MATHEMATICAL MODEL OF OVERLAND FLOW AND MECHANISM OF SOIL CONSERVATION FOR FORESTED STEEP HILLSLOPE

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＯＶＥＲＬＡＮＤＦＬＯＷＡＮＤＭＥＣＨＡＮＩＳＭＯＦＳＯＩＬＣＯＮＳＥＲＶＡＴＩＯＮＦＯＲＦＯＲＥＳＴＥＤＳＴＥＥＰＨＩＬＬＳＬＯＰＥ（１）ＡｎａｌｙｔｉｃａｌＳｏｌｕｔｉｏｎｔｏｔｈｅＯｖｅｒｌａｎｄＦｌｏｗｏ...     

MATHEMATICAL MODEL OF OVERLAND FLOW AND MECHANISM OF SOIL CONSERVATION FOR FORESTED STEEP HILLSLOPE－－（II）Mechanism of Soil Conservation Over Steep Hillslope

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＯＶＥＲＬＡＮＤＦＬＯＷＡＮＤＭＥＣＨＡＮＩＳＭＯＦＳＯＩＬＣＯＮＳＥＲＶＡＴＩＯＮＦＯＲＦＯＲＥＳＴＥＤＳＴＥＥＰＨＩＬＬＳＬＯＰＥ－－（ＩＩ）ＭｅｃｈａｎｉｓｍｏｆＳｏｉｌＣｏｎｓｅｒｖａｔｉｏｎＯｖｅｒＳｔ...     

COMPREHENSIVE MANAGEMENT OF SMALL WATERSHED FOR SOIL AND WATER CONSERVATION IN CHINA

ＣＯＭＰＲＥＨＥＮＳＩＶＥＭＡＮＡＧＥＭＥＮＴＯＦＳＭＡＬＬＷＡＴＥＲＳＨＥＤＦＯＲＳＯＩＬＡＮＤＷＡＴＥＲＣＯＮＳＥＲＶＡＴＩＯＮＩＮＣＨＩＮＡＤＵＡＮＱｉａｏｆｕ２Ｉ．ＧＥＮＥＲＡＬＣｈｉｎａｉｓｏｎｅｏｆｔｈｅｃｏｕｎｔｒｉｅｓｓｕｆｆｅｒｉｎ...     

WATER AND SEDIMENT INFLOW OF HYPERCONCENTRATED FLOODS AND THE ASSOCIATED CHANNEL AGGRADATION IN THE YELLOW RIVER

ＷＡＴＥＲＡＮＤＳＥＤＩＭＥＮＴＩＮＦＬＯＷＯＦＨＹＰＥＲＣＯＮＣＥＮＴＲＡＴＥＤＦＬＯＯＤＳＡＮＤＴＨＥＡＳＳＯＣＩＡＴＥＤＣＨＡＮＮＥＬＡＧＧＲＡＤＡＴＩＯＮＩＮＴＨＥＹＥＬＬＯＷＲＩＶＥＲＺＨＡＯＹｅ＇ａｎ；ＰＡＮＸｉａｎｄｉａｎｄＦＡＮＺｕｏ...     

DISCUSSION ON “RESEARCHES ON ENVIRONMENTAL CHANGES AND WATER AND SEDIMENT TRANSPORT OF THE YELLOW RIVER BASIN”

ＤＩＳＣＵＳＳＩＯＮＯＮ“ＲＥＳＥＡＲＣＨＥＳＯＮＥＮＶＩＲＯＮＭＥＮＴＡＬＣＨＡＮＧＥＳＡＮＤＷＡＴＥＲＡＮＤＳＥＤＩＭＥＮＴＴＲＡＮＳＰＯＲＴＯＦＴＨＥＹＥＬＬＯＷＲＩＶＥＲＢＡＳＩＮ”ＷＡＮＧＺｈａｏｙｉｎ；ａｎｄＰＡＮＧＢｉｎｇｄｏｎｄ（Ｐｒ...     

