نتایج جستجو برای: Two-layer soil-water balance model

تعداد نتایج: 4838615  

Journal: :desert 2014
jaber rahimi ali khalili javad bazrafshan

estimated effective precipitation (pe) in dryland areas is an essential element of water resource management. itrepresents the amount of precipitation available in the crop root zone to meet the needs of evapotranspiration. thecurrent study compared different approaches for estimating pe in different climatic zones of iran. a two-layer soil–water balance (swb) model was adopted based on the pro...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده مهندسی علوم آب 1393

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

Journal: :آب و خاک 0
سید سجاد رضوی کهنمویی کامران داوری بیژن قهرمان علی نقی ضیائی عزیزالله ایزدی کاظم اسحاقیان مهری شاهدی

limitation of water resources in iran motivates sustaining and preserving of the resources in order to supply future water needs. fulfilling these objectives will not be possible unless having accurate water balance of watersheds. the purpose of this study is to estimate the water balance parameters using a distributed method. the large number of distributed models and methods was studied and “...

Journal: :آب و خاک 0
هادی دهقان امین علیزاده سیدابوالقاسم حقایقی مقدم

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 ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1392

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

Journal: :آب و خاک 0
مجتبی شفیعی بیژن قهرمان بهرام ثقفیان کامران داوری مجید وظیفه دوست

uncertainty analysis is a useful tool to evaluate soil water simulations in order to get more information about the models output. these information provide more confidence for decision making processes. in this study, swap model is applied for soil water balance simulations in two fields which are planted by wheat and maize in an arid region. first the amount of uncertainty is estimated and co...

ژورنال: علوم آب و خاک 2017

Bi-level drainage system is a type of underground drainage systems, in which adjacent drainage lines are installed at different depths. In the Hydraulics Laboratory, Ferdowsi University of Mashhad, a model was built, that include a cube tank 2 meters in length, width and height of 1 meters was made ​​of galvanized. In this model, two rows 20 cm apart from each other drains were installed. As dr...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

a one dimensional dynamic model for a riser reactor in a fluidized bed catalytic cracking unit (fccu) for gasoil feed has been developed in two distinct conditions, one for industrial fccu and another for fccu using various frequencies of microwave energy spaced at the height of the riser reactor (fccu-mw). in addition, in order to increase the accuracy of component and bulk diffusion, instanta...

Journal: :تحقیقات مهندسی کشاورزی 0
منصور پاره کار استادیار مؤسسه تحقیقات فنی و مهندسی کشاورزی علی نشاط دانشجوی دوره دکتری آبیاری، واحد علوم و تحقیقات دانشگاه آزاد اسلامی، تهران فریدون کاوه دانشیار دانشگاه آزاد اسلامی، واحد علوم و تحقیقات

evaporation from the soil surface has an important role in the water balance model in nature, so that the major part of rain fall and irrigation water in arid and semi-arid regions is lost via evaporation from the soil surface. in such areas, there are some regions with high water table and because of evaporation from the soil surface, salts accumulation also occur in the soil surface. so evapo...

2006
Yongqiang Zhang Martin Wegehenkel

Water shortage is a serious constraint on crop production on the North China Plain (NCP), where cropland is mainly irrigated by pumping groundwater from alluvial aquifers. To develop a sustainable ground water and irrigation management strategy, we developed a three-layer soil water balance model which is easy to use, robust, but physically based simulation tool. The model successfully simulate...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید