The authors translate and comment a digression from the Kitāb al-āṯār al-bāqiya on several hydraulic and hydrological subjects. The passage reveals al-Bīrūnī’s understanding of fluvial regimes, water physical behaviour, and of a handful of peculiar natural phenomena. Al-Bīrūnī departs from a discussion of weather forecast and seasonal fluvial regimes of the Tigris, Euphrates, Oxus, and Nile. The main concern of al-Bīrūnī is to defend the principle that water moves only downwards in absence of external forces. In doing so, the Khwarazmian scientist touches on the origin of salinity of the seas, the functioning of syphons related hydraulic machines, and relates a report of an artificial phenomenon, that he dismisses as result of faulty observations, that could be recognised as a hydraulic jump. In addition, the passage contains much relevant information on al-Bīrūnī’s understanding of the inhabitability of subequatorial regions, the possibility of the void, and the water cycle.

中文翻译：

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AL-BĪRŪNĪ 的 KITĀB AL-ĀṮĀR AL-BĀQIYA 通道中的水力和水文学

作者翻译并评论了一篇题外话Kitāb al-āṯār al-bāqiya在几个水力和水文主题。这段话揭示了 al-Bīrūnī 对河流流域、水的物理行为和一些奇特的自然现象的理解。Al-Bīrūnī 离开了对底格里斯河、幼发拉底河、阿克萨斯河和尼罗河的天气预报和季节性河流流域的讨论。al-Bīrūnī 的主要关注点是捍卫水在没有外力的情况下只会向下移动的原则。在这样做的过程中，花剌子模科学家触及了海洋盐度的起源，与虹吸管相关的液压机器的功能，并涉及了一个人工现象的报告，他因观察错误而驳斥了这种现象，这可能被认为是一种液压跳。此外，