Regulation of Seine River
(1) From 1848 to 1867, two high-water levees were built between Lai River and Lile River in Ramayet to restrain the water flow, and the tops of the levees were higher than the average high tide level. However, due to the excessive narrowing of the riverbed at high water level, the flood discharge is sharply reduced, and the drainage is not smooth during flood, which leads to serious siltation in the upper and lower reaches of the regulation river. Later, in order to maintain the shipping of Rouen Port, another canal had to be built from le havre to Tongkaville.
(2) From 1898 to 1920, the lower reaches of Tangkawell waterway will be regulated. North high embankment is built on the north bank, and groins are built along the embankment; On the south bank, a south submerged dike will be built on the corresponding length. After the project is completed, the navigation channel is still uncertain. The construction of groins at the upper end of the north dike forced the channel to move southward, and sandbanks were formed at the end of the south dike. 1932 adopts bend scheme, aiming at stabilizing the navigation channel and excavating some sandbars. 1939 started, and World War II was interrupted.
⑶ Since 1950, a series of tests have been carried out on the waterway and engineering effect by using the movable bed model. The test results show that the river channel should be uniform and arc-shaped, with the concave surface facing north, and the river channel between the cave and Wengfule must be on the side of a high-water dike-Xinbei dike. The new north dike extends all the way to the downstream of Onfleur until it reaches the -3.0m riverbed, and there is a slat riprap submerged dike under it, which plays a diversion role for the downstream tidal current of Onfleur. /kloc-in 0/956, a new south dike was built between Lilehe and Onfleur, with a length of 10.5km and a length of 1957 ~ 1958. Lathiere riprap submerged dike was built with a length of 8.0km and an elevation of +2.0 ~+3.5 m, which can guide high tide and low tide.
(4) 1959 Demolition of some old north dikes. 1960, a new north dike was built, and the principle of combining regulation with dredging was adopted. Ships with a channel depth of 2.5m and a draft of 8.0m and 10.0m can enter Rouen Port at low tide and high tide respectively, and Rouen Port has developed rapidly.
5] Starting from 1970, a new 5.0km long north low dike will be built by using the gravel excavated by upstream dredging. After the embankment was built, the depth of the riverbed was obviously improved. Then, the riverbed sediment with a length of about 6.0km, which can not be impulsive by the current, will be removed, so that the current is smooth and the draft of the ship will increase by more than1.0m.
[6] Extend the north low dike from 1977 to 17km, and leave a gap to continue dredging the waterway. 1979, after the channel water depth increases to 2.0 ~ 2.4m.. 1980, the 35000t ship can reach Rouen Port.
good name
The upper reaches of the Seine lie in the rolling hills of Lange Highland. The rock structure is alternating with chalk and clay, and the depth of the chalk layer from the ground is different, generally about 50 meters. Rain and snow fell to the ground, some places penetrated underground, and some places returned to the ground, becoming the source of the Seine. The hilly land is not high, generally between 100 ~ 400 meters above sea level, and the slope is gentle. Therefore, the upper reaches of the Seine River are gentle, and they are known as "girls of peace". Parisians call it a "loving mother" and say that "Paris is the daughter of the Seine".