PREDICTION OF SEASONAL AND ANNUAL PRECIPITATION BY USING GEOGRAPHICAL INDICES

Abstract

In this study, the daily precipitation observations of 428 weather stations across Iran were used. Statistic period of 40 years (1965-2004) was chosen. We used Kriging interpolation method to map of average daily precipitation with spatial resolution of 15kmx15km. As a result, mean monthly and seasonal precipitation were produced for more than 8000 point over Iran. The maps were plotted based on the Global Positioning System (GPS). The run-test was carried out to check validity and uniformity of the precipitation data. In this study, the effect of geographical factors (altitude, latitude, longitude) affecting the precipitation regime was verified. It is shown that that precipitation regime in northern sites are more exposed to local factors and seasonal precipitation than those of southern sites. Seasonal and annual regression equations are also presented. The results of this research can be applied in land–use, environmental plans projects and water resources management in case of lack or shortage of data and the places which rainfall data are not available.

Keywords

• Precipitation regime
• Prediction
• Three-variable regression
• Iran.