The Climate zoning role on net irrigation requirement determination of orchards in Kurdistan province, Iran

The current study was conducted to estimate of orchards water requirements based on various climate zones in Kurdistan province، Iran and to compare those requirements of the same crops based the province cities. Basic information and essential data such as meteorological and vegetation data were extracted from reports and available maps. The Kurdistan climate was derived using De Martonne method and the water requirements in each climate were determined using CROPWAT8. 0 model. Cities water orchards requirements having synoptic station were estimated using this model. Recognizing of various climates in a city level revealed that water requirement estimation studies based on climates give better results than those were conducted based on the cities in the province. As the calculated water requirements values based on city’s border can be trusted while the whole city located in a climate zone such as the Ghorve and Bijar. The findings of the research indicated a significant difference between the calculated water requirements based on cities and those derived considering the climate zones distinguished in the same city، such as Sanandaj، Saghez and Marivan. The most visible differences in calculated water requirement based on climate zone revealed in group 1of orchards in semi-arid climates for Sanandaj which were increased as 22% more than that estimated based on the city’s border. In addition، the 0. 9% increments in water requirements in group 2 for humid zone in Sanandaj were the slightest changes obtained in this research due to altering of the calculation based on city’s border to climate zone. The results would be of interest of researchers and those who are involving in agriculture and water resources management fields through the allocation of limited water resources based on the climatic conditions.