क्रमशः परिवर्तित प्रवाह (Gradually Varied Flow - GVF) प्रोफाइल का निम्नलिखित में से कौन सा संयोजन अस्तित्व में नहीं होता है?

The rise of water level above its normal level upstream of a bridge or structure due to constriction is called:

Which of the following conditions represents uniform flow in an open channel, where dhdx is the variation of water depth along the bottom of the channel?