Masoomeh Abbasi Khalaki; Ardavan Ghorbani; Sahar Samadi Khanghah
Abstract
Seed priming is a technique by which the seeds of the conditions before getting on their bed and ecological environment in terms of physiological and biochemical readiness to receive germination. Experiment was conducted using a completely randomized design in summer 2015 in rangeland laboratory– ...
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Seed priming is a technique by which the seeds of the conditions before getting on their bed and ecological environment in terms of physiological and biochemical readiness to receive germination. Experiment was conducted using a completely randomized design in summer 2015 in rangeland laboratory– University of Mohaghegh Ardebili. Treatments include: osmopriming (primed with KNO3 with the Concentration of 0.3 and 0.2 %), hormopriming (primed with GA3 with the concentration of 500 and 1000 ppm) and control (distilled water). Drought stress was applied by using solution of PEG-6000 with three levels of 0, -6 and -12 bar. Analysis of variance showed that the osmopriming and hormopriming treatments and levels of drought stress had significant difference (p<0.01) on germination and early seedling growth of F. ovina in germination percentage, germination rate, root and shoot length, vigor index, allometric coefficient and mean germination time. In general, osmopriming had more desirable performance compared with hormopriming and control. Except allometric coefficient in other Indicators, NO3 0.2 % in drought 0, has had the most impact on germination and early growth of these species.
Salman Zare; Mohammad Jafari; Hassan Ahmadi; Hasan Rouhipour; Reza Khalil Arjomandi
Abstract
In this regard, the present study aimed to evaluate the performance of some of the non-oil mulch to stabilize sand dunes in the Kashan's Rig-boland desert. monthly surveys are conducted in the desert areas. To evaluate the effect of mulch on stabilizing the sand dunes, the effect stabilization index ...
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In this regard, the present study aimed to evaluate the performance of some of the non-oil mulch to stabilize sand dunes in the Kashan's Rig-boland desert. monthly surveys are conducted in the desert areas. To evaluate the effect of mulch on stabilizing the sand dunes, the effect stabilization index was used. The results indicate there is a significant difference between different mulch. The comparison test showed that the highest coefficient effect of stabilization with significant effect done on the biological mulch. After that, however, three other mulches including resins, inorganic and polymer are, respectively had the most significant effectiveness. Although there was not significant difference between these three types of mulches. Biopolymer Mulch with the lowest coefficient of stabilization effect showed significantly different from other mulches. Mulching in the hills with biological mulch, due to tightly crust formation against erosion, removal of sand and dunes almost stopped and hill completely has been stabilized. In this study, used mulches were initially very resistant and feasting the sands dune surface such as resistance crusts which were loss against any tensile and compressive force before mulching practices. . Therefore, different mulches treatments according to their durability and nature of structural have different effectiveness in reducing wind erosion effect. Among the studied mulches, just biological mulch and has usability and is capable for executive pilots.
Seyed Masoud Soleimanpour; Amin SalehpourJam; Ali Akbar Noroozi; Naser Khalili
Abstract
Implementation of watershed management projects without the participation of people has not been very successful. Therefore, prioritizing indices and sub-indicators affecting their poor participation is an important step in managing of watersheds and it can lead to taking measures to eliminate barriers ...
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Implementation of watershed management projects without the participation of people has not been very successful. Therefore, prioritizing indices and sub-indicators affecting their poor participation is an important step in managing of watersheds and it can lead to taking measures to eliminate barriers to participation and maximum participation of stakeholder in planning. Therefore, in this research the priority of investigation of stakeholders in prioritizing factors affecting their poor participation in watershed management projects in Morad Abad watershed in Meymand, west of Fars province so after completing 72 questionnaires from the head of the household using T test and Friedman nonparametric test were done. The results showed that from the views of stakeholder, the indicators such as "economic", "educational-extensional", "design-executive" and "social" were the maximum and minimum priorities of poor participation of stakeholders in watershed projects in this watershed. Also, the most important sub-indicators on poor participation of stakeholders in watershed projects in this watershed are "low income residents of the watershed," "lack of local power in implementing projects (job creation)", "ignoring income for stakeholders as a direct incentive to implement of watershed management projects ", and" low level of literacy and awareness". Accordingly, the range of average ratings varies from 6.93 to 10.25, so that the sub-indicator "low income residents of the basin" with an average rating of 10.25 has the highest relative priority and "late watershed project efficiency" with an average of 6.93 had the least relative priority in poor participation of stakeholders in watershed projects in this watershed.
