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Impact of water and sediment discharges on subaqueous delta evolution in Yangtze Estuary from 1950 to 2010

water Science and Engineering 2014年第3期7卷 331-343页

作者： Yun-ping YANG Yi-tian LI Yong-yang FAN Jun-hong ZHANG Key Laboratory of Engineering Sediment Tianjin Research Institute for Water Transport EngineeringMinistry of Transport State Key Laboratory of water Resources and Hydropower Engineering Science Wuhan University

In order to determine how the subaqueous delta evolution depends on the water and sediment processes in the Yangtze Estuary, the amounts of water and sediment discharged into the estuary were studied. The results show that, during the period from 1950 to 2010, there was no significant change in the annual water discharge, and the multi-annual mean water discharge increased in dry seasons and decreased in flood seasons. However, the annual sediment discharge and the multi-annual mean sediment discharge in flood and dry seasons took on a decreasing trend, and the intra-annual distribution of water and sediment discharges tended to be uniform. The evolution process from deposition to erosion occurred at the -10 m and -20 m isobaths of the subaqueous delta. The enhanced annual water and sediment discharges had a silting-up effect on the delta, and the effect of sediment was greater than that of water. Based on data analysis, empirical curves were built to present the relationships between the water and sediment discharges over a year or in dry and flood seasons and the erosion/deposition rates in typical regions of the suhaqueous delta, whose evolution followed the pattern of silting in flood seasons and scouring in dry seasons. Notably, the Three Gorges Dam has changed the distribution processes of water and sediment discharges, and the dam＇s regulating and reserving functions can benefit the subaqueous delta deposition when the annual water and sediment discharges are not affected.

关键词： water discharge sediment discharge, seasonal change delta Yangtze Estuary

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Artificial neural network simulation for prediction of suspended sediment concentration in the River Ramganga,Ganges Basin,India

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International Journal of Sediment Research 2019年第2期34卷 95-107页

作者： Mohd Yawar Ali Khan Fuqiang Tian Faisal Hasan Govind Joseph Chakrapani Institute of Hydrology and water Resources Department of Hydraulic EngineeringSchool of Civil EngineeringTsinghua University Department of Earth Sciences Indian Institute of Technology Roorkee Department of Mechanical Engineering Aligarh Muslim University

The relation between the water discharge(Q) and suspended sediment concentration(SSC)of the River Ramganga at Bareilly,Uttar Pradesh,in the Himalayas,has been modeled using Artificial Neural Networks(ANNs).The current study validates the practical capability and usefulness of this tool for simulating complex nonlinear,real world,river system processes in the Himalayan *** modeling approach is based on the time series data collected from January to December(2008-2010)for Q and *** ANNs(T1-T3)with different network configurations have been developed and trained using the Levenberg Marquardt Back Propagation Algorithm in the Matlab *** were optimized using the enumeration technique,and,finally,the best network is used to predict the SSC values for the year *** values thus obtained through the ANN model are compared with the observed values of *** coefficient of determination(R2),for the optimal network was found to be *** study not only provides insight into ANN modeling in the Himalayan river scenario,but it also focuses on the importance of understanding a river basin and the factors that affect the SSC,before attempting to model *** the temporal variations in the study area,it is possible to model and successfully predict the SSC values with very simplistic ANN models.

关键词： ANN water discharge Suspended sediment concentration prediction Ramganga River Himalayas

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Response of delta sedimentary system to variation of water and sediment in the Yellow River over past six decades

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Journal of Geographical Sciences 2010年第4期20卷 613-627页

作者： PENG Jun CHEN Shenliang State Key Laboratory of Estuarine and Coastal Research East China Normal University Shanghai 200062China

