Abazar Esmaili; Mohammad Golshan
Abstract
Watersheds are a vast area with different conditions that simulation and studying the processes of runoff and sediment production in these area are critical for managing and maintaining resources. The Kozatopraghi watershed with an area of 766 km2 is located in the south and upstream of the Garesou basin, ...
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Watersheds are a vast area with different conditions that simulation and studying the processes of runoff and sediment production in these area are critical for managing and maintaining resources. The Kozatopraghi watershed with an area of 766 km2 is located in the south and upstream of the Garesou basin, Ardebil province. Between the hydrological models, based on the capabilities of the SWAT model, this model was used to simulate the hydrological processes of the area in sub watershed scale. Also, for a more accurate examination the rainfall simulator was used in the hydrologic response units (HRUs), the obtained results were generalized to the sub watershed scale. The results of SWAT model were assessment with statistical parameters R2, NSE and RMSE. In the calibration and validation periods these coefficients for simulation runoff obtained 0.8-0.74, 0.71-0.69 and 0.32-0.33, respectively, and for simulation sediment yield obtained 0.75-0.66, 0.72-0.64 and 35.27-26.39, respectively. Assessment the obtained results of rainfall simulator showed that Loamy soils, located in 8 HRUs have high effect in sediment yield production. The maximum runoff and sediment yield by rainfall simulator and SWAT model were observed in sub watersheds 13 and 1, that indicating poor and inappropriate conditions in these subwatersheds. Comparing the study methods showed that the SWAT model have better performance than rainfall simulator for simulation runoff. Also, the estimated sediment yield by this model is lower than rainfall simulator that is close to observed values.
s.h Parvari Asl1; ahmad Pahlavanravi; ali reza Moghaddam Nia
Volume 63, Issue 2 , September 2010, , Pages 149-16
Abstract
Desertification is the consequence of series of processes in which climate change and human activities are more important factors than others. Arid and semi-arid areas have occupied most parts of Iran. Sistan region is one of arid areas of Iran where wind erosion is an important factor of land degradation ...
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Desertification is the consequence of series of processes in which climate change and human activities are more important factors than others. Arid and semi-arid areas have occupied most parts of Iran. Sistan region is one of arid areas of Iran where wind erosion is an important factor of land degradation and soil deterioration. For classification of desertification intensity, several methods have been proposed so far. ESAs Model is on of the best and recent methodologies introduced by the European Commission in 1999 and evaluated by most of European as well as Middle Eastern countries. ESAs has more advantageous than other methods because of its accuracy, particular weighing of layers, use of geographical information systems in overlaying of maps, use of geometric mean over arithmetic one or sum in computing indices and final desertification map. The method was chosen to monitor desertification in the study area. The factors which affect on desertification were evaluated based on the related tables. According to the conditions of the study area, it was found that four factors including vegetation cover, soil, climate and land use management are the most important desertification factors. The results showed that climate play vital role in land degradation and desertification. Based on the results of it is found that the study area has critical conditions. It includes high critical (C3), moderate critical (C2) and low critical (C1) classes of desertification which cover 68%, less than 1% and 31% of the region, respectively.
H. Arzani; A. Esfandiari; H. Nourozian; M. Ghorbani; J. Torkan
Volume 62, Issue 2 , October 2009, , Pages 175-186
Abstract
Knowledge on animal requirement, available forage and its quality is fundamental for successful livestock and range management. Since sheep is dominant grazing animal of rangelands in Iran and there are over 27 sheep breeds and each breed has special body size, physiological condition and consequently ...
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Knowledge on animal requirement, available forage and its quality is fundamental for successful livestock and range management. Since sheep is dominant grazing animal of rangelands in Iran and there are over 27 sheep breeds and each breed has special body size, physiological condition and consequently different daily nutrition requirement, animal unit should be determinated for dominant breed of sheep in every region to be calculated the forage requirement based on body weight, daily energy requirement and quality of available forage. In this study, two herds of Kermanshah's Sanjabi breed have been weighted including 50 animals in each herd (15 heads three years old ewe, 15 heads four years old ewe, 5 heads three years old ram, 5 heads four years old ram, 5 heads three months old lamb and 5 heads six months old lamb) in three stages. The body weight of Sanjabi breed (based on average body weight of three and four years old ewe) was 60.68 ±0.56 kg. Animal unit equivalent (AUE) for ewe, ram and lamb were 1.29, 1.88 and 0.63 kg, respectively. The results of analysis of variance indicated that there are significant differences between weight of ewes and rams (P
Fazel Amiri; Hassan Yeganeh
Abstract
فرآیند ارزیابی پوشش گیاهی به وسیلة تصاویر ماهواره‌ای نیازمند استفاده از شاخص‌های گیاهی است. شاخص گیاهی بطور گسترده‌ای برای ارزیابی و پایش تغییرهای بو شناختی (اکولوژیک) ...
