List of Articles Potential evapotranspiration

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  1 - Estimating water requirement of forage maize and sugar beet using remote sensing (case study: Qazvin plain)
  حمیده نوری ALI Mokhtari Alireza Badiyeneshin
  In this study, Kc curves of early- and late-planted fodder maize and sugar beet were obtained based on two main satellite-based methods: (1) ratio approach (2) vegetation indices (VIs) approach. In the ratio approach, basal crop coefficient (Kcb) and single crop coeffic More

  In this study, Kc curves of early- and late-planted fodder maize and sugar beet were obtained based on two main satellite-based methods: (1) ratio approach (2) vegetation indices (VIs) approach. In the ratio approach, basal crop coefficient (Kcb) and single crop coefficient (Kc) was directly calculated from the ratio of potential transpiration (Tp) to ET0 (using SWAP) and ETp to ET0 (using SWAP and the Priestly-Taylor equation), respectively. The VI approach makes use of Landsat 7 (ETM+) and 8 (OLI) and also MODIS imagery in order to extract soil adjusted vegetation index (SAVI). The Kcb curves were evaluated against field measured leaf area index (LAI) in 2012 growing season. After each Kc curve was modeled, net irrigation requirement (NIR) was calculated on daily and season basis. Results showed that the SWAP approach was weak in estimating the Kcb and Kc curves especially at late-season stage. The VI approach could properly detect changes in vegetation cover during an entire growing season. But, when it came to Kc curve modelling, the VI approach was limited to the values given in FAO 56. However, the Priestly-Taylor approach compensated for the aforesaid limitation; therefore, yielded more sensible trends in Kc curves. Therefore satellite-based approaches derived from more realistic Kc curves during the entire growing season. Overall, making use of the satellite-based approaches could improve water management on regional scales. Manuscript profile
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  2 - Estimate of potential evapotranspiration in Freiman using the priestiley-taylor method and remote sensing technique
  Mosayeb Moqbeli Dameneh Seyed Hossein Sanaeinejad
  Evapotranspiration is one of the important components of water balance which is measured and estimated by several methods. Since these methods mainly involve point-by-point measuring and requiring a large amount of grounded data, so they have limitations. In this study, More

  Evapotranspiration is one of the important components of water balance which is measured and estimated by several methods. Since these methods mainly involve point-by-point measuring and requiring a large amount of grounded data, so they have limitations. In this study, potential evapotranspiration for 8 days in 2014, 2015 and 2016 was estimated using the Priestley-Taylor method and remote sensing technique in Fariman area in Khorasan Razavi province using Landsat 8 Operational Land Imager (OLI). To determine the accuracy of the estimates, the results of this study were compared with the FAO Penman-Monteith method (the reference method for estimating potential evapotranspiration). Comparison of the obtained results by the Priestley-Taylor method with the FAO Penman-Monteith method showed that the R2 and Root Mean Square Error (RMSE) are 0.91 and 0.78 mm/d, respectively. This result indicates that the high accuracy of this method in estimating potential evapotranspiration in a semi-arid climate. Manuscript profile
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  3 - بررسی اثر تغییر اقلیم بر روند افزایش درجه حرارت و تبخیر و تعرق پتانسیل با استفاده از مدل SDSM در شهرستان اهواز
  الهه ذرتی‌پور امیر سلطانی محمدی فاطمه برادران
  تغییر اقلیم ناشی از افزایش غلظت گازهای گلخانه ای(خصوصا CO2) در اتمسفر باعث تغییر در رژیم بارندگی، نرخ رواناب، سرعت باد و تشعشعات خورشیدی اتمسفر می‌گردد. در تحقیق حاضر، با استفاده از داده‌های هواشناسی روزانه ایستگاه سینوپتیک اهواز و داده‌های مدل Hadcm3، تحت سناریوهای A2 More

  تغییر اقلیم ناشی از افزایش غلظت گازهای گلخانه ای(خصوصا CO2) در اتمسفر باعث تغییر در رژیم بارندگی، نرخ رواناب، سرعت باد و تشعشعات خورشیدی اتمسفر می‌گردد. در تحقیق حاضر، با استفاده از داده‌های هواشناسی روزانه ایستگاه سینوپتیک اهواز و داده‌های مدل Hadcm3، تحت سناریوهای A2 و B2 پارامترهای حداکثر دما و حداقل دما در دوره پایه 2088-1979 و دو دوره آینده 2020-1979 و 2090-2070 شبیه‌سازی گردید. برای ارزیابی توان مدل در شبیه‌سازی پارامترهای اقلیمی از آماره‌های ضریب تعیین و میانگین مجذور مربعات خطا استفاده شد، همچنین با روش هارگریوزسامانی مقادیر تبخیر و تعرق پتانسیل برای دوره‌های مذکور محاسبه و پیش‌بینی گردید. نتایج نشان داد حداکثر درجه حرارت، حداقل درجه حرارت و تبخیر و تعرق پتانسیل تحت سناریو A2 و B2 در ایستگاه مطالعاتی اهواز در آینده افزایش می‌یابد. حداکثر و حداقل درجه حرارت برای دوره آینده(2049-2020)  به‌ترتیب برابر با 47/33 و 042/19 تحت سناریوA2و 49/33 و036/19 سانتی‌گراد تحت سناریو B2 بوده و برای دوره آینده(2099-2070) به‌ترتیب برابر با 13/34 و95/19 تحت سناریوA2و 80/33 و 95/19 سانتی‌گراد تحت سناریو B2 می‌باشد. تبخیر و تعرق پتانسیل شبیه‌سازی شده برای دوره آتی 2049-2020 به طور متوسط، برابر 97/10 و 95/10 میلی‌متر بر روز تحت سناریوA2 وB2 بوده و این مقدار برای دوره آتی 2099-2070 برابر 33/11 و26/11میلی‌متر بر روز تحت سناریوA2 وB2 می‌باشد. بیشترین افزایش برای هر سه دوره و تحت هر دو سناریو در ماه ژوئن مشاهده شد. Manuscript profile
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  4 - Estimation of Potential Evapotranspiration and Crop Coefficient of Wheat at Rupandehi District of Nepal
  Govinda Bhandari
  This study is carried out to estimate the potential evapotranspiration (PET) and crop coefficient (Kc) for Wheat, BL 3235 variety. A lysimeter is installed to estimate PET at the experimental farm of Agricultural Research Center of Bhairahawa, which is located in wester More

