H. Saidian; H. R. Moradi; F. Tarnian
Volume 63, Issue 1 , June 2010, , Pages 1-12
Abstract
Using of different systems of soil plough after changing unconsciously and non-scientific of land use, other soil physical and chemical characteristics affected. This fact, especially in marginal lands and mountainous regions is more visible. This research compared with the purpose of studying land use ...
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Using of different systems of soil plough after changing unconsciously and non-scientific of land use, other soil physical and chemical characteristics affected. This fact, especially in marginal lands and mountainous regions is more visible. This research compared with the purpose of studying land use changing on some soil physical and chemical characters like very tiny sand percent, pH, Ec, clay percent, sand percent, silt percent, soil moisture, calcium carbonate in Gachsaran and Aaghajari formation. So that in aghajari formation 7 points and with 3 replicates and in gachsaran formation 6 points and with replicates in three land uses range, residential and agricultural land uses sampling of soil was done. Sampling of the depth 0-20 cm soil was done. After tests implement are concerned, the results were investigated. According to the results, range land in two Aghajari and Gachsaran formations in terms of clay percent, sand, EC, pH, moisture and Calcium Carbonate a meaningful difference have, and in other cases was not seen any disagreement. between agriculture land use in two Aghajari and Gachsaran formations in terms of very tiny sand percent, sand, clay, moisture and calcium carbonate meaningful difference have, and in other cases was not seen any disagreement. In residential land use in two Gachsaran and Aghajari formations only in clay percent and EC, there are a meaningful difference, and in other cases was not seen any disagreement. In each formation also land uses had effective role in soil physical and chemical characteristics.
Maryam Azarakhshi; Jalil Farzadmehr; Mahdi Eslah; Hossein Sahabi
Abstract
Climate change is defined as long term and irreversible changes in the climatic behaviorof a region. Many studies have been conducted in different regions of the world on climatechange. The results of these studies show considerable changes in climatic factors especiallyin precipitation and temperature. ...
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Climate change is defined as long term and irreversible changes in the climatic behaviorof a region. Many studies have been conducted in different regions of the world on climatechange. The results of these studies show considerable changes in climatic factors especiallyin precipitation and temperature. In this research, the trend of changes in annual and seasonalrainfall and temperature in 24 synoptic stations over a 50-year data period (1956-2005) wasinvestigated in Iran. The Mann- Kendall test and linear regression technique were used to analyzethe trend of changes in climatic factors. The results showed both increasing and decreasingtrends in annual rainfall at various regions of Iran. Annual rainfall in northern slopes of Alborzand western slopes of the Zagros Mountain as well as in eastern and southeast parts of Iran hada decreasing trend while in the central of Iran the trend of changes was increasing. In southernregion of Iran the rainfall had an increasing trend. The results also showed that temperature inmost of the studied stations over the considered period was increasing. The highest and lowestchanges in temperature were seen in the mean temperature of summer and winter, respectively.Ahwaz and Khorramabad stations had a decreasing trend and over all seasons would go towardmore cooling. The temperature trend in Oromiye was decreasing in autumn and summer whileShahrekord and Bandar abbas had the same trend in summer and winter.
Zakariya Asadolahi; Mahdi Vafakhah; Seyed Hamidreza Sadeghi
Abstract
Todays, dynamic models are supposed as the most important tools in erosion and sediment phenomenadue to their complexities and existence of many affecting factors. Towards, the present study wasconducted in the Kojour watershed for daily sediment modeling using daily rainfall, discharge andsediment during ...
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Todays, dynamic models are supposed as the most important tools in erosion and sediment phenomenadue to their complexities and existence of many affecting factors. Towards, the present study wasconducted in the Kojour watershed for daily sediment modeling using daily rainfall, discharge andsediment during 2007 to 2010. The modeling process was carried out all data and the monthly andseasonally classification data in linear and nonlinear models. The results indicated that daily linear andnon-linear models did not indicate a suitable model. The monthly and seasonally classification of thedata led to achievement of better models with determination coefficient significant at 5 percent leveland relative error less than 40 percent as compared with those obtained from no classification. It wasalso found out that daily sediment of Kojour watershed was affected by discharge occurred event dayand before four days. The discharge occurred event day is the most effective factor in 80% selectedmodels in the study watershed. The nonlinear models were better estimation than linear models inJuly, September, December and March and autumn but linear models were better than nonlinearmodels in other months and seasons.
