Research Of The Erosion-deposition Characteristics About The Trail Channel Of The Yellow River From1964to2012

The Yellow River is the second longest river in China and is famous for its highsediment concentration, trail channel siltation diverted to change frequently,bringheavy disaster to the people’s life, but also because of its rich sediment loads to formthe delta. Based on the sediment data from1964to2012of Lijin hydrologicalstation,the river elevation, nearshore sea water depths,different years of the remotesensing and sediment grain size in this paper, systematically analyzes the feature andsilting changes from1964to2012of the tail channel of the Yellow River, mainlyanalyzes the characteristic in different flow between the channel deposition and erosionin sand and water movement and change,futher analysis of the current flow trailchannel sediment granularity,shoreline change,nearshore subaqueous slope variationcharacteristics,and carried on the discussion from two aspects of natural andhuman factors, including the long-term implementation of water andsediment engineering on the upstream channel and subaqueous slope erosion charac-teristics have a significant impact, the main conclusions are as follows:(1)1964to2012the runoff and sediment the Yellow River dicerased year byyear,internannual change is bigger and the year change is relatively small, this is due tothe combine effect of climate change and human activities result. Vary widely betweendifferent flow into the sea sediment: the water and sediment of the Diaokou path islargest and Qing8path is smallest. As a result of the implementation of thewater-sediment regulation engineering the runoff of the current channel increasedbetween2002and2012but still less than years (1964-2012) average.(2) Due tochanges in water and sediment volume, making the main channel of tail channel in theearly diversions trail channel main scour channel as a whole, and then fill up the riverand on the coming water and sediment changes is consist, the river changed relativelycomplex.Because of the long-term implementation of the water-sediment regulationengineering since2002, forming a water and sediment conditions favorable to the rivererosion, making the trail channel of the current flow scouring lower status in the wholechannel.(3) Long-term implementation of the water-sediment regulation projectchanged the hydrodynamic of the trail channel at the same time maked the particle sizeshow a trend of gradual coarsening in1997-2011. The shoreline change in the study area as a whole is given priority to extend to the sea during the period of2005-2013.(4)Affected by the change of water and sediment into the sea, there is obvious influenceon the erosion and deposition of the nearshore subaqueous slope: from the nearby ofthe estuary, sediment source is rich, deposited within25-35km, and the deposition rateis between0.18-0.63m/a in2002to2012, eroded intensively in35-45km for reducingthe sediment supply; with less supply sediment in the far away from the estuary, theunderwater slope has been erosion from the shore to45km. In46km outside, no longeraffected by the water and sediment into the sea, sedimentation balance, offshoreunderwater bank slope stability.