study of the minimum, average and maximum temperature in south khorasan to identify relevant areas for saffron cultivation using gis

abstract knowledge of the coordination of the agricultural activities in every region with the weather and climate condition of that area is necessary for any kind of agriculture activity. therefore, understanding the climate and analyzing the ecophysiological characteristics of plants are the most important factors in production. saffron is one of the most valuable plants, which is planted in special climate conditions and has a unique growth process. at the present, iran produces of 90% of total saffron production. despite its old culture compared to other crops produced in the country, production of saffron in iran that has relied primarily on indigenous knowledge. analysis of the effect of the weather parameters on the performance of saffron and determining the suitable areas for planting saffron according to these parameters are important for agriculture and the economy. the statistics and data of 20 years taken from all the weather station in the region and the ten years performance of saffron were used in this study. regression analysis and create of equation using minimum, average, maximum temperature and the relation between these parameters by saffron yield were accomplished by the use of jmp4 software. the digital climate maps of zoning scheme using software arcgis9.2 were drawn. the results showed that minimum temperature was the most effective factor on the performance during the month of mehr, aban, azar and dey compared with the other months and considering average temperature, the most affected months are mehr, aban, azar and dey. maximum temperature was most effective on the performance during the month of aban, azar, dey and esfand compared with the other months also after analyzing the equation and the climate zonation maps and the final map it become obvious that the most of the areas of the province were able to be ranked as suitable. the north and north-eastern areas were the best areas regarding the parameters discussed in order to grow saffron. the center of province was considered average region to grow saffron and the southern and south-western areas were determined the least suitable for growing saffron.