  This study is carried out to estimate the potential evapotranspiration (PET) and crop coefficient (Kc) for Wheat, BL 3235 variety. A lysimeter is installed to estimate PET at the experimental farm of Agricultural Research Center of Bhairahawa, which is located in western part of Nepal. The Blaney-Criddle formula is used to estimate the Kc for wheat. The estimated values of PET and Kc for wheat at the four crop growth stages (initial, crop development, mid-season/reproductive and late season/maturity) are 3.5 cm, 7.82 cm, 11.3 cm, 1.16 cm and 0.34, 0.67, 0.73, 0.06 respectively. The total value of PET and average value of Kc for Wheat is 23.78 cm and 0.45. Aridity index (AI), the ratio of precipitation to PET, is an important parameter to determine the dryness of a region. The average value of AI at the Wheat growing season (January to April, 2011) in Bhairahawa is 0.39, and is classified as a semiarid region. Manuscript profile
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  5 - Estimation of Potential Evapotranspiration and Crop Coefficient of Maize at Rupandehi District of Nepal
  Govinda Bhandari
  This study was conducted to determine the potential evapotranspiration (PET) of maize, the crop coefficient (Kc) under full water requirement as well as the cause of decrease in maize yield. It was determined that the seasonal PET of maize is about 486.6 mm. The Kc unde More

  This study was conducted to determine the potential evapotranspiration (PET) of maize, the crop coefficient (Kc) under full water requirement as well as the cause of decrease in maize yield. It was determined that the seasonal PET of maize is about 486.6 mm. The Kc under full water supply was found to be: 0.11, 0.35, 1.51 and 0.34 for initial, development, midseason and the late season stages respectively. The study also revealed that maintenance of sufficient moisture need of maize has a significant effect on growth, development and fruiting of the crop. Manuscript profile
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  6 - Water- Balance and Agro- climatic Analysis in Shiraz Region, By Thornthwaite's methods
  Abbas Ali Abounoori
  Drought is a random characteristic of natural phenomena, brought about by the irregulardeficit or shortage of available water, affects injuriously the plant growth and reduces their yield. Drought does not begin when rain ceases but rather only when plant roots can no l More

  Drought is a random characteristic of natural phenomena, brought about by the irregulardeficit or shortage of available water, affects injuriously the plant growth and reduces their yield. Drought does not begin when rain ceases but rather only when plant roots can no longer obtain soil moisture in needed amounts. To estimate the intensity and the frequency of droughts will help to reduce the injurious effect of drought. In this Study we used the water- budget methods and Thornthwaite's aridity index and its standard deviation for Shiraz during 88<8-9228 to show the frequency and the intensity of drought effects in this place. During this period this station is faced :< times different type of droughts on that five time severe and from the years of 9222 its severity and intensity is increased. We also find out that every ten year this station will affect : times severe type of drought. The most severe drought was the years 9228,and it was repeated lower intensity in the year of 9221 Manuscript profile
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  7 - Estimation of the water requirement of several species of shrubs in the green space of Shiraz using the landscape plant factor
  Majid Abasizadeh mohammad shokrollahzadeh
  Today, the importance of water in maintaining life, especially in arid and semi-arid areas, is not hidden from anyone,.. There are various techniques to determine evaporation and transpiration, which include the use of empirical formulas, lysimeters, remote sensing and More

  Today, the importance of water in maintaining life, especially in arid and semi-arid areas, is not hidden from anyone,.. There are various techniques to determine evaporation and transpiration, which include the use of empirical formulas, lysimeters, remote sensing and satellite methods. It is micro-climatic technologies and methods of using plant transpiration coefficient. This research started in April 2014 and was completed by the middle of September 2014. Studies were conducted on three species of bay leaf (Laurus nobilis L.), rosemary (Rosmarinus officinalis L.) and oleander (Nerium oleander L.) located in the parks and boulevards of all 9 districts of Shiraz municipality. To calculate the rate of evaporation and transpiration of the target plant, first the rate of evaporation and transpiration of the reference plant was calculated using the data of the Shiraz synoptic station and the standard Penman-Mantis-FAO method, and then the coefficient (KL) was calculated based on the California method. This coefficient is the key factor in estimating the water requirement of green space. The highest rate of reference evaporation and transpiration is related to the months of August and July, respectively, and the lowest is related to the months of Bahman and January. . The highest water requirement is between June and October. In order to solve a large part of the lack of water resources mentioned, methods such as recycling and reuse of returned water, using non-conventional water sources (sewage, sewage, gray water, etc.) and surface water and runoff are suggested as solutions. Manuscript profile