Hossein Bashari; Mostafa Tarkesh; Tayebeh Shahabadi; Mohammad Reza Mosadeghi
Abstract
Abstract
This study aimed to investigate the effects of urban wastewater on some soil physical and chemical properties in Segzi, East Isfahan. Six sites were selected considering the planted species (Haloxylon persicum and Nitraria schoberi) and irrigation types (control or no irrigation, water logged ...
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Abstract
This study aimed to investigate the effects of urban wastewater on some soil physical and chemical properties in Segzi, East Isfahan. Six sites were selected considering the planted species (Haloxylon persicum and Nitraria schoberi) and irrigation types (control or no irrigation, water logged and furrow irrigation methods). The 4 to 12 replications were chosen in each site depending on its' size. Soil samples were collected in all replications from the 0‒10 and 10‒30 cm layers. Soil properties such as texture, organic matter, acidity, electrical conductivity, total soluble sodium, calcium and magnesium concentrations, and structural stability (dispersible clay) were measured for 94 collected soil samples. One-way ANOVA, Duncan's mean test and Principal Component Analysis were used to analyze and interpret the data. The results showed that wastewater affected some soil properties by leaching soluble salts into deeper soil horizons and also adding organic matter and some minerals into the soil. Electrical conductivities of the 0‒10 cm layer in control sites (no irrigation) and the 10‒30 cm layer in sites with furrow irrigation method were significantly greater than water-logged irrigated sites (α= 0.05). Applying wastewater increased soil organic matter content and aggregate stability significantly (α= 0.05). Irrigating the sites with wastewater decreased soluble sodium contents and dispersible clay of the soil surfaces; hence the soil structural stability was increased. Overall, applying wastewater to irrigate the planted seedlings in rangeland restoration projects has benefits as its use in these areas has lower environmental risk when compared with agricultural fields.
Hassan Esmaeili; Javad Hadian; Mohammad Hossein Mirjalili; Hassan Rezadoost
Abstract
Satureja rechingeri, an endemic species from Iran, is distributed in narrow habitats in Ilam andKhuzestan provinces. This study was conducted in 2013 and some morphological characteristics, oilcontent, rosmarinic acid content and ecological features of different populations of S. rechingeriwere studied. ...
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Satureja rechingeri, an endemic species from Iran, is distributed in narrow habitats in Ilam andKhuzestan provinces. This study was conducted in 2013 and some morphological characteristics, oilcontent, rosmarinic acid content and ecological features of different populations of S. rechingeriwere studied. Identified habitats of S. rechingeri are located in sub-tropical areas of Ilam andkhuzistan provinces, within 32-33◦ longitude and 46-49◦ latitude and the plant mainly grows oncalcareous rocks in the northern and southern slopes. The highest coefficient of variation among thetraits of S. rechingeri was obtained for leaf surface area (43.01%) and the lowest (9.25%) wasobtained for the diameter of the calyx. The coefficient of variation for essential oil yield was33.71%. The lowest (2.1%) and the highest (3.51%) average essential oil yields were observed inKaver and Lives populations, respectively. Minimum (0.93%) and maximum (6.2%) essential oilyields were observed among the individuals of the Lives and Kaver populations, respectively.Highest (54.49%) coefficient of variation for rosmarinic acid content was observed in Bone Adabpopulation. Amount of rosmarinic acid of methanolic extract of under study populations showedhigh variability and varied from 0.54 to 7.29% among individuals, while the average rosmarinicacid in populations varied from 1.62 percent (Kaver population) to 4.14 percent (Zarrin Abadpopulation). Diversity of S. richingeri within populations was higher than among them showinglimited segregating of populations.
Payam Ebrahimi; mehdi Eslah; Maryam Azarakhshi
Abstract
One kind of the mass wasting which takes much toll and leaves much damage in the world and many locations in Iran is landslide. Landslide susceptibility mapping allows recognizing susceptible areas to be considered in environmental programs. Present research is aimed at Landslide susceptibility mapping ...