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فرآیند ارزیابی پوشش گیاهی به وسیلة تصاویر ماهواره‌ای نیازمند استفاده از شاخص‌های گیاهی است. شاخص گیاهی بطور گسترده‌ای برای ارزیابی و پایش تغییرهای بو شناختی (اکولوژیک) مانند پوشش گیاهی، بیوماس پوشش سطح خاک و شاخص سطح برگ استفاده می‌شود. اهداف این مطالعه شامل بررسی قابلیت داده‌های ASTER به منظور برآورد پوشش گیاهی در حوزه آبخیز قره آقاچ و همچنین انتخاب شاخص‌های گیاهی مناسب در تهیه نقشه پوشش گیاهی منطقه، می‌باشد. پیش‌پردازش‌های مختلف شامل تصحیح هندسی با استفاده از تصاویر موجود مربوط اردیبهشت 1387 با RMSE حدود 5/0 پیکسل انجام شد و تصحیحات اتمسفری و توپوگرافی به ترتیب به کمک روش تفریق عارضه تاریک و مدل لامبرت انجام شد. از شاخص‌های گیاهی و طبقه‌بندی نظارت شده برای تهیه نقشه پوشش گیاهی استفاده شد. عملیات برداشت زمینی در اردیبهشت ماه 1387 در سطحی معادل 25/8962 هکتار آغاز شد. تیپ‌های مختلف گیاهی به روش نمونه‌برداری سیستماتیک- تصادفی، سطحی که اختلاف مهمی در ترکیب فلورستیک- فیزیونومیک نداشت، به عنوان تیپ گیاهی مستقل و یکنواخت در نظر گرفته شد. در کل منطقه حدود 60 نقطه تصادفی انتخاب و اندازه‌گیری پوشش گیاهی به روش برآورد انجام گرفت. اطلاعات رقومی و شاخص‌ها به عنوان متغیر مستقل و اطلاعات زمینی به عنوان متغیر وابسته معرفی شدند. معادلات مختلف با استفاده از شاخص‌ها بر روی تصاویر اعمال و سپس تصاویر به 5 کلاس پوشش طبقه بندی شد. در نهایت نقشه پوشش و نقاط نمونه‌برداری برای بررسی صحت نتایج، کنترل گردید. نقشه پوشش منطقه با اعمال پردازش‌های گوناگون بر روی تصویر تهیه گردید. با بهره گیری از سامانه اطلاعات جغرافیایی تمام لایه‌های اطلاعاتی با یکدیگر ترکیب و نقشه پوشش اراضی منطقه تهیه شد. نتایج این پژوهش نشان داد که، شاخص NDVI همبستگی بالایی با درصد پوشش گیاهی داشت (01/0P?). صحت کلی و ضریب کاپا برای نقشه پوشش با شاخص NDVI به ترتیب برابر 5/68 % و 4/72 % بدست آمد. نتایج این مطالعه نشان داد که پوشش گیاهی با درصد تاج پوشش 40-20 درصد، وسیع‌ترین طبقه تراکمی پوشش این منطقه می‌باشد. نتایج این پژوهش همچنان نشان داد که تصاویر سنجنده ASTER و شاخص‌های گیاهی ابزار قدرت مناسبی برای تهیه نقشه پوشش گیاهی می‌باشد. بنابراین، می توان از نقشه پوشش تهیه شده از داده‌های ASTER برای برآورد پوشش و تولید و ارزیابی مراتع استفاده کرد.
Mohsen Padyab; Sadat Feiznia; Hassan Ahmadi; Ardeshir Shafei
Abstract
Small precipitation with temporal and spatial variation of rainfall is the main responsible factors on flood occurrence in arid and semi arid regions. Floods in their regions usually contain high concentration of sediments which when they are deposited on the surface of lands, they change the properties ...
