اevaluation of rainfall effect to programing and management of agricultural (case study: golestan region)

evaluation of rainfall effect on programing of agricultural management (case study: golestan region) abstract securing of water need in agricultural is important. precipitation are one of the most important of water resources in agricultural, in golestan province, especially , because alborze mountains are in golestan south. in research has investigated effects of rainfall to cropping pattern and intensification in golestan farms. rainfall used: a) have forecasted rainfalls by minitab-13 program, b) different probabilities of rainfalls by lst program. then estimated effective rainfall (by usda method). for optimization used lingo-8 program. evaluations shown that in southern region (climate is: smi wet), if rainfall decreased, area of tomato and potato decreased , but canola area increased. in central and north regions (climates are: semi dried to dried), if rainfall decreased, watermelon area decreased, but canola area increased. also if drought conditions, planting of canola, watermelon and cotton crops are important.