Parviz Alizadeh; ِAli Tavili; Mohammad Ali Zare Chahouki; Mohammad Jafari
Abstract
In this research, after making culture capsules from biodegradable mesh plates with bacterial, hydrogel and nanoclay substrates, which is from mixing bacteria, hydrogel and nanoclay and transferring the seedlings produced to the capsules as capsule culture compared to pots. Conventional nylon plants ...
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In this research, after making culture capsules from biodegradable mesh plates with bacterial, hydrogel and nanoclay substrates, which is from mixing bacteria, hydrogel and nanoclay and transferring the seedlings produced to the capsules as capsule culture compared to pots. Conventional nylon plants in conventional cultivation, which were used as controls, were carried out in the form of a completely randomized design with the two factors of cultivation type (capsule and conventional) and capsule type (hydrogel, bacteria and nanoclay) in the greenhouse of the Faculty of Natural Resources, University of Tehran. The results of this research showed the significant effect of the type of hydrogel capsule culture on all the morphological traits of the investigated plant; So that the length of the stem with an increase of 42.6%, the diameter of the collar by 14.8% and the dry biomass of the root and the aerial organs with an increase of 7.2% and 23.7%, respectively, have the highest values. They gave. In addition, regarding some physiological traits of the investigated plant, the amount of chlorophyll was also affected by the type of capsule culture and its concentration in capsule culture of hydrogel, bacteria and nanoclay showed an increase of 56.8%, 32.1% and 36.9% respectively. They gave. Also, the results of comparing the averages showed that the concentration of proline in plants grown in hydrogel capsules decreased by 33.20% compared to conventional culture. This reduction process in the soluble sugar content of plants grown in hydrogel capsules was obtained compared to the conventional culture of 20.78.
Mahboobeh Abasi; Mohammad Ali Zare Chahouki; Hossein Bagheri
Abstract
The main objectives of this study were to prepare a prediction map of the potential habitat of Agropyron intermedium and Find important factors influencing the establishment and distribution of this species and the preferred tendency of the species was relative to environmental factors Using the Maxent ...
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The main objectives of this study were to prepare a prediction map of the potential habitat of Agropyron intermedium and Find important factors influencing the establishment and distribution of this species and the preferred tendency of the species was relative to environmental factors Using the Maxent model. For modeling, region condition information was prepared including topography, climate, geology and soil, satellite images, digital elevation model (DEM), geology map, and climatology data. Then soil and plants sampling was performed and Soil samples were transferred to the lab. Soil properties were measured including gravel, pH, EC, lime, organic matter, N, K, P, sand, clay, and silt in the laboratory. Geostatistical methods were used for data analysis and mapping of environmental variables and the Maxent model was used for prediction maps. Kappa coefficient indicates that the Maxent model predicted A. intermedium habitat at a very good level (kappa = 0.85). Also, the accuracy of the classification of habitat maps predicted in the Maxent model is acceptable according to the analysis of the area under the curve (AUC = 0.771). The results showed that topographic variables and clay soil factor in the occurrence and distribution of A. intermedium has the greatest effect and increasing lime and ec have a negative influence on the presence of this species. A. intermedium is a desirable species that in addition to being used in creating hand-planted pastures, it is very important in improving and developing rangelands, especially in cold regions. Therefore, maintaining genetic and scientific,
Nadia Kamali; Hossein Azarnivand; Shervin Ahmadi; Mohammad Ali Zare Chahouki; Ahmad Sadeghipour
Abstract
This study was conducted to evaluate the effect of polymer mulches and plant mulch on some soil physical properties. For this purpose, effects of synthetic polymer, natural polymer, natural - synthetic polymer, and litter, On some physical properties of soil at two depths (0-5 cm and 5-30 cm) and two ...