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Small precipitation with temporal and spatial variation of rainfall is the main responsible factors on flood occurrence in arid and semi arid regions. Floods in their regions usually contain high concentration of sediments which when they are deposited on the surface of lands, they change the properties of soils of the area. In this research, the effect of floodwater spreading on physic-chemical characteristics of soil in Gachsaran floodwater spreading station, after 12 years of floodwater spreading, is investigated. For this purpose, soils and sediments were sampled from 0-15, 15-30, 30-45 and 45-60 centimeter depths, from the flood spreading and representative (without floodwater spreading) fields. Samples were analyzed for following proportion: percentages of clay, silt, sand and gravel, pH, EC, percentage of lime, anions and cations. The result have show that the amounts of clay, silt and sand have increased, chemical properties have changed slightly and among the chemical properties, pH and percentage of lime have higher change so that pH decreased and lime increased in floodwater spreading field respect to the representative field. It is concluded that due to floodwater spreading, physical properties of the field underwent considerable amount of changes and gravelly texture has changed to less gravelly texture. The surface soil has undergone more changes and from the surface to the depth, change of physical and chemical properties becomes negligible.
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.
Maryam Rostami; Ali Salajegheh; Forood Sharifi; Arash Malekian; TAYYEBEH MESBAHZADEH
Abstract
AbstractPrecipitation plays an important role in climatic, water, energy and biogeochemical cycles. Several global and regional data sets currently provide historical estimates of this variable over Iran, including the MWEP and WFDEI forcing datasets and production of some institutions such as MOHC, ...
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AbstractPrecipitation plays an important role in climatic, water, energy and biogeochemical cycles. Several global and regional data sets currently provide historical estimates of this variable over Iran, including the MWEP and WFDEI forcing datasets and production of some institutions such as MOHC, SMHI and IITM. All these datasets provide data with different resolutions based on gage stations, satellite Images and models output. In this study, we do an inter comparison between these data sets during 1990- 2008. We also validate all ten data sets against independent ground station observations over 30 second-order basins of Iran. MSWEP and WFDEI have an acceptable compatibility with observational data on different spatial and temporal resolutions. RMSE and Bias are 5.68, 6.34 and 0.58, 2.75 for these two datasets during 228 months, respectively. However, it is needed that MSWEP improves in the western and northwestern parts of the country and WFDEI in June and September months. Our findings in this research provide valuable guidance for a variety of stakeholders, including rainfall- runoff and land-surface modelers, watershed management studies and data providers.
Sadegh Tali-Khoshk; Mohsen Mohseni Saravi; Mahadi Vatakhah; Shahram Khalighi-Sigarodi
Abstract
Because of insufficient factors including facilities, budget, human resources as well as time watershed operation is not applicable throughout the basin. As a result, watershed operation should be performed in the sub-basins in which is more affectionate and the risk frequency of some events such as ...
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Because of insufficient factors including facilities, budget, human resources as well as time watershed operation is not applicable throughout the basin. As a result, watershed operation should be performed in the sub-basins in which is more affectionate and the risk frequency of some events such as destruction, degradation; physical and financial damage and also flooding are considerably high. In addition, due to hydrometric stations, defects or the lack of stations in some areas, some efforts have been made experts recently to assess and consequently introduce some novel and reliable methods for prioritizing on the basis of current data obtained from sub-basins features of different geographical regions. In current study, the utilization possibilities of neuro-fuzzy technique and SCS in HEC-HMS model that have different potential to examine a wide range of advantageous and disadvantageous in making various decisions were studied. To determine the prediction accuracy of these methods, the rate of flow and sediment output of Taleghan sub-basins were taken over one year. The results of these methods were then compared with the maximum two-year return period flow observations. Our results revealed that in making prioritization, neuro-fuzzy as compared with the SCS method can produce the best prediction as long as the coefficients of errors, efficiency compared to the observational data and predictions are taken into account.
MohammadReza Akbari; majid rahimi
Abstract
Extreme events such as drought and floods in Iran have always been one of the most important and harmful issues in the country and their occurrence and prediction have been in the focus of most researchers. Occurrence of floods in recent years and the inability of the management system to act in a timely ...
