Abstract
In this study, we investigated water use in 5 upland irrigation districts to estimate the influence of greenhouse ratio on capacity of farm pond and water distribution system. First, we measured the water level of farm pond and estimated the amount of hourly water distribution. Then, we calculated a (indicating the ratio of the regulating capacity to amount of the daily water distribution) and F (indicating hourly concentration of water use). The capacity of farm pond or water distribution system restrict a free water use, it is difficult to clarify the relationship between greenhouse ratio and these two indices especially during the period when water requirements were intensive. We estimated the values of a and F without restriction of free water use. The results showed a positive correlation between these two indices and greenhouse ratio. When applying the value of these two indices to the amount of maximum daily water requirement, we found that the required capacity of farm pond in open field area and greenhouse area were 20m3/ha and 40m3/ha respectively.
