Anna University, Chennai
SIXTEEN MARK QUESTIONS
1) What are the merits and demerits of irrigation? Merits of irrigation:
• Reduced water stress
• Better germination and stands
• Higher plant populations
• More efficient use of fertilizer
• Improved varieties
• Leaching of salts
• Frost protection
• Plant/soil cooling
• Chemical application
• Wind erosion control
Demerits of irrigation Rising of water table Formation of marshy lands Dampness in weather
2) What are the factors affecting duty?
Soil characteristics Climatic condition Rainfall
Type of crop
Topography of agricultural land
Method of ploughing Method of irrigation Water tax
3) Briefly explain about irrigation efficiencies?
1.Water conveyance efficiency
2. Water application efficiency
3. Water use efficiency
4. consumptive use efficiency
4) What are the consumptive use of water?
consumptive use of water is defined as the total quantity of water used for the growth of the plantsby transpiration and the amount lost by evaporation. Methods of consumptive use of water:
2.Field experimental method
3.Soil moisture study
5) Briefly explain about planning and development of irrigation project?
Planning of irrigation project: Availability of irrigation water
Selection of probable site for barrage or dam
Discharge observation for the river Marking of alignment of main canal Marking of G.C.A
Preparation of drawings
1.Briefly explain about canal irrigation?
Types of canal irrigation:
2.Perenniel irrigation a)Direct irrigation system b)storage irrigation system
2.Briefly explain about lift irrigation? Types of lift irrigation:
Lifting of water by man or animal power
Lifting of water by Mechanical power
By man or animal power: Doon
By Mechanical power: Open well
3.Briefly explain about surface irrigation? Types of surface irrigation:
Contour farming method
4.Briefly explain about flooding methods? Flooding methods:
Free flooding Basin flooding Check flooding Border strips
Zig- zag method b)uncontrolled flooding
5.Briefly explain about sprinkler irrigation methods? Types of sprinkler irrigation:
Perforation on lateral pipes
Fixed nozzles on lateral pipes
1. What are types of dams?
Based on Materials: Rigid dam
Non rigid dam
Based on structural behavior: Solid gravity dam
2. Briefly explain about types of spillways?
types of spillways: Drop spillway Ogee spillway Syphon spillway
Volute siphon spillway
3. What are the causes of failure of Earthen dam?
2.Due to seepage failure
4. What are types Weirs?
The subsurface flow of water place on important
role for the stability of hydraulic structures like weir or barrage
Types of Weirs: Masonry Weir Rockfill weir Concrete weir
5.What are forces acting on a dam?
Forces acting on a dam:
§ Weight of the dam
§ Water pressure
§ Uplift pressure
§ Seismic force
§ Silt pressure
§ Wave pressure
§ Ice pressure
1. What is the necessity of river training works?
· Proper protection work should be adopted.
· In rainy season , the flood water may submerged the vast cultivated area by overflowing the tank.
· The erosion of river water may damage the structure .
2. Describe in brief different Stages of river training works?
stages of river training works: Rocky stage
Boulder stage Trough stage Delta stage
3. What are the types of spurs? Types of spurs:
4.State the types of canal falls? Types of canal falls:
Ogee fall Rapid fall Stepped fall Trapezoidal fall
5.Briefly explain about classification of cross drainage works?
classification of cross drainage works: Aqueduct
1.Briefly explain about on-farm-development works?
· Formation of field channels
· Formation of internal irrigation channels
· Field drains
· Drops in field drains
· Crossing on field drains whenever required.
2.What are the types of water losses? Types of water losses:
Percolation losses Evaporation losses Transpiration losses
3.What is the need for PIM?
Sustained need and the need for accurate and timely information.
Reducing that people themselves are solution
agents for than need and problems.
Cutting down time consuming long methods of survey which give results after considerate time.
4.Briefly explain about factors depending losses? Permeability of water
Depth of water
Velocity of water
Amount of silt
Age of the channel