Abstract
This paper discusses estimation of the area applicable for winter-flooded rice fields based on observation of water requirement Observation survey on water use and interviews were carried out in a study area of winter-flooded rice field in Miyagi Pref. The main findings were as follows. 1) Lot water requirement was estimated 5.0mm/d to 8.0mm/d. 2) The flow rate of water in the dual-purpose canal during the non-irrigation period was identified 259m³/s from the observation. 3) The flow rate of water in the drainage canal during the non-irrigation period was identified 19.9m³/s, and it was functioning as a supplemental source and playing a big role to maintain the water level. 4) The range of allowable flooded area was estimated roughly from 0.42ha to 2.99ha.
