日治時期大嵙崁溪水利事業的形成、發展與頓挫

Abstract

水利與交通兩項事業，是日治初期創制的「臺灣事業」之中，帶動臺灣出現現代式經濟成長的要素裡，編列預算規模最大的兩個。其中，大嵙崁溪從水利事業開創之始，即為其核心構成計畫項目。對於臺北盆地與桃園臺地兩個炯異的地理區域而言，由於開發行為破壞生態環境，造成連年洪患與旱災不斷，唯有實現「水的控制」臺北大都會區才能形成，也唯有實現「水的利用」才能讓桃園大圳灌溉區成為「北臺糧倉」。此舉非但保障了首要之地的糧食安全，在日本政府築起的關稅壁壘裡，運用公債募集制度，將水利事業作為中心，刻意打造以米糖成為主要出口產品的北南分工體系，從而也將臺灣殖民地的經濟納入帝國內部供應鏈循環系統的一環。這是大嵙崁溪水利事業的貢獻，也是本文立論的目的。據此，本文運用的研究方法有三。其中主要的是「歷史途徑研究法」，即將所搜集的相關史料與文獻，進行整理、排比、分析、詮釋與解讀。其次，配合輔助的是「田野調查研究法」，是以口述訪談資料與史料文獻進行佐證比對，過濾冗贅，具有故事價值者則寫入文稿。另外，作為研究觀點的佐證資料，本文採用「計量經濟分析法」，利用與臺灣總督府有關且詳實可信的統計數據，作為本文提出解釋的憑據。在研究成果部分，全文的討論都圍繞著大嵙崁溪水利事業是為了解決臺北盆地的洪患與桃園臺地的旱災，這兩個主要的問題，從而開展敘事的歷程。大嵙崁溪水利事業從1908年立案之後就被分成三期計畫，執行主要項目有三項：利水事業的桃園埤圳工程、治水事業的砂防治水工程與水力發電的重力拱壩工程。三個項目在三個相繼承續的時期裡，成為三代水利技師亟欲實現的目標。另外，大嵙崁溪水利事業從通過法制化程序開始，即以美國水利事業作為典範和學習目標。本文以十川嘉太郎、張令紀與八田與一等三人作為日治時期三代水利技師的代表人物，三位技師分別在明治、大正與昭和時期，規劃在大嵙崁溪建造能夠締造東亞與世界紀錄的重力拱壩。雖然此一目標，終究未能實現，卻也成為戰後石門大壩規劃歷程之中，重力拱壩設計案的指標方案。Water resources and transportation projects are among the"Taiwanese Projects" created in the early period of the Japanese Rule with enormous budgets and drove Taiwan's modernized economic growth. Among the projects, Taikokan River has been the core component since the water resources project began. Within the two distinct geographical areas of the Taipei Basin and the Taoyuan Terrace, continuous floods and droughts have happened for years due to the destruction of the ecological environment caused by development activities. Only through realizing "water control" can the Taipei metropolitan area be formed, and only via realizing "water utilization" can the Taoyuan Canal Irrigation District become the "Northern Taiwan Granary." The acts guaranteed the food security of such a crucial place. Furthermore, from the perspective of the tariff barriers erected by the Japanese government, the public debt-raising system has been used, and water resources projects have also played the central role in deliberately creating a north-south division of laborsystem in which rice and sugar act as the main export products. In turn, the economy of the Taiwanese colony was integrated into the circular system of supply chains within the empire.This study uses three research methods on the thesis of the contribution of Taikokan River Water Resources Project mentioned above. The most important method is the"historical approach," which sorts out, compares, analyzes, annotates, and interprets relevant historical materials and documents. Secondly, "field research" is used as a supplemental method, through which oral interview data and historical documents are used to compare pieces of evidence and avoid redundancy, so data with the story value can be written into the manuscript. In addition, as supporting material for the research viewpoint, this study adopts the "econometric analysis" method. It uses detailed and credible statistical data related to the Government-General of Taiwan as evidence for the explanation proposed in this study. The result section focuses on the argument that Taikokan River Water Resources Project is to solve the problem of floods in the Taipei Basin and the drought in the Taoyuan Terrace. These two main issues are thus developed throughout the narrative of the research. Taikokan River Water Resources Project has been divided into three phases since it was put on record in 1908, along with three main implementation projects: Taoyuan pond and canal engineering of water utilization project, sand control and water control engineering of water control project, as well as gravity arch dam engineering for hydropower generation. The three projects became the goals that three water resources technicians from three generations desperately wanted to achieve in three consecutive periods. In addition, since the legalization of Taikokan River Water Resources Project, American water resources projects have been used as models and goals to achieve. This study takes Kataro Sogawa, Chō Reiki, and Hatta Yoichi as representatives of water resources projects from the three generations of Japanese Rule. During the Meiji, Taisho, and Showa periods, these three engineers planned to build a gravity arch dam on the Taikokan River that could set world and East Asian records. Although this goal was not realized, it has become the indicator for the gravity arch dam design of the post-war Shimen Dam projects.