the study of most important climatic parameters influencing on potato yield with climate change paradigm (studied case, in kermanshah province)

climate change  is one of the most important challenges in recent years. heavy flood, hot weather, early coldness, most of drought replications, risen of sea water level, pests and plant disease ,reducing of ozone layer thickness, global worming ,and melting ices, are cases that introduced climate change issue in recent decades more. climate is one of the most important  factors for crop  changing rate and its yield in recent decades .in regard to that potato is one of the most important agricultural crops in country ,and almost is planted in most areas, in this survey we  have  considered to studying temperature impacts and fall raining and its  shifts  as most important parameter influencing on potato yield in kermanshah province. because of this reason , cities having acceptable agricultural and climatic statistics are  chosen.(6 cases )and then in regarding to phonological cycles  of potato and agricultural calendar , the climatic parameters are divided to 6 variants. according to different climatic characteristic  in kermanshah, in gis environment and using of zonal statistic capacity of this software ,statistical characteristics of production  yield and other variants  are  derived based on classifying climate and finally in spss software ,most important climatic parameters influencing on yield and also changes  trend  is measured in all of kermanshah province .results showed that temperature of ending  winter and early spring  were important parameters influencing on potato yield in most areas  in kermanshah province. and if these temperature is increased , yield rate of potato is increased  in most areas  in kermanshah.