岡山歴史のまちしるべ多言語版（H22幸島新田）

Kohjima-Shinden

幸岛新田

幸島新田

고지마신덴

　The first plan to develop rice paddies was devised in the year 1657, but it was considered difficult to reclaim the estuary with the technology available at the time. Kumazawa Banzan, a Yangming, Neo-Confucianism scholar who was also a major authority on flood control at the time, stated that floods occur when large amounts of water flowing from upstream are blocked by seawater at high tide, also explained the adverse effects of developing rice paddies at the mouth of a major river.

　However, Tsuda Nagatada devised a method in which sluice gates and retention ponds were installed at the ends of the drainage channel in the rice paddies. The gates are closed during high tide to allow river water to stagnate in the retention ponds, then at low tide the gates are opened to discharge the river water into the sea. This method is known as the retention pond and sluice gate combination method. Nagatada was the first to use these techniques in the reclamation of Kohjima-Shinden, with construction starting in February of 1684 and the tidewater control work being completed in June of that year. By accomplishing the development of Kohjima-Shinden, Nagatada showed that it was possible to reclaim land at the mouth of the river, which was considered impossible at the time.

　进行新田开发的计划最初始于明历3年（1657），但是一般认为以当时的技术对河口部进行排水开垦还比较困难。另外，当时的治水学大师、阳明学者的熊泽蕃山解释了关于大河的河口新田开发的弊害，他认为从上流流下来的大水满潮时无法流入海中，因而会引起洪水。

　但是，津田永忠想出了解决措施。在新田的排水路末端设置上泄水道和滞洪池，满潮时关闭泄水道，让河水留在滞洪池中，待退潮时再打开泄水道，让河水流入海中这个就是“滞洪池”和“泄水道”相结合的方法。永忠把该技术首次用于幸岛新田的排水造田中，天和4年（1684）2月开工，当年的6月即完成潮止工程。幸岛新田的开发成功后，永忠证实了当时被认为不可能的河口部分的排水造田也是可能的。

　新田開發計畫最初始於明曆3年（1657），一般認爲當時因技術不足而使得河口處的開墾難以實行。且當時的治水學專家，同時也是陽明學者的熊澤蕃山闡述了大河河口新田開發之弊害，他認為因為上游流下來的水量過大，在海水滿潮時會無處疏通而導致洪水氾濫。

　津田永忠便想了個解決之道，即是在新田排水道末端設置排水閘門及滯洪池，滿潮時關閉排水閘門讓河水滯留於滯洪池中，待退潮時再打開排水閘門將河水釋放到海裡，該方法有效結合了「滯洪池」與「排水閘門」。永忠在幸島新田開墾時初次使用該技術，天和4年（1684）2月動工並於同年的6月完成了潮止工程。成功完成幸島新田的開發後，永忠證明了當時被認為無法執行的排水造田是可行的。

　신덴 개발은 1657년에 처음으로 계획되었으나 당시 기술로는 하구부 간척이 어렵다고 여겨졌습니다. 또한, 당시 치수학(治水学)의 대가이기도 한 양명학자 구마자와 반잔(熊沢蕃山)은 상류에서 흘러오는 많은 양의 물이 만조 때 바닷물에 막혀 홍수가 일어난다며 큰 강의 하구 신덴 개발의 폐해를 설명했습니다.

　하지만 쓰다 나가타다(津田永忠)는 신덴의 배수로 끝에 통문과 유수지를 만들어 만조 때는 통문을 닫아 강물을 유수지에 가두었다가 간조가 되면 통문을 열어 강물을 바다로 방류하는 방법을 고안했습니다. 그것이 ‘유수지’와 ‘통문’의 결합이라는 방법입니다. 나가타다는 이 기술을 고지마신덴의 간척에서 처음 사용했으며, 1684년 2월에 착공해 그해 6월에는 둑을 쌓아 해수 차단 공사를 완료했습니다. 고지마신덴 개발을 완수해냄으로써 나가타다는 당시 불가능하다고 여겨졌던 하구부 간척이 가능하다는 것을 실제로 증명해냈습니다.

　最初に新田開発が計画されたのは明暦3年(1657)ですが、当時の技術では河口部の干拓は困難とされていました。また、当時の治水学の大家でもある陽明学者・熊沢蕃山は、上流から流れてくる大水が満潮時の海水に行く手をふさがれて洪水が起こるとし、大河の河口新田開発の弊害を説いていました。

　しかし、津田永忠は、新田の排水路末端に樋門と遊水池を設け、満潮時は樋門を閉めて川水を遊水池に滞留させ、干潮を待って樋門を開き、川水を海へ放流する方法を考えました。それが「遊水池」と「樋門」の結合という方法です。永忠は、この技術を幸島新田の干拓で初めて使用し、天和4年(1684)2月に着工、その年の6月には潮止工事を完了させました。幸島新田の開発を成し遂げたことで、永忠は当時不可能とされていた河口部の干拓が可能であることを実証しました。