A. Lashkari; A. Alizadeh; M. Bannayan Awal
Abstract
Abstract
Development and evaluation of mitigation strategies are very crucial to manage climate change risk. Research objectives of this study were (1) to quantify the response of maize grain yield to potential impacts of climate change and (2) to investigate the effectiveness of changing sowing date ...
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Abstract
Development and evaluation of mitigation strategies are very crucial to manage climate change risk. Research objectives of this study were (1) to quantify the response of maize grain yield to potential impacts of climate change and (2) to investigate the effectiveness of changing sowing date of maize as a mitigation option for Khorasan Province which is located in northeast of Iran. Two type of General Circulation Models (HadCM3 and IPCM4) and three scenarios (A1B, A2 and B1) at four locations (Mashhad, Birjand, Bojnourd and Sabzevar) employed in this study. Statistical downscaling method was applied for developing quantitative relationship between large scale atmospheric variables (predictors) and local variables (observes), and generating daily climatological variables performed by LARS-WG stochastic weather generator. The CSM-CERES-Maize model was used to achieve study objectives. The result showed that the simulated grain yields of maize gradually would decrease (ranged from -1% to -39%) during future 100 years compared to baseline under different scenarios and two GCM at all study locations. In general, Bojnourd experienced the highest simulated grain yields of maize under A1B scenario (12234 Kg/ha), A2 scenario (12662 Kg/ha) and B1 scenario (12653 Kg/ha) during the period of 2010-2039 by planting date of 19 June. Sabzevar experienced the lowest simulated grain yields of maize under A1B scenario (3320 Kg/ha), A2 scenario (2370 Kg/ha) and B1 scenario (3582 Kg/ha) during the period of 2070-2099 by planting date of 4 June. Delayed sowing of maize crop (from May to June) at all locations, except for Sabzevar is the most effective management factor in mitigating the thermal detrimental effects.
Keywords: Climate change scenarios, Crop growth simulation, General Circulation Model, Maize yield
Z. Shirmohammadi; H. Ansari; A. Alizadeh
Abstract
Abstract
Potential evapotranspiration is one of basic parameter in hydrologic cycle that should be estimate in irrigation design and scheduling, watershed hydrology studies. Many applications in diverse disciplines require estimates of evapotranspiration (ET) at hourly or smaller time steps. The ...
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Abstract
Potential evapotranspiration is one of basic parameter in hydrologic cycle that should be estimate in irrigation design and scheduling, watershed hydrology studies. Many applications in diverse disciplines require estimates of evapotranspiration (ET) at hourly or smaller time steps. The primary objectives of this study were to compare the American Society of Civil Engineers (ASCE) and FAO-56 Penman–Monteith equations for hourly ET0 (ET0,hourly,ASCE and ET0, hourly,FAO) estimations for semiarid climate conditions and to compare the 24 h sum of ASCE (ET0,24 h,ASCE) and FAO-56 hourly ET0 (ET0,24 h,FAO) with the daily ET0 (ET0,d,FAO) computed from the daily FAO-56 equation, which is identical to ASCE daily ET0 equation. 278-days, i.e., 2008–2009 continuous hourly and daily weather data from the automated internet weather station where placed in private Farm in fariman khorasan razavi province were used. It was evident that during the day, ET0,hourly,ASCE was higher than ET0, hourly ,FAO due to a lower surface resistance parameter value, while at night ET0, hourly,ASCE was lower than ET0, hourly,FAO due to a higher surface resistance parameter value. The ET0, hourly,FAO was about 18% less than ET0, hourly,ASCE and ET0,24 h,FAO was about 14% lower than ET0,24 h,ASCE. The difference between ET0, hourly,ASCE and ET0, hourly,FAO during the day and night was highly dependent on wind speed. For the entire year, ET0,24 h,FAO was 2.6% higher than ET0,d,FAO while ET0,24 h,ASCE was 17% higher than ET0,d,FAO. These results demonstrated that for applications that require hourly time steps or daily ET0 for the entire year, the use of ET0, hourly ,FAO and ET0,24 h,FAO, respectively, will yield more consistent outcomes.
Keywords: Reference evapotranspiration, Surface resistance, ASCE penman-monteith, FAO-56Penman-Monteith, Summation of hourly, Fariman
R. Daempanah; Gh.H. Haghnia; A. Alizadeh; A.R. Karimi
Abstract
Abstract
In the recent decades, application of geostatistic and remote sensing for mapping salinity and sodicity of surface soil and monitoring it's changes have been developed. The goal of this research was to compare the capability of geostatistic and remote sensing methods for mapping salinity-sodicity ...