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One kind of the mass wasting which takes much toll and leaves much damage in the world and many locations in Iran is landslide. Landslide susceptibility mapping allows recognizing susceptible areas to be considered in environmental programs. Present research is aimed at Landslide susceptibility mapping in Hafshejan watershed in Chaharmahal-o-Bakhtiari province using Spatial Multi Criteria Evaluation (SMCE) method via geographic information system (GIS) and ILWIS software and AHP technic. Therefore, regarding the sites where landslides occurred, comparative studies, and the findings of other scholars, eight informational layers were identified for this research. Then, the tree of factors and restrictions was designed in ILWIS software. All layers were standardized and were evaluated and weighted applying AHP model. Last but not least, upshot model and landslide hazard zonation map were prepared and presented for the relevant study area. It was found out that from among effective factors, distance from road, distance from fault and distance from stream of 0.4047, 0.2239 and 0.1302 weight respectively are the most important factors triggering landslide in study area. According to the presented model, about 1.32 percent of watershed area (1013900 square meters) is extremely high risk and 9 percent (6909800 square meters) is high risk. The results of accuracy evaluation of the presented model are indicative of ascendantal trend of landslide index from very low hazard zone to very high hazard zone and they are indicative of sufficient precision of this model.
nayefe adak; Hossein Arzani; Sayed Mahdi Heshmatol vaezin
Abstract
Beekeeping is one of the agricultural production activities that can create employment with a small amount of investment. Beekeeping can be heeded as one approach to increase stakeholder’s income of rangelands, balance between livestock and rangeland resources, enhancing the economic status of ...
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Beekeeping is one of the agricultural production activities that can create employment with a small amount of investment. Beekeeping can be heeded as one approach to increase stakeholder’s income of rangelands, balance between livestock and rangeland resources, enhancing the economic status of the villagers and participation in range management plans. Zhiwar rangelands have great potential of land uses variety .Therefore in this study, we decided to determine the amount of increasing income from beekeeping. some of the factors that can affect the income of beekeepers were studied in this research. some of this factors include individual traits of beekeepers, the unit traits of beekeeping, the Costs, incomes. the datas of questionnaires in this study were collected by interview and filling out questionnaires. Questionnaire analysis was performed by using SPSS software. The results showed that the number of hives, the ratio of sugar to honey had significant impacts on the income of beekeepers and honey production. Among whole costs, sugar had the greatest proportion which causes decreasing in prices and thus, profitability. On one side the Increase of the percentage, causes the ascendancy in production and income, on the other side, it causes reducing in the costs and increasing in expenses. Thus, reducing the profitability is not only because of the high consumption of sugar, it may be also due to poor marketing. But the number of hives due to reducing average costs causes increasing profitability
maryam etehadi abari; a a; a a; meghdad jur gholami
Abstract
Land cover is also important factor for protecting the soil against erosion. A fully forested watershed experiences relatively little surface erosion, but timber harvest alters the canopy cover, exposing the soil to water and wind. Forests provide the maximum amount of soil protection. Reduction of vegetative ...
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Land cover is also important factor for protecting the soil against erosion. A fully forested watershed experiences relatively little surface erosion, but timber harvest alters the canopy cover, exposing the soil to water and wind. Forests provide the maximum amount of soil protection. Reduction of vegetative cover by forest harvesting generally increases the average surface runoff volume and sediment While, the hydrologic response of forest harvesting has been rarely considered. Towards this attempt, the present study has been conducted to investigate the effect of vegetation cover on hydrological components in plot scale (2m*1m) with four replicates in tow slope scale (0-20%, 20-40%) in Kheyrud Forest of Iran during December 2014 until December 2015. The rain depth was measured by using a rain gauge installed in the study area. The runoff volume and sediment yield were also measured through field data collection and lab analyses by weighting and decantation methods. The results of the study showed significant effects of vegetation cover (P ≤0.01) on runoff volume and sediment yield. Natural forest without harvesting, forest with selective harvesting treatments exhibited the lowest amounts of runoff and sediments, with averages of 372.31, 878.96 cc, and 0.08, 0.17 gr m-2 respectively, in comparison to other treatments. Linear regression among mentioned parameters (precipitation, runoff, and sediment) were determined. The results show that there were significant correlation and linear regression among precipitation, runoff and sediment.
payam ebrahimi; Ali Salajegheh; Mohsen Mohseni Saravi; Arash Malekian; Amir Sadoddin
Abstract
One of the important criteria for quality of life is the health of the watershed. Researches in this field show that in Iran, a model for assessing the health of the watershed is not prepared. So, In this study, using the statistical data of 27 years (1990-2016) 5 environmental variables in the Taleghan ...
