2013 Volume 29 Issue 4 Pages 161-167
We examined the degree to which we can distinguish parcels planted with rice by visual interpretation of high resolution satellite images in an area in Inashiki-City, Ibaraki Prefecture. In this area, rice planting became difficult over a wide area in 2011 because many irrigation facilities were damaged and sand liquefaction occurred in many paddy fields due to the 2011 off the Pacific coast of Tohoku Earthquake in March 11, 2011. Pansharpened images at a resolution of 0.5 m from the WorldView-2 satellite data acquired on June 29, 2011 were used. Three persons with no prior experience of visual interpretations determined whether rice was planted in paddy parcels by visual interpretation of printed satellite images. We then verified the accuracy of the interpretations by comparing with data from a field survey carried out the next day. The distinction accuracy was 96.0 – 97.6%. Most parcels incorrectly distinguished were fields planted with a small percentage of vegetative cover of oats and the entire soil surface wet, or fallow fields (after plowing or puddling) without vegetative cover and with the entire soil surface wet. The accuracy of distinction was highly dependent on rainfall before the satellite observations.
