Sharif Digital Repository

Several dust storms originated from western countries deserts of Iran hit different cities in Iran and substantially elevates PM10 levels. To the date, some studies on trend and origin of the dust storm have been carried out. However, not enough information is available on the contribution of different deserts around the country to the aerosol concentration in Iranian cities. In this study, the deserts of potential dust sources have been identified and their contributions to PM10 concentration in Tehran have been investigated. The PM10 data collected over a 5 year period from 2006 to 2010 at monitoring stations in Tehran were used. A statistical approach was implemented in order to determine... 

Cesium-137 is one of the more important radionuclides in the environment because it is relatively abundant, it has a moderately long half-life (~30 y), its decay produces highly penetrating gamma radiation in addition to beta particles, and its biogeochemical properties allow it to move readily through food chains. It is a radioactive isotope of cesium which is formed as one of the more common fission product by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons.
In this reseach a model is introduced that could simulate a nuclear accident, its distribution into air, deposition into soil and absorption by plant. Nuclear accident and... 

Since Iran is a part of Afro-Asian belt of deserts, 21 percent of its area belongs to desert lands. By the increasing number of dust storms in western adjacent countries dust particle concentration’s value has been critical. PM10 modeling and finding out dust origins can extremely help to manage methods by decision-makers to control dust from the origin. HYSPLIT modeling tool is benefited to get to this aim. In this study metropolises which hardly confront air pollution according to EPA statement were selected. HYSPLIT was calibrated and validated by comparing the results with measurement stations. According to the point that that particles were transported from western parts of Iran,... 

Particulate matter is an important source of air pollution. Particulate matters have an Undesirable effect on the environment, economic, and the health of Tehran Citizens. Annually, more than 8 thousands of tons of mineral dust from Internal and external resources deposit in Tehran city. In this project, the increase in the level of PM10 concentration during June, 12th to 14th, 2015 have been considered. The intrusion and dispersion of mineral dust during June, 11th to 15h, 2015 have been simulated with the HYSPLIT Model. Also, the Trajectory of particle end in Tehran during the mentioned days simulated and plotted with the HYSPLIT. The results show that more than 85% of PM10 reported by Air... 

At Lake Urmia (LU) greatest extent, it was the largest lake in the Middle East and the sixth-largest saltwater lake on Earth, with a surface area of approximately 5,200 km2. The lake has shrunk to 10% of its former size due to damming of the rivers that flow into it, and the pumping of groundwater from the surrounding area. Moreover, as the lake shriks its potentional to be a major dust sources increases. A Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to investigate and track the extent of dust emission and aerosol concentration over Lake Urmia marginal dust spots in order to identify the affected and critical areas. Also, percent movement, propagation... 

In recent years, the increase of particulate matter concentration due to frequent dust storms has become one of the most important dilemmas of people around the world. The high concentration of dust particles causes irreparable respiratory diseases, premature death, economic and social damages. Because of placement in the vicinity of the main sources of dust, Iran has been severely affected by the phenomenon of dust storms and damage caused by it.In this research, two dust storms occurred in Tehran are simulated using WRF-Chem and HYSPLIT models. The first event took place on February 2, 2016, and the second event took place on May 22, 2018. In order to determine the empirical parameters of... 

The Yazd province is located in the dry and desert region of Iran and is constantly exposed to strong winds and dust storms due to its climatic conditions and geographical location. The first objective of this thesis is to assess the dust storm events that have occurred in Yazd province in order to identify their source and pathways of transport during the long-term period of 2012-2019. A novel multi-criteria framework for identifying the sources of dust storms and dust events in Yazd province has been presented using the HYSPLIT model. In this framework, the numerical results, along with geographical features, observational and satellite data, were used as criteria in the multi-criteria...