ISSN:0022-1686    

DOI:10.1080/00221689909498507

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The meaning of the regime channels is explained and the prominent ways of their investigation are outlined. A particular attention is given to the determination of regime channels by the current "rational" methods: the present paper is the authors' contribution to this approach. The computational method suggested herein rests on the regime channel formation criterion, which is revealed on the basis of the Second Law of Thermodynamics and the Gibbs' equation. The (usual) consideration of the transport rate formula is replaced by the authors' regime width relation; thus the need for the beforehand knowledge of the transport rate is eliminated. The validity of the relations derived is tested by comparing them with the field and laboratory data of various sources.

ISSN:0022-1686    

DOI:10.1080/00221689909498508

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

To remove reservoir sediment accumulation for the sustaining of the useful life of reservoir has received increased attention due to the difficulty of constructing new dams. This article is to review current status on the flushing sediment through reservoirs and also to stress the needs of incorporating the risk analysis for the planning of flushing sediment operation through dams.

ISSN:0022-1686    

DOI:10.1080/00221689909498509

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In the paper we review some recent work on the mechanics of formation and development of river bars. The emphasis is placed on the instability process which leads to the spontaneous development of bars in almost straight reaches of alluvial rivers. A three dimensional formulation of the problem is presented along with a discussion on the relevant closure relationships. Results of linear and non linear theories for free bars under bedload dominated conditions are summarised. Furthermore, account is given on the effect on bar instability induced by suspended load, grain sorting and width variations. Some as yet unpublished results are also presented.

ISSN:0022-1686    

DOI:10.1080/00221689909498510

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221689909498511

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Recently, vegetation is a key of river management where environmental aspects should be taken care of as well as the safety against flood and the water resources utilization. Then, the management of fluvial processes related to vegetation is inevitably important, and fluvial hydraulics and hydraulics of flow with vegetation must support it. These two fields have been recently developed obviously, and coupling them must provide us answers to various emerging problems in new river engineering.

ISSN:0022-1686    

DOI:10.1080/00221689909498512

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Alluvial fans are fan-shaped zones of sediment deposition associated with a transition from an erosional or transportational upland to a depositional basin. The agents of formation of alluvial fans may be debris flows, channelized fluvial flows or unchannelized sheet flows. The debris flows may range from dense ones carrying boulders to relatively thin mud flows. The fluvial flows may be in the meandering, wandering, anastomosing or braided configuration, and may be transitional to unchannelized sheet flows or mud flows. Here a description of the many manifestations of alluvial fans is presented. The factors controlling fan development are discussed. Engineering problems associated with fans are introduced. Progress in the experimental, theoretical and numerical modeling of fans is reviewed. Finally, suggestions for future research are presented.

ISSN:0022-1686    

DOI:10.1080/00221689909498513

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Large scale changes in floodplain geometry, as contemplated for the Rhine River as part of combined renaturalisation and flood control projects in The Netherlands, will change the rate of floodplain sedimentation. To investigate the seriousness of the anticipated increase, a modelling approach was developed to simulate floodplain sedimentation along extended river reaches with a series of floodplains alternatingly located on both sides of the main channel. The floodplains are schematised as sedimentation basins, which function as sinks for the suspended sediment, which is conveyed to the floodplains during floods via convective transport from the main channel. To assess the deposition of fine sediments in a floodplain, the method of Chen (1975) is used. Via the repetitive use of the continuity equation for fine sediments, a longitudinal reduction in sediment concentration is found. The modelling approach was verified using suspended load data from the IJssel River, one of the distributaries of the Rhine River in The Netherlands, during flood. Using the developed approach the local and the downstream effect of e.g. lowering the floodplain levels with several meters could be determined.

ISSN:0022-1686    

DOI:10.1080/00221689909498514

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The analysis of natural hydraulic networks over a wide range of scales, allowed by modern digital mapping technology, reveals extraordinary diversity of natural forms, and yet deep regularity and symmetry, regardless of geology, climate, vegetation or exposed lithology. River networks are indeed a paradigm of scale-invariant, or fractal, forms ubiquitous in nature, whereas tidal networks bear the both the signatures of scaling processes and of different dynamic origin and susceptibility to environmental factors. Here I review a subjective choice of linked results, suggesting that the dynamic origin of the recurrence of similar network forms in nature relates to a common mechanism of growth and stabilization of open, dissipative systems with many degrees of freedom.

ISSN:0022-1686    

DOI:10.1080/00221689909498515

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221689909498516

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor