1854. Which of the following methods is used to estimate flood discharge based on high water marks left over in the past ?

A. slope-area method
B. area-velocity method
C. moving boat method
D. ultra-sonic method
✅ The correct answer is option A.

1858. The ratio of the quantity of water stored in the root zone of the crops to the quantity of water actually delivered in the field is known as__________________?

A. water conveyance efficiency
B. water application efficiency
C. water use efficiency
D. none of the above
✅ The correct answer is option B.

1860. The useful storage is the volume of water stored in the reservoir between________________?

A. minimum pool level and maximum pool level
B. minimum pool level and normal pool level
C. normal pool level and maximum pool level
D. river bed and minimum pool level
✅ The correct answer is option B.