1.Which of the following is a remedial measure for water-logging?
a) Controlling seepage from the canals
b) By lowering the F.S.L of the canals
c) Quick disposal of rainwater
d) Installation of lift irrigation systems
Explanation: Installation of lift irrigation system is one of the remedial measures adopted to reclaim the water-logged area and others are preventive measures which keep the land free from water-logging. It is found to be a very effective method of reclaiming water-logged land.
2. Which of the following factor do not contribute to water-logging?
a) Inadequate drainage
b) Seepage from unlined canals
c) Frequent flooding
d) Excessive tapping of groundwater
Explanation: The various factors that contribute to the rise in water table i.e. water-logging are –
• Over and intensive irrigation
• Seepage of water through canals and adjoining high lands
• Inadequate natural drainage and surface drainage
• Excessive rains and submergence due to floods
• Impervious obstruction.
3. Which one of the following is not a remedial measure for waterlogging?
a) Good drainage for irrigated land
b) Conjunctive use of water in the basin
c) The lining of canals and watercourses
d) Contour bunding
Explanation: Contour bunding or contour farming is the sustainable land management practice of planting or farming across a slope. The following are the measures adopted for controlling waterlogging are –
• Canal lining
• Crop rotation and optimum use of water
• Provision of intercepting drains
• Reducing the intensity of irrigation
• Improving the natural drainage system and providing an efficient drainage system.
4. Which factor depends upon the depressions of the terrain and causes water logging?
a) Irregular Topography
b) Impervious Obstruction
c) Inadequate Surface Drainage
d) Excessive Rains
Explanation: In hilly areas, the water is drained quickly, but in case of flat or irregular terrains having depressions the drainage is not adequate. This leads to more stagnation of water causing percolation and rising of water table.
5.Which factor is concerned with the growth of weeds?
a) Excessive Rains
b) Submergence due to Floods
c) Over and Intensive Irrigation
d) Seepage of Water through the Canals
Explanation: If a particular is continuously submerged under due to floods, this paves the way for the growth of water plants like weeds and grasses e.t.c. and obstructs the natural surface drainage flow causing waterlogging.
6. Due to inadequate drainage which factor causes waterlogging with constant percolation?
a) Over and Intensive Irrigation
b) Impervious Obstruction
c) Inadequate Surface Drainage
d) Flat Topography
Explanation: During rains storm water gets mixed with irrigation water. The irrigation water should be removed so as to not mix with storm water as this leads to percolation. Moreover, if proper drainage is not present constant percolation happens and water table rises.
7. What factor creates temporary and continuous waterlogging?
a) Submergence due to Floods
b) Flat Topography
c) Impervious Obstruction
d) Excessive Rains
Explanation: Excessive rainfalls create temporary waterlogging, but if adequate drainage is not present or provided then it leads to continuous waterlogging.
8. Which factor leads to waterlogging due to obstruction?
a) Inadequate Natural Drainage
b) Flat Topography
c) Impervious Obstruction
d) Over and Intensive Irrigation
Explanation: Generally, water after seeping the soil moves horizontally before even seeping further. But this movement is sometimes is obstructed by some obstructions like stone, ice, or some impervious stratum below the top layers of pervious soil. In these cases seeping water cannot go deep and resulting in the rise of water table.
9. Which factor comes into play when less permeable substratum is present?
a) Flat Topography
b) Impervious Obstruction
c) Excessive Rains
d) Inadequate Natural Drainage
Explanation: When there is the presence of less permeable substratum below the top layers of permeable soils there is poor drainage of water into the deep ground. So, therefore if proper natural drainage is present waterlogging takes place.
10. When a canal is taken as an example what factor about it causes waterlogging?
a) Seepage of Water from the High Lands
b) Seepage of Water through the Canals
c) Over and Intensive Irrigation
d) Excessive Rains
Explanation: When a canal is unlined then there room for seepage losses through the side slopes, and bed of the canal. This leads to the rise of water table in the adjoining areas due to percolation of water, which ultimately leads to waterlogging.