| Based on the new MOD16 remote sensing data sets and the precision validation, statistically analyzed the sptio-temporal evolving characteristics and the difference of evapotranspiration (ET) by various land using types in Guanzhong region during 2000—2012 with support of GIS and RS technology. The results showed that: (1) MOD16-ET data has a good precision in Guanzhong region, the validated relative error and correlation coefficient were 10.38% and 0.69, respectively; (2) The average multi-years ET in Guanzhong Region was 520.05 mm·a-1, the spatial distribution was showed the three step pattern as approximately decreasing from southwest to northeast. The ET spatial distribution in four seasons was the basic consistent with the multi-year average situation. (3) The ET spatial distribution had a significant effect by the land cover types, the sequence of ET intensity for each land cover type is forest (623.67 mm·a-1) >grassland (504.51 mm·a-1) >garden (460.86 mm·a-1)>farmland (448.89 mm·a-1) >bare land (408.77 mm·a-1); (4) The annual variation trend of ET in Guanzhong Region was increased at 0.87 mm·a-1, the spatial distribution was showed a tendency of decreasing in east and increasing in west, among them, in spring and summer seasons had a rather greater proportion for changing areas, while in autumn and winter seasons, most of Guanzhong Region has no obvious ET variation. The monthly ET roughly showed a change trend of increasing first then decreasing, also the annual ET was mainly concentrated in summer season. |