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Abstract
In the recent decades, application of geostatistic and remote sensing for mapping salinity and sodicity of surface soil and monitoring it's changes have been developed. The goal of this research was to compare the capability of geostatistic and remote sensing methods for mapping salinity-sodicity of soils in playa from sourthern Mah Valat county, in the Khorasan Razavi province. 88 samples of surface soil from depth of 0 to 10cm on the crossing lines of 1000×1000 meter grids were taken, and their EC, PH and SAR were measured. After normalizing variables, checking anisotropy and determining the parameters of variogram, the salinity and sodicity maps of soil were prepared using kriging method with an accuracy of 60 and 58 percent. the Results revealed that kriging had trimmed salinity and sodicity data because it had lowered the standard deviation. The IRS-P6 images were used to map salinity and sodicity maps. After pre-processing of images, PCA, salinity indexes of SI1, SI2, BI and NDSI were calculated and digital number of sampling points were extracted. By checking the correlation between variables and digital numbers of images, the SI1 that had the highest Pearson coefficient, was selected and salinity map of surface soil was prepared by the method of supervised classification. There was no correlation between images and sodicity data, and also between sodicity, salinity and pH data. Probability of extracting sodicity map by this method was evaluated poor. The result of this resarch also showed that for increasing accuracy in kriging maps more points should be taken, while in the remote sensing with less points while saving time and money, it’s possible to have more accurate maps.
Keywords: IRS, EC, Geostatistic, Salinity index, Superwised classification, Mah Valat
M.S. Ghazanfari Moghadam; A. Alizadeh; M. Mousavi baygi; A.R. Farid-Hosseini; M. Bannayan Aval
Abstract
Abstract
Precipitation as the most important factor plays the main role in many application researches which are based on climatic parameters. Many researches in the field of hydrology, hydrometeorology and agriculture employs rain-gauges (such as synoptic and climatologic stations) data. Precipitation ...
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Abstract
Precipitation as the most important factor plays the main role in many application researches which are based on climatic parameters. Many researches in the field of hydrology, hydrometeorology and agriculture employs rain-gauges (such as synoptic and climatologic stations) data. Precipitation characteristics, such as rainfall intensity and duration, usually exhibit significant spatial variation, even within small watersheds; while rain gauge network density could not provide desirable cover. Nearly all related researches use interpolation methods for places without rain gauge data. Many studies showed that the estimated error was usually high by usual interpolation methods. Employing satellite data with high spatial and temporal resolution could provide accurate precipitation estimation. PERSIANN (Precipitation estimation from remotely sensed information using artificial neural network) model works based on the ANN (artificial Neural Network) system which uses multivariate nonlinear input-output relationship functions to fit local cloud top temperature (Tb) to pixel rain rates (R). In this study, PERSIANN model and two interpolation methods (Kriging & IDW) were employed to estimate precipitation for North-Khorasan between the years 2006 until 2008. Results show better correlation between PERSIANN outputs and station data than other two interpolation methods. while correlation coefficient for Kendal`s test is 0.805 between model and Bojnord Station data, this coefficient is 0.488 for IDW and 0.565 for Kriging methods.
Keywords: PERSIANN model, IDW, Kriging, Interpolation methods, Precipitation estimation
H. Dehghan; A. Alizadeh; A.Gh Haghayeghi; H. Ansari
Abstract
Abstract
Using mathematical models for irrigation management have great impacts to increase irrigation efficiency and product amount, in fields. In this study, simulation results by SWAP model for moisture, compared with soil profiles moisture values, measured in the field. Moisture data, measured at ...
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Abstract
Using mathematical models for irrigation management have great impacts to increase irrigation efficiency and product amount, in fields. In this study, simulation results by SWAP model for moisture, compared with soil profiles moisture values, measured in the field. Moisture data, measured at three wheat farms in the Neyshabur plain, were used to predict moisture. Results show good agreement between simulated and measured moisture values. R2 coefficient values was 0.611 for Farob Roman farm, 0.648 for Haji Abad farm and 0.679 for Soleimani farm, respectively. Model absolute value was between 1.5 to 2.9 percent and root mean square error (RMSE) value was between 1.9 to 4 percent. According to these statistical indices, SWAP model has been able to simulate moisture, in soil profile in different depths and times, accurately. Therefore, SWAP can be used for irrigation management in Neyshabur plain, with relatively sufficient accuracy.
Keywords: Moisture simulation, Irrigation management, Soil hydraulic parameters, Neyshabur plain, SWAP
A. Alizadeh; N. Sayari; M.R. Hessami Kermani; M. Bannayan Aval; A.R. Farid-Hosseini
Abstract
چکیده
تغییر اقلیم دارای اثرات مستقیمی بر فرآیندهای هیدرولوژیکی نظیر تبخیر از سطح آب، تعرق از گیاه، تغذیه آبهای زیرزمینی، رواناب یا ذوب برف دارد. در این مقاله اثرات احتمالی ...
