九州大学大学院農学研究院生産環境科学部門地域環境科学講座灌概利水学研究室
Laboratory of lrrigation and Water Utilization, Division of Regional Environment Science, Department of Bioproduction Environmental Science, Faculty of Agriculture, Kyushu University
九州大学大学院農学研究院生産環境科学部門地域環境科学講座灌概利水学研究室
Laboratory of lrrigation and Water Utilization, Division of Regional Environment Science, Department of Bioproduction Environmental Science, Faculty of Agriculture, Kyushu University
九州大学大学院農学研究院生産環境科学部門地域環境科学講座灌概利水学研究室
Laboratory of lrrigation and Water Utilization, Division of Regional Environment Science, Department of Bioproduction Environmental Science, Faculty of Agriculture, Kyushu University
The object area of the present study is paddy area in Cidanau watershed of west Java, Indonesia. ln this area, unstable mountain stream is taken and used repeatedly by plot-to-plot irrigation and dual-purpose canals. And thus water management of this area is high-efficient. Evapo-transpiration of this area fluctuates very little and shows 4.6mm/d throughout the year. ln addition, it is estimated that the base discharge of inflow to this area is about 4.3mm/d in the dry season. In this way, the paddy field is ponded for only two weeks after the rice transplanting and after that it is not ponded as roots of paddy reach the.groundwater surface and absorb it. lt is also repeated in the same way at the next field. A shortage of irrigation water in the dry season is made up for by this water management. That is the reason why various growing stages of paddy shifted by about two weeks exist. The actual condition of this water management is proven by the simulation for water distributiori. As the result of this simulation, it is clarified that most of the water flows on the surface of paddy field and the percolation to the underground is very little.