the stady and analysis of rice agroclimatology in lenjan

the west of esfahan province, iran, is one of the most important agricultural areas throughout the country due to the climate variability and life-giving water of zayanderood river. rice is one of the major and economic crops in this area. the most important climatic elements in agricultural activities which should be considered include temperature, relative humidity, precipitation and wind. so it seems necessary to analyze climatic elements for appropriate planning of planting, reaping and harvesting timing of crops. forasmuch as rice is the most important daily meal and it has been grown in lenjan city for consecutive years and also according to government support of rice cultivation to reduce dependences, the expansion rice cultivation in this area would be useful for farmers and other related jobs. in this research, for more detailed study of climatic elements (include temperature, precipitation, wind and relative humidity) on rice yield, in addition to daily data of lenjan’s climatic elements, data collected from other 4 weather stations ( include esfahan, daran, natanz and najaf abad) during a period of 15 years( 1375- 1390) about different stages of rice cultivation are analyzed. then the correlation between climatic elements and rice yield has been analyzed in selected stations. ultimately after drawing the climatic maps, height levels and slope, final map of zoning appropriate areas from inappropriate ones for rice cultivation according to effective elements is drawn by means of gis. results of this research indicate that there is a completely appropriate area about 492 square kilometers which located in the central areas and in alluvial plains. minimal damage due to late spring frost and early fall frost occurred in this areas of land. primary roots, stems and rice clusters rise up rapidly, but it may be facing a shortage of precipitation to supply required water. the appropriate areas encompass the most part of the map which is about 738 square kilometers. the appropriate and completely appropriate areas encompass about 75 percent of total areas. 345 square kilometers of this area is poor or inappropriate for rice cultivation which located in altitude margin and close to the mountain and is composed of rocky and steep and non-agricultural land. climatic elements analyses indicate that in all selected stations, wind and temperature affect most of the appropriate and completely appropriate areas during different stages of rice growth, but precipitation rate in selected stations for all stages of rice cultivation does not provide required water and rice needs to be irrigated. furthermore relative humidity rate during different stages of rice cultivation in lenjan city is adequate and of other studied stations are sustainable. key words: rice, agro climatology, temperature, precipitation, relative humidity, wind and lenjan.