Volume 5, Issue 3 (12-2018)                   Jsaeh 2018, 5(3): 83-102 | Back to browse issues page


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1- climatology shahid Beheshti University , 44ahmadi@gmail.com
2- climatology shahid Beheshti University
Abstract:   (1052 Views)
Problem statement
The occurrence of terrible floods due to climate change has caused much damages in different parts of the world in recent decades, and the effect of these changes is more pronounced in dry areas. Floods are the most common environmental damage. On average, 60 floods occur annually in Iran, with an average annual flood loss of 141 people, meaning more than 2 deaths per year per flood event.
Research Methodology
The study area consists of six stations located in Hormozgan, Kerman, Yazd, Kohgiluyeh, and Fars provinces. In this study, two types of ground and high data are used as follows:
A) - Using daily rainfall data of the 44 years (1967-2014) statistical stations of the region obtained from the country's Meteorological Organization
B) Use of high-level data. Includes revised data for geopotential heights, sea level pressure, wind direction, meridian wind, omega, and humidity, from the National Center for Environmental Excellence at Colorado. To conduct synoptic analysis, the circular environmental method was used; after observing the daily rainfall during the statistical period of all rainfall over 50 mm in selected stations of Yazd, Jiroft, Shiraz, Bandar Abbas, and Yasuj, 118 heavy rainfall events were investigated. After identifying and separating days, 105 observation systems were identified and analyzed.
After the evaluation and control of the pressure maps of the sea of the systems of landing, 4 patterns were selected and identified.
Explain and interpret the results
The results showed that heavy precipitation occurred in the months of December, December, February, February, and November, respectively. Since November, with the retreat of high-performance dynamic systems to the southern latitudes and the influx of western winds from high latitudes on the area, conditions for the occurrence of heavy rainfall are provided. Most centers with 9 heavy rainwater systems of Sudan's lowland, 6 the moderate Sudanese-Mediterranean component of the Middle East has been on Iraq, and the four satellite systems have been the Mediterranean-Sudan-Mediterranean integration. The most frequent Sudanese pattern in 2-day continuity with 17 cases was Sudan-Mediterranean integration pattern with 7 cases in 3-day continuation, Sudanese-Mediterranean integration pattern in the Eastern Mediterranean, 4-day continuity with 7 events, and equidistant Mediterranean pattern The continuity of 2 to 4 days has been due to the increased load of Mediterranean systems ranging from 70 to 90 mm.
 
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Type of Study: Research | Subject: Special
Received: 2018/03/11 | Accepted: 2018/09/5 | Published: 2019/01/7