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چکیده
تغییر اقلیم دارای اثرات مستقیمی بر فرآیندهای هیدرولوژیکی نظیر تبخیر از سطح آب، تعرق از گیاه، تغذیه آبهای زیرزمینی، رواناب یا ذوب برف دارد. در این مقاله اثرات احتمالی تغییراقلیم بر تبخیر و تعرق در آینده بررسی شده است. به همین دلیل تأثیر تغییراقلیم بر دما (حداقل، حداکثر و میانگین) و بارش تحت سناریوی A2 و برای سه دوره 2039-2010، 2069-2040 و 2099-2070 و با استفاده از ریزمقیاس نمایی آماری و خروجی های مدل گردش عمومی جو HadCM3 در حوضه کشف رود مورد بررسی قرار گرفت. در مرحله بعدی با استفاده از پارامترهای پیش بینی شده، تبخیر و تعرق گیاهان الگوی کشت این حوضه شامل گندم، چغندرقند، گوجه فرنگی، سیب و ذرت با استفاده از روش هارگریوز و سامانی محاسبه و برای دوره های مختلف مورد مقایسه قرار گرفتند. نتایج حاصل نشان داد که دما (حداقل، حداکثر و میانگین) در هر سه دوره پیش بینی نسبت به دوره پایه 1990-1961 افزایش خواهد یافت. میانگین سالانه بارش پیش بینی شده در دوره های مذکور تفاوت معنی داری نداشت ولی توزیع آن در فصلهای مختلف تغییر خواهد کرد. بدینصورت که مقدار بارش برای ماههای زمستان و تابستان کاهش و برای ماههای پائیز و بهار افزایش خواهد یافت. میزان تبخیر و تعرق محاسبه شده برای تمامی ماهها و برای تمامی دوره ها تحت تأثیر دما افزوده خواهد شد. نتایج نشان می دهد که در صورت افزایش دمای هوا به میزان 1، 2 و 4 درجه سانتی گراد نیاز آبی الگوی کشت گیاهان در دشت کشف رود به ترتیب 6، 10 و 16 درصد افزایش پیدا خواهد کرد.
واژه های کلیدی: مدلهای گردش عمومی جو، ریزمقیاس نمائی آماری، تبخیر وتعرق گیاه، حوضه کشف رود، تغییراقلیم
M.S. Ghazanfari Moghadam; A. Alizadeh; M. Naseri; M. Mousavi baygi
Abstract
Abstract
The limitation of water sources in most places all over the world, especially in arid and semi-arid lands is an important Issue for those who live in these areas. Many governments have dedicated their efforts toward finding new water resources to obtain water. Fog and cap clouds harvesting ...
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Abstract
The limitation of water sources in most places all over the world, especially in arid and semi-arid lands is an important Issue for those who live in these areas. Many governments have dedicated their efforts toward finding new water resources to obtain water. Fog and cap clouds harvesting are one of the candidate methods to produce pure water. Many countries including Chile, Peru, Ecuador, Canada, Namibia and Nepal Have yet invested on fog harvesting. On the other hand, no significant calculation studies have been yet carried out on quantifying fog harvesting. In this work, we examined the Physical and dynamic relationship between cloud physics and atmosphere humidity; factors such as distribution of particle amounts, collection efficiency, water including base cloud and vapour flux were all considered. We also presented a new method to estimate fog harvesting, based on fractal theory and concerning the characteristics of collecting devices. Finally, we successfully evaluated the theories for fractal dimension of particle distribution, using the real data of fog harvesting. The incremental fractal dimension reliability was found to be 83% acceptable.
Keywords: Cap cloud, Fog, Fog harvesting, Fractal theory
F. Koorosh Vahid; K. Esmaili; M. Faghfur Maghrebi; A. Alizadeh; B. Naghavi
Abstract
Abstract
Bottom intake is one of the most appropriate systems for diverting discharge in steep rivers. Bottom intake with porous media is a new system of diverting discharge which can be replaced by bottom rack intakes. To investigate the hydraulic flow characteristics on diverted discharge of this ...
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Abstract
Bottom intake is one of the most appropriate systems for diverting discharge in steep rivers. Bottom intake with porous media is a new system of diverting discharge which can be replaced by bottom rack intakes. To investigate the hydraulic flow characteristics on diverted discharge of this intake, an experimental model was designed in which the inflow, diverted discharge and remained flow of porous media intake can be measured. In the present research, measurements of the diverted discharge were performed for different rates of flow, grain size distributions as well as surface slopes of intake with clear water. According to the obtained results, by increasing the inflow discharge, the rate of diverted discharge increases gradually and then reaches to a constant value. Any increment of the surface slope above the intake also decrease the relation diverted flow. It is found that the grain size of the porous media has a great influence on the diverted flow. By increasing the grain size diverted flow increases, too. Dimensional analysis and experimental results were used to estimate the discharge coefficient of porous media. Analytical analysis on experimental data shows that the discharge coefficient of porous media intake is about 0.1. Also an empirical-theoretical relation is proposed to evaluate the diverted discharge of this kind of bottom intakes.
