temporal and spatial study of water use productivity of strategic crops in regional scale (case study: hamedan province)

water use productivity is one of the most important factors in scientific agriculture. it is equal to 0. 7 kg of production per cubic meter of irrigation water (kg/m3) in iran which is very low in comparison with advanced countries (1 to 2 kg/m3). current research studies temporal and spatialchanges of water use productivity in hamedan province in iran using geographic information system (gis), as to find evapotranspiration values for wheat and to transform it to raster level using inverse weight distance interpolation (idw) in arcgis9.2 software. as location and time dimensions are studied simultaneously, combination of both leads to more effective analysis.evapotranspiration is the denominator of water use productivity and the nominator is products’ performance which the values are obtained using statistics of iran agriculture ministry and hamedan province agricultural organization in particular and location extension map for wheatproductivity is obtained from overlay of 2 raster of evapotranspiration layer and the performance layer.