STUDY ON RECHARGE OF GROUNDWATERS AND INTERRELATIONS BETWEEN VARIOUS WATERS BY MEANS OF ENVIRONMENTAL ISOTOPES

ＳＴＵＤＹＯＮＲＥＣＨＡＲＧＥＯＦＧＲＯＵＮＤＷＡＴＥＲＳＡＮＤＩＮＴＥＲＲＥＬＡＴＩＯＮＳＢＥＴＷＥＥＮＶＡＲＩＯＵＳＷＡＴＥＲＳＢＹＭＥＡＮＳＯＦＥＮＶＩＲＯＮＭＥＮＴＡＬＩＳＯＴＯＰＥＳ￥ＳｅｖｉｌＧｕｌｅｒ；ＥｒｇｕｎＤｅｍｉｒｏｚ（Ｓｐｅｃ...     

RESEARCHES ON ENVIRONMENTAL CHANGES AND WATER AND SEDEMENT TRANSPORT OF THE YELLOW RIVER BASIN

ＲＥＳＥＡＲＣＨＥＳＯＮＥＮＶＩＲＯＮＭＥＮＴＡＬＣＨＡＮＧＥＳＡＮＤＷＡＴＥＲＡＮＳＥＤＥＭＥＮＴＴＲＡＮＳＰＯＲＴＯＦＴＨＥＹＥＬＬＯＷＲＩＶＥＲＢＡＳＩＮＹＥＱｉｎｇｃｈａｏ２Ｉ．ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｍａｊｏｒｐｒｏｊｅｃｔ″Ｒｅｓｅ...     

THE RIVER CHANNEL ADJUSTMENT AS INFLUENCED BY THE FLOODPLAIN GEOECOSYSTEM： AN EXAMPLE FROM THE HONGSHAN RESERVOIR

ＴＨＥＲＩＶＥＲＣＨＡＮＮＥＬＡＤＪＵＳＴＭＥＮＴＡＳＩＮＦＬＵＥＮＣＥＤＢＹＴＨＥＦＬＯＯＤＰＬＡＩＮＧＥＯＥＣＯＳＹＳＴＥＭ：ＡＮＥＸＡＭＰＬＥＦＲＯＭＴＨＥＨＯＮＧＳＨＡＮＲＥＳＥＲＶＯＩＲ￥ＸＵＪｉｏｎｇｘｉｎ；ＳＨＩＣｈａｎｇｘｉｎｇ（Ｐｒ...     

EFFECT OF ANNUAL RAINFALL AND RUNOFF COMPOSITION ON SEDIMENT YIELD IN SMALL WATERSHEDS

ＥＦＦＥＣＴＯＦＡＮＮＵＡＬＲＡＩＮＦＡＬＬＡＮＤＲＵＮＯＦＦＣＯＭＰＯＳＩＴＩＯＮＯＮＳＥＤＩＭＥＮＴＹＩＥＬＤＩＮＳＭＡＬＬＷＡＴＥＲＳＨＥＤＳＳｌｏｂｏｄａｎＰＥＴＫＯＶＩＣａｎｄＪｏｖａｎＳＴＥＦＡＮＯＶＩＣ（ＰｒｏｆｅｓｓｏｒｏｆＨｙｄｒａ...     

MATHEMATICAL MODEL FOR SEDIMENT TRANSPORT CAPACITY OF HYPERCONCENTRATED FLOW

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＦＯＲＳＥＤＩＭＥＮＴＴＲＡＮＳＰＯＲＴＣＡＰＡＣＩＴＹＯＦＨＹＰＥＲＣＯＮＣＥＮＴＲＡＴＥＤＦＬＯＷＩＮＤＩＶＥＲＳＩＯＮＣＡＮＡＬＳ￥ＣＡＯＲｕｘｕａｎ；ＷＵＰｅｉａｎ；ＲＥＮＸｉａｏｆｅｎｇａｎｄＬＩＵＭｉｎｇ...     

ON THE SHRINKAGE OF RIVER CHANNEL

ＯＮＴＨＥＳＨＲＩＮＫＡＧＥＯＦＲＩＶＥＲＣＨＡＮＮＥＬＣＨＥＮＤｏｎｇ１,ＣＡＯＷｅｎｈｏｎｇ２ａｎｄＺＨＡＮＧＱｉｓｈｕｎ３ＡＢＳＴＲＡＣＴＡｌｏｎｇｗｉｔｈｔｈｅｒａｐｉｄｄｅｖｅｌｏｐｍｅｎｔｏｆｓｏｃｉａｌｅｃｏｎｏｍｙ,ｄｅｖｅｌｏｐｍｅ...     