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Extreme events such as drought and floods in Iran have always been one of the most important and harmful issues in the country and their occurrence and prediction have been in the focus of most researchers. Occurrence of floods in recent years and the inability of the management system to act in a timely manner to reduce its effects on flood-prone communities have led everyone to use various methods to predict floods. However, the lack of facilities for monitoring and collection of meteorological and hydrological data in the country's watersheds is considered a major obstacle to flood studies. Therefore, using the minimum available data to predict floods can be a good way to plan and study floods in Iran quickly. Therefore, in this study, the application of ARIMA time series modeling and ARIMA-Fourier hybrid model for modeling the maximum instantaneous discharge on an annual scale in 6 stations of Gorganroud watershed was investigated. The results showed that the use of ARIMA model alone cannot have an acceptable result, especially in the annual data scale, but the application of ARIMA-Fourier model could well increase the accuracy and efficiency of the model, so that the accuracy and efficiency indices of the model were significantly improved. As a result, the use of hybrid models such as ARIMA-Fourier can be used to improve the modeling efficiency of flood flows time series.
Mohsen Armin; hasan rouhipour; Hassan Ahmadi; Ali Salajegheh; mohammad Hossein Mahdian; vajihe ghorban nia kheybari
Abstract
Knowledge of soil components controlling aggregate stability is very important to soil structure conservation. Also, identification of the critical soil properties affecting aggregate stability is central to understanding where erosion might be located within a catchment as a result of natural patterns ...
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Knowledge of soil components controlling aggregate stability is very important to soil structure conservation. Also, identification of the critical soil properties affecting aggregate stability is central to understanding where erosion might be located within a catchment as a result of natural patterns in aggregate stability. The objective of this study, which was carried out in surface soils from Taleghan, was to relate aggregate stability to selected soil properties. In this study, based on homogeneity in slope, aspect and lithology work units were prepared, and then by relying on results of geostatistical studies in homogeneous work units in soils of Taleghan watershed, with 3260 hectares in area, 84 points as the soil sampling points were selected. The indices of stability used are the mean weight diameter (MWD) and wet aggregate stability (WAS). Correlation between mean weight diameter and measured properties were extracted using Pearson correlation coefficient and evaluated in terms of their statistical significance. Then based on the results of correlation and using stepwise regression, models of aggregate stability prediction were developed. The unexpected results have been obtained from correlation between soil properties and aggregate stability so that the correlation between aggregate stability and the percentage of Caco3, clay and saturation are negative while that with fine sand and very fine sand are positive. Thus the improvement of aggregate stability and soil erosion control in Taleghan watershed depends on management of these soil properties and soil conservation projects in order to adjust and optimize them
ayad aazami; Mohamad Fayaz; Jeafer Hosianzadeh
Abstract
Depending on in which season or in which section of rangeland livestock grazes, it shows certain behavior. Present study is therefore aimed at exploring preference value of species in Saleh Abad rangelands of Ilamprovince from 2007 to 2010. In this study, the preference value of 17 species and annual ...
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Depending on in which season or in which section of rangeland livestock grazes, it shows certain behavior. Present study is therefore aimed at exploring preference value of species in Saleh Abad rangelands of Ilamprovince from 2007 to 2010. In this study, the preference value of 17 species and annual plants was investigated through the method of percent of consumption. The results showed that the effect of year, month and plant species on preference value is significant. Due to drought, average preference value in 2008 was more than that in 2007, 2009 and 2010, respectively. Preference value of rangeland species was higher in April than in March and statistically the difference was significant. Results showed that the species Ankyropetalugypsophiloides, Annual grass & forbs, Salvia compressa, and Sanguiosorba belong to Class III and of moderate palatability. Other non-palatable species were categorized in class IV and V. In study area, the last two months of grazing season (March and April) matched the first two months of plant growth. Annual grasses and forbs species and Sanguiosorba minor were equally consumed by animals in both March and April.Toward the end of the grazing season (end of April) perennial species are consumed. For example, relative consumption of Salvia compressa and Ankyropetalum gypsophiloides was and 92 percent, respectively. In April, an increase in consumption trend of other perennials was witnessed. Therefore, with presence of livestock in from April to June, fresh forage of perennial herbs is grazed by livestock but farmer s believe that the amount of forage production of perennial herbs is not enough that forces the livestock out of rangeland.
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.
Farhad Aghajanlou; Morteza Akbarzadeh; Ahmad Mousavi
Abstract
The effect of exclosure on the changes of vegetation cover of rangelands of Ahmad-Abad region located in Zanjan province has been studied during 2002 to 2006. Three transects comprises of 60 fixed quadrate were establish within exclosure area and outside as well. The changes of vegetation cover were ...