A. Fathzadeh; M. Mahdavi; R.C. Bales; A. A. Abkar; Askari Shirazi
Volume 62, Issue 1 , June 2009
Abstract
In highland watersheds, runoff generated by snow melting plays an important role in stream water supply. SRM (Snowmelt Runoff Model) is a hydrologic model which simulates and predicts daily flow in mountain watersheds dominated by snow melting process. The SRM is based on the degree-day procedure which, ...
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In highland watersheds, runoff generated by snow melting plays an important role in stream water supply. SRM (Snowmelt Runoff Model) is a hydrologic model which simulates and predicts daily flow in mountain watersheds dominated by snow melting process. The SRM is based on the degree-day procedure which, is a widely used method but does not consider physical factors. In the current research, the factor of radiation was added to the degree-day model to develop a simple energy balance equation. Daily average radiation was calculated by albedo, shortwave and longwave radiation, daily maximum and minimum temperature and relative humidity. The snow covered area (SCA) was obtained from daily MODIS images. The developed model was applied to the stream flow data of Karaj Basin located in northern Iran and the results revealed that the coefficient of determination of the observed and estimated data was 0.677 while the differences between estimated and observed volume of runoff was -5.58%. Therefore, the radiation based of SRM increased the coefficient of determination of estimated and simulated discharge about 9.3%.
Zohreh Alijani; Fereydoun Sarmadian; Seyed Rouhollah Mousavi
Abstract
Today, extensive improvements in fields of soil mapping have increased the purity and accuracy ofsoil maps. Usual mapping methods moreover depend on skills and experience of surveyor inidentifying and delineating the boundaries, also need the high cost and time consuming that face thesoil mapping with ...
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Today, extensive improvements in fields of soil mapping have increased the purity and accuracy ofsoil maps. Usual mapping methods moreover depend on skills and experience of surveyor inidentifying and delineating the boundaries, also need the high cost and time consuming that face thesoil mapping with restrictions. In this study, aerial photographs with 1/40000 scale were used in orderto preparation of the initial interpretive map and determination of sample region. Then, the numbers of24 profiles were described in determined units. After sampling and necessary physicochemical tests,soil map of Kouhin (Qazvin) was prepared and accuracy of map was calculated in two methods in alllevels of taxonomy. The first method was formation of error matrix and calculation of kappa index andsecond was comparison the geopedological map with described profiles and evaluation the results ofeach. Then a part of a geopedological map that had overlapping with map prepared by usual methodwas compared with this map. Results showed the overall accuracy of 67.5, 90.5 and 98.5 percent inlevels of family- subgroup and great group- suborder and order of soil for geopedological methodrespectively.
Sakine Saedi; Ali Akbar Mehrabi; Ali Tavili; Seideh Heydari
Abstract
Development impact assessment is key to achieving a comprehensive planning aligned with landsustainability. In human and natural systems studies, changes can be simultaneously examined intwo different systems. The purpose of this paper is to understand the effects of dam construction onland prices and ...
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Development impact assessment is key to achieving a comprehensive planning aligned with landsustainability. In human and natural systems studies, changes can be simultaneously examined intwo different systems. The purpose of this paper is to understand the effects of dam construction onland prices and land use change in nearby villages of Taleghan Dam. Descriptive - qualitativestatistics were used in this research and library and field methods were used for collecting therequired information. In order to specify the land value of the four villages of the area of the damfor four decaes, based on the prices of the year 1390, the land vlue formula was applied. Also, TMsatellite images of 1379 and 1386 were used for pinpointing land use changes. The results of thesestudies indicate that dam construction in 1380s and 1390s increased land price significantly andchanges in land price affected upon land use changes in nearby villages of dam and the price of landin the Zydasht village overlooking the dam increased dramatically.Based on the results of thisresearch, it can be stated that the dynamics of the land use of the area was affected by land pricethat for achieving sustainability in the watershed, an effective law must be enforced to prevent landdegradation and control land prices.
farshad soleimani sardou; Ali Salagegh; Mahdie Sanjari; Ali Azare
Abstract
Nowadays, designing hydraulic structures for flood damage mitigation has a significant importance in water engineering. One of the necessary parameters for the design of flood control measures is the probable maximum 24-hour precipitation in a 1000-year return period. This research was done using Jiroft ...
