Monitoring of Climatic Factors Affecting on Dust & Sand Storm in Tehran Province
Abstract
In this study, according to the objectives and implementation method, climatic factors affecting the dust phenomenon in active meteorological stations in Tehran province for a period of 30 years were studied and analyzed. The results showed that in Mehrabad meteorological station, temperature, humidity, rainfall, evaporation factors were directly related to DSI indices, wind trend and dust storm changes, Lancaster, wind and storm diagrams, SPEI and the increase of drought indices in the statistical period increased with temperature, evaporation and decrease. Rainfall and humidity are proportional. DSI dust storm indexes were compared to 1 and Lancaster drought index was compared to 50 and SPEI index was compared positively and negatively in different years of the statistical period in the region and was classified in terms of drought and wet season. The results of monthly and annual changes in wind trend and dust storms showed that the region has no wind in all months and seasons with a speed of more than 20 meters per second. In terms of wind speed and frequency percentage, the highest wind speed was related to late May and early June, and the lowest wind speed was related to late December and early January. In addition, according to the changes in the wind trend and the documents of the winds and thunderstorms, the prevailing wind direction in the region was from the west.