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The effect of exclosure on the changes of vegetation cover of rangelands of Ahmad-Abad region located in Zanjan province has been studied during 2002 to 2006. Three transects comprises of 60 fixed quadrate were establish within exclosure area and outside as well. The changes of vegetation cover were studied to made comparison between the changes of manipulated factors and soil elements using t test. The results showed that total vegetation cover and vegetation cover of shrubs , perennial grasses and forbs of last year had significant difference compared to those of first year within exclosure (p
Omid Asadi Nalivan; Seid Saeid Ghiasi; Sadat Feiznia; Narges sagghazade
Abstract
At present, Groundwater contamination by nitrate, serves as one of the most important environmental issues. In respect to various land uses of Silveh basin, its ground water quality parameters might vary spatially and temporally. For this, ground water samples taken from 145 points were evaluated. After ...
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At present, Groundwater contamination by nitrate, serves as one of the most important environmental issues. In respect to various land uses of Silveh basin, its ground water quality parameters might vary spatially and temporally. For this, ground water samples taken from 145 points were evaluated. After determining nitrate spatial variations by varyogram, different methods involved distance inverse method and geo-statistics methods of radial estimator approaches, local estimator, ordinary kriging, simple kriging and global kriging were evaluated using GIS software and nitrate spatial distribution map were prepared in two time intervals (pre and post-harvest). Criteria based on the Root Mean Squared Error(RMSE), ordinary kriging method has the lowest error, and the accuracy considerably. Spatial distribution of nitrate in area groundwater indicated that there was high concentration of nitrate in land uses of agriculture and arid area. Of course, presence of shale-stone causes nitrate releases, intensifying issues. Comparison of nitrate samples concentration with national and international standards suggested that 1.38%(2 Point) of all samples have been nitrate-contaminated before harvesting, while 11.03%(16 Point) of them have been contaminated after harvesting.
Hosein Raheli; Baballah Hahati; Ghader Dashti; Amin Shakeri; Jafar Seyyed Akhlaghi
Abstract
Insurance industry is one of the effective factors of developing sustainable agriculture. Natural resources that are more pone to influence than other phenomenon such as: Drought, there are limited areas under insurance. From 86.4 million hectares of country Ranges, there are nearly 3 million hectares ...
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Insurance industry is one of the effective factors of developing sustainable agriculture. Natural resources that are more pone to influence than other phenomenon such as: Drought, there are limited areas under insurance. From 86.4 million hectares of country Ranges, there are nearly 3 million hectares under insurance. Semnan province are compared to other areas has more Range insured. Therefore, in this research effective factors in accepting Range insurance by Semnanian's livestock have been investigated. This research is experimental and applied in the purpose also collected information and documents library. Desired statistical community is all Range man in the Semnan. Among this number of 147 persons using a random sampling as a statistical sample was selected for the 75 samples insurance range men receiver and 72 samples of range men were incompliant insurance. Logit model estimated results show that the class extension, the amount of range feed production, and to borrow the amount preserve and income are efficacious and the number of cattle is negative and significant in the acceptance of ranges insurance.
Elham alsadat Abrisham; Sadat Feiznia
Abstract
The Derakhte Senged area is located in south of Neishaboor town at Khorasan Razavi province. In this research, desertification intensity of Derakht senged area was evaluated using IMDPA, one of the newest method to Assess desertification potential in arid and semi arid regions of Iran. To evaluate desertification ...
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The Derakhte Senged area is located in south of Neishaboor town at Khorasan Razavi province. In this research, desertification intensity of Derakht senged area was evaluated using IMDPA, one of the newest method to Assess desertification potential in arid and semi arid regions of Iran. To evaluate desertification intensity, based on the primary research in this area, 4 criteria were selected including vegetation cover, soil, climate, geology and geomorphology. Each criterion was assessed based on the selected indices which result in qualitative mapping of each criterion cased on geometric mean of the indices. Then, sensitive map of region was extracted using geometric mean of all criteria. By laminate of thematic databases layers and using geometric mean of main criteria intensity map was obtained. The results showed that 0.37 % of study area categorized in low class, 80% was medium and 19.63% involved high class of desertification. Analysis of desertification criteria in this region showed that among study criteria, vegetation cover criteria is a major problem with a geometric average of 3.05 which shows high class, while geology and geomorphology with a weighted average of 1.8, has moderate effect in desertification. Also, climate and soil criteria with a geometric average of 2.04 and 2.21 show medium class desertification.
parisa sadat ashofteh; Omid Bozorg Haddad
Abstract
Food security in the world that water shortages are faced is very important, especially in arid regions. Effects of climate change on agricultural water requirement have doubled this importance. In this study, the risk of water demand has been assessed for a wide range of products under climate change. ...