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One of the important criteria for quality of life is the health of the watershed. Researches in this field show that in Iran, a model for assessing the health of the watershed is not prepared. So, In this study, using the statistical data of 27 years (1990-2016) 5 environmental variables in the Taleghan watershed in the province of Alborz is estimated using gene expression and Bayesian network techniques. By using the gene expression programming and the Bayesian network of each variable, the years from 1991 to 2006 selected as a training data and 2006 to 2014 as test data, and from 2014 to 2016 selected as validation period (predictive accuracy). In comparison, the estimation accuracy of the gene expression and Bayesian network, the mean correlation values of 5 variables are 0.87 and 0.78, respectively. In the case of the gene expression model, the values of the coefficient of determination in the training section were: 0.87 for discharge, sediment, 0.92, precipitation, 89.9, temperature 0.91 and evaporation 0.77, and also in the Bayesian network, the values were 0.73, 0.88, 0.78, 0.71 and 0.81. The amount of gene expression scheduling will have a high power in simulating future values, given the generation of a generation of 200,000 times. The results of this study indicate that the health state of the watershed with a score of 8 in 2016 has advanced cancer status, and according to the results of the model in 2017, it can be in the recurrence of cancer.
faraz estelaji; alireza abasi semnani; ehsan alipouri
Abstract
Evaluation and planning of crisis management with natural disaster approach includes many components. In this regard, one of the basic pillars of construction management is based on resilience. With this view, attention to planning and research priorities of our country shows the present and future. ...
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Evaluation and planning of crisis management with natural disaster approach includes many components. In this regard, one of the basic pillars of construction management is based on resilience. With this view, attention to planning and research priorities of our country shows the present and future. Construction management in flood-prone areas is one of the most important priorities for studies and planning for sustainable development in the country. According to the studies conducted, the study area is one of the flood-prone areas and according to the floods, damages have occurred. We have witnessed a lot of lives and infrastructure in this area. A review of the construction of settlements in the study area shows that with the approach of construction management, many constructions have been carried out and are being carried out in this area. There are many challenges from the crisis management approach. The opinion is the method and nature of survey and exploration. In this regard, in this article, Lorestan flood zoning has been done in GIS system and strategies to increase productivity have been presented
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.
Maryam Azarakhshi; Behnoush Farokhzadeh; Mohammad Mahdavi; Hossein Arzani; Hassan Ahmadi
Abstract
Iran is located in dry belt of the earth and always involved with drought in different sections. Drought has already caused many losses to natural plant cover, agriculture and human society. For drought monitoring, we can use some drought indecies. In this research, the Standard Index of Annual Precipitation)SIAP),Sandardized ...
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Iran is located in dry belt of the earth and always involved with drought in different sections. Drought has already caused many losses to natural plant cover, agriculture and human society. For drought monitoring, we can use some drought indecies. In this research, the Standard Index of Annual Precipitation)SIAP),Sandardized Precipitation Index (SPI) and Palmer Drought Severity Index (PDSI) were used for assessment of drought effects on rangeland plant production. The research area is located in Qom province that contains eight rangeland sites. Plant production and soil factors were measured in rangeland readiness period from 1997-1998 to 2005-2006 annualy. Regression techniques were used between drought indices and total production and also production of different vegetation forms in seven time scales (early March to late July (growth season) and early February to late July (growth season and the previous month), March to June, March to May, March to April and March (start of growth season). The best drought index was then selected based on the highest correlation coefficient and lowest standard error. The result showed that the best drought indices in Qom rangelands are SPI-3, PDSI, SPI-24 and SPI-6, respectively. Also the most significant time step was resulted growth season and specially early stage of growth season.