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Nowadays, designing hydraulic structures for flood damage mitigation has a significant importance in water engineering. One of the necessary parameters for the design of flood control measures is the probable maximum 24-hour precipitation in a 1000-year return period. This research was done using Jiroft Halilrud watershed data to evaluate Hershfild methods. Firstly, the maximum annual precipitation data series were used to do a frequency analysis using linear moments method to determine the maximum precipitation in 1000-year return period. Then this parameter was determined using the Hershfild method. The results showed a good agreement between the two methods according to correlation coefficient (0.87). The results of this research can be used for the monitoring system of the region
ALIREZA Arabameri; khalil rezaei; mojtaba yamani
Abstract
Gully erosion is one of the erosive processes that mostly change the shape of the earth surface and has severe environmental and economic damages. The aim of this research is modeling between geo-environmental parameters effective in gully erosion and gully occurrence in the study area and gully erosion ...
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Gully erosion is one of the erosive processes that mostly change the shape of the earth surface and has severe environmental and economic damages. The aim of this research is modeling between geo-environmental parameters effective in gully erosion and gully occurrence in the study area and gully erosion susceptibility mapping using evidential belief function (EBF) data driven model in toroud watershed that has high susceptibility to gully erosion. At first, a gully erosion inventory map is prepared, using extensive field surveys and 80 gullies which have been identified, 70 percentage (56 gully location) randomly selected to modeling, while the remaining 30 percentage (24 gully location) are used to validation. In modeling, if there was high correlation among parameters, reduce accuracy of model, thus has done multi-collinearity test among independent variables. Tolerance and the variance inflation factor (VIF) are two important indexes for multi-collinearity diagnosis. Finally 15 parameters including geomorphological, geological, environmental and hydrological are selected for modeling. In evidential belief function model four relationships were calculated: belief (Bel), disbelief (Dis), uncertainty (Unc), and plausibility (Pls) and belief function are used for gully erosion susceptibility mapping. Area under the curve are used for model validation. According to results, EBF model with prediction rate (1) and success rate (0.959) had excellent accuracy and capability in identification of prone areas to gully erosion in study area. The results indicates that 21.79 percentage (90.84 km2) in study area located in high and very high susceptibility class.
Ghasem Ali Dianati Tilaki; Aliyeh Keshavarz; Bahram Amiri; Ehsan Sadati
Abstract
Effect of salt stress on the stomata variations was studied in Hedysarumcoronarium L. and HedysarumcriniferumBoiss., using optical microscope. The experimental design was a two factorial (species treatments and salt concentrations including 0, 100, 200, 250 mMNaCl) which arranged in a completely randomized ...
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Effect of salt stress on the stomata variations was studied in Hedysarumcoronarium L. and HedysarumcriniferumBoiss., using optical microscope. The experimental design was a two factorial (species treatments and salt concentrations including 0, 100, 200, 250 mMNaCl) which arranged in a completely randomized design with four replicates and 50 seeds per replicate. Seeds were grown in plastic pots with sterile sand. All pots were irrigated by distilled water until germination stage. Then the pots were irrigated uniformly every other day with modified Hoagland’s nutrient solution during 40 days and finally stomata traits were measured. The data was analyzed using SPSS software. The difference between the means was compared using Duncan test (P<0.05). Results showed that the lowest amount of the stomata length, stomata width and area of stomata were observed at 300 Mm salinity stress. Length and width of stomata were reduced by increasing salinity stress. The length stomata decreased 22.33 and 23.76 (μm) for H. coronarium and H. criniferum respectively, while width stomata decreased by 17.13 and 18.62 (μm) respectively. The area of stomata decreased 397.11 and 442.83 (μm²) for H. coronarium and H. criniferum respectively. Salinity stress had positive effect on stomata density (mm²). The highest density of stomata was found in H. criniferumin 250 and 300 mM salinity levels.
Hadi Eskandari Damaneh; Hamid Gholami; Rasool Mahdavi; Asad Khoorani; Junran Li
Abstract
In this study, water use efficiency index (WUE) was used to assessing the effect of drought on the carbon and water cycle. To calculate this index, we used the gross primary product (GPP) and evapotranspiration (ET) products obtained from the MODIS sensor, and the trend of their changes and reaction ...
