Question

The slope area method is extensively used in

• A. development of rating curve
• B. estimation of flood discharge based on high­ water marks
• C. cases where shifting control exists
• D. cases where back-water effect is present

Answer 1

The correct option is B estimation of flood discharge based on high­ water marks

When it is not possible to make direct measurement especially during floods, slope-area method is a most commonly used indirect method of measurement. In this method discharge is computed on the basis of a uniform flow equation involving channel characteristics.water surface profile and a roughness coefficient. The drop in water surface profile for a uniform reach of channel represents losses caused by bed roughness. Discharge is calculated using Manning's equation in this method.