THE FORMING CONDITIONS OF ALLUVIAL RIVER CHANNEL PATTERNS

1 INTRODUCTION It is well known that the river channel patterns are determined by long-term water-sediment conditions. However, quantitative expressions for river channel patterns and their fluvial processes still remain not clear. Existing theories in this aspects, such as geomophological theory, theory of maximum energy consuming rate, stability theory, theory of probability, and statistic analysis, are developed based on certain simplified assumptions and can not be successfully used t…     

The impact of afforestation on stream bank erosion and channel form

Modification of the land use of a small catchment through coniferous afforestation is shown to have influenced stream bank erosion and channel form. Field mapping and erosion pin measurements over a 19-month period provides evidence of more active bank erosion along forested channel reaches than along non-forested. Extrapolation of downstream increases in bankfull width, bankfull depth, and channel capacity with increasing basin area for the non-forested catchment has demonstrated that afforestation of the lower part of the catchment has had a marked effect on channel form. Channel widths within the forest are up to three times greater than that predicted from the regression. These changes in bankfull width have led to stream bed aggradation and the development of wide shallow channels within the forest, and channel capacities within the forest are over two times that predicted from the basin area. The relationship between channel sinuosity and valley gradient for non-forested reaches of the river also indicated decreased sinuosity resulting from afforestation. These changes in channel form result from active bank erosion within the forest with coarse material being deposited within the channel as point-bars and mid-channel bars. Active bank erosion is largely attributed to the suppression by the forest of a thick grass turf and its associated dense network of fine roots, and secondly to the river attempting to bypass log jams and debris dams in the stream channel.     

Overbank sediment deposition patterns for straight and meandering flume channels

Experiments with the 10 m Flood Channel Facility at HR Wallingford, UK, indicate a fundamental dependency of the overbank deposition pattern of channel suspended sediments on channel planform. Two experiments (100 and 140 l s^?1) in a 1·95 m wide straight channel showed deposition concentrated in a berm along the channel bank. Little sediment was transferred further onto the floodplain. For the larger flow, the berm formed further from the channel. A single experiment (103 l s^?1) with a 1·31 m wide meandering channel showed deposition across the entire floodplain tongue between successive meanders. Maximum deposition occurred on the downstream side of the meander, just past the bend apex. These generalized flume results complement the real‐world but site‐specific data of field studies. Copyright © 2002 John Wiley & Sons, Ltd.     

COMPLICATED FILL-SCOUR BEHAVIORS OF THE YELLOW RIVER AND THE CHANNEL-FORMING PROCESSES

IINTRODUCTIONStreamflowformostriversintheworldcanberegardedasasolid-liquidtwo-phaseflow.Theexistenceofsuspendedsedimenthassomeinfluenceonthestreamflow'sphysicalandmechanicalproperties,whichinturnaffectsthestreamflow'ssedimentcarryingbehaviors(ChienandWan,1983;Chien,1989).Forriverswithrelativelylowsuspendedsedimefltconcentrations,theabove-mentionedeffectisnegligible.However,withtheincreasesinsuspendedsedimentconcentration,thiseffectbecomesincreasinglysignificant;thesediment-carryingbehavi…     

CHANNEL EVOLUTION AFTER THE CONSTRUCTION OF THE 1ST PHASE OF THE DEEPWATER CHANNEL PROJECT OF THE YANGTZE ESTUARY

1 INTRODUCTION Among the world's rivers, the Yangtze River ranks third in length, fifth in average water discharge at its mouth, and fourth in suspended sediment discharge (Shen et al., 1983). The huge suspended load has created a bar system with heights greater than 10 m below sea level extending over 40 km along each waterway in the Yangtze Estuary (Milliman et al.,1985). Natural evolution of the sand bars has been studied by many scientists and engineers (Prichard, 1967; Ludwig and …     