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In this study, water use efficiency index (WUE) was used to assessing the effect of drought on the carbon and water cycle. To calculate this index, we used the gross primary product (GPP) and evapotranspiration (ET) products obtained from the MODIS sensor, and the trend of their changes and reaction of this index to drought were calculated for the period 2017-2001 in Fars province. Finally, we assessed the land degradation and desertification in different land uses for study area. The results showed that the indices of evapotranspiration, GPP, water use efficiency, and drought increased by 75.25%, 29.9%, 78.51%, and 67.23%, respectively. The effects of drought on evapotranspiration in agricultural lands and grasslands showed more than 67% positive relationship and also, in these land uses, we observed a significant positive relationship (33.4% and 12.5% for the agricultural lands and grassland, respectively). However, in shrubs lands, and savannas, it is more than 66.6% and 87.5%. The effect of drought on water use efficiency in grassland showed that more than 87% of these areas have a positive relationship. The effectiveness of water use efficiency in plants shows a positive relationship in 40.9% in this area, of which only 0.9% has a significant positive relationship. The negative relationship of this land use is about 59.1% of it. Of this negative amount, only 1.6% of the area had a significant negative relationship. The study of this relationship in the use of savannas shows 75% of this area, which includes 1.5 square kilometers.
hassan Miladfar; hossen Barani; ramtin Julaie; parviz Riyazifar
Volume 63, Issue 1 , June 2010, , Pages 105-14
Abstract
The establishment of rational balance between number of users and productivity capacity of rangelands and suitable number of the folk in the ranch units is one of the necessities of the sustainable management of rangelands. Also growth and efficiency of the productive factor would lead to the economical ...
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The establishment of rational balance between number of users and productivity capacity of rangelands and suitable number of the folk in the ranch units is one of the necessities of the sustainable management of rangelands. Also growth and efficiency of the productive factor would lead to the economical benefit maximum .This study was done in order to evaluate the optimal ranch size basis on the social and economical relative sustainability in the rangelands of Urmiya. The statistical information were derived from 203 questionnaire collected from 34 rangeland ranch units in the study area at the year of 2007-2008. Then the costs, incomes and grazing capacity were evaluated in each unit. The suitable number of folk and optimal ranch size were determined based on some criteria such as Total Efficiency Index. Productivity factors and annual costs of family were analyzed using Eviews economic software. The results showed that ranch size per a rancher is not optimal and each productivity unit has used from the rangeland less than optimal limit. At present, utilizable rangeland average per a user is 71 ha. Also the suitable minimum size of folk and rangeland per a family including 5 members is 550 and 350 ha, respectively. So it is able to supply the annual costs of family. Also economically suitable folk number and optimal ranch size were determined 667 and 297 ha, respectively. Therefore we can totally conclude that the folk size of 300 to 350 is a suitable size, either with respect to efficiency of production factors livelihood or preparing of the livelihood per a family unit, which completely depends on the ranching in the region.
Asghar Rahmani; Fereydoon Sarmadian; Sayed Roholla Mousavi; Seyyed Erfan Khamoshi
Abstract
Conventional soil mapping is related to High density sampling, affected by scale and expert knowledge So using of new data mining methods in digital soil properties mapping was the main aim of this study for resolving conventional soil survey problems. In this research, 62 surface soil samples based ...
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Conventional soil mapping is related to High density sampling, affected by scale and expert knowledge So using of new data mining methods in digital soil properties mapping was the main aim of this study for resolving conventional soil survey problems. In this research, 62 surface soil samples based on regular grid and expert knowledge opinion were selected after that soil organic carbon(SOC), clay content and CaCO3 were determined in some part of Dryland Kuhin region with area of 372 ha. Data sets were divided to two 80%(calibration) and 20%(validation), respectively. From digital elevation model with 10-meter spatial resolution were derived 19 geomorphometric attribute in SAGA GIS software. Three geomorphometric covariate included TPI, TRI, DEM and landform map unit were chosen PCA and expert knowledge. RStudio and SoLIM Solution software were used for random forest (RF) and fuzzy logic modelling, respectively. The RF modelling results show that for SOC, clay and CaCO3 based on determination coefficient (R2) had 0.63,0.75,0.63 and RMSE 0.17,7.5,5.77 percentage and for SoLIM method revealed that R2 0.47,0.42,0.42 and RMSE 0.2,8.08,4.68 percentage, respectively. Generally, the RF model with creating nonlinear relationship among soil properties and environmental covariate can predicted digital map with appropriate precision for management and sustainable land utilization
Alireza Sepahvand; Hasan Ahmadi; Aliakbar Nazari Samani; Sebastiano Trevisani
Abstract
The geomorphometric indexes have been widely used for separation of surface landform features in the geomorphology science over the past decades. In this study, Multilayer Perceptron Neural Network (MPNN) was used to provide karstic landform classification. To that regard, initially, geomorphometric ...
