Analysis of the amount, frequency and intensity of annual precipitation in Caspian region over during 1966-2016

Precipitation is one of the most important climatic elements in every given region that plays a decisive role in urban and rural planning, industrial location, architecture, agriculture, industry, and so on. Accordingly, the present study attempts to evaluate the amount, frequency and intensity of annual precipitation in the Caspian coastal region in which the economical planning is fundamentally based on precipitation. To this end, the daily data of 385 stations, under Meteorological Organization and the Ministry of Energy's supervision have been used for the period of 2016-1966 (51 years). Then, the amount, frequency and intensity of annual precipitation were studied and finally, the trend was verified by fitting the linear regression model by using parametric method. The results showed that the annual precipitation in 61.4% and the frequency of precipitation in 47.1% of the under investigation area has an increasing trend. The annual precipitation is also stationary in all under study area. The trend of the coefficient of variation in the month- to- month precipitation indicated that the stationary trend is overcome in the majority of the area. Precipitation is one of the most important climatic elements in every given region that plays a decisive role in urban and rural planning, industrial location, architecture, agriculture, industry, and so on. Accordingly, the present study attempts to evaluate the amount, frequency and intensity of annual precipitation in the Caspian coastal region in which the economical planning is fundamentally based on precipitation. To this end, the daily data of 385 stations, under Meteorological Organization and the Ministry of Energy's supervision have been used for the period of 2016-1966 (51 years). Then, the amount, frequency and intensity of annual precipitation were studied and finally, the trend was verified by fitting the linear regression model by using parametric method. The results showed that the annual precipitation in 61.4% and the frequency of precipitation in 47.1% of the under investigation area has an increasing trend. The annual precipitation is also stationary in all under study area. The trend of the coefficient of variation in the month- to- month precipitation indicated that the stationary trend is overcome in the majority of the area. Consequently, precipitation throughout the coastline and parts of Alborz mountain chain has not changed during the year. Some parts of the area including the eastern parts, the Alborz mountain (south of the Caspian Sea), parts of the western Alborz, and a very small part of the west have experienced declining trend in the coefficient of variation in the annual rainfall. Precipitation is one of the most important climatic elements in every given region that plays a decisive role in urban and rural planning, industrial location, architecture, agriculture, industry, and so on. Accordingly, the present study attempts to evaluate the amount, frequency and intensity of annual precipitation in the Caspian coastal region in which the economical planning is fundamentally based on precipitation. To this end, the daily data of 385 stations, under Meteorological Organization and the Ministry of Energy's supervision have been used for the period of 2016-1966 (51 years). Then, the amount, frequency and intensity of annual precipitation were studied and finally, the trend was verified by fitting the linear regression model by using parametric method. The results showed that the annual precipitation in 61.4% and the frequency of precipitation in 47.1% of the under investigation area has an increasing trend. The annual precipitation is also stationary in all under study area. The trend of the coefficient of variation in the month- to- month precipitation indicated that the stationary trend is overcome in the majority of the area. Consequently, precipitation throughout the coastline and parts of Alborz mountain chain has not changed during the year. Some parts of the area including the eastern parts, the Alborz mountain (south of the Caspian Sea), parts of the western Alborz, and a very small part of the west have experienced declining trend in the coefficient of variation in the annual rainfall. Precipitation is one of the most important climatic elements in every given region that plays a decisive role in urban and rural planning, industrial location, architecture, agriculture, industry, and so on. Accordingly, the present study attempts to evaluate the amount, frequency and intensity of annual precipitation in the Caspian coastal region in which the economical planning is fundamentally based on precipitation. To this end, the daily data of 385 stations, under Meteorological Organization and the Ministry of Energy's supervision have been used for the period of 2016-1966 (51 years). Then, the amount, frequency and intensity of annual precipitation were studied and finally, the trend was verified by fitting the linear regression model by using parametric method. The results showed that the annual precipitation in 61.4% and the frequency of precipitation in 47.1% of the under investigation area has an increasing trend. The annual precipitation is also stationary in all under study area. The trend of the coefficient of variation in the month- to- month precipitation indicated that the stationary trend is overcome in the majority of the area. Consequently, precipitation throughout the coastline and parts of Alborz mountain chain has not changed during the year. Some parts of the area including the eastern parts, the Alborz mountain (south of the Caspian Sea), parts of the western Alborz, and a very small part of the west have experienced declining trend in the coefficient of variation in the annual rainfall.