Keywords: Bottom intake, Porous media, Discharge coefficient, Free surface flow
M. S. Ghazanfari; A. Alizadeh; M. Naseri; A.R. Farid-hosseini
Abstract
Abstract
Urban expansion, pollution augmentation, and extention of major industrial activities in metropolitan areas impacted local climates of major cities. Transforming big cities into heat islands is one of the most prominent results of such a micro-climate change. In this study, variation of precipitation, ...
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Abstract
Urban expansion, pollution augmentation, and extention of major industrial activities in metropolitan areas impacted local climates of major cities. Transforming big cities into heat islands is one of the most prominent results of such a micro-climate change. In this study, variation of precipitation, temperature and some other important climatic parameters including relative humidity, and percentage of cloudiness were reviewed in order to study micro-climate change. The city of Mashhad selected for this study, as metropolitan area. The study was performed by comparing the climate parameters of this city with the neighboring regions, which were identified as the same climate category. Due to the effective role of rainfall in the urban weather modification and decreasing of pollution, rainfall variation is more important and crucial. The result of this research showed that the rainfall variation followed the temperature trend. A significant correlation between temperature and precipitation change showed the effect of heat island on urban climate parameters. The urban heat island phenomenon increase the hot season rainfall while its effects on cold season rainfall decrease.
Keywords: Urban Heat Island, Air pollution, Microclimate, Climate change
N. Sayari; M. Bannayan Aval; A. Alizadeh; M.B. Behiar
Abstract
Abstract
Accurate prediction of hourly minimum temperature is required for various crop models which simulate photosynthesis and transpiration. Such data can be used for crop protection and reducing the crops injuries due to freezing as well. Our objective of this study is employing trigonometric and ...
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Abstract
Accurate prediction of hourly minimum temperature is required for various crop models which simulate photosynthesis and transpiration. Such data can be used for crop protection and reducing the crops injuries due to freezing as well. Our objective of this study is employing trigonometric and pattern recognition (k-NN) approaches to evaluate their potential in prediction of hourly temperature for the whole 24 hours and also minimum temperature time occurrence. Our observed data contain every 3 hours minimum temperature data for 16 years of synoptic Mashhad climate station. Various scenarios were employed to predict the minimum temperature for first of Aban and first of Ordibehesht using, 1 day, 7 days, 110 days and 315 days observed data for next day minimum temperature prediction. Our results showed that if there is no full access or partly access to the minimum temperature data then the trigonometric function including Sine function is able to reproduce the required data. k-NN approach showed that as the distance of data to target data decreased the accuracy of prediction increased.
Keywords: Minimum temperature, Freezing, Sine model, Sine-Expo model, Prediction, Mashhad
M. Bannayan Aval; A. Mohamadian; A. Alizadeh
Abstract
Abstract
Climate variability empowers critical consequences on sustainability of soil and water resources. In this paper the trend of annual and seasonal time scale of temperature (minimum, maximum, average), relative humidity (minimum, maximum, average), precipitation, wind speed, extreme events, cloudiness, ...
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Abstract
Climate variability empowers critical consequences on sustainability of soil and water resources. In this paper the trend of annual and seasonal time scale of temperature (minimum, maximum, average), relative humidity (minimum, maximum, average), precipitation, wind speed, extreme events, cloudiness, reference evapotranspiration employing Mann-kendall and least square errors were studied. These parameters showed direct or indirect effect on climate variability in northeast of Iran. The results, for example in Mashhad station, showed an increasing trend in temperature, decreasing trend in humidity and no trend in precipitation. In addition, there were an increasing trend in the number of clear days (no cloud) and a decreasing trend in number of cloudy days across all study stations but Mashhad.
Keywords: Trend Analysis, Temperature, Relative Humidity, Precipitation, Wind Speed, Extreme Climate Events, Reference Evapotranspiration, Mashhad Climate Change
N. Khalili; K. Davari; H. Ansari; A. Alizadeh
Abstract
Abstract
Drought is one the most complicated and unknown natural disasters and rainfed agriculture is often the first sector to be affected by drought. In this research, we consider the drought monitoring from both meteorological and agricultural points of view. We have selected Standardized Precipitation ...