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The geomorphometric indexes have been widely used for separation of surface landform features in the geomorphology science over the past decades. In this study, Multilayer Perceptron Neural Network (MPNN) was used to provide karstic landform classification. To that regard, initially, geomorphometric indicators were extracted from Digital Elevation Model (DEM), and then these indexes were used as neurons of input layer in artificial neural network. Furthermore, the box plots were applied to analyze the relationship between karstic landforms (such as dolines, hills, karstic plains, karstic valley and headland) and geomorphometric indexes. The results showed that 34, 6.9, 1.07, 48.5, 9.51 percent of the studying area are spatially covered by valleys, plains, dolines, highlands and hills respectively. It has also been found that the optimal structure of artificial neural networks for classification of landform is model No. 12-9-1 by having the learning rate 0.1 and 87.18 percent of determination coefficient. Also, it should be noted that the accuracy of the innovative method for classification of karstic landform is 90.58 percent. The analysis revealed that variations in geomorphometric indexes are very visible in the landform of hills, highlands and karstic valleys, whereas there are slightly overlapping in the plains and dolines.
Gh. A. Fallah Ghalhary; M. Mousavi Baygi; M. Habibi Nokhandan; J. Khoshhal
Volume 62, Issue 1 , June 2009, , Pages 111-124
Abstract
The research show that global climate changes and atmospheric general circulation are affected by large scale phenomena that occurred in the sea surface. These large scale phenomena are often named "climate large scale signals". These signals are calculated based on criteria such as sea Level Pressure ...
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The research show that global climate changes and atmospheric general circulation are affected by large scale phenomena that occurred in the sea surface. These large scale phenomena are often named "climate large scale signals". These signals are calculated based on criteria such as sea Level Pressure (SLP), Sea Surface Temperature (SST) and so on. A method for weather forecasting is a special approach based on statistical modeling. In this study, data of 37 rainfall stations were used to model the relation between precipitation and Sea Level Pressure (SLP), Sea Surface Temperature (SST), Sea Level Pressure gradient (?SLP) and the difference between sea surface temperature and air temperature at 1000 HP. The results show that statistical modeling can successfully predict the amount of annual rainfall. The mean root square error for stepwise model were obtained 49 millimeters.
Valiollah Raufirad; Ataollah Ebrahimi; Hossein Arzani; Zahra Shojaei Asadeiye
Abstract
Palatability includes plants physical and chemical property that encourages an animal selecta plant for grazing. This study is an attempt for intruducing an indicator for determining thepalatability of rangeland plants. To do this, the relationship between palatability and foragequality of rangeland ...
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Palatability includes plants physical and chemical property that encourages an animal selecta plant for grazing. This study is an attempt for intruducing an indicator for determining thepalatability of rangeland plants. To do this, the relationship between palatability and foragequality of rangeland plants in Karsanak rangelands of the Chaharmahal-va-Bakhtiari provincewas studied. First, plant composition based on plant canopy cover and production wasdetermined using of the systematic random sampling method (in each plant type there are2 transects of 200 m and 15 plots along each transect). Also, the percentage of present eachplant in the livestock diet (sheep and goat) was determined using the filming method. Then,the selection index of each plant species by sheep and goat was determined. In the next stage,the forage quality of some plant species was determined by determining the percentage ofCP, ADF, DMD and ME. Finally, the relationship between plant quality indices (independentvariables) and the selection index of plant species by sheep and goats (dependent variable)was determined using the SPSS software (Ver.15). Results showed that there is a significantrelationship between the selection index of each species (both percentage canopy cover andproduction) and ADF, DMD, and ME by the sheep (P ≤0.05). However, such a significantrelationship was not found for CP. And, there is not a significant relationship between theselection index of each species (both percentage canopy cover and production) and ADF,DMD, ME and CP by the goat (P ≤0.05). Considering the results, the quality of forage can be an indicator in determining their palatability.
S. Saadati; S. Soltani; S. eslamian
Volume 62, Issue 2 , October 2009, , Pages 257-270
Abstract
Drought is universal phenomenon that can occur everywhere and can cause harmful impacts on human beings and natural ecosystems. Thus, it is very important to study drought character ristics part of for water resources management. In this study, the Standardized Precipitation Index (SPI) is used for drought ...
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Drought is universal phenomenon that can occur everywhere and can cause harmful impacts on human beings and natural ecosystems. Thus, it is very important to study drought character ristics part of for water resources management. In this study, the Standardized Precipitation Index (SPI) is used for drought frequency analysis in Isfahan province. After collecting the precipitation data in the province stations and removing those stations with incomplete data, frequency analysis of drought was carried out by 12-month SPI time series scale end of March. Then, the maps of drought return periods were prepared and analyzed by SURFER software. These maps show that moderate and severe drought with long return period mainly in the west the province and extreme drought events in the east and north east of the province with short return periods which indicate high sensitivity and the necessity for suitable managing programs to deal with the problem of drought.
