SEDIMENT QUALITY AND ECOLOGICAL RISK OF THE RIVER MOUTHS AROUND BOHAI BAY

1 INTRODUCTION Bohai Bay suffers from eutrophication and red tide has been occurring frequently since the 1990s. The water pollution is caused by pollutants originating inland that account for 87% of all pollutants entering the bay. More than 40 rivers flow into the bay carrying 95% of the total pollutants and nutrients from inland sources (Zhao and Kong, 2000). Among these rivers, the Yellow, Liaohe, Luanhe, Haihe and Jiyun Rivers are the largest, which carry 1.3 109 t of sediment lo…     

WATER POLLUTION IN THE RIVER MOUTHS AROUND BOHAI BAY

Twelve water samples were collected and analyzed. The samples were taken from the river mouths around Bohai Bay including the Jiyun. New Yongding, Haihe, Dagu, Duliujian, Qingjinghuang, Qikou, Dakou, and Yellow Rivers, and tested for concentrations of heavy metals, arsenic, total nitrogen (TN) and total phosphorus (TP). The results show that the river mouths are polluted and the water quality exceeds Class V of the Environmental Quality Standard for Surface Water (EQSSW). The main pollutants are Hg, nitrogen (N) and phosphorus (P). The concentrations of the other pollutants are within Class II of the Standard. The Hg content in the Haihe River mouth is now 10 times higher than it was 20 years ago, indicating that the accelerating water pollution has reached an alarming level. The high concentrations of N and P cause eutrophication of the waters. Analysis indicates that the terrestrial pollutants and nutrients are the main cause of frequently occurring red tides in the Bohai Sea.     

SEDIMENT CARRYING CAPACITY OF SEA CURRENT AND THE TRAINING OF THE YELLOW RIVER MOUTH

1INTRODUCTIONTheYellowRivercarries1.6billiontonsofsedanmentload,rankedthefirstintheworld.Sedimentationinthelowerreachesresultedinfrequentlyshiftoftherivercourses.ThroughoutthehistoryofChina,theYellowRiverhasbeenassociatedwithfloodsandfamine,earningtherivername"China'ssorrow"(Hu,l996).Instabilityoftheriverchannel,especiallythedeltachannel,restraintstheeconomicdevelopmentofthearea.TheDongyingmunicipalgovernment,theShenliOilCorporationandtheYellowRiverMouthManagementBureauofYRCC(Yel…     

DEFORMATION OF RIVER BED AND THE CHARACTERISTICS OF SEDIMENT TRANSPORT DURING HYPER-CONCENTRATED FLOOD IN THE YELLOW RIVER

LINTRODUCTIONTheYellowforeriswellknownasaheavilysilt-caacingriverintheworld.Haaer-concentratedfloodsoftenoccurinitsmasterstemandaswellasthetriblltaries.ThecharacteristicsofdeformationandsedimellttranSportdifferfromreachtOreach.Duetohighsedimelltconcelltration,StrongfluvialactionandthenatUreofunSteadysedimenttranSPOrt,problemsandabnormalphenomenonareoflencreated.ThelaterbringinimpacttOnoodcontrolOfthelowerreach.Thus,itishelpfultoenhancetheunderstandingofthemotionlawsOfhaer-concentrat…     

EROSION AND SEDIMENT MANAGEMENT STRATEGIES FOR THE ILLINOIS RIVER

1INTRODUCTIONTileillinoisRiver,oneofthemajortributariestotheMississippiRiverinthecentralUnitedStates,hasadrainageareaof75,156kmZthatcoversportionsof1llinois,Indiana,andWisconsin(Figllre1).Asaresultofrepeatedlevelingbyglaciers,mostofthe1llinoisRiverwatershedisflatandcoveredwithfineloesssoil,makingitoneofthebestagriculturalregionsinNorthAmerica.Morethan80percentoftheIllinoisRiverbasinispresentlyusedforagricultUralpurposes.IllinoisagricultUrestartedtoexpandveryrapidlyinthe19thcentury,g…     

FINE SEDIMENT OF THE UPPER MISSISSIPPI AND ILLINOIS RIVERS AND THE DISASTROUS CONSEQUENCES

IINTRODUCTIONLanddevelopmentandlandusepatternsinthewatershedcaninduceincreasedsedimentloadsinriversandstreams.AGREATIllstudy(1982)illustratedthatsedimentyieldsfromagriculturallandcouldbeseveralfoldsmorethanothertypeoflandusesanderosionsources.ThesamestudyalsodemonstratedthatfinesedimentsweretheheaviestportionoftotalsoillossesfromeachtypeoflandusesinthetwelvehydrologicareasitinvestigatedintheUMRS.Thesamecouldbetrueforotheruplandareasalso.Howeverfinesediments,formthewashloadofthestream…     