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This study was conducted to evaluate the effect of polymer mulches and plant mulch on some soil physical properties. For this purpose, effects of synthetic polymer, natural polymer, natural - synthetic polymer, and litter, On some physical properties of soil at two depths (0-5 cm and 5-30 cm) and two time periods in a completely randomized design with four replications was studied. 10*10 meter experimental plots were considered and mulches covered 2 cm of the soil surface in each plot. The results showed that the use of mulches in the first week of applying, affected the bulk density (3.6% increase in synthetic polymer), porosity (6.01% increase in synthetic polymer), temperature (2.52% increase in litter and 1.85 decrease in natural polymer) and humidity (16.67% increase in synthetic polymer) at the layer of 0-5 cm, Soil moisture (16.67% increase in synthetic polymer) was also affected at the depth of 5-30 cm. Six months after the experiment began, mulches were applied, made a significant difference compared to control in the bulk density (4.81% and 2.12% decrease in synthetic polymer for 1st and 2nd layers respectively), porosity (8.23% increase in synthetic polymer for 1st layer and 4.12% increase in natural - synthetic polymer for 2nd layer) and moisture content of both surface and beneath soil (103.53% and 48.6% increase in natural - synthetic polymer for 1st and 2nd layers respectively), also the electrical conductivity of the first depth of soil (6.23% decrease in natural - synthetic polymer) was affected.
Raziyeh Dehghani; Mohammad Jafari; Mohammad Ali Zare Chahouki; Salman Zare; ِAli Tavili; Babak Moteshrezadeh
Abstract
The use of biochar as a soil amendment is one of the new methods to improve soil properties and increase plant yield. In this study, in order to evaluate the effect of adding natural biochar on soil properties and yield of Pamirian winterfat (Eurotia ceratoides) plant, an experiment in a completely randomized ...
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The use of biochar as a soil amendment is one of the new methods to improve soil properties and increase plant yield. In this study, in order to evaluate the effect of adding natural biochar on soil properties and yield of Pamirian winterfat (Eurotia ceratoides) plant, an experiment in a completely randomized design were performed with 11 treatments by different levels of biochar (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10% by weight) and three replications in greenhouse conditions. After the end of the growing season, some physical and chemical properties of the soil (pH, EC, organic matter (%), lime, bulk deisty, particle density, and porosity percentage), germination percentage, and yield of E. ceratoides were measured. In all the studied traits of the soil (except for the particle density), and the characteristics of the E. ceratoides plant, the statistical difference between the various levels of biochar was significant (a = 0.01). Adding different levels of biochar increased pH, ECy, soil porosity percentage, soil organic matter, whereas decrased bulk density, lime percentage, clay percentage, sand, and silt.
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.
Maryam Saffariha; Hossein Azarnivand; Mohammad Ali Zare Chahouki; ِAli Tavili; Samad Nejad Ebrahimi; Daniel Potter
Abstract
Salvia limbata is an herbaceous plant which belongs to Lamiaceae family and is native to Iran. In this study, essential oils and variety of chemical compounds of Salvia limbata in flowering stage in different altitudes in July were studied. In order to study the active ingredients of plant in studied ...
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Salvia limbata is an herbaceous plant which belongs to Lamiaceae family and is native to Iran. In this study, essential oils and variety of chemical compounds of Salvia limbata in flowering stage in different altitudes in July were studied. In order to study the active ingredients of plant in studied sites in flowering stage nine plant samples were examined for phytochemical analysis. Identification of the basic constituents (quantity and quality) with GC / MS and GC-FID (gas chromatography coupled to mass spectrometer) has been done. The yield of essential oils in flowering stage in Paeein Taleghan 0.34% in Mian Taleghan 0.34% and in Bala Taleghan is 0.46%. According to the results, difference in altitudes in three habitats shows a significant difference among the percentages of the obtained compounds. The most important constituents of essential oil include α-Pinene, β-Pinene, allo-aromadendrene and Spathulonol. Also, Salvia is reported as one of the sources for the extraction of α -pinene.
Mohammad Ali Zare Chahouki; mahbobe abbasi
Abstract
Rheum ribes species is one of the important medicinal plants in the world. In this study were used maximum entropy method (Maxent) and the MAXENT software to this prediction habitat map. Measure environmental variables was soil variables including gravel percentage, pH, electrical conductivity, percent ...