Kazem Nosrati
Abstract
The term hydrological drought is applied to represent low water levels in streams, reservoirs and lakes as well as a low groundwater level. Base flow index (BFI) as one of low flow indices gives the ratio of base flow to total flow and investigates basin’s ability to store and release of water in drought ...
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The term hydrological drought is applied to represent low water levels in streams, reservoirs and lakes as well as a low groundwater level. Base flow index (BFI) as one of low flow indices gives the ratio of base flow to total flow and investigates basin’s ability to store and release of water in drought periods. The objectives of this study were to determine BFI and to validate this index in drought studies of Sefidrood Drainage Basin. To view of this, first three homogenous regions were identified based on the threshold level using cluster analysis. Then, daily BFI was calculated in 28 gauging stations of the homogenous regions. The results showed that the regional mean of BFI with value of 0.65 (SD=0.19) is stable during long-period data. BFI ranged between 0.17 and 0.86 and also based on the 25, 50 and 75 percentiles, river flow regime in the study area is divided into four categories that show more than 50 percent of the catchments in the study area have low or unstable regime. So it would be hard that the catchments able to provide river flow during drought periods. Therefore the results of this study can be used in assessment of groundwater recharge, water supply system, irrigation management, and hydrological drought monitoring as well as regional modeling of water resources storage and hydrological drought in ungauged areas
Mehrnoush Ghadimi; Hasan Ahmadi; Ebrahim Moghimi; Mansour Jafarbeyglou
Abstract
To evaluate the hydrogeochemical characteristics of karst water resources of Oshtorankooh, chemistry details of springs has been considered as the most important evacuator of karst resources. This research has been performed to study hydrogeochemical nature of karst springs and their origin with an emphasis ...
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To evaluate the hydrogeochemical characteristics of karst water resources of Oshtorankooh, chemistry details of springs has been considered as the most important evacuator of karst resources. This research has been performed to study hydrogeochemical nature of karst springs and their origin with an emphasis on the type of formation. Accordingly, five samples of the water of permanent springs of this region in the water scarcity time period have been collected and analyzed. To precisely characterize the hydrochemistry of the region, Piper as well as Stiff graphs were employed. The former graph confirmed that the dominant type of the water the region is Calcite-Bi carbonate based. This water possesses a temporal hardness wherein according to the Stiff graph the dominant cautions and anions are bicarbonate and calcium, respectively. The water of the springsPanbekar S1 and Gahar lake S3 are saturated of calcite mineral, and the positive saturation index implies a diffusive flow. The respective flow reflects less development of fractures in the catchment of the springs. The saturation index of dolomite in the springs of Absefid S2, Tamdarbasoo S4 and Mehrghayoonja S5 is negative implying the saturation conditions and reflecting the higher density of surface and sub-surface fractures as well as the type of conduit-diffusion flow along the flow path of these springs. The results of hydrogeochemical analysis also XRF of Karst springs of the field demonstrated that super saturation phenomenon mainly occurs in water scarcity period. Moreover, the chemical nature of the underground waters present in the carbonated stones (rocks) is strongly dependent on the dissolution of calcite also dolomite. The higher water temperature of the Panbekar spring is affected by saturation index of dolomite in Dalan formation. The results of factor analysis also verified that the most important factor could be dissolution of carbonate then magnesium and electrical conductivity. The water of this spring is classified in the group of relatively hard and hard waters.
Salahudin Zahedi; Farhang Ghasriani; Mina Bayat
Abstract
To study the effect of different harvesting intensity on forage production of Bromus tomentellus was considered of Majid Abad Qorveh. Treatments included four harvested intensity 25, 50 and 75 percent and control (no harvest).Data were analyzed based on splitplot over time during four years(1386-1389) ...
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To study the effect of different harvesting intensity on forage production of Bromus tomentellus was considered of Majid Abad Qorveh. Treatments included four harvested intensity 25, 50 and 75 percent and control (no harvest).Data were analyzed based on splitplot over time during four years(1386-1389) using SAS and IRRISTAT software. The results showed that the main effect of year, different harvesting intensity and interactions effect of different harvesting intensity and years are significant on forage production and vitality of Bromus tomentellus. Comparing the harvesting intensity of 50 and 25 percent indicated no significant difference between them. The highest intensity of production is harvest intensity of 25 percent with 390 mm perecipition in 1389 and the lowest harvest intensity is 50 and 75 percent with170 mm perecipition in 1387. Regarding to AMMI Analysis, the first interaction principal component(IPC1) had a significant effect and express a 93/6 percent of the interaction of the sum of squares. The first main component biplot interaction showed that the 25 percent treatments had a highest average production and stability is relatively good, control treatment had a lowest stability and 75 percent treatment had a highest stability. According to the results, to preserve the production and vitality of Bromus tomentellus the harvesting intensity of 25 percent is recommended.
vahideh Abdollahi; Hossein Arzani; Javad Motamedi
Abstract
Ecotourism, as a side activity of rangeland, can be effective in improving the livelihood of rangers and will reduce the pressure on rangelands by economizing rangeland. In this study, with the aim of evaluating the potential rangelands of Dermian , for ecotourism use, based on environmental and ecological ...