ON THE REDUCTION OF WATER AND SEDIMENT YIELD OF THE YELLOW RIVER IN LATE YEARS

ＯＮＴＨＥＲＥＤＵＣＴＩＯＮＯＦＷＡＴＥＲＡＮＤＳＥＤＩＭＥＮＴＹＩＥＬＤＯＦＴＨＥＹＥＬＬＯＷＲＩＶＥＲＩＮＬＡＴＥＹＥＡＲＳＧＵＷｅｎｓｈｕＡｂｓｔｒａｃｔ：ＴｈｅｒｅｃｏｒｄｅｄｈｙｄｒｏｌｏｇｉｃｄａｔａｏｆｔｈｅＹｅｌｌｏｗＲｉｖｅｒｉｎｄ...     

EFFECT OF SUSPENDED SEDIMENT ON THE TRANSPORT AND TRANSFORMATION OF 4 - NITROCHLOROBENZENE IN THE YELLOW RIVER

I.INTaonUCTIOXP-NCBisatoxiccompoundwhichmaycausecarcinogenicoramutation.NowthetransPOrtandtransformationofthiskindOfsubstanceinnaturalwaterbodyisthefocusofresearchofscientistsintheworld.ThroughthestudytherelationshipbetweennonionicorganiccomPOunds,suchasP-NCB,andsuspendedsedimentisfoundtobeveryclOSe,suspendedsedimentareload-supPOrtingofmovementandmediateagentofreactionofP-NCBinwater.TheYellowRiverisheavilysediment-laidenriverintheworld.Sometimesthesuspendedsedimentcanbeupto200kgpe…     

SEDIMENT BUDGET OF THE ILLINOIS RIVER

1 BACKGROUND The Illinois River is the most significant river in the state of Illinois. The river drains nearly half of the state and has a drainage area of 28,906 mi2 (74,867 km2). Except for about a 4,000 mi2 (10,360 km2) area in Indiana and Wisconsin, the watershed is located in Illinois (see Fig. 1). The watershed contains the drainage basins of several of the state's significant rivers such as the Sangamon, LaMoine, Spoon, Mackinaw, Vermilion, Fox, Kankakee, and Des Plaines Ri…     

SEDIMENT TRANSPORT IN THE YANGTZE RIVER ESTUARY

SEDIMENT TRANSPORT IN TIIE YANGTZE RIVER ESTUARYSHEN Zhigang'ANSTa^CTThe hy~ntalc and the sedimen tranSport Patter'nS within the estUaIy of the YangtZe mver arecomPlex because of intemehon of fluvial and the hdal forCes, depending on freshwate discharge andhdal range. Based on the data measuIed in meent years, thes papo discusses the characterishcs of flowand sNnt movemen in the tw forer EstUaIy and their iIifluences on the evolution of theestuaryKey W: YangtZe mver…     

THREE DIMENSIONAL MATHEMATICAL MODEL OF SEDIMENT TRANSPORT IN ESTUARINE REGIONS -A CASE STUDY OF THE HAIHE RIVER MOUTH

1 INTRODUCTIONUnderstanding the flow characters in open channel or other water area, whether natufal water bodies(such as rivers and estuaries) or man-made strUctures (such as navigational channels, harbors), isimportant for addressing numerous hydraulic engineering problems. These include the selechons ofsuitable waste disposal sites, contndnant transport, sediment transport and other ecological problems.The major difficulty for solving these problems is that it often requires an optimal…     

WATER QUALITY SIMULATION OF HEAVY METAL TRANSPORTATION IN THE YELLOW RIVER

ＷＡＴＥＲＱＵＡＬＩＴＹＳＩＭＵＬＡＴＩＯＮＯＦＨＥＡＶＹＭＥＴＡＬＴＲＡＮＳＰＯＲＴＡＴＩＯＮＩＮＴＨＥＹＥＬＬＯＷＲＩＶＥＲＳＨＥＮＸｉａｎｃｈｅｎ１,ＦＥＮＧＨｕｉｈｕａ２,ＷＡＮＧＦｅｎｇｒｏｎｇ３ａｎｄＬＩＵＬｉｎｈｕａ４ＡＢＳＴＲＡＣＴＡ...     