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Abstract
Drought is one the most complicated and unknown natural disasters and rainfed agriculture is often the first sector to be affected by drought. In this research, we consider the drought monitoring from both meteorological and agricultural points of view. We have selected Standardized Precipitation Index (SPI) among the meteorological indices, with a one month time scale for the synoptic station of Bojnurd. Although there are few exceptions in during (1996-2005) in 1996, 1998, 1999, and 2000, in which the severely and extremely dry category have been matched to the growth season of the rainfed, the results of SPI index from precipitation data of this station and the trend of drought variations from 1996 to 2005 show that in Bojnord synoptic station, the meteorological drought has not happened in the growth season of the rainfed wheat (23 Oct. To 17 June) or at least it has been near normal category. The periods from June 1998 to May 1999 and from June 2004 to June 2005 have been the driest and wettest periods, respectively. The meteorological indices such as SPI, either are only the function of precipitation, or consider a long term time scale. In the first case they do not give a comprehensive analysis on the drought phenomena and cannot give be used for the monitoring of the crop moisture situation and in the later case, they are not applicable for short term time scales such as daily or weekly monitoring. Therefore, to monitor the agricultural drought and influence the other factors such as the temperature along with precipitation, the crop moisture index (CMI) has been introduced for weekly monitoring. To achieve this goal, we have used the climatic data of Bojnord synoptic station over ten years from 1996 to 2005. The results from CMI index show that in the last week of grain filling, around the last week of May, extremely drought (-2.7>CMI>-3) has happened. Also, during the crop maturity, a exceptional drought has been monitored with CMI
H. Dehghan; A. Alizadeh; A.Gh. Haghayeghi
Abstract
Abstarct
Precise knowledge of all components of water balance is essential to optimize water use in irrigated agriculture. However, water balance components are difficult to measure in required time intervals because their measuring is time consuming and costly. Unsaturated zone simulator models are ...
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Abstarct
Precise knowledge of all components of water balance is essential to optimize water use in irrigated agriculture. However, water balance components are difficult to measure in required time intervals because their measuring is time consuming and costly. Unsaturated zone simulator models are useful tools for predicting the effects of agricultural management on crop water use and can be used to optimize agricultural practices such as agricultural water use. This research has been done on Wheat irrigated farms in Neyshabur plain, that is one of important plains in Khorasan Razavi province. SWAP Agro-hydrological model, was used for simulation of water balance components and crop growth in three wheat fields: Farob Roman, Hajiabad and Soleimani. Input data for model was a combination meteorological and field data. RETC software package was employed to evaluate and calibrate the soil hydraulic parameters, used. Simulation period was selected from October 2008 until early June 2009, in accordance with the wheat growing season. Sensitivity analysis to soil hydraulic parameters showed that the model is more sensitive to and coefficients. Also, acoording to presented statistical parameters, the results showed that SWAP is able to simulate water flow in soil, truly. Mean R2 coefficient value was 0.62, Mean Error was between -0.1 to -2.28 and Relative Error was fluctuated between -0.33 and -12.69. Therefore, calibrated SWAP model can be used as an instrumental tool for calculating all components of water balance in field scale, with time and cost saving.
Keywords: Soil hydraulic functions, SWAP model, Water balance components
A. Arabi-Yazdi; A. Alizadeh; F. Mohamadian
Abstract
Demand and supply of water in Iran is unbalanced. This situation has caused a great challenge in water resources management. In order to overcome this problem, the role of international trade of virtual water has been ignored. Virtual water trade is one of the key solutions for water scarcity. Each country ...
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Demand and supply of water in Iran is unbalanced. This situation has caused a great challenge in water resources management. In order to overcome this problem, the role of international trade of virtual water has been ignored. Virtual water trade is one of the key solutions for water scarcity. Each country should adapt virtual water trade based upon its socio-cultural, economical, and climatic condition of the country. However, before any action is implemented, there is a need to evaluate ecological water footprint (EWF) of the country. EWF is the amount of water which is needed for the population and consumptive use and remediation of all pollution related to this consumption. In this study EWF of Iran has been calculated for the year 2007. The results showed that EWF in Iran is 104 billion cubic meter (bcm) of water in agricultural section. In 2007, Iran has imported 12 bcm of water due to virtual water trade. In this computation, irrigation efficiency has not been included. Considering the amount of 60% for irrigation efficiency virtual water trade in the above mentioned year was 20 bcm. Without this trade, the country had to spend 112 bcm of water for producing all required food in the country which was out of reach.
A. Alizadeh; M.H. Najafimood; J. Moosavi; B. Alizadeh
Abstract
Abstract
Environmental pollution has made urban citizens to focus on landscapes. In this respect Lown is very important plant. From the other hand water resources in many arid and semi-arid region is saline. For this purpose a research was conducted to study the effect of sprinkling irrigation with ...