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Ecotourism, as a side activity of rangeland, can be effective in improving the livelihood of rangers and will reduce the pressure on rangelands by economizing rangeland. In this study, with the aim of evaluating the potential rangelands of Dermian , for ecotourism use, based on environmental and ecological factors (climate, topography, soil, distance from water sources and vegetation attractions) and infrastructure (distance from the city and from roads), was done. From the combination of maps in the GIS environment and based on the FAO limiting factor approach,, the rangeland suitability was determined. Based on the results, 36.7% of rangelands are in the middle suitability category (S2), 46.5% in the low suitability category (S3) and 16.8% in the non-suitable category (N) in terms of ecotourism. In this regard, 61.5% of the rangelands for livestock grazing, have low suitability (S3) and 38.5%, unsuitable (N). The percentage of vegetation and,, the poor condition of soil erosion, are factors limiting the suitability for ecotourism and livestock grazing. , it is necessary to reduce the number of livestock and graze livestock in accordance with ecological principles; that used the rangeland of the region for ecotourism along with livestock. This, in addition to compensating for the economic problems, will also help restore vegetation. Due to the need to preserve rangeland,, forest parks can be created to accommodate tourists, up to a suitable radius of the desired rangelands, and by placing remote viewing platforms and sidewalks, from the amount of damage to vegetation and reduced soil degradation.
Seyed Hamidreza Sadeghi; Shirkouh Ebrahimi Mohammadi; Kamran Chapi
Abstract
The behavior of suspended sediment during flood events is not only a function of energy conditions, i.e. sediment is stored at low flow and transported under high flow conditions, but also is related to the variations in sediment supply and sediment depletion. These changes in sediment availability result ...
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The behavior of suspended sediment during flood events is not only a function of energy conditions, i.e. sediment is stored at low flow and transported under high flow conditions, but also is related to the variations in sediment supply and sediment depletion. These changes in sediment availability result in so-called hysteresis effects. Therefore, Hysteresis pattern analysis is of great importance in sediment studies in the watersheds. However, their analyses has been rarely considered. In this study, based on the discharge and sediment concentration data collected from 8 storm events occurred during March 2 011 to April 2012, event suspended sediment dynamics of 7 tributaries of the Lake Zarivar watershed was investigated using hysteresis patterns. Based on the fact that all sampling points were not active in all events, about 46 hysteresis patterns were obtained. The analysis of results showed that 16, 13, 11, and 6 events had clockwise, irregular, complex and counterclockwise patterns, respectively. Small tributaries of the Zarivar lake watershed showed the rapid responses to the variation of storm intensity and the most hydrographs of different storms were multi peak discharges and consequently high suspended sediment variations led to different hysteresis patterns. The diversity of patterns suggested that the detailed processes of sediment transport were not only complicated during one event but also varied from event to event. The reasonable and statistically significant relationship (p<0.05) between suspended sediment yield and peak discharge of each sampling point indicated that the data from all events may be statistically well described by a simple regression equation, regardless of different inter and intra-storm variations of the suspended sediment.
mojtaba jannatrostami; mohammad rahimi; hassan kaboli
Abstract
Most of the studies on dust storms are concentrated in the western-eastern provinces of the country and less research has been done in other parts of Iran. In this research, some of the southern plains of Alborz; which have the potential to produce dust were selected. Daily data of 18 meteorological ...
