Echo sounding is useful for:
a. depth profiles
b. determination of sediment thickness
c. penetrating sediment to find rock
d. mapping subsurface currents

Th correct answer is letter A. Echo sounding is very useful for depth profiles where SONAR is used to determine the depth of water through the transmission of sound pulses. It is calculated by checking the interval between the mission and the pulse that is recorded within the SONAR device.

Answer the use of flood plains and irrigation;