In order to find out the variation process of water-sediment and its effect on the Yellow River Delta, the water discharge and sediment load at Lijin from 1950 to 2007 and the decrease of water discharge and sediment load in the Yellow River Basin caused by human disturbances were analyzed by means of statistics. It was shown that the water discharge and sediment load into the sea were decreasing from 1950 to 2007 with serious fluctuation. The human activities were the main cause for decrease of water discharge and sediment load into the sea. From 1950 to 2005, the average annual reduction of water discharge and sediment load by means of water-soil conservation practices were 2.02×10^9 m^3 and 3.41×10^8 t respectively, and the average annual volume by water abstraction for industry and agriculture were 2.52×10^10 m^3 and 2.42×10^8 t respectively. The average sediment trapped by Sanmenxia Reservoir was 1.45×10^8 t from 1960 to 2007, and the average sediment retention of Xiaolangdi Reservoir was 2.398×10^8t from 1997 to 2007. Compared to the data records at Huanyuankou, the water discharge and sediment load into the sea decreased with siltation in the lower reaches and increased with scouring in the lower reaches. The coastline near river mouth extended and the delta area increased when the ratio of accumulative sediment load and accumulative water discharge into the sea （SSCT） is 25.4-26.0 kg/m^3 in different time periods. However, the sharp decrease of water discharge and sediment load into the sea in recent years, especially the Yellow River into the sea at Qing 8, the entire Yellow River Delta has turned into erosion from siltation, and the time for a reversal of the state was about 1997.

关键词： Yellow River water discharge sediment load human activities delta

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Assessment of water Quality of the Trans-Boundary Zarafshan River in the Territory of Uzbekistan

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Journal of water Resource and Protection 2013年第1期5卷 17-26页

作者： Rashid Kulmatov Christian Opp Michael Groll Dilafruz Kulmatova Department of Applied Ecology National University of UzbekistanTashkentUzbekistan Department of Geography Philipps-Universitat MarburgMarburgGermany

The Zarafshan river is a main trans-boundary river of the Aral Seabasin. As the main water resource, the Zarafshan river water is mainly used by the republics ofTajikistanandUzbekistan. We explored the trends of space-time pollution of river water with ammonium, nitrates, phosphates, biological oxygen demand (ВОD), fluorine and some heavy metals at seven water sampling points along theZarafshanRiver inUzbekistan. The experimental data showed that the water quality of the Zarafshanriver in 2002-2009 has undergone a considerable transformation, even by the length of the river. The chemical composition of the Zarafshan river water underwent changes due to the agricultural collector-drainage discharges and the sewage of the cities of Samarkand and Navoi. The water pollutants of the Zarafshan river, as a con- sequence of the agricultural pollution, consisted of mineralization, ammonium, nitrate, phosphate, and pesticides. Therefore, it is necessary to monitor the chemical composition of the large agricultural collector-drainage discharges into the river. The main sources of the heavy metals (primarily arsenic and zinc) in the Zarafshan river water were probably ore processing manufactures located interritoryofTajikistan.

关键词： Trans-Boundary River Zarafshan River water Pollution water discharge Collector-Drainage discharge Sewage

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Sediment Load of Asian Rivers flowing into the Oceans and their Regional Variation

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Marine Science Bulletin 2002年第1期4卷 61-70页

作者：刘曙光郑永来诸葛正技李从先 Key Laboratory of Marine Geology Tongji University Shanghai 200092 Department of Geotechnical Engineering Tongji University Shanghai 200092

Study of the major Asian rivers discharge to the ocean reveals variations of their water discharges and sediment loads, and local characteristics of river sediment concentrations. On the basis of this, the Asian rivers fall into three regions, including Eurasia Arctic, East Asia, Southeast and South Asia Regions. The Eurasia Arctic Region is characterized by the lowest sediment concentration and load, while the East Asia Region is of the highest sediment concentration and higher sediment load, and the South-East and South Asia Region yields higher sediment concentration and highest sediment *** sediment loads of these regions are mainly controlled by climate, geomorphology and tectonic activity. The Eurasia Arctic rivers with large basin areas and water discharge, drain low relief which consists of tundra sediment, thus causing the lowest sediment load. The East Asia rivers with small basin areas and lowest water discharges, drain extensive loess plateau, and transport most erodible loess material, which results in highest sediment concentration. The SE and South Asia rivers originating from the Tibet Plateau have large basin areas and the largest water discharges because of the Summer Monsoon and high rainfall influence, causing the highest sediment *** Asia, tectonic motion of the Tibet Plateau plays an important role. Those large rivers originating from the Tibet Plateau transport about 50% of the world river sediment load to ocean annually, forming large estuaries and deltas, and consequently exerting a great influence on sedimentation in the coastal zone and shelves.

关键词： Asia river flowing into the ocean sediment load water discharge

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