小流域における水田貯留の洪水抑制効果に関する現地観測と流出解析

抄録

In order to deal with recent change of runoff characteristics by urbanization of a river basin, construction of facilities for rainwater storage and infiltration has been planed as a flood control measure in the basin. However, the construction plan has not been in progress due to high costs and limited sites for the facilities. In this paper, we propose a new utilization method of paddy fields remained in the basin as an alternative measure. This research aims to evaluate rainwater storage function of paddy fields and to verify a new procedure to improve the function, through on-site observations and simulation analyses. A water-balance model on storage-drainage process in each paddy field is identified based on observed data, and by using a runoff analysis model based on the kinematic wave theory, the runoff processes from a drainage area consists of many paddy fields are simulated for a probabilistic design rainfall. From results of the runoff simulation, it is found out that paddy fields have applicability as the runoff control facilities.