Ebrahim Omidvar; Ataollah Kavian
Abstract
Landslides are the major natural hazard, causing significant damage to properties, lives and engineering projects in all mountainous areas in the world. In order to estimate the role of the landslides in erosion processes and evaluation of their risks, it is necessary to quantify landslides. This quantifying ...
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Landslides are the major natural hazard, causing significant damage to properties, lives and engineering projects in all mountainous areas in the world. In order to estimate the role of the landslides in erosion processes and evaluation of their risks, it is necessary to quantify landslides. This quantifying can be performed by applying the probability distributions that show the landslide size against the probability density. This study was investigated the behavior of landslide areas and volumes on Frequency distributions in Mazandaran province. Also total number, area and volume of landslides that have occurred over time were estimated using the approach suggested by Malamud et al. Result of cumulative frequency distribution of landslide area and volume revealed the significant proportion of large landslides in determining the total landslide area and volume. According to Malamud et al. approach total number of landslides were estimated to be 9823±2323. These landslides have been obliterated over the time by soil erosion, vegetation growth or by human activities and total of their affected area and volume by these landslides were 31.5±7.1 km2 and 0.232±0.052 km3, respectively. The obtained results also presented an area of 2×10-3 km2 as a critical threshold area for transition between resistances against slope failure.
S. Ebrahimi; S.H Sadeghi
Volume 62, Issue 2 , October 2009, , Pages 167-173
Abstract
Recognition of rangeland species with the maximum efficiency and the minimum water usage is very important, since major parts of rangelands in Iran are located in arid and semiarid climate. In addition, the rangeland improvement and management on the basis of transpiration rate of rangeland species in ...
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Recognition of rangeland species with the maximum efficiency and the minimum water usage is very important, since major parts of rangelands in Iran are located in arid and semiarid climate. In addition, the rangeland improvement and management on the basis of transpiration rate of rangeland species in different climatic conditions has great importance. The goal of this research is comparison and measurement of transpiration rate in four important species of Medicago sativa, Trifolium repens, Sanguisorba minor and Trifolium pratens as well as the assessment of their efficiency in dry matter production under semi natural conditions in College of Natural Resources and Marine Sciences, Tarbiat Modares University, during spring and summer of 2005. The rates of daily transpiration of the mentioned species were measured in small vases with upper area of 50.27cm2 in 5 replications and adjacent to five control vases during 85 days using weighting method. The results of the study showed that the maximum and minimum rate of transpiration per dry matter is related to Trifolium pratens and Medicago sativa with the values of 498.253 and 59.274 ml, respectively. The applications of such type of result facilitates the determination of water requirement of rangeland ecosystems under improving operations and also lead to select the most suitable improvement method and rangeland species as well.
Mojtaba Akhavan Armaki; Hossein Azarnavand; Mohammad Hasan Asareh; Ali Ashraf Jafari; Ali Tavili
Abstract
Environmental stress especially drought is one of the most important factors to reduce and disturbance in different stages of floral growth especially sprouting in dry and semi-dry lands of Iran. For this purpose a factorial essay executed in accidentally manner with four iterations in vitro condition. ...
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Environmental stress especially drought is one of the most important factors to reduce and disturbance in different stages of floral growth especially sprouting in dry and semi-dry lands of Iran. For this purpose a factorial essay executed in accidentally manner with four iterations in vitro condition. Four genotypes of Bromus tomentellus pasture types were used (92 Tehran, 630 Kordestan, 3414 Shahrekord and 9507 Lorestan) and four drought care (-3, -6 and -9 times distilled water). In this essay the sprouting percentage, Root length, Shoot length, Seedling length, Root length to Shoot length rate, Seedling dry weight, Seedling fresh weight, dry to fresh weight rate sprouting rate and seed health index were determined. The result showed that the with stress drought increase, all attributes except the dry weight to fresh weight proportion reduced significantly. The reduction in all under assessment properties were from -3 to -6 in potential. In general, in tested genotypes, Lorestan (9507) genotype showed a better sprouting in under study potentials and had a meaningful preference to other genotypes. From assessed parameters, Seedling length and seed index standard showed the most possible reaction to changing potential of water. The best levels to assess the stability to drought were the -6 and -9 load potentials in all drought levels.
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.
ali azarnivand; Mohammad Ebrahim Banihabib
Abstract
Owing to the oncoming needs and increasing the population of Lake Urmia Watershed, providing equilibrium between water supply and demand seems quite challenging and the Lake cannot be successful in meeting its ecological demands in this critical condition. In this unfavorable situation, water resources ...
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Owing to the oncoming needs and increasing the population of Lake Urmia Watershed, providing equilibrium between water supply and demand seems quite challenging and the Lake cannot be successful in meeting its ecological demands in this critical condition. In this unfavorable situation, water resources must be managed through a sustainable context. With this knowledge in hand, a multi attributes framework was applied to investigate the preference of supply or conservation alternatives. Preference of sustainable development attributes was calculated in a pairwise hierarchical structure and instead of time-consuming conventional procedure, Absolute Measurement was used that compares qualitative scales instead of alternatives and can overcome the problem of rank reversal in pairwise comparison. Ranks of the Alternatives were evaluated by VIKOR method which can provide a set of compromise solutions instead of one solution. Due to sensitivity analysis performance, VIKOR was introduced as a robust model in ranking the water resources alternatives. With regards to the results of this two-stage hierarchical-compromising approach, dealing with Watershed crisis is depended on organized indigenous collaboration, water use optimization and protecting available natural resources. On the other hand, supplying water by structural development without sustainability consideration would not be effective.
Mohsen Asadollahi; Mohammad Jafari; vahid sayare; Ali esmaeili; Mohammad Tahmoures
Abstract
Wind erosion is one of the most important aspects of land degradation in arid and semi-arid regions, which 20% of land area of the world has been influenced by wind erosion. The wind increases the desertification process by displacing sand dunes. Therefore, the stabilizition and preventing the moving ...
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Wind erosion is one of the most important aspects of land degradation in arid and semi-arid regions, which 20% of land area of the world has been influenced by wind erosion. The wind increases the desertification process by displacing sand dunes. Therefore, the stabilizition and preventing the moving sands is essential. A strategy to combat this phenomenon is to reduce wind speed or to increase surface cover and soil resistance against erosion winds. The application of mulch or soil cover is one of the methods widely used to stabilize moving sands. For this purpose, a study was done at the Research Station International Desert Research Centre in Kashan city. The main purpose of this study was to investigate the effect of Multivariate biopolymer treatment at three concentrations (15%, 30% and 60%) on the moisture content of three sand depths (first depth of 0-5 cm, second depth of 5-10 cm and depth of third 10-20 cm), and study this mulch Compared with levels without mulch on the sand. Results showed soil moisture retention in Mulching compared to the control treatment, and statistically, there was significant differences between different depths of soil moisture Mulching compared to the control treatment and in between the first, second and third depths, the first depth had the highest increase in moisture holding compared to the Control treatment.
nasim arman; Ali Salajegheh; Sadat Feiznia; Hassan Ahmadi; Jamal Ghoddousi; ali kiani rad
Abstract
Identification of homogenous watershed sub basins allows generalization of environmental study results. For this purpose, first available data for 27 selected watersheds in North Alborz regarding 21 variables including physiographic and climatic characteristics was gathered. The most important factors ...
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Identification of homogenous watershed sub basins allows generalization of environmental study results. For this purpose, first available data for 27 selected watersheds in North Alborz regarding 21 variables including physiographic and climatic characteristics was gathered. The most important factors impacting upon soil erosion and sediment yield were equivalent rectangular length, mean annual precipitation, rock susceptibility, aspect and drainage density which were identified using factor analysis (Principle Component Analysis : PCA) and a 80.72 percent variation of data was observed (KMO =0.516). For determination of homogenous region, different methods of cluster analysis (hierarchical, K-means and two step clustering) were used and three homogeneous regions were specified. Discriminant function analysis was employed and confirmed the results of cluster analysis in homogenous region. On the other hand, based on these five factors, a discriminant function was defined and canonical correlation, chi-square, wilks’ lambda values revealed that three homogenous regions were quite separate.
sara Edrisnia; Ahmad Pahlevanroy; Alireza Moghadamnia; Aliakbar Nazarisamani; Abas Miri
Abstract
In Low rainfall, dry areas such as Iran that surface fresh water resources are limited and this water is exposed to pollution risk, finding and preserving underground water supplies is the best way for removing water needs. In addition, in some parts of Iran, climate and tectonic structure have created ...