RESPONSE OF SEDIMENT YIELD TO BASIN CHARACTERISTICS IN THE MIDDLE YELLOW RIVER BASIN

1 INTRODUCTION The Middle Yellow River Basin of China is well-known worldwide for its severe soil erosion. The basin extends across arid and desert steppe, semi-arid steppe, and warmly temperate semi-humid forest-steppe from north to south, and morphological characteristics consist of mountains alternating with inter-mountain basins. Landforms change frequently from rocky mountains through rock-loess mixed mountains or hills to loess gullied hills and loess tableland from mountain to bas…     

THE OPTIMAL GRAINSIZE COMPOSITION OF SUSPENDED SEDIMENT OF HYPERCONCENTRATED FLOW IN THE MIDDLE YELLOW RIVER

LINTRODUCTIONThetributariesofmiddleYellowRiverarefamousintheworldforthehighestsuspendedsedimentconcentrationandsedimentyield.Forexample,atWenjiachuanstationofKuyeheRiverthemeasuredhighestsuspendedconcentrationis1700kg/m',andthemeanannualsedimentyieldis25000t/(kln'.a).Theformationofhyperconcentratedflowsandtheirinfluenceonerosionprocessesareofgreatimportancenotonlyfromatheoreticalpointofviewbutalsoforpracticalpurposes.Therefore,scientistsfromChinaandallovertheworldhavedrawntheirintensio…     

RESUSPENSION OF FINE SEDIMENT IN RESERVOIRS - A CASE STUDY OF THE LOWER INN RIVER

1 THE LOWhR unR INNThe Inn river has its source in the alPine region of the GraubUnden canton of Switzerand. ThecatChment area of about 260(X} kIn2 includes mountains of the central Alpes up to 40(X) m. The river runs5l7 km thrOugh the countries of SwitZerand, Austria and Germany on itS way into the Danube mver. Thedischarge of the river at its mouth in the city of Passau is mainly infiuenced by the snow melt in themountainous catchment area and vches between apProx. 200 m3ls durin…     

EFFECTS OF WATERSHED MANAGEMENT ON THE REDUCTION OF SEDIMENT AND RUNOFF IN THE JIALING RIVER,CHINA

The Three Gorges Project is one of the largest hydro-projects in the world and has drawn many debates inside China and abroad. The major concern is that sediment load from the river basin may eventually fail the functions of the project for flood control and power generation. To reduce sedimentation in the reservoir, watershed management has been adopted. However, there is limited information regarding the effectiveness of various control measures such as terracing and afforestation on a watershed scale. The Jialing River, a main tributary of the Yangtze River, contributes approximately 25% of the total sediment load in the main river but only represents 8% of the whole basin area. There have been various land use patterns and extensive human activities for thousands of years in the Jialing River watershed. Based on analysis of the major factors affecting erosion in the Jialing River watershed, the main watershed management strategies (afforestation, farming and engineering practice) are illustrated, and their effects on the reduction of sediment and runoff are studied in detail. The sediment budget of the watershed shows that 1/3 of the sediment yield is trapped by the erosion control measures (afforestation and farming) on the slope, 1/3 is trapped by the reservoirs, ponds and dams within the watershed, and only about 1/3 is transported into the Yangtze River, which will affect the Three Gorges Project.     

REGULATION OF FLOW AND SEDIMENT LOAD IN THE YELLOW RIVER

Small runoff, large sediment load, and incompatible relationship of flow and sediment load are very important characteristics of the Yellow River. They are also the crux of the most prominent problems of the Yellow River. To solve these problems, the regimes of flow and sediment load have to be improved by increasing water, reducing sediment load, and by using reservoirs to regulate flow and sediment load. The results of experiments for regulating the flow and sediment load in the last three years by the Xiaolangdi Reservoir have indicated that this measure is a realistic and effective way to mitigate the prominent problems in flood control of the Lower Yellow River at present and in the near future. However, the regulation system is still imperfect. It is advisable to speed up the pace of research and construction of the system for regulating flow and sediment load.     

SEDIMENT TRANSPORTED BY DEBRIS FLOWTO THE LOWER JINSHA RIVER

1INTRODUCTIONSedimentdepositionisoneofthemajorcausesofflood.ThelollgtermallllualtransportofsedimentrecordedattheYichangHydrologicalStationis530Mt,ofwhich256Mt(accountingfor48.8%ofthetotal)isfromtheJinshaRiverand140Mt(26.6%)fromtheJialingRiver.The783-kmstretchoftilelowerJillshaRiverfromDukoutoYichangisthekeyareaofsedimentyield,andsupplies83.5%ofthetotalsedimentintheriverbasin(Guo,1998).Intheotherwords,sedimentloadinthelowerJinshaRiverconstitutesabout40%ofthatilltileupperYangtzeRiver…     

CHARACTERISTICS OF SEDIMENT TRANSPORT AND CHANNEL FORMATION BY FLOODS AT HYPERCONCENTRATIONS OF SEDIMENT IN THE YELLOW RIVER

1. INTRODUCTIONThe Yellow River is a heavily sediment--laden river. Floods at Hyperconcentrationso f sediment (hereinafter simply referred to as hyperconcentrated flood) frequently occurring in the main river and its tributaries possess different characteristics of sedimenttransport. Sometimes they cause severe deposition whereas at other times they are capable of carrying substantial amount of sediment over long distances. The study on the lawof sediment transport is of significance to …