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Abstract
Environmental pollution has made urban citizens to focus on landscapes. In this respect Lown is very important plant. From the other hand water resources in many arid and semi-arid region is saline. For this purpose a research was conducted to study the effect of sprinkling irrigation with saline water on growth parameters of three Lown varieties. These varieties were Poa partensis, Festuca arundianca and Lolium prenne. A complete randomized block with 3 irrigation treatments and 9 replications were used. The salinity of irrigation waters were EC=2.4 and EC= 5.3 dS/m. growth parameters were followed for 7 months. After this period of time, germination rate, height of plant, dry weight of ground canopy and length of roots were measured. The results showed that Festuca is resistance to salinity while Poa could not tolerate and dried immediately after increasing air temperature.
Key words: Salinity, Sprinkling irrigation, Lown varieties, Lolium, Festuca, Poa
H. Sharifan; A. Alizadeh
Abstract
Abstract
In order to estimate the reference evapotranspiration different equation is used. Validity of each methods depends upon the climate and the parameters which are used in these equations. Therefore it is necessary to calibrate these methods for any specific area and for any desired frequency. ...
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Abstract
In order to estimate the reference evapotranspiration different equation is used. Validity of each methods depends upon the climate and the parameters which are used in these equations. Therefore it is necessary to calibrate these methods for any specific area and for any desired frequency. In this study common temperature and radiation based methods were used for calculating crop evapotranspiration and the results were compared with standard method of estimating reference evapotranspiration. The results showed that Jensen-Haise(J-H) method overestimate ET compare to Hargreaves-Samany(H-S) method. The difference is more in 3 days period of irrigation than 5 days period. Also for wheat and barely H-S method estimates higher value of ETc compared with J-H method. However, J-H method overestimate ETc for cotton and rice. By increasing the probability level, the difference between calculated ETc by J-H and H-S decreased significantly.
Key words: Peak water requirement, ETo, ETc, Radiation, Temperature, Probability
A. Hosseinpour; Gh. Haghnia; A. Alizadeh; A. Fotovat
Abstract
Abstract
Population increase, limitation of water resources, and increasing volume of municipal wastewater, has caused the necessity of wastewater reuse. Application of wastewater on soils seems to be the most economical method of its disposal and by percolating wastewater through the soil, its chemical ...
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Abstract
Population increase, limitation of water resources, and increasing volume of municipal wastewater, has caused the necessity of wastewater reuse. Application of wastewater on soils seems to be the most economical method of its disposal and by percolating wastewater through the soil, its chemical quality is improved. For this purpose, a greenhouse experiment was carried out with polyethylene columns (150 cm in length and 11 cm in diameter) during 7 periods of 15 days in Ferdowsi University of Mashhad. A statistical completely randomized design was used. Raw and treated wastewaters from Parkandabad Treatment Plant were applied intermittent in columns filled with sandy loam soil. At The end of experiment, sampled of leachate were analyzed for parameters sach as pH, salinity, SAR, NO3-N, PO4-P, TOC, and two heavy metals of Cd and Ni. The results showed that the mean values of each of the above mentioned parameters, with the exception of pH, were lower in the leachate compared to the wastewaters entering the soil. However, with continuous application of wastewaters increase in the amount of these components was observed. Considering the effect of type of wastewater on values of above parameters, mean of pH value was significantly lower for raw wastewater (7.65) in the leachate as compared to the treated wastewater (7.71). NO3-N, PO4-P and Ni showed an opposite trend. The mean values of these parameters leached out from soil columns were 21.96, 0.055 and 0.015 (mg/l) for raw wastewater and 20.48, 0.024 and 0.012 (mg/l) for treated wastewater, respectively. Type of wastewater did not have any significant effect on other parameters. In generall, with respeet to the amount of SAR, NO3-N and TOC in the leachate as well as Ni and Cd specially in the raw wastewater and their hazardous consequences, their long-term disposals on soils need sound and suitable management practices.
Key words: Raw wastewater, Treated wastewater, Chemical characteristics of leachate, Soilu column
H. Sharifan; B. Ghahraman; A. Alizadeh
Abstract
Evaluation of Rainfall Effect on Programing of Agricultural Management (Case Study: Golestan region)
Abstract
Securing of water need in agricultural is important. Precipitation are one of the most important of water resources in agricultural, in Golestan province, especially , because Alborze mountains ...
