台湾河川流域淹水指数评估研究

Evaluation of inundation index for river basins in Taiwan

目前水利主管机关为有效管理流域中下游洪水灾害,已建立许多防洪治水工程,包括堤防、排水系统及抽水站等,但随着集水区中上游土地利用急剧改变,致使原先设计之防洪设施可能已不足应付开发所增加之洪流量,因此近年来已投入适当资源,并以工程与非工程防洪方法并重为原则,让台湾防洪工作进入崭新的一页。本研究主要是选定淹水指数评估参数之项目,并以阶层分析程序法(Analytic Hierarchy Process,A.H.P.)及所设计之专家学者问卷,决定淹水指数评估参数之权重,以研拟河川流域淹水指数评估方法,与评估河川流域淹水损失之严重性,未来将可应用于评估河川防洪排水等整治工程之施设优先顺序,并做为评定工程整治后成效以及满足防灾应变预警之参考。目前研究以淡水河、头前溪、浊水溪、高屏溪及秀姑峦溪为例,根据其水文、水理及人文现况,进行淹水指数试算,其淹水指数分别为60.1、36.9、33.4、38.3及35.2。由于本次试算中,因某些参数资料难以获得,所以在试算中是以初估之方式进行评估,建议未来可配合实际现况,对各项评估参数之评分标准做适当之调整,以使淹水指数之计算更为合理。

Numerous flood disaster mitigation and prevention structures were built by Water Resources Agency （WRA） for improving the watershed management in Taiwan, including banks, drainage systems and pumping stations. Due to the changes of land exploitation in many major watersheds, the original designs for these structures are incapable to achieve flood prevention objectives. Recently, inundation areas for most of rivers in Taiwan have been delineated to provide information by nonstructural measures for floodplain management. The main purpose of this study is to establish the inundation index by Analytic Hierarchy Process （A. H. P. ） method, which can provide quantifiable information to assess the construction efficiency of the flood structures and to support the decision making of the flood emergency responds.