Dam Construction and Change of Flood Level at Downstream

초록

Floods are among the most frequent and costly natural disaster in terms of human hardship and economic loss. Since floods may be both physical and socio-economic phenomena which impinge upon, and are of direct interest over, a wide range of activities, it is perhaps not surprising that they may be categorized by a wide range of measurable variables. Undoubtedly, the most common index of flood magnitude probably is water stage or flow rate which has the advantage that it may be measured directly and is of immediate relevance if flood-relating structures are likely to be overtopped. This index can be also employed to investigate the flood control effect obtained as a dam is constructed. This study estimates water stage and flow rate at downstream when Youngwol dam exists in upstream of Han river, Korea. To investigate the flood control effect we may use the deterministic or statistical models which can describe rainfall-runoff processes in a river basin. This is a common way to explain the characteristics of a river basin and to estimate the change of water stage or flow rate at the downstream during a rainfall period. However, the models may require the parameter estimations or the verification for its validity and they are time-consuming. Therefore our concern in this study is to estimate water stage or flow rate without the model’s common procedures.