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Evaluation of Rainfall Effect on Programing of Agricultural Management (Case Study: Golestan region)
Abstract
Securing of water need in agricultural is important. Precipitation are one of the most important of water resources in agricultural, in Golestan province, especially , because Alborze mountains are in Golestan south. In research has investigated effects of rainfall to cropping pattern and intensification in Golestan farms. Rainfall used: a) have forecasted rainfalls by Minitab-13 program, b) Different probabilities of rainfalls by LST Program. Then estimated effective rainfall (by USDA method). For optimization used Lingo-8 program. Evaluations shown that in southern region (climate is: smi wet), if rainfall decreased, area of tomato and potato decreased , but canola area increased. In central and north regions (climates are: semi dried to dried), if rainfall decreased, watermelon area decreased, but canola area increased. Also if drought conditions, planting of canola, watermelon and cotton crops are important.
Key words: Cropping pattern, Intensification, Precipitation, Golestan
Z. Toufaninezhad; Gh.A. Kamali; A. Alizadeh
Abstract
Abstract
Obtaining reliable precipitation observations is important for hydrological simulations and weather forecasting. Radar data can provide insight in the spatial variation of precipitation and can also detect large areas of rain and estimate rainfall rates. Weather radar systems nearly always ...
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Abstract
Obtaining reliable precipitation observations is important for hydrological simulations and weather forecasting. Radar data can provide insight in the spatial variation of precipitation and can also detect large areas of rain and estimate rainfall rates. Weather radar systems nearly always operate in S-, C- or X-band. Since X-band systems require smaller antennas than those at C- or S- band, they are particularly suitable for monitoring small hydrological working. However, radar rainfall estimation can be prone to errors because of attenuation and ground clutter. In this study, the potential of X-band radar systems for rainfall estimation over an urban area in the Netherlands was discussed. A methodology was presented for removing ground clutter and attenuation from X-band radar measurements and finally measurements of rainfall from radar were compared against measurements from 4 tipping bucket rain gauges for a rainfall event. In general, the analysis demonstrated that the radar follows the general trend of the rain gauge measurements but the radar measurements need to be calibrated and corrected for errors.
Key word: Ground base radar, Ground clutter, Attenuation, Rainfall estimation
A. Alizadeh; N. Sayari; J. Ahmadian; A. Mohamadian
Abstract
Abstract
Saffron (Crocus sativus, L.) is one of the most important economical crops for Khorasan farmers. Almost all saffron yield in Iran comes from Khorasan provinces. First irrigation times is the crucial factors which affect the amount and quality of yield based upon an on farm investigation it ...
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Abstract
Saffron (Crocus sativus, L.) is one of the most important economical crops for Khorasan farmers. Almost all saffron yield in Iran comes from Khorasan provinces. First irrigation times is the crucial factors which affect the amount and quality of yield based upon an on farm investigation it was found that when air temperature reaches to 12 ۫c The most amount of flower is yielded. Also it was found that 2 to 3 weeks after irrigation flowering starts. The one irrigation should be applied in such a way that after this period of time saffron could be harvested. In this study the most appropriate date for the time of irrigation with 50, 75 and 95% probability was derived for different points of Khorasan provinces. Also Khorasan provinces were zoning for this purpose. Based on results, flowering date and first irrigation time for saffron are very different and depended on climate and temperature of studied zone. In the locations with higher elevation above the sea level and lower daily air mean temperature, usually flowering date and first irrigation time are very soon in the autumn early while decreasing of elevation above the sea level and increasing of daily air mean temperature, flowering date and first irrigation time are in the mid autumn or even autumn late.
Keywords: Saffron, Khorasan, temperature, flowering, first irrigation
A. Alizadeh; N. Khalili
Abstract
Abstract
Solar radiation, nowadays has a lot of application in different fields of agriculture, irrigation, and hydrology engineering and due to these various applications, different models has been proposed for it’s estimation. Angstrom-Prescott equation is one of the most important well known models ...
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Abstract
Solar radiation, nowadays has a lot of application in different fields of agriculture, irrigation, and hydrology engineering and due to these various applications, different models has been proposed for it’s estimation. Angstrom-Prescott equation is one of the most important well known models for solar radiation estimation. This equation has empirically coefficient that various for each location. In this paper, the data gathered in Mashhad Synoptic station during 1378 and 1380, Angstrom-Prescott coefficient has been identified according to the ratio of actual sunshine hours (n) to the maximum sunshine hours (N). Also a Regression local equation has been proposed considering several meteorology parameters including daily gathered data of saturation vapor pressure deficit, precipitation, air temperature mean, relative humidity percentage and n/N. Finally the proposed model has been evaluated according to the independent measured data during 1381 to 1382. The statistical analysis of the results not show a significant difference between multi coefficients-local equation with Angstrom-Prescott equation, and therefore without more accuracy and more additional meteorology data and only with the data including sunshine hours and calculating extraterrestrial solar radiation, global solar radiation can be used with a high precision. For instance our model for Mashhad can be used with a=0.23 and b=0.44 which are the coefficient of the Angstrom-Prescott equation. This coefficient should be calibrated and validated for each zone individually.
