Assignment #-01

CE 6608: Irrigation and Drainage Engineering

Assignment Topic: Comparative Statement of

Different Irrigation Methods

Submitted by : Abdullah Al Masud

Registration: 21215005

Submitted To: Professor Dr. Anika Yunus

Date: 02/03/2025

Department of Civil Engineering: University of

Asia Pacific
Contents
Introduction................................................................................................................ 4

Irrigation methods...................................................................................................... 4

Surface Irrigation Methods......................................................................................... 4

Type of Surface irrigation methods:........................................................................4

Wild or Uncontrolled Flooding Irrigation.....................................................................4

Advantages............................................................................................................. 5

Disadvantages......................................................................................................... 5

Border or Border Strip Irrigation Method....................................................................5

Advantages............................................................................................................. 5

Disadvantages......................................................................................................... 5

Check or Check Basin Irrigation Method.....................................................................6

Description:............................................................................................................. 6

Suitability:............................................................................................................... 6

Types of Check Irrigation:....................................................................................... 6

Advantages:............................................................................................................ 6

Limitations:............................................................................................................. 6

Basin Irrigation Method........................................................................................... 6

Description:............................................................................................................. 6

Key Features:.......................................................................................................... 7

Advantages:............................................................................................................ 7

Limitations:............................................................................................................. 7

Furrow Irrigation Method............................................................................................ 7

Description:............................................................................................................. 7

Key Points:.............................................................................................................. 8

Advantages:............................................................................................................ 8
 Disadvantages:........................................................................................................ 8

Efficiency Improvement:.......................................................................................... 8

Subsurface Irrigation or Subirrigation Method............................................................8

Description:............................................................................................................. 8

Field Layout:............................................................................................................ 8

Advantages:............................................................................................................ 9

Sprinkler or Overhead Irrigation Method....................................................................9

Description:............................................................................................................. 9

Conditions Favoring Sprinkler Irrigation:.................................................................9

Advantages:............................................................................................................ 9

Limitations:........................................................................................................... 10

Types of Sprinkler Systems:.................................................................................. 10

Drip or Trickle Irrigation Method...............................................................................10

Description:........................................................................................................... 10

System Layout:..................................................................................................... 10

Advantages:.......................................................................................................... 10

Limitations:........................................................................................................... 11

Use Cases:............................................................................................................. 11

Assessment of Irrigation Systems............................................................................11

Recommendation..................................................................................................... 12

Conclusion................................................................................................................ 12
Introduction
Irrigation and drainage engineering are vital components in the sustainable
management of water resources in agriculture, ensuring crops receive adequate
moisture for optimal growth while preventing water-related damage. This
assignment, titled "Comparative Statement of Different Irrigation Methods,"
explores various irrigation techniques, including surface irrigation, subsurface
irrigation, sprinkler irrigation, and drip irrigation. Each method will be assessed
based on water efficiency, cost, labor requirements, crop suitability, and potential
environmental impacts. By comparing these methods, we aim to provide a