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Rheum ribes species is one of the important medicinal plants in the world. In this study were used maximum entropy method (Maxent) and the MAXENT software to this prediction habitat map. Measure environmental variables was soil variables including gravel percentage, pH, electrical conductivity, percent lime, gypsum, organic matter, soluble salts (Ca+, Na+, K+, Mg2+, CL, HCO3, SM and SO2), sand, clay and silt and variable topography (slope, aspect and elevation) and rainfall variable. Those were effective variables on the presence of species. The model classification accuracy using the area under the curve (AUC) was 95% (good Level), and kappa coefficient was obtained 0.92 that measuring from the agreement of prediction maps with ground truth, which is at a high level. The results of this study showed that the habitat of this species is in the soils with low pH (less than 8), clay Low (less than 40%), coarse texture and organic matter more than 4.0 percent. And the presence of this species has inverse relationship with a pH of both the depth and the clay first depth and with has directly relationship to organic matter of both depths.
afshin sadeghirad; Hossein azarnivand; mohamad jafari; mohamadali zarechahoki
Abstract
Nowadays climate change, is the most significant threat in terms of sustainable development, particularly in developing countries. So regarding to rangeland ecosystems and their ability is a Particular attention to sequester carbon. This study aimed to assessing the carbon sequestration potential of ...
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Nowadays climate change, is the most significant threat in terms of sustainable development, particularly in developing countries. So regarding to rangeland ecosystems and their ability is a Particular attention to sequester carbon. This study aimed to assessing the carbon sequestration potential of natural and planted ranges through selected three species S. barbata, S.rigida and A.canescens. sampling from vegetation and soil have done along three 200 meters parallel transects by Systematic - random method. So that were taken 30 vegetable and 36 soil samples which were measured the organic carbon plants samples and some physical and chemical properties of soil In the laboratory. Then, by multiplying the amount of organic carbon in soil bulk density, was calculated total weight of carbon sequestration in soil depth. The results showed that among the three sites, the depth first of the soil, the amount of silt, sand, organic carbon, PH and EC (electrical conductivity) and In the second depth of the soil, the amount of silt, organic carbon, nitrogen, PH and EC there was a significant difference at 5% level. The comparison of carbon sequestration to the total habitat by Duncan's test showed that all three species were significantly different from each other at 5% level, So that the greatest amount of carbon stored is in the A.canescens planting of rangeland (39/84 ton/ ha) and the lowest Natural rangeland S.rigida (36/24 ton/ha), However the Natural range S.barbata was intermediate between both other species (31/34 ton/hac).
Nooshin Shakerian; Gholamreza Zehtabian; Mohammad Ali Zareh Chahooki; Hassan Khosravi
Abstract
Nowadays, land degradation and desertification are serious and complex problems that have turned into a worldwide crisis in the world. Using evaluative systems to study degradation and adopting an appropriate strategy to deal with this phenomenon is necessary and important. The first step in the ...
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Nowadays, land degradation and desertification are serious and complex problems that have turned into a worldwide crisis in the world. Using evaluative systems to study degradation and adopting an appropriate strategy to deal with this phenomenon is necessary and important. The first step in the study of land degradation and desertification is determining criteria and indicators that affect upon this process. Therefore, in this study the importance and priority of a considerable number of criteria and indices that influence upon land degradation and desertification were examined. Accordingly, 8 criteria and 49 indicators were chosen based on questionnaires and expert panel and they were evaluated based on eight metrics. We weighted suitable criteria for evaluation indicators with the help of Shannon entropy method, and then by using the TOPSIS method (one of Multiple Attribute Decision Making Methods) we determined the most effective indicators on land degradation and desertification for management and dealing with this phenomenon. The results show that among the evaluation criteria and indices that should be considered for a benchmark or index, a scale, has the highest weight and importance, and being sensitive to change, has the minimum weight and importance.The results of the prioritization and ranking criteria and indicators based on TOPSIS model indicates that the severity of exploitation of water resources in the factor of water with the 0.79 efficiency, has the most effect and the use of facilities and personal management in the management factor with the 0.11 efficiency has less effect in land degradation and desertification.