Keywords: Angstrom-Prescott, Solar radiation, Sunshine hours, Mashhad
A. Hosseinipour; Gh. Haghnia; A. Alizadeh; A. Fotovat
Abstract
Abstract
Due to the necessity of wastewater reuse in arid regions and the necessity of investigation on the fate of added materials into the soil, a greenhouse experiment was carried out with polyethylene columns (150 cm in length and 11 cm in diameter) filled with a sandy loam soil during 7 periods ...
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Abstract
Due to the necessity of wastewater reuse in arid regions and the necessity of investigation on the fate of added materials into the soil, a greenhouse experiment was carried out with polyethylene columns (150 cm in length and 11 cm in diameter) filled with a sandy loam soil during 7 periods of 15 days. A statistical factorial design was used. Raw and treated wastewaters from Parkandabad treatment plant were applied to the columns under continuous and intermittent flood irrigations. The results showed that PO4-P and Cd were retained by the soil while a large portion of soluble cations and anions, NO3-N and TOC as well as a part of Ni were leached out. The type of wastewater had a significant effect on transport percentage of elements except K and Mg. The transport percentage of all elements (with the exception of NO3-N and PO4-P) was higher for treated as compared to raw wastewater. Ca, HCO3 and Ni were significantly affected by the mode of application. For the intermittent flood conditions more Ca was leached out, while a reverse case was observed for the other two elements. Due to relatively rapid leaching of soluble cations especially Ca and Mg, NO3-N and TOC from the soil, and also high amount of heavy metals and TOC in raw wastewater, disposal of wastewaters (especially raw wastewater) should be managed carefully.
Key words: Column study, Raw and treated wastewater, Continuous flooding, Intermittent flooding,Transport perecentage
M.H. Najafi mood; A. Alizadeh; A. Mohamadian; J. Mousavi
Abstract
Abstract
In order to estimate the freezing depth and developing a simple and rational relationship between air temperatures at the screen and soil temperature at different depths a study was conducted during 1386. The maximum and minimum daily air temperatures (2 meter above ground) and the soil temperature ...
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Abstract
In order to estimate the freezing depth and developing a simple and rational relationship between air temperatures at the screen and soil temperature at different depths a study was conducted during 1386. The maximum and minimum daily air temperatures (2 meter above ground) and the soil temperature at 5, 10, 20, 30, 50 and 100 centimeter depths were measured at 12 stations of Khorasan Razavi province. Functional relationships were developed between air and soil temperatures for each station. Also, soil freezing depths were estimated by four standard methods. The estimated depths were compared with actual freezing depths which were measured during the year of observation. The results showed that the Finnish and Norway methods were more reliable than U.S. and SNipll – 15 – 74 methods.
Key words: Air temperature, Soil temperature,Freezing depth
M. Vazifedoust; A. Alizadeh; Gh.A. Kamali; M. Feyzi
Abstract
Abstract
To explore the on-farm strategies which result in higher economic gains and water productivity (WP), a physically based agro-hydrological model, Soil Water Atmosphere Plant (SWAP), was calibrated and validated using intensive measured data at 8 selected farmer fields (wheat, fodder maize, sunflower ...
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Abstract
To explore the on-farm strategies which result in higher economic gains and water productivity (WP), a physically based agro-hydrological model, Soil Water Atmosphere Plant (SWAP), was calibrated and validated using intensive measured data at 8 selected farmer fields (wheat, fodder maize, sunflower and sugar beet) in the Borkhar district, Isfahan during the growing seasons of 2004-05. The WP values for the main crops were computed using the SWAP simulated water balance components i.e. transpiration (T), evapotranspiration (ET), irrigation (I), and the marketable yield (Y)M in terms of YM T -1, YM ET -1 and YM I -1. The average WP, expressed as YM T -1 (kg m-3) was 1.18 for wheat, 3.38 for fodder maize, 0.33 for sunflower and 1.72 for sugar beet. This indicated that fodder maize provided the highest economic benefit in the Borkhar irrigation district. Soil evaporation caused the average WP values, expressed as YM ET-1 (kg m-3), to be at least 11 to 27% lower than the average WP, expressed as YM T-1. Furthermore, due to percolation from root zone and stored moisture content in the root zone, the average WP values expressed as YM I-1 (kg m-3), had a 24 to 42 % reduction as compared with WP expressed as YM ET-1. Improved irrigation practices in terms of irrigation timing and amount, increased WP in terms of YM I-1 (kg m-3) by a factor of 1.5 for wheat and maize, 1.3 for sunflower and 1.1 for sugar beet.
Key words: Water productivity, Irrigation practices, Wheat, Fodder maize, Sunflower, Sugar beet