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Most of the studies on dust storms are concentrated in the western-eastern provinces of the country and less research has been done in other parts of Iran. In this research, some of the southern plains of Alborz; which have the potential to produce dust were selected. Daily data of 18 meteorological stations with long-term statistical period from 2008 to 2017 and to calculate the indicators of agricultural drought, MOD13Q1 and MOD11A1 products were used in the same period. Standardized precipitation index and standardized precipitation-evapotranspiration index were calculated and from the dust hourly meteorological codes, the experimental dust storm index was obtained. Then the relationships between climatic indices, vegetation and experimental index of dust storm were investigated using Pearson correlation and multivariate regression statistical method. The highest frequency of DSI index during 10 years is related to Imam Khomeini station with a value of 30.5 and the lowest is Taleghan station with 0.05. The Year-on-year changes in the dust index show that in the early years, the central and southeastern parts of the region were affected by dust storms, and sudden decrease had a significant effect on the results and reduced the long-term trend. The highest and the lowest correlation is respectively wind speed and Temperatur .Regarding the results of monthly multivariate regression, are somewhat variable in different months of the year, so that the effect of climatic elements and vegetation changes in different months, in general wind speed, TCI and SPEI have the most important effect on increasing
Sedigheh Zarekia; Mohammad Fayyaz; Niloofar Zare
Abstract
Defining the preference value of plant species is necessary for planning and management of livestock and rangeland. The purpose of this study was to investigate the preference value of plant species grazed by sheep during the grazing period in Khoshkeh rood Saveh Rangeland of Markazi Province using species ...
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Defining the preference value of plant species is necessary for planning and management of livestock and rangeland. The purpose of this study was to investigate the preference value of plant species grazed by sheep during the grazing period in Khoshkeh rood Saveh Rangeland of Markazi Province using species selection index.
Production and consumption data of species in and out of the enclosure was collected over six months of grazing season for three years to calculate the species selection index. Maximum preference values for Poasinaica (in whole grazing season) and Salsolalaricina (especially November and December) and minimum preference values for Cousiniacylindracea (in whole grazing season and especially in dry years) was recorded. Reduction in rainfall in 2008 increased the percentage of utilization and preference index of species. As in April 2008, Artemisia sieberi with preference index 2 was a relatively palatable species and Noaeamucronata and Stachysinflata with preference index over 2.1 were considered quite palatable species. Salsolalaricina in November and December in all the years with preference index over 1.4 was considered as relatively palatable species.
Salsolalaricina is a critical resource for livestock of steppe rangelands throughout the year, especially from mid-November to mid-March. So that in this time, this species has higher palatability than other species accompanied and with proper grazing management should be prevented from excessive utilization.
Mohammad Ali Zare Chahouki; Masoud Yousefi; Mohammad Jafari; Hossein Azarnivand; Marjan Shafizadeh Nasrabadi
Abstract
The current research was carried out to find out the most effective environmental factors in plant species occurrence by classification and ordination methods. For this purpose, the study was conducted in Nir rangelands of Yazd province and topography, climate, soil and grazing intensity data of the ...
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The current research was carried out to find out the most effective environmental factors in plant species occurrence by classification and ordination methods. For this purpose, the study was conducted in Nir rangelands of Yazd province and topography, climate, soil and grazing intensity data of the region were determined. Sampling method was randomized–systematic and within each sampling unit 3-5 parallel transects with 300-500 m length, each containing 30-50 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–10*10m (2-100 m2). Soil samples were taken from 0-30 and 30-80 cm in starting and ending points of each transect. Measured soil properties included gravel, texture, available moisture, saturation moisture, organic matter, lime, gypsum, pH and electrical conductivity. To analyze environmental data, classification (using TWINSPAN) and ordination (using PCA, CCA) were used. The results indicated that soil salinity, texture and available water play the main role in distribution of plant species.
Sareh Rasekhi; Ali Akbar Mehrabi; Seyed Akbar Javadi; Mehdi Ghorbani
Abstract
Renewable natural resources are national capital and are of paramount importance in each country. Preservation and developing these resources is incumbent upon relevant institutions and all people especially the beneficiaries. In this regard, various approaches have been recommended for optimum use and ...
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Renewable natural resources are national capital and are of paramount importance in each country. Preservation and developing these resources is incumbent upon relevant institutions and all people especially the beneficiaries. In this regard, various approaches have been recommended for optimum use and sustainable preservation of natural resources especially rangelands among which co-management is highly emphasized. To pinpoint challenges and barriers before co-management, the integrated institution-beneficiaries network (institutions related to rangeland management and rangeland users) of Ghasr-e-Yaghoub village in Safashahr was analyzed applying social network analysis method. Results demonstrated that cohesion level among rangeland users and institutions related to rangeland and also network sustainability in the study area was moderate and Village Islamic Council and Jihad-e Keshavarzi (Agricultural Development Agency) were the two most influential institutions. In other words, they were core actors among all institutions. Therefore, reinforcement of cohesion among actors and recognizing key actors in different levels are necessary approaches for implementation of co-management action plan. Additionally, it helps natural resource managers for sustainable management of rangelands.