Channel erosion along the Carmel river,Monterey county,California

Historic maps, photographs, and channel cross-sections show that the channel of the Carmel River underwent massive bank erosion, channel migration, and aggradation in a major flood in 1911, then narrowed and incised by 1939. The channel was stable until 1978 and 1980, when bank erosion affected some reaches but not others. The narrowing and incision were in response to a lack of major floods after 1914 and construction in 1921 of a dam that cut off sediment supply from the most actively eroding half of the basin. Localized erosion in 1978 and 1980 occurred during low magnitude events along reaches whose bank strength had been reduced by devegetation. These events illustrate that the stability of a fluvial system can be disrupted either by application of a large erosive force in a high magnitude event (the 1911 flood) or in a low magnitude event, by reducing the resistance to erosion (bank devegetation). The Carmel River is a potentially unstable system. Its discharge and slope characteristics place it near the threshold between meandering and braided. On the Lower Carmel, the presence of bank vegetation can make the difference between a narrow, stable meandering channel and a wide shifting channel with braided reaches.     

CHANNEL WIDENING DURING DEGRADATION OF ALLUVIAL RIVER

1 INTRODUCTIONThe fluvial processes such as transihon of river pattrms, bank chat and advance, sedimentation anderosion of flood plains and channel beds can be Observed in alluvial rivers. These fluvial PrOcesses are allattributed to variations of the sediment caping caPacity of the flow and the erodibillty of bank matrialor soil. A river sechon may be widened by bank erosion and failure.For examPle, a river channel downstream of a reservoir is scoured because the flow released frOm the…     

IMPACTS OF FLOOD EVENTS IN COARSE SEDIMENT-PRODUCING AREAS ON CHANNEL SILTATION AND FLUVIAL PROCESS OF THE LOWER YELLOW RIVER

The method of multiple regression is used to analyze the influences of flood events from the coarse sediment producing areas on the channel siltation and fluvial process of the lower Yellow River based on the flood events from 1950 to 1985. The results showed that the flood events from the coarse sediment producing areas carry larger amounts of sediment load and coarser particle sizes than from other source areas, which increases deposition in the lower river channel. And there exist good correlations between channel siltation of the lower reaches of the Yellow River and the coming water and sediment of flood events from the coarse sediment producing areas. Through these correlations, the amounts of sediment deposition in the lower river channel could be roughly estimated based on the runoff and sediment load of flood events from the coarse sediment producing areas. The sediment deposition caused the fluvial process. There exists a complex response of channel form change to the coming water and sediment load of flood events from the coarse sediment producing areas. When the sediment concentration is smaller than 200kg/m3, the ratio between wide-depth ratio after flood and wide-depth ratio before flood((B/h)a / (B/h)b) will increase with the increase of the maximum sediment concentration; when the sediment concentration is near 200kg/m3, (B/h)a / (B/h)b reaches the maximum value; and when the sediment concentration reaches the limits of hyperconcentrated flow, (B/h)a / (B/h)b will decrease with the increase of the maximum sediment concentration. Generally, flood events from the coarse sediment producing areas made channel form of the lower Yellow River deeper and narrower, but a large amount of sediment deposition simultaneously occurs. So, the impacts of flood events from the coarse sediment producing areas on the channel of the lower Yellow River are lessened.     

Fluvial geomorphology of the Middle Reach of the Huai River

The Middle Reach of the Huai River （MRHR） flows northeast into the Hongzehu Lake. Before entering the Hongzehu Lake, the Huai River has a braided channel which is shallow and wide, and the riverbed has a negative slope. Based on the characteristics of the MRHR, this river reach can be divided into the following sections： a quasi-straight （or mildly curved） section, a bend section, and a braided section. The majority of the MRHR is quasi-straight. In this paper, several parameters are used to assess the geomorphology of the MRHR. Statistical analyses are performed to establish a relationship between the span length ＂L＂ and channel width ＂B＂ for different channel patterns. The relationship between the meandering length ＂S＂ and bankfull channel width ＂B＂ is also derived. Results indicate that the bankfull channel width ＂B＂, the bankfull cross sectional area ＂A＂ and the average flow depth ＂H＂ are mainly dependent on the dominant discharge in the channel. A relationship is derived that describes the denendencv of the curvature radius ＂R＂ on the dominant discharae ＂O＂. water surface slone ＂J＂and the turning angle ＂α＂.