Characterization of the non-uniform geometry of mountain rivers

The objective of the study is the characterization of the non-uniform geometry of a mountain river and the development of a method that identifies this geometry. Identification of the geometry enables simplification of a certain river section in modelling, which can be applied in a wide range of applications, for example the prediction of water...

Longitudinal profiles of rivers with a composite cross-section

In one-dimensional river modelling it is common to schematise the cross-section into a rectangular cross-section with a constant width. If a quasi-steady flow is assumed, the equilibrium longitudinal profile is known and unique: the bottom slope is constant and equals the water surface slope. However, numerical calculations at DELFT HYDRAULICS...

Research on bifurcations in rivers

One of the unsolved problems in the water resource engineering is the morphological behaviour of bifurcations in rivers. Bifurcations can be found in deltas, in estuaries and in braided rivers. When modelling river reaches which contain a bifurcation, a nodal point relation is needed. The problem is to determine this nodal point relation. The...

1-D morphological river models: Schematisation and interpretation

This study contains two topics which are important for the use of a one-dimensional computer model, calculating morphological changes in time. Firstly, for a good prediction of the morphological changes by the model a good reproduction of the water movement and the sediment movement is necessary. One of the conditions for a good reproduction of...

On the morphology of rivers on volcano slopes

The rivers on the slopes of the Kelud volcano in Indonesia are marked by steep slopes and fine sediment. Therefore often supercritical flow and large sediment transports occur. In this exploratory study a mathematical model has been developed for this type of rivers. The properties of this model are examined with an analysis of the...

Morphological reaction of rivers due to sediment mining

In many rivers sediment is mined at same distance from the river mouth. Examples are the Brantas river at Java, Indonesia and the Mekong river, Thailand. This study contains the research of sediment mining in general. The sediment mining has its consequences on the river morphology: The bedlevel and the waterlevel decrease downstream as weIl as...

Watermovement over a horizontal bed and solitary sanddune

In order to predict waterlevel changes in rivers due to floodwaves and local bedshapes for navigation, the local behaviour of the riverbed should be known. In many cases the bed of a river ~onsists of dunes, which propagate downstraam due to the sediment transport along the dunes. In this report mainly the watermovement but also the sediment...

A numerical model for morphological computations in rivers with non-uniform sediment

l model whithout this restriction this has been done by taking more grain fractions into consideration. (Model for non - uniform or graded sediment). This extension of the mathematical model for uniform sediment is described in chapter 1, where the basic equations of the model for uniform as well as for non - uniform sediment are derived. The...