Document Type : Research Paper

Authors

• Hossein Babazadeh ¹
• Saeadamir Shamsniya ²
• Fardin Bostani ³
• Elnaz Norozyaghdam ⁴
• Davood Khodadadydehkardy ⁵

¹ Islamic Azad University, Tehran Science and Research Branch, Department of Water Engineering, Tehran

² Irrigation and Drainage, Islamic Azad University, Science and Research Branch of Tehran

³ Islamic Azad University, Fars Science and Research Branch

⁴ Middle Branch

⁵ Irrigation Department, Islamic Azad University, Science and Research Branch of Khuzestan

Abstract

Stochastic models have been used as one technique to generate scenarios of future climate change. Temperature and precipitation are among the main indicators in climate study. The purposes of this study is analysis of the status of climatic parameters of monthly precipitation and mean monthly temperature, years of drought and years of wetness due to precipitation deficiency, simulation and forecasting using stochastic methods. In this study, the 21 year data on the precipitation and mean monthly temperature at shiraz synoptic station are used and based on ARIMA model, the autocorrelation and partial autocorrelation methods, evaluation of all possible models regarding their invariability, examination of parameters and types of model, the suitable models for prediction of monthly precipitation: ARIMA (0 0 0)(2 1 0) 12 and for forecasting of the mean monthly temperature: ARIMA (2 1 0)(2 1 0) 12 were obtained. After validation and evaluation of the model, the forecasting for the agriculture years 2008-09 and 2009-10 were made. In view of the forecasting made, despite of a continuing drought, it is likely that the precipitation will improve. As regards the mean monthly temperature, the trend of increasing temperature, especially in recent years, has continued and the findings of the forecasting show an increase in temperature along with a narrowing of the range of variations.

Keywords

• Precipitation
• Temperature
• Stochastic Methods
• ARIMA