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南特塞夫尔河发源于法国德塞夫勒省,流入卢瓦尔河。它与曼恩河汇流后经数公里到达南特的蓬卢梭地段。南特塞夫尔河是卢瓦尔河左岸的最后一条支流,同卢瓦尔河一样,受潮汐的影响。潮汐与水流方向相反,使河口处形成不稳定的淤泥滩,造成塞夫尔河下游河床逐渐抬高。在塞夫尔河流入卢瓦尔河之前,在南特塞夫尔河上兴建蓬卢梭大坝的主要目的在于:a)避免枯水期和低潮时水位过低,以维持该河段的最低水位;b)控制淤泥的流入和沉积,防止该河段潮水水位的上升;c)控制该河段水位在潮幅、流速和频率方面的变化,避免两岸失稳。
Nantes Sever River originated in the French Desevre province, flowing into the Loire. It converged with the Mann River and reached the Pensouli Lot in Nantes after several kilometers. The Nantes-Sèvres, the last tributary of the left bank of the Loire, is affected by the tides like the Loire. Tidal currents run in the opposite direction to the flow of water, creating an unstable silt beach at the mouth of the river, resulting in a gradual elevation of the riverbed downstream of the Sèvres. Prior to the introduction of the Sèvres into the Loire, the main purpose of building the Ponensau Dam on the Nantes-Sèvres was to: a) Avoid water levels too low in low and dry periods in order to maintain the lowest water level in the section; b) Controlling the inflow and sedimentation of silt to prevent the rise of the tidewater level in the reach of the river; c) controlling the change of tide level, velocity and frequency in the river reach to avoid the instability of the two sides.