جستجوی مقالات مرتبط با کلیدواژه "ریزگرد" در نشریات گروه "مهندسی آب"

Dust is created by wind erosion. In nature, based on the size of the particles, the movement of soil particles due to wind is carried out in three ways. Rolling, jumping and suspension. In the wind ranges that usually occur in nature, proportional to the diameter of the soil particles, these three modes of particle motion are somewhat separable. Particles smaller than 0.1 mm in diameter are usually suspended, soil particles with a diameter of 0.05 to 0.5 mm usually bounce, and soil particles with a diameter of 0.5 to 2 mm move in a crawling (rolling) manner. In the wind tunnel tests, which were conducted on the soil samples collected from the dust centers in the southeast of Ahvaz. It showed that at the reference point, when the wind blows, a lot of dust is formed in front of the soil mass.The obtained results show that the maximum amount of dust is formed in the first 150 seconds. The maximum amount of dust produced occurs in the first 85 seconds, which is about 7 times more than the dust after the first 150 seconds.

The dust crisis in Khuzestan province is an environmental crisis that is currently one of the main centers of dust production in the desert areas of southern Ahvaz and the destroyed parts of Shadegan wetland. Destruction of vegetation in arid areas is the cause of desertification, which is the biggest cause of dust production. In this study to evaluate the criteria and indicators effective in desertification of the region, with the help of the model (IMDPA) which includes 9 criteria that Two criteria, climate and vegetation, each of which contains 3 specific indicators, have been selected. The numerical value of each criterion is obtained from the geometric multiplication of its indicators and finally the total desertification of the region is obtained from the geometric multiplication of two criteria. Finally, the intensity of desertification in the region was calculated to be 1.99 based on the selected criteria, which was in the medium desertification class according to the model scoring table.

In the recent decade, the occurrence of regional dust storm which is partly originated from drying Mesopotamia Wetlands (especially Hawizeh Wetland) had significantly increased in west of Iran and caused a lot of problems in impacted areas. Dust storm is a cross-border phenomenon so an international solution is required to assess and control it. The aim of this study is to evaluate the use of cooperative (partial bankruptcy) and non-cooperative (Nash method) game theory in allocating Hawizeh Wetland environmental water right in different water allocation scenarios for Iran, Iraq and Turkey. The results indicated that the best option to encourage Turkey to release more water from the Tigris to provide environmental water rights of Hawizeh Wetland is Iran-Iraq coalition to reach an integrated political and economic agreement with Turkey. By comparing cooperative and non-cooperative methods, it was revealed that the non-cooperative method allocates larger shares of water to Iran compared to cooperative method. The proposed method of this paper can be used to evaluate supply of environmental water rights for trans-boundary waters.