a close relationship between the nomadic community and their social integration. Nomadic community needs should be provided in the form of nomad's social integration. Finally, the tribal system of the country should be viewed as a cultural heritage and it should not be measured by modern development indicators.
Shahab oddin Zarezade Mehrizi; Asadollah Khoorani; Javad Bazrafshan; Ommolbanin Bazrafshan
Abstract
Gamasiab River is one of the five main branches of the Karkheh River and plays a basic role in preserving the life and ecosystem of the region. The first step in the adoption of proper and sustainable methods for managing the water resources of the Gamasiyab river is to gain continuous knowledge of the ...
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Gamasiab River is one of the five main branches of the Karkheh River and plays a basic role in preserving the life and ecosystem of the region. The first step in the adoption of proper and sustainable methods for managing the water resources of the Gamasiyab river is to gain continuous knowledge of the quantitative and qualitative status of the water as well as its variations. The use of hydrological models is common to simulate quantitative and qualitative processes associated with the water cycle. One of the models that is widely used in the international level is the SWAT model. In this research, we evaluated the efficiency of SWAT model in simulation of Gamasiyab river flow. For running this model requires a DEM, soil map, land use map and slope classification. Initially, discharge data in daily step at Polchehr Hydrometric Station was calibration (1977-1995 AD) and then validation (1996-2005 AD) by using precipitation data of two synoptic stations and three weather stations and minimum and maximum temperature of two synoptic stations. Statistical coefficients including Nash-Sutcliff coefficient, R2, P-factor and R-factor for calibration period were 0.71, 0.73, 0.79, 1.36 respectively and for validation period were 0.57, 0.61, 0.71 and 1.34 respectively. These results indicate that the SWAT model has the ability to simulate the Gamasiyab River discharge and researchers can use this model to apply management scenarios in short time and low cost for better decision making.
ghobad rostamizad; ali salageghe; ali akbar nazari samani; jamal ghodoosi
Abstract
One of the types of water erosion and land degradation which causes imbalance, is the gully erosion phenomenon. Land degradation, a broken ecological balance of the land and landscape and risk of falling at biological resources in these areas, the study of the gully, is inevitable and necessary especially ...
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One of the types of water erosion and land degradation which causes imbalance, is the gully erosion phenomenon. Land degradation, a broken ecological balance of the land and landscape and risk of falling at biological resources in these areas, the study of the gully, is inevitable and necessary especially in the Darrehshahr Township. In this regard, Gully 36 number were selected in Darrehshahr area in the ilam province. To this end, were identified environmental factors, Physical - Chemical Soil properties, cover and hydrological properties of gullies tested using aerial photography, the digital maps and field operations. To determine the extent effect these factors on each of the gully geometry characteristics using fuzzy logic and information theory, the membership function and the weights of the membership function of each of the factors was calculated. Then relationship between the independent and dependent variables was obtained by using multivariate regression. Results of statistical analysis using multiple regression (stepwise method) revealed that length of gully with upstream area of the gully, top and bottom width and cross section of the Gully with basin elongation, deep gully with basin elongation and slope curvature, high of head Gully with local slope of the gully and steep walls of gully with percentage cover have a significant relationship. So could be concluded that characteristics of geometry gully in the study area would be a function of the upstream, basin elongation, curvature slope, Local slope of the gully head and the percentage of canopy cover catchment area of gully.
sadegh hoseinniaee; Hossein Azarnivand; Mohammad Jafari; Mohammad Ali Zare Chahouki
Abstract
Haloxylon is one of the resistant plants in desert areas, which has always been considered by researchers and practitioners since controlling sandy soils as one of the solutions to erosion and sand fixation by biological methods. In this study was conducted in forest plantations eshtehard, Bases of haloxylon ...
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Haloxylon is one of the resistant plants in desert areas, which has always been considered by researchers and practitioners since controlling sandy soils as one of the solutions to erosion and sand fixation by biological methods. In this study was conducted in forest plantations eshtehard, Bases of haloxylon thate wilting and drying effects are visible, was chosen and pruning them. This factorial experiment based on completely randomized design with four treatments, pruning time (September, October, December, February) and four sub-plots pruning height (Complete pruning, 25 cm, 50 and 75 cm) were implemented. Before applying pruning, for homogeneous and the same size the bases, Variable height, canopy cove diameter and crown diameter was measured on every base. The end of July condition bases was investigated in terms of Tillering and not tillering. Results showed that pruning stimulates been tillering. Because 97.5 percentage of bases was tillering. Pruning in January from height of 75 cm with 100 tiller hade the greatest number tiller. The lowest tiller regarding of November with 5 tiller. There is no significant difference between treatments in term of tiller diameter, but in general thickest tiller was for pruning in January. Therefore, it can be said that pruning is about 75 centimeters in December as the best pruning time and heigh.
