بررسی شاخص SPI در پایش خشکسالی در استان تهران

In order to investigate dry and wet years and their effects on the increase or decrease of days with dust, the situation of drought years and periods is checked using the SPI index. This index is obtained based on the difference of precipitation from the average for a certain time scale and then dividing it by the standard deviation, and the only effective factor in calculating this index is the element of precipitation. According to the objectives of the research, the data related to climatic factors affecting the phenomenon of dust (temperature, humidity, precipitation, evaporation, wind, number of days of dust) were collected, reconstructed, extended and completed and in the form of an index. Droughts were investigated and analyzed in a statistical period of 30 years (1369 to 1398). In this study, the days with dust as a dependent variable during the study period were compared with the simultaneous data of temperature, evaporation and rainfall as independent variables. The results of the study will show the relationship of these variables from the aspect of climate effect on the dust phenomenon. In order to investigate dry and wet years and their effects on the increase or decrease of days with dust, the situation of drought years and periods was investigated using the SPI index.