razie shahbandari; Hossein Arzani; naser baghestani meybodi; Mohammad Ali Zare Chahouki
Abstract
The most important factor affecting forage quality is phenological stage that if it is recognized correctly, the appropriate grazing time will be determined. In this study, four species including Artemisia sieberi, Salsolakerneri, AelieniasubaphyllaandEurotiaceratoides in different phenological stages ...
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The most important factor affecting forage quality is phenological stage that if it is recognized correctly, the appropriate grazing time will be determined. In this study, four species including Artemisia sieberi, Salsolakerneri, AelieniasubaphyllaandEurotiaceratoides in different phenological stages (vegetative, flowering and seedling) were sampled. Samples were taken from the rangelands of Nodooshan-Yazd in 1389 and 1390. At each stage, five replicates for each plant species were selected and at least five vegetable bases from different locations of vegetation type in the region were selected. Samples were grinded after drying and separating different parts (flower, leaf and stem) and then they were analyzed using infrared spectroscopy in the laboratory. Important indicators of quality such as crude protein (CP), acid detergent fiber (ADF), dry matter digestibility (DMD) and metabolic energy (ME) were determined. Results showed that the highest percentage of crude protein is found in leaves of A. subaphyllaand in vegetative stage (9.19%), highest percentage of ADF is in shoot and in seedling stage (53.42%) and the highest percentage of DMD (48.13%) and the highest amount of metabolic energy (6.18 MJ/KgDM) is in leaves of A. sieberi and in vegetative stage, respectively. The end of the vegetative period can be considered the best time for grazing.
Hossein Piry; Mohammad Ali Zare Chahouki; Hossein Azarnivand
fatemeh naghizadeh; mohammad jafari; hosein azarnivand; Mohammad Ali Zare Chahouki
Abstract
In this study, the role of soil properties in making difference between plant communitieswas examined. First, four plant types were identified, including Pteropyrumaucheri-Salsolarigida، Astragalus gossypinus - Acanthophyllum herateens، Amygdalus scoparia – Achilla millefolium and Ephedra intermedia ...
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In this study, the role of soil properties in making difference between plant communitieswas examined. First, four plant types were identified, including Pteropyrumaucheri-Salsolarigida، Astragalus gossypinus - Acanthophyllum herateens، Amygdalus scoparia – Achilla millefolium and Ephedra intermedia – Erigon capestra, through randomized systematic sampling and field survey in representative area of each type. In each plant type, three 500-meter transects were selected and in each transect, ten plots were placed along each transect. Characteristics of vegetation such as type and percentage of cover, gravel percentage, litter percentage and bare soil percentage were determined within each plot. In addition, in order to study the soil properties, at the beginning and at the end of each transect, a profile was dug and soil samples were taken from the depths of 0-20, 20-80 cm. Soil physical and chemical properties (texture, pH, electrical conductivity, organic matter percentage, gypsum percentage, lime percentage, salts such as sodium, potassium, calcium and magnesium, sodium absorption ratio, sodium exchange percentage) were determined in soil laboratory. Then, the role of soil properties in making difference between plant communitieswas determined by using ANOVA statistical analysis, and the key factors making this difference were introduced as sand percentage, organic matter percentage, and electrical conductivity.
Mohammad Jafari; ِAli Tavili; Yahya Esmaeilpour; Hossein Azarnivand; Mohammad Zare Chahouki; Hamid Reza Asghari
Abstract
Abstract In this study the effects and costs of application of two kinds of super absorbent polymer on the establishment and surviving of seedlings was investigated. Experiments were done in the field and on two kind of soil with different salinity (EC: 4.5 and 8 dsm-1). The results showed: the establishment ...
