最近30从www.hoelymoley.com 2023 - 07 - 10 - t12:26:57z //www.hoelymoley.com/feeds/question/9222 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/9222 3 kingledion //www.hoelymoley.com/users/6703 2016 - 11 - 29 - t19:02:30z 2016 - 11 - 30 - t11:21:53z

< p >假设每世纪海平面上升1米。看< a href = " http://geology.com/sea-level-rise/ " rel = " nofollow noreferrer " >地形图< / >孟加拉quicly变得清晰,荷兰,较低的密西西比州,南美索不达米亚等都将很快在水下。< / p > < p >河流,如果有的话,沉积物沉积三角洲或嘴巴快到足以抵消每世纪海平面上升1米吗? < / p >

//www.hoelymoley.com/questions/9222/-/9227 # 9227 5 戈登斯坦格 //www.hoelymoley.com/users/4507 2016 - 11 - 30 - t11:21:53z 2016 - 11 - 30 - t11:21:53z

< p >这是一个非常复杂的问题,一个绝对的答案需要详细的流域模型和标定过程。简短的回答是,在短期内许多河流沉积沉积物比假设1 m /世纪更迅速,因为沉积物运输大概是成正比的四次方流速度。所以非常高沉积发生在几个小时每年的洪峰流量。然而,年平均沉积是一个不同的问题,非常地难以衡量。一个典型的沉积沉积速度是大约每年2到3毫米+ / -至少一个数量级。这是略低于当前平均海平面上升的速度,但是记住,海平面上升的速度加快,并可能继续加速到下个世纪。预计海平面上升到2100年的利率很难估计(太多的未知数)但> 10毫米/年看来,在这种情况下,可能没有明显的河流能够补偿由高淤积量。偶尔会有异常,如河流在菲律宾的皮纳图博火山喷发,这令人惊叹的泥沙量的火山爆发后的几年中,由于大量的在整个集雨un-cemented火山灰,加上台风降雨。< / p > < p >非常大的河流常年高的沉积物,湄公河和Ganges-Meghna-Brahmaputra认为之一,这两个有巨大的季风沉积物通量。最近两水系pro-graded他们增量惊人。 Check out their delta areas on Google Earth. All of that sediment was deposited during the last 6000 years. During most of that time, sea level rise seems to have been very modest, averaging about 1.5 to 2.5 mm/year.
Since you pose a climate-change related rate of sea level rise, one must also consider how climate change will affect the hydrologic response of these catchments, and hence how the rate of sedimentation will change? Even with a three-year research grant I would be hard-pressed to answer that question, but my suspicion is that sea-level rise will win, and most of the major deltas will succumb to the waves.

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