نتایج جستجو برای: irrigation networks

تعداد نتایج: 469567  

2005
Giorgio Corriga Alessandro Giua Giampaolo Usai

The paper describes a formal procedure to construct a Petri net model starting from the differential equations that describe the behavior of a canal network. In a first approach, the equations are discretized and the corresponding model takes the form of a deterministic timed Petri net. In a second approach, timed continuous Petri nets are used. The dynamic behavior of the system can be studied...

Journal: :آب و خاک 0
احمد غفاری علی اصغر منتظر علی رحیمی جمنانی

abstract the present study was carried out for developing and evaluating of the optimization model of cropping pattern in irrigation networks using analytical hierarchy process (ahp). the model was programmed into two sub-models. the objective of the first sub-model was ranking of crop appropriately, and the objective of the second sub-model was ranking of cropping area of each crop. ten criter...

Journal: :پژوهش آب در کشاورزی 0
پوریا عطائی دانشجوی دکتری ترویج کشاورزی دانشگاه تربیت مدرس. نسیم ایزدی دانشجوی دکتری ترویج و آموزش کشاورزی دانشگاه بوعلی سینا.

irrigation management transfer to farmers is one of the important and necessary issues for irrigation planners globally. irrigation management transfer or participatory irrigation management by water users’ associations (wua) is a widespread strategy in the world and a good way to remove the country's irrigation and drainage systems problems. the main objective of this research was respons...

Journal: :آب و توسعه پایدار 0
علیرضا کیانی فریبرز عباسی

the three practical steps that are need to be taken by government agencies in order to increase irrigation efficiency include economic motivation for optimization of water use, modification of existing irrigation systems in the short term and modernization of traditional methods in the long-term plan. the present research aims at identifying farmers' knowledge regarding irrigation and water iss...

Journal: :اقتصاد و توسعه کشاورزی 0
تبرایی تبرایی سلطانی سلطانی خاکسار آستانه خاکسار آستانه زمان زاده زمان زاده

abstract among different water usage in iran, agricultural sector with 94 percent is the largest water user. considering the share of agriculture in water usage, farmers are the main factor in water resources management. therefore, optimal utilization of irrigation and drainage networks would depend on farmers’ effective role. due to the limited water resources in different country regions, inc...

2014
Karl Jandoc Ruben Juarez James Roumasset

Both the economics and the engineering of irrigation design are typically based on the assumption of a single source. The more general economic problem is to determine which sources should be developed and how water should be allocated and delivered to various receptor-farmers. This is a problem in network economics. We begin our exploration with the problem of allocating irrigation water from ...

Behrooz Dahanzadeh Farrokh Falahat Hossein Fathian,

One of the problems of existing irrigation networks is seepage phenomena. Seepage problem and its control in irrigation channels is one of the most important issues in the design, construction, maintenance and operation of these channels. In this study, simulated the rate of seepage and phreatic lines in the Mianab irrigation and drainage channels located in the Karun basin using mathematical t...

Journal: :مدیریت آب و آبیاری 0
میناسادات سیدجواد کارشناس ارشد دانشگاه تهران، پردیس ابوریحان، پاکدشت ، ایران. محمود مشعل دانشیار دانشگاه تهران، پردیس ابوریحان، پاکدشت، ایران

one of the consequences of poor management and operation of irrigation systems, poor water delivery and distribution channels and divisions and consequently improper distribution of water level downstream. the study of simulation and performance evaluation software using hydrodynamic sobek varamin irrigation is done. in order to evaluate the network performance and compare the results of simula...

2011
Jianwen Li Xihuan Sun Juanjuan Ma Xianghong Guo Jingling Li

With the aim of estimating infiltration properties of surface irrigation and further saving water efficiently, a zero-inertia model was adopted for simulating the surface flow of border irrigation. The parameters identification of the model has been derived from hybrid volume balance model coupling artificial neural networks and numerical inversion approaches including differential evolution. W...

2012
Liang Ma Feng Liu Liangliang Chen Ming Hong

Crop evaportranspiration was studied with measured data of Kongque river irrigation district in Xinjiang Province based on application of BP neural networks, a sensitivity analysis about crop evaportranspiration was conducted according to each input factor by using default factor method, and the grey relational analysis method was applied to certify the results.The results showed that the artif...

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