圖書典藏及影音數位平台

台灣在有限資源的需求下,常需在河道建攔河堰取水,而攔河堰的施設往往造成下游河道劇烈沖蝕,在民國89年921地震之車籠埔斷層引起河床差異隆起後,河道縱坡降及泥砂運移更呈現不連續現象,近年來由於河道坡度自然調整,加速攔河堰下游軟弱岩床裸露河道沖刷行為,最大沖刷深度已達數10公尺,危及水資源及防洪構造物安全.當水利工程師專注於軟弱岩床河段消能工法及其沖刷防制下,劇烈之軟弱岩床沖蝕導致其下游河道劇烈擺盪幅度加大,影響軟弱岩床沖刷河段下游現有堤防及橋梁之安全,因此影響集集攔河堰下游劇烈沖蝕河段之沖刷行為,除了水資源及防洪需求下之人為干擾外,並包括自然營力等複雜因素.

Rivers in Taiwan typically have steep slopes and subject to high sediment transportation flows.During the past decades,earthquake induced riverbed uplift,in stream structure,and sand mining are the main agents lead to the tremendous channel migration in the river reaches of the west-central Taiwan.After experienced significant alluvial erosion,the soft bedrock exposed immediately downstream of water intake cross-stream structures,the severe erosion due to slope adjustment become extremely complex between alluvial,bedrock and mixed river channel.So the river stability becomes an important issue for the limited water resources in Taiwan.To mitigate the damage of downstream cross-stream infrastructures and flood prevention works from the severe bedrock erosion.A number of engineering schemes have been proposed and implementation. However,the allocation of every single stable river engineering need a principal of stable channel for a comprehensive stability solution under the continuing morph-dynamic processes.