Urakodan - Urakodan

…The height of a levee is usually determined by adding a margin to the river's flood water level (called the planned high water level) based on the improvement plan, and also adding an extra bank to prepare for future subsidence of the levee body and the ground. The standard cross section is a levee with a certain width, with slopes from both ends (the shoulders) of the crest (the top surface of the levee), and if the slope (called the front slope and back slope) is long, a front berm and a back berm are provided halfway up the slope, and a narrower step called a curb is also provided on the inside of the levee (the side where houses are located) (Figure 2). [Nakazawa Kazuhito] …

*Some of the terminology explanations that refer to "Ura Kodan" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…　堤防の高さは，改修計画に基づいた洪水時の川の水位(計画高水位という)に余裕高を加え，さらに将来の堤体や地盤の沈下などに備えた余盛りを加えた高さとするのがふつうである。その標準的な断面は，ある幅をもった天端（てんば）(堤防の最上面)の両端(法肩)から前後に傾斜をつけ，その斜面(表法，裏法という)が長いときは斜面の途中で表小段（こだん），裏小段を設け，また堤内(人家などのあるほう)側にはさらに犬走りと称する幅の狭い段を設ける(図2)。【中沢 弌仁】。…

※「裏小段」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報