چکیده:
Climate change disturbs the distribution of precipitation patterns and affects water resources. A lot of evidences imply that the increased atmospheric concentration of greenhouse gasses in turn increases the precipitation changes around the world. Thus, since Iran is located in an arid zone of the earth, identifying the effects of CO2 concentrations on Iran precipitation rate is highly important in planning the projects for water resources. Statistical data from 31 selected synoptic stations between 1975-2010 have been used. Also data for CO2 (ppm) were taken from the website of NOAA and then were analyzed by Pearson Correlation Coefficient (PCC). Our results indicate that CO2 had a positive (incaresing) effect on the spring precipitation in the northern areas of Iran and a negative (decreasing) effect in the southern parts of the country. There is not a specific pattern for the distribution of precipitation in the summer; the related data were not much reliable. In the fall, CO2 had an increasing effect on the precipitation rate in the eastern parts and, conversly, a decreasing effect observed in the northern parts (particularly in the southwestern coast lines of the Caspian Sea). Finally, in the winter, precipitation rate showed an increasing pattern and, in some western and northeastern parts of the country, a decreasing pattern was observed.
خلاصه ماشینی:
Our results indicate that CO2 had a positive (incaresing) effect on the spring precipitation in the northern areas of Iran and a negative (decreasing) effect in the southern parts of the country.
Climate change and its impacts on earth surface, associated with the increase in greenhouse gases and changes in global temperatures, radiation budget, and hydrological cycles, have increasingly attracted the attention of researches in different areas (Ramos et al.
(2012), with multivariate analysis of seasonal variation of temperature and precipitation over the past 60 years in the Mediterranean climate region of North East Spain, concluded that in all stations according to the different seasons, the temperature increases about 1.
Meaning that the effect of this gas on the southern coasts and western regions of Iran winter precipitation and precipitation stations Sabzevar, Yazd, and Kerman is negative and positive relation of a reduction in the central part has been increasing.
In order to analyze the spatial distribution of atmospheric CO2 effects on spatial distribution of precipitation in study area, the calculated correlation coefficients between CO2 and precipitation of stations were drawn in Figure 3.
This means that the effect of CO2 on spring precipitation in southern and central parts of the semi-reduced is negative, it is positive in northern coast, and in other parts of the country are almost without unaffected.
alysis of CO2 gas effect in summer precipitation oscillations The relation between Summer precipitations and CO2 was investigated, then calculated correlation coefficients are presented in Table 3.