نتایج جستجو برای: meteorological parameters such as wind speed

تعداد نتایج: 6356657  

ژورنال: علوم آب و خاک 2020

The occurrence of wind erosion and the spread of dust particles can be regarded as one of the most important and threatening environmental factors. Climate change and the frequency of droughts have played an important role in exacerbating or weakening these events. The primary objective of the present study was to investigate the trend of changes in four important climatic elements (precipitati...

Journal: :دانش آب و خاک 0
محمد رضا حامی کوچه باغی گروه مهندسی آب دانشگاه تبریز امیر حسین ناظمی استاد- گروه مهندسی آب دانشکده کشاورزی دانشگاه تبریز علی اشرف صدرالدینی استاد- گروه مهندسی آب دانشکده کشاورزی دانشگاه تبریز رضا دلیر حسن نیا استادیار گروه مهندسی آب دانشکده کشاورزی دانشگاه تبریز

from the mathematical point of view, the fao penman-monteith equation shows a homographic function related to the wind speed. the homographic function has horizontal and vertical asymptotes. in this issue horizontal asymptote is applicable; because the vertical asymptote occurs for negative values of wind speed but the negative sign indicates the direction of the wind speed and only the absolut...

The present study analyzes air quality for Carbon monoxide (CO), in Esfahan with the measurements taken in three different locations to prepare average data in the city. The average concentrations have been measured every 24 hours, every month and every season with the results showing that the highest concentration of CO occurs generally in the morning and at the beginning of night, while the l...

Journal: :Environmental research 2015
Hongliang Zhang Yungang Wang Jianlin Hu Qi Ying Xiao-Ming Hu

Meteorological conditions play a crucial role in ambient air pollution by affecting both directly and indirectly the emissions, transport, formation, and deposition of air pollutants. In this study, the relationships between meteorological parameters and ambient air pollutants concentrations in three megacities in China, Beijing, Shanghai, and Guangzhou were investigated. A systematic analysis ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده مهندسی عمران 1388

چکیده روش های متعددی برای برآورد رواناب حاصل از بارش در حوضه های آبریز وجود دارد. یکی از این روش ها استفاده از مدل های هیدرولوژیکی است. با استفاده از مدل های هیدرولوژیکی و شبیه سازی فرآیندهای هیدرولوژیکی می توان با صرف کمترین زمان و هزینه، رواناب و مولفه های دیگر چرخ? هیدرولوژیکی را برآورد کرد. از آنجا که در حوضه های آبریز اندازه گیری تمام کمیت های مورد نیاز برای تحلیل رواناب ممکن نیست، انتخاب...

Journal: Pollution 2017

The present study analyzes air quality for Carbon monoxide (CO), in Esfahan with the measurements taken in three different locations to prepare average data in the city. The average concentrations have been measured every 24 hours, every month and every season with the results showing that the highest concentration of CO occurs generally in the morning and at the beginning of night, while the l...

Introduction: The present study aimed to investigate the change of air pollutants in 2020 in Qom compared to the same period in 2019 in five scenarios. Materials and Methods: The hourly air quality data was obtained from air quality monitoring stations of Qom Environmental Protection Organization (EPO). The meteorological parameters were obtained from Iranian Meteorological Organization websi...

ژورنال: فیزیک زمین و فضا 2013
عباسعلی علی‌اکبری بیدختی نفیسه پگاه‌فر پیمان زواررضا

Mixing height of the atmospheric boundary depends on the vertical variation of temperature in the atmosphere which includes temperature inversion (including surface and elevated inversions) that has a significant effect on air quality. The mixing height like some other meteorological variables has diurnal variations. The reason for that is its dependence on some other basic meteorological param...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ارومیه 1377

‏‎applications such as high definition viedeo reproduction, portable computers, wireless, and multimedia demand, and ever-increasing need for ligh-frequency high-resolution and low-power analog-to-digital converters. flash, two-step flash, and pipeline convertors are fast but consume large amount of power and require large area. to overcome these problems, successive approximation converter blo...

ژورنال: سلامت و محیط زیست 2021

Background and Objective: The aim of this study was to investigate dust origin particulate (PM2.5) in Mashhad city in a long period of time (2014-2019) based on unhealthy days. Furthermore, changes in meteorological parameters and their relationship with dust storms have also been investigated. Materials and Methods: In order to locate dust pollution hotspots in mashhad air, first, information...

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