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In Low rainfall, dry areas such as Iran that surface fresh water resources are limited and this water is exposed to pollution risk, finding and preserving underground water supplies is the best way for removing water needs. In addition, in some parts of Iran, climate and tectonic structure have created good conditions for forming karstic table. Following America, China and Turkey, Iran has the highest percentage of karst and more than eleven percent of Iran’s area is covered by karstic constructors.The purpose of this study is exploring the relationship between lineaments extracted from satellite imageries, tectonic elements, hydrography network and topography factors with Karstic water resources abundance in Maharloo using GIS and remote sensing. Information layers including lineaments, range curvature, elevation classes, slope, vegetation, springs, tectonic elements and hydrography network were provided through field visits, topographic maps, geology, satellite imagery and digital models. Findings were analysed with statistical tests such as Chi square, Pearson correlation coefficient, PCA test, and principal component analysis. It was found out that there is a close tie between formation type, topography (egslope, elevation and range curvature), lineaments and hydrological factors with spring abundance. The significant role of environmental and structural factors drives the necessity of paying attention to them in investigation of the abundance of springs and transmission of groundwater in Karstik areas.
A Ahmadi; A Sanadgol
Volume 63, Issue 3 , December 2010, , Pages 277-287
Abstract
Desert and marginal lands of playas which are covered with halophyte shrubs, play a great role in supply of forage for livestock as winter rangelands. In this research, plant samples were collected from four palatable halophyte species for Zandi sheep of Qom desert rangelands including Seidlitzia rosmarinus، ...
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Desert and marginal lands of playas which are covered with halophyte shrubs, play a great role in supply of forage for livestock as winter rangelands. In this research, plant samples were collected from four palatable halophyte species for Zandi sheep of Qom desert rangelands including Seidlitzia rosmarinus، Halocnemum strobilaceum، Alhagi camelorum and Tamarix passerinoides in two phenological stages (vegetative growth and seed ripening). The plant samples were dried and analyzed by AOAC methods for qualitative indices such as: crude protein (CP %), acid detergent fiber (ADF %), dry matter digestibility (DMD %) and metabolizable energy (ME). The results showed significant differences (p
Hossein Arzani; Mehdi Moameri; Javad Motamedi; Mashaallah Mohammadpour
Abstract
One of the important factors to make a balance between number of grazing livestock and grazing capacity is whether forage contains sufficient energy and protein during grazing period or not. Therefore in this study, forage quality was evaluated for important species in steppe rangelands of Changuleh ...
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One of the important factors to make a balance between number of grazing livestock and grazing capacity is whether forage contains sufficient energy and protein during grazing period or not. Therefore in this study, forage quality was evaluated for important species in steppe rangelands of Changuleh located in Ilam province. To do this, samples from four species of Hammada salicornia, Salsola lanchnantha, Convolvulus oxyphyllus and Pteropyrum noeanum, those made considerable components of rangelands vegetation in the region, were collected during three phenological stages (active growth, flowering and maturating) over 2008. Then chemical compositions were determined including crude protein (CP), acid detergent fiber (ADF), dray matter digestibility (DMD) and metabolizable energy (ME). According to the results, maximum CP was obtained from Hammada salicornia in active growth stage. Crude protein component of this species was more than critical level (7%) for sheep in the maintenance condition. Also in this species, ME was in higher critical level (8 Mj/kg) compared with the other species
sahar Aryaeefar; Abolfazl Tahmasebi; Majid Mohammad Esmaeili; Ali Rahemi Karizaki
Abstract
Atriplex leucoclada Boiss is one of the most important native species of dry and semi-arid rangelands in Iran which is faced to low germination and seed dormancy. In order to investigate the effective methods of breaking dormancy of this species, an experiment was conducted in a completely randomized ...