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Food security in the world that water shortages are faced is very important, especially in arid regions. Effects of climate change on agricultural water requirement have doubled this importance. In this study, the risk of water demand has been assessed for a wide range of products under climate change. AOGCM models have been used to simulate climate variables. The climate change scenarios of climatic variables were weighted by mean observed temperatures and precipitation method and their probability distribution functions were produced. Using the Monte Carlo method, 200 samples (discrete values) of the probability distribution function of the monthly climatic variables downscaled for each month were extracted by SIMLAB and finally time series of climatic variables has been produced in future. Potential evapotranspiration in the future through the relationship of temperature and potential evapotranspiration in the base period was calculated. With introducing about 200-monthly time series of climatic variables in future period to model, water requirement and changes in crops water demand volume were investigated. Investigations indicate water demand volume for crops based on current area under cultivation will increase between 0.05 to 0.96 (106 m3/yr) for risk of 25%, between 0.04 to 6.87 (106 m3/yr) for risk of 50%, and between 1.16 to 12.68 (106 m3/yr) for risk of 75%. Therefore, the results indicate that risk of water requirements will increase. The volume of water demand will be about 2.5, 16 and 31 (106 m3/yr) with risk of 25, 50 and 75 percent, respectively.
F. Amiri; H. Arzani; E. Gavili
Abstract
Existence of pollen and nectar plants in vegetation composition of natural environment is essential for apiculture as one of the utilization types in multiple uses of environmental resources. Therefore, development of this strategy based on indigenous knowledge will increase stakeholder income, which ...
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Existence of pollen and nectar plants in vegetation composition of natural environment is essential for apiculture as one of the utilization types in multiple uses of environmental resources. Therefore, development of this strategy based on indigenous knowledge will increase stakeholder income, which can decrease stocking rate based on range grazing capacity. Due to high dependence of bee to plant flowers, recognition of such plants, studying their phonology and distributed regions is an important issue. Such information can help mangers to classify environmental suitability for bee keeping. The present study investigates the potential of plant species in Ghareh Aghach Watershed in beekeeping. Sample collection was carried out from vegetation species, percentage and composition along two hundred meter transects in three replications and within 30 one square meter quadrates of each Vegetation type. The most import vegetation families utilized by bees in the area were Labiatae, Fabaceae, Asteraceae, Umbelifera, Rosaceae and Cruceferae. Among 114 plant species, 78 species are utilized by bees. These species were not palatable for grazing animals but were dominant in degraded rangelands. Therefore, it is important to define species and flowering time which essential for preparing beekeeping calendar and potential of this utilization type in the area.
leila abdollahi; Mohammad Faraji; ali haghizadh; Somayeh Dehdari
Abstract
Abstract The effects of droughts on surface water and groundwater resources reduce the amount of water available to different sectors. Hydrological drought initially begins with decreasing rainfall and is usually associated with lower levels of lakes and reservoirs. To this end, in order to ma ke appropriate ...
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Abstract The effects of droughts on surface water and groundwater resources reduce the amount of water available to different sectors. Hydrological drought initially begins with decreasing rainfall and is usually associated with lower levels of lakes and reservoirs. To this end, in order to ma ke appropriate management decisions to prevent the harmful effects of drought, it is necessary to assess the characteristics of this phenomenon by assessing and monitoring the drought. In this research, the time series analysis and SDI shaking technique were used to evaluate the hydrological drought at the hydrometric station at the Marian River during the period from 1982 to 2015. The results of hydrological drought on the sunshine station showed that the highest frequency of droughts was related to mild droughts with 29.41% and severe drought with 11.74% and medium drought of 2.94%. Also, the results of self-correlation series analysis, which showed significant correlation for all months except Azar, before the analysis of its effect was removed by Hamed and Rao (modified by Mann-Kendal), and in December, the ordinary Mann-Kendall test used. In all months of the station, except for the month of Aban and Azar (non significant), during the period of 1982-2015, gradual changes are significant at 5% level, and the sudden changes of the time series are significant at 5% level and have a decreasing trend. Also, the results of the Paty's homogeneity test showed that the sudden changes in the time series were significant at all levels at the 5% level.
