The Yellow River has the largest sediment content in the world. Why not fill up the Bohai Sea?The sea it fills up is much larger than the Bohai Sea
When it comes to the world’s major rivers, our Yellow River and Yangtze River are all on the list of course, which is not only related to their length flow, but also because of their origin with the origin of civilization, especially the Yellow River, as the starting point of the Central Plains civilization, here can be said to be the beginning of all our Chinese and Yellow descendants.Nevertheless be in today, what people mentions Yellow River chats more is another topic however, its contain sand, yellow of Yellow River is worthy of the name, because it always is carrying a lot of silt, of body size is big, the world place is rare, since that has so much silt, why did not fill smooth bohai sea?First, let’s talk about the Yellow River.From its source to its mouth, the Yellow River sways through more than half of China. Therefore, in order to distinguish and understand it, we usually divide it into the upper, middle and lower reaches.Upstream from cradle to the estuary in Inner Mongolia, the basin area and flow rate are the biggest, and the economic value is also very significant, mainly because here many alpine valleys, water flow through these places, will produce a great potential energy, good for hydroelectric power, we are familiar with the results of hydropower station is located in the basin.The middle reaches of the river is divided between the mouth of the river and the peach blossom valley. Because of entering the relatively flat terrain, many other tributaries join the river system, which is more developed than the upper reaches.From the peach blossom valley down, is the lower reaches of the Yellow River, because there is basically no terrain ups and downs, so basically are gentle path.In terms of hydrological characteristics, the upper reaches of the river is the clearest part of the whole river, but in the middle reaches of the river, it begins to take on a distinct yellow color, which is derived from the loess plateau.Due to perennial soil erosion, the soil becomes loose and abnormal, coupled with the dry climate and low vegetation coverage. Basically, as long as there is water passing through, it can be carried away effortlessly, not to mention the water body with great impact force like rivers, even ordinary rainfall can take away a lot.In addition, the Yellow River reached the middle reaches of the region, and from all directions into many tributaries, the whole flow of a sudden surge, greatly increased the ability to scour, the loess and silt into tons of tons of water, so we can see the Yellow River.That’s why people along the coast know the saying, “one bowl of water, half a bowl of mud.” It sounds like an exaggerated expression, but it’s much more than that.Sediment and bohai sea so Yellow River carried after all how many sediment?On a yearly basis, the sediment content is at least 1.6 billion tons, and an estimate of nearly 4 billion tons was put at one point in the 1930s.For those unfamiliar with hydrological science, this figure may not make much sense, but as the saying goes, half or more of a bowl of water is silt, which is not much in any river in the world.Of course, there is a more intuitive way to get a sense of the power of sand, and that is the land-making capacity of the Yellow River. For more than 100 years, the Yellow River has accumulated sand near its mouth, paving over 5,000 square kilometers of land for us.So also have expert forecast, if develop according to such trend go down, want not 200 years of time we may not see the Bohai Sea, at that time liaodong peninsula and Shandong peninsula is no longer across the sea, but directly connected.After all bohai sea itself area is not big, average depth is less than 20 meters even, and the silt that Yellow River flushes bohai sea every year can stably spread on 10 centimeters, look so, fill smooth Bohai sea is a time problem only.More specifically, the sediment of the Yellow River is actually far more than filling up a small Bohai Sea, we can simply do a math to know.According to the annual transport sediment minimum value of 1.6 billion tons to calculate, conversion into engineering earthwork is 1.2 billion, if that these soil are used to build the earth wall, the length of even enough we have been from the earth to the moon are more, this is actually very scary, to calculate, bohai sea is really completely not a thing.Of course, the most serious sediment problem in the Yellow River is not reclamation, but the dangerous above-ground river downstream.We say Yellow River is in midstream already carried enormous silt, borrow by huge wallop ability all the way rush into bohai sea, but what enter bohai sea truly actually is only a small part, more stayed in the middle of downstream river course.From the middle reaches to the lower reaches, the terrain opens up and becomes more gentle, with far less velocity and impact than the river in front.As a result, a large number of sediment will be deposited, time grows, it slowly pile of higher and higher, and the flow of the river did not decrease, in order to avoid the production and living on both sides of the residents is affected, must want to build DAMS, the repair at the beginning, have never stopped, slowly take higher and higher, the repairing the suspension, became a veritable river on the ground.Some people ask, why not just dig out the mud?It sounds reasonable at first, but in fact, it is easy to say, and in the last century, our country did try to do this, but in practice, it was found that this approach is not feasible.Sediment of the Yellow River is not a one-off, but a steady stream of, if we are willing to spend huge manpower and financial resources to clean up the sediment, speed is also far behind the pace of the upstream brings the number of, if not finish digging, during flood season approaching, the dam is not carrying the flow of the river, it is possible to happen bursts, bring disaster to the people on both sides of the.Conclusion if the silt of place of deposit on the ground river can enter bohai sea smoothly, perhaps the pressure that we face wants much smaller, but the problem that also exists follow-up to bohai sea, if arrived that day really, bohai sea was filled up by these silt, and Yellow River silt is still endless, when the time comes will where to go again?