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Abstract In this study the effects and costs of application of two kinds of super absorbent polymer on the establishment and surviving of seedlings was investigated. Experiments were done in the field and on two kind of soil with different salinity (EC: 4.5 and 8 dsm-1). The results showed: the establishment rate of seedling in control was about 40 percent. The percentage of seedling establishment in the hydrogel treatments significantly increased and statistically is equal to the optimal surviving of the seedling (80%). Soil salinity on seedling establishment in the same treatments did not produce significant differences. The results were compared with a similar project to determine the costs and benefits. Based on the results a 30 percent reduction in water usage per round and 33 to 50 percent reduction in the number of irrigation replicate were recorded. The costs in compare to the normal project varied from -2 to 29 percent respectively for treatment Herbosorb® 0.5% and Aquasorb 1%. The treatments Herbosorb® and Aquasorb with usage level of 0.5% caused about 2.5 percent for each one percent increasing in the cost. There is no significant increase in the percentage of seedling survival by using 1% super-absorbent compared to 0.5 percent.
leila khalasiahwazi; Mohammad Ali Zare Chahouki
Abstract
Zygophyllum atriplicoides is one of the most important rangeland plants that often seen as associated species and rarely seen as the dominant species in ranglands rangelands which is very critical for soil in starting and ending points of each transect. Measured soil properties (included gravel, ...
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Zygophyllum atriplicoides is one of the most important rangeland plants that often seen as associated species and rarely seen as the dominant species in ranglands rangelands which is very critical for soil in starting and ending points of each transect. Measured soil properties (included gravel, texture, organic matter, lime, pH and electrical conductivity) and physiography (elevation and slope) is measured also. By importing the information layers in appropriate model and using necessary statistical analysis in ENFA model, the map of its potential habitat has been created. The results showed that 25200 hectares of study site is potential habitat of Zygophyllum atriplicoides which is 34 percent of study site. To evaluate the verity of this model, Boyce index has been used and model rectitude in this test was determined as 87.2 percent. The result of this model is shown that PH and Lime are the main effective factor to determine potential suitable of this plant species.
TAYYEBEH MESBAHZADEH
Abstract
This research was done in order to submit a model for salinity map made with TM satellite data and salinity values in a Buienzahra. The necessary processings such as principal component analysis and producing of different indices was done on the main bands. The 38 soil samples using random sampling (with ...
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This research was done in order to submit a model for salinity map made with TM satellite data and salinity values in a Buienzahra. The necessary processings such as principal component analysis and producing of different indices was done on the main bands. The 38 soil samples using random sampling (with 10×10 km dimension) from different horizons were designed and performed on the study area. The position of each node was registered with global positioning system (GPS), and the surface electric conductivity of samples was measured using EC meter instrument in soil saturation extract. Correlation between spectral values (main bands, produced indices) with electrical conductivity values were investigated for 80% of the samples. The regression analysis of ECe showed that there is a significant correlation between ECe with spectral data in all of main bands and with BI, NDMI, SI1, SI2, SI3 indices in 99% levels. The accuracy assessment of estimations using validation 20% samples was done. Results showed the produced ECe model could predict the soil salinity with ME and RMSE of 0.08 and 2.53 dS/m respectively. At finally, Salinity map with different salinity classes ( 0-2, 2-4, 4-16, 16-32, 32< dS m-1) was produced.
shima nikoo; Hossein Azarnivand; Gholam Reza Zehtabiyan; Hasan Ahmadi; Mohammad Ali Zare Chahouki
Abstract
Combating desertification which is a serious threat for the environment and human welfare requires understanding complex issues of this phenomenon using evaluation, awareness of severity of it's processes and determination of it's factors. So here, after recognizing the characteristics of the region ...