Ommolbanin Bazrafshan; Ali Salajegheh; Ahmad Fatehi; Abolghasem Mahdavi; Javad Bazrafshan; Somayeh Hejabi
Abstract
Drought is random and nonlinear phenomenon and using linear stochastic models, nonlinear artificial neural network and hybrid models is advantaged for drought forecasting. This paper presents the performances of autoregressive integrated moving average (ARIMA), Direct multi-step neural network (DMSNN), ...
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Drought is random and nonlinear phenomenon and using linear stochastic models, nonlinear artificial neural network and hybrid models is advantaged for drought forecasting. This paper presents the performances of autoregressive integrated moving average (ARIMA), Direct multi-step neural network (DMSNN), Recursive multi-step neural network (RMSNN), Hybrid stochastic neural network of directive approach (HSNNDM) and Hybrid stochastic neural network of recursive approach(HSNNRM) with time scale monthly and seasonally for hydrology drought forecasting and SDI selected as predictor in the Karkheh river basin. The results shown performances of HNNDA was found to forecast hydrological drought with greater accuracy for SDI forecasting, so performances model in monthly scale was greater accuracy to seasonality scale.
Ali Jafari; Fatemeh Tavakoli rad
Abstract
Flood spreading has an effective role in the soil improvement and fertility, ground water storage, revival of vegetation and prevention of fluent sands movement. One of the main problem of flood spreading projects is the entrance of sediment to the spreading systems and sedimentation in it. Sediment ...
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Flood spreading has an effective role in the soil improvement and fertility, ground water storage, revival of vegetation and prevention of fluent sands movement. One of the main problem of flood spreading projects is the entrance of sediment to the spreading systems and sedimentation in it. Sediment reduces the efficiency of the flood spreading system and after awhile lose its efficiency.The main aim of this research is the investigation of infiltrate changes trend under effect of flood spreading in Tangestan flood spreading station (Bushehr province). In this research, soil surface infiltration in spreading and control area were measured with double rings method. For investigating of these changes the intervals between flood spreadng channels, the first, second and third rows were selected. Data were analyzed by Kruskal-Wallis test. Due to the significant level of this test, less than 0.01, can be expressed that between the infiltration of flood spreading rows and control area were significant difference.
Omid Asadi Nalivan; Mohsen Mohseni Saravi; Ghavamodidn Zahedi Amiri; Ali Akbar Nazari Samani
Abstract
Sustainability is a concept that emphasizes substantially on investments conservation (natural, social and economic) toward intra-generation equity. When sustainable development is achieved an overlapping is created between ecological, economic and social classes. The goal of this study is to measure ...
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Sustainability is a concept that emphasizes substantially on investments conservation (natural, social and economic) toward intra-generation equity. When sustainable development is achieved an overlapping is created between ecological, economic and social classes. The goal of this study is to measure and evaluate watershed sustainability. In order to evaluate sustainability in Zidasht basin 1, an ecosystem approach has been used to create balance between three categories of economic, social and ecosystem. Selective variables were obtained by common assessment methods. The IUCN method was used to analysis and evaluate the sustainability of the study basin. By and large, two subjects of human welfare and ecosystem sustainability are dealt with within IUCN approach. Two criteria, six indices and 28 variables were measured in human welfare section and also four criteria and 10 indices and 35 variables were evaluated in ecosystem sustainability section. Above mentioned indices measurement using software Wellbeing Score has scored based on intervals 0-100.finall indices and criteria Arithmetic Mean method integration was completed and map was developed in GIS. Final scores for ecosystem and social and economic issues were derived equal to 51 and 49, respectively. Final results of this study based on the Barometer of Sustainability showed that sustainability of Zidasht 1 basin is moderate. This situation can be improved by ecosystem conservation and people life style quality enhancement.
