2. SEDIMENT PROPERTIES 2. 1 General remarks 2.2 Particle size characteristics 2. 3 Specific gravity 2.4 Settling velocity 2. 5 Other properties 3. HYDRAULICS OF ALLUVIAL STREAMS 3. 1 Some general definitions 3.2 Critical bed shear 3.3 Transport mechanisms 3.4 Bed configurations 3. 5 Shape effect 3. 6 The effective bed shear 4. THE SIMILARITY PRINCIPLE 4. 1 Basic parameters 4. 2 Hydraulic resistance of alluvial streams 4.3 Sediment discharge 4.4 Limitation of the theory 5. FLUVIOLOGY 5. 1 General aspects 5.2. Application of the principle of similarity 6. NUMERICAL EXAMPLES 6. 1 Prediction of stage-discharge relations 6.2 Design of channels