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Combating desertification which is a serious threat for the environment and human welfare requires understanding complex issues of this phenomenon using evaluation, awareness of severity of it's processes and determination of it's factors. So here, after recognizing the characteristics of the region showing existence desertification, we assess its current status with emphasis on climate, water, geology-geomorphology, soil and wind erosion as the most criteria of desertification. According to more consensus on regional model or flexible model to modify, Iranian Model for Desertification Potential Assessment (IMDPA) ,which is calibrated to use in arid area of Iran, was chosen. At first the rainfall seasonality indicator was added to the model as a special climate character. Then primary assessment of desertification was done. At last according to the result of primary assessment, the area environmental conditions and revealed issues during assessment the model was modified, final assessment and mapping of desertification were done. At last according to the result of primary assessment, the area environmental conditions and revealed issues during assessment the model was modified, final assessment and mapping of desertification were done. Based on the results desertification intensity in 33/94% and 66/06% of the area are severe and moderate respectively. Also the major factors affecting desertification across Damghan region are climate, salinization of water and soil resources, improper land use, over exploitation of underground water, over grazing and improper irrigation method.
Mohammad Ali Zare Chahouki; Lyla Khalsi Ahvazi; Hossein Azarnivand
Abstract
The aim of this study was providing plant species predictive habitat models by using logisticregression method. For this purpose, study area conducted in north east rangelands of Semnanmodeling vegetation data in addition to site condition in formation including topography, and soil wasprepared. sampling ...
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The aim of this study was providing plant species predictive habitat models by using logisticregression method. For this purpose, study area conducted in north east rangelands of Semnanmodeling vegetation data in addition to site condition in formation including topography, and soil wasprepared. sampling was done within each unit of sampling parallel transects and 1 vertical transectwith 750m length, each containing 15 quadrates (according to vegetation variations) were established.Quadrate size was determined for each vegetation type using the minimal area method. Soil sampleswere taken from 0-20 cm and 20-80 cm in starting and ending points of each transect. Logesticregression (LR) techniques were implemented for plant species predictive modeling. To plantpredictive mapping, it is necessary to prepare the maps of all affective factors of models. To mappingsoil characteristics, geostatistical method was used based on obtained predictive models for eachspecies (through LR method). The accuracy of the predicted maps was tested with actual vegetationmaps. In this study, the adequacy of vegetation type mapping was evaluated using kappa statistics.Predictive maps of Astragalus spp. ( κ =0.86), Halocnemum strobilaceum ( κ =0.51), Zygophylumeurypterum ( κ =0.58) and Seidlitzia rosmarrinus ( κ =0.6) with narrow amplitude is as the same ofactual vegetation map prepared for the study area. Predictive model of Artemisia sieberi ( κ =0.33),due to its ability to grow in most parts of north east rangeland of Semnan with relatively differenthabitat condition, is not possible.
Mohammad Ali Zare Chahouki; Lyla Khalsi Ahvazi; Hossein Azarnivand; Asghar Zare Chahouki
Abstract
The aim of this study preparation of the predicted soil maps by using kriging and Inverse Distance Weighting methods in east rangeland of Semnan. Sampling was done within each unit of sampling parallel transects and 1 vertical transect with 750m length. Soil samples were taken from 0-20 cm in starting ...
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The aim of this study preparation of the predicted soil maps by using kriging and Inverse Distance Weighting methods in east rangeland of Semnan. Sampling was done within each unit of sampling parallel transects and 1 vertical transect with 750m length. Soil samples were taken from 0-20 cm in starting and ending points of each transect. There were used kriging and Inverse Distance Weighting methods by Gs+ and GIS software to predict clay, sand, lime, EC and available moisture factors. For comparing these methods, cross validation were used by statistical parameters of MAE and MBE. Results showed that kriging method is better than Inverse Distance Weighting method in all factors except clay factor.
Jamal Imani; Hossein Arzani; Mohammad Ali Zare Chahouki
Abstract
For assessment and comparison of measuring density methods of Festuca ovina, Bromus tomentellus and prangos ferulacea, three plants communities are selected. In all of plant community, reference area was defined and samples 7000 (70*100) square meter was selected. Whole the area, sampling was accumplished ...
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For assessment and comparison of measuring density methods of Festuca ovina, Bromus tomentellus and prangos ferulacea, three plants communities are selected. In all of plant community, reference area was defined and samples 7000 (70*100) square meter was selected. Whole the area, sampling was accumplished as systematic-random. In each area, 5 transect 100 meter are established. Then in areas 7000 square meter, all of the basic species are counted by strip transect and real plant density is measured. This plant density is remarked as a control and plant density that is measured by others methods are compared with it. Density measuring methods in this research were: species counting counted in quadrate of 1 square meter, point-centered quarter, angle order, nearest-neighbor, random pairs and closest individual methods. The results showed that among these methods for Festuca ovina, neighbor nearest method is most accurate and angle order method has low accurate. Moreover angle order method is the slowest and quadrate method is rapid. In Bromus tomentellus, among these methods for this species, point-centered quarter method is the most accurate. Angle order method has low accurate in these methods. Also angle order method is slowest and counted quadrate method is rapid. In Prangus ferulacea, In these methods for this species, point-centered quarter method is the most accurate and angle order is the least accurate. Moreover angle order method is the slowest and count plant quadrate method is rapid.
I Islami; A.A Mehrabi; GH.R Zehtabian; M.R Ekhtesasi; M.A Zare Chahooki
Volume 63, Issue 3 , December 2010, , Pages 287-305
Abstract
Yazd province because of cultural and historical background of the distant past always had known as ambitious and hard-working people. Manifesting multiple efforts of these people is seen in water harvesting. In Yazd province, background issues such as evaluation and assessment of water, ownership and ...
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Yazd province because of cultural and historical background of the distant past always had known as ambitious and hard-working people. Manifesting multiple efforts of these people is seen in water harvesting. In Yazd province, background issues such as evaluation and assessment of water, ownership and agricultural water share refers to the distant past which has been changes over time in type and form. The purpose of this article, meanwhile a short review of management method and operation of water with a focus on Mirab, the evolution of ownership, irrigation circuit changes over time and changes in water price has been paid. Research methodology is single-type reticulum (monographic). Location research has been Chrkhab village of Yazd. Irrigation cycle of village has changed in four stages to the final cycle of water from 16 days to 21 days and 20 hours has become at present. Now, 53 Owner of the well are operating. In this study, according to the classification made, those of their right of water irrigation period were less than one hour (small landowners). This group, forming the highest frequency, equivalent of 33/6 percent was. According to the results, in extent of water right distribution between owners and various whiskers, the owners try to allocate more shares for them in order to play higher roles in the rural society. Study of the current water price changes for fifty years shows, the price of general inflation society has not follow. In this review the current water price increase rate (growth rate), 0/12 percent obtained.
v Payravand; ali Salajegheh; mohamad Mahdavi; mohamad ali Zare Chahouki
Volume 63, Issue 2 , September 2010, , Pages 131-18
Abstract
One of the most appropriate approaches for flood forecasting is using peak discharge data of hydrometric stations in each region. However, lack of such stations or short duration of data in most parts of the country, make it necessary to use some alternative methods in order to estimate the flood discharge ...
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One of the most appropriate approaches for flood forecasting is using peak discharge data of hydrometric stations in each region. However, lack of such stations or short duration of data in most parts of the country, make it necessary to use some alternative methods in order to estimate the flood discharge properly. One of these approaches is regional flood analysis method that in a region using observation discharge data in separate points, it calculates relevant regional flood models. These approaches give us possibility at a region without gauging station with similar and homogenous hydrological condition to estimate flood discharge for different return periods with acceptable accuracy. In this research three methods of regional flood analysis including index flood, multivariate regression and hybrid method were considered in 20 watersheds of central Alborz region. After taking into account, the hypothesis and limitations of each method, the results were compared with observed flood discharges using RMSE and MBE. Considering the hypothesis and validation of multiple regression model indicated it is not appropriate. Finally Index Flood method in return periods of 2, 5 and 10 years and hybrid method in return periods of 50 and 100 years proved higher accuracy in the whole region and no difference between these two methods in return period of 25 were shown.