Hesam Ahmady-Birgani; Sadat Feiznia; Hasan Mirnejad; Hassan Ahmadi; Ken Mc Queen; Mohammad Ghorban Pour
Abstract
This study investigates the mineralogy and physico-chemical properties of atmospheric particulates collected at Abadan (southwestern Iran) near the Persian Gulf coast and Urmia (northwestern Iran) during ambient and dust events over 6 months (winter 2011; spring 2012). Particle sizes collected were: ...
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This study investigates the mineralogy and physico-chemical properties of atmospheric particulates collected at Abadan (southwestern Iran) near the Persian Gulf coast and Urmia (northwestern Iran) during ambient and dust events over 6 months (winter 2011; spring 2012). Particle sizes collected were: TSP (total suspended particulates); PM10 (particulates <10µm); and PM2.5 (particulates <2.5µm). Minerals were identified using X-ray diffraction (XRD); particle morphology and composition were examined by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX). Major minerals detected are calcite, quartz, clay minerals and gypsum, with relative abundance related to sampling site, collection period, wind direction, sampling head, and total sample amount. The anomalously high calcite content appears a characteristic feature originated from calcareous soils of the region. SEM observations indicated a wide range of particle morphologies over the 1-50 µm size range, with spherical, platy, cubic, elongate and prismatic shapes and rounding from angular to rounded. Energy dispersive X-ray analysis of TSP samples from both sites for non-dusty periods indicated that the sampled mineral suite contained Al, Mg, Na, Cl, P, S, Ca, K, Fe, Ti, and Si, mostly reflecting calcite, quartz, aluminosilicates, clays, gypsum and halite. Additionally, As, Pb, Zn, Mn, Sc, Nd, W, Ce, La, Ba and Ni were detected in TSP, PM10 and PM2.5 samples collected during dust events.
hamide afkhami; azam habibi pour; mohammad reza ekhtesasi
Abstract
Evaporation is considered one of the key climatic variables, especially in arid regions and evaporation losses is one of the important issues in irrigation and water resources management in these areas. Therefore, it is important being aware of the amount of evaporation and its modeling, as one of the ...
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Evaporation is considered one of the key climatic variables, especially in arid regions and evaporation losses is one of the important issues in irrigation and water resources management in these areas. Therefore, it is important being aware of the amount of evaporation and its modeling, as one of the most important hydrological variables in agricultural research and water and soil conservation. In recent decades, artificial intelligence techniques have proven high capability and flexibility to estimate and predict nonlinear phenomena. In this study, three important data mining techniques including Artificial Neural Network, Active Neuro-Fuzzy Inference System and Regression Decision Tree were used for predicting evaporation. For this purpose, 8 climatic variables (Minimum average temperature, average maximum temperature, average temperature, sunshine hours, wind speed, wind direction, relative humidity and evaporation averages) were employed in this study. The results showed three models are able to predict evaporation for 12 months after. Finally among the used models, ANN showed better performance with coefficient efficiency of 0.97 and RMSE of 5.1and ME of 0.48. Also, The results showed that there is not significant difference in simulation results to predict the evaporation between two scenario, original data and normalized data.
majid mohammad esmaeili; mohammadreza Mojtahedi; Khironesa Mirnia
Abstract
Flooding is one of the most important environmental stresses that affect the performance of plants. The effects of flooding height on the performance of the two species A.littoralis, J.maritimus were studied. This experiment was carried out the factorial experiment in a completely randomized design with ...
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Flooding is one of the most important environmental stresses that affect the performance of plants. The effects of flooding height on the performance of the two species A.littoralis, J.maritimus were studied. This experiment was carried out the factorial experiment in a completely randomized design with 4 treatments and 8 replications. After 2.5 months of ultimate recovery tests were performed. The number and length of stolons of A. littoralis were counted separately in each treatment. The number and length of rhizome J. maritimus species in each plot (pot) were counted. The total weights of dry matter, shoot dry weight, dry weight of underground organs were measured in each experimental unit. Analysis of variance showed that the effects in controlling the height of flooding on all performance indicators studied (excluding the effects of flooding on root dry weight) of two species A. littoralis and J. maritimus is significant. Comparison of performance indicators A. littoralis species show between the two treatment groups (7 cm below the water level and water treatment) and treatment (treatment without irrigation and 15 cm below the water level) there is a significant difference. Comparison of performance indicators J. maritimus species show a significant difference in the number of rhizome, total length of underground rhizome and dry weight were observed. Comparison of dry pasture species show the highest production of the two types of treatment 7 cm below the water level.
