Investigation of modeling for annual rainfall estimation in different climates (Case Study: Golestan Province)

Dry farming is a part of agricultural practice in Golestan province. Increasing dry and irrigated lands is connected with rainfall. Dry farming is important in countries with developed economy and agriculture. Therefore modeling for estimation of annual rainfall is important. This research used data of daily rainfall (34 years) of 8 stations in Golestan region. Climate of stations were cold semi dry to temperate (mild). Results showed that in equation between t167.5 (data of rain value=167.5 mm from the first of autumn in mild climate) and t107.5 (cold dry climate) annual rainfall decreases. Some another parameters were not suitable for these equations.