GATE Agricultural Engineering Practice Quiz

Question 1

In the design of a horizontal subsurface drainage system, the drainable porosity is primarily required to estimate which design quantity?

Accepted Answer

Time required to lower the water table after recharge

Question 2

For a homogeneous isotropic soil under steady recharge, if the design drainage coefficient increases while all other parameters remain unchanged, the required spacing between parallel subsurface drains will generally:

Accepted Answer

Decrease

Question 3

In a saline waterlogged area, one reason for selecting a relatively deeper water table criterion in subsurface drainage design is to:

Accepted Answer

Reduce upward capillary rise into the root zone

Question 4

A subsurface drainage design based solely on very high auger-hole conductivity measured near saturation may fail in the field mainly because:

Accepted Answer

Actual effective conductivity controlling drainage may be lower due to anisotropy and disturbed conditions

Question 5

A field has a highly permeable topsoil over a much less permeable subsoil. For steady-state spacing design of subsurface drains, which approach is most appropriate?

Accepted Answer

Use a layered-soil drainage equation such as Hooghoudt/Ernst type treatment

Quizzes