Page - 633 - in Book of Full Papers - Symposium Hydro Engineering

Fig. 5 a shows the annual temperature variation of the Zidasht station in the middle part of the basin. As shown, the annual temperature rise is significant at a 99% probability level and represents an increase of about 4.56 ° C over 1966 to 2012. This means that the studied basin experienced a Mean temperature increase of 12.2 ° C per year. It is interesting to note that the above studies were carried out for the Joestan station in the basin, but practically, as shown in Fig. 5b, due to the steady slope, there is no particular trend at annual temperatures. Indeed, the upper section of the basin shows a constant annual heat scale, and climate change in terms of the thermal system is not probable in this part of the basin. Figure 5: The annual temperature trend in A) Zidasht station, B) Joestan station Figure 6: Temperature trend of the Ziadsht station in A) January B) February Tables 6 and 7 demonstrate the results of trend analysis of precipitation, temperature and runoff variables in monthly and seasonal scales in selected stations. 633