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Atriplex leucoclada Boiss is one of the most important native species of dry and semi-arid rangelands in Iran which is faced to low germination and seed dormancy. In order to investigate the effective methods of breaking dormancy of this species, an experiment was conducted in a completely randomized design with eight treatments including scarification treatments 100 and 200, hypochlorite: at 5, 10, 15, 20, 25 minutes, boiling water treatment: submerging seeds in boiling water for 1, 5, 10, 15, 20, 25 minutes, wet chilling : putting Seeds in a refrigerator at 4 ° C and continuously wet at intervals of 1, 2, 3, 4, 5, 6, 7, 8 weeks, Sulfuric acid treatment: Seeds in Sulfuric Acid 98% Diets: 5 seconds, 30 seconds, 5, 10, 15, 20, 30 minutes, Seeds Dry chilling: in a refrigerator at 4 ° C at intervals of 1, 2, 3, 4, 5, 6, 7, 8 weeks, and Seed burial treatments were carried out in four replications in two laboratory sections (petri-dish cultivation) and cultivation was done in a pot. In the laboratory section, no significant results were obtained, but in the culture, results of data analysis indicated that 25 min hypochlorite treatment had the highest rate of germination and 100 mg treatment and hypochlorite treatment of 25 minutes had the best effect on seed dormancy.
Hossein Arzani; vahideh Abdollahi; Javad Motamedi; Majid Akhshi
Abstract
Nowadays, most attention is focused on physical and non-destructive methods, such as NIRS, to measure the chemical composition of rangeland species. Therefore, the purpose of this study is to provide calibration models for Infrared NIRS to estimate the forage quality of shrub species, so that in addition ...
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Nowadays, most attention is focused on physical and non-destructive methods, such as NIRS, to measure the chemical composition of rangeland species. Therefore, the purpose of this study is to provide calibration models for Infrared NIRS to estimate the forage quality of shrub species, so that in addition to saving time and cost, the quality of these plants could be estimated with proper accuracy. For this purpose, 654 samples of vegetative, flowering and seeding stages were irradiated by the DA7200 Perten Instrument to estimate the values of nitrogen (N), crude protein (CP), acid detergent fiber (ADF), dry matter digestiblility (DMD) and metabolizable energy (ME) via NIRS. Then, the data were transferred to the Unscrambler software for multivariate analysis. Before fitting the model, S.Golay and SNV methods were used for normalization of data distribution. Calibration and validation of model were performed using PLS1 method and Cross Validation method, respectively. Then, the predictability of models was evaluated by considering the calibration statistics. A total of 18 calibration programs were developed. Considering the calibration statistics, it could be said that the coefficient of determination was above 80% in all the factors studied. Also, at all growth stages, the correlation coefficient between the reference data and the data estimated by NIR was above 90%. Our results clearly showed that NIR calibrations obtained in this study could be used in current and future programs to assess the forage quality of shrub species used by livestock.
Fazlolah Ahmadi Mirghaed; Babak Souri; Mahtab Pir Bavaghar
Abstract
Rangelands are among the natural resources which have a considerable effect on environment and man’s life. Iranian rangelands mostly have poor condition and exhausted by intensive over grazing, should be utilized according to their ecological capability and land suitability. The main objective ...
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Rangelands are among the natural resources which have a considerable effect on environment and man’s life. Iranian rangelands mostly have poor condition and exhausted by intensive over grazing, should be utilized according to their ecological capability and land suitability. The main objective of this study is to evaluate ecological capability and land suitability of Gheshlagh dam’s watershed area-parcel A (In Kurdistan province, western Iran) to develop range management plan. Following data collection; determination of the important parameters for evaluation of rangelands environmental capability in the study area was carried out and then obtained parameters were given values based on Analytical Hierarchy Process (AHP) method. Finally, the obtained values were applied to the important parameters for evaluation of rangelands environmental capability according to technique for order performance by similarity to ideal solution (TOPSIS). The results approved that suitability of a land is classifiable for various types of land uses using MCDM methods. Also according to the results specified that the physical criteria of land have more effective than other parameters to develop range management plan. Moreover, land evaluation of study area showed that eastern parts of the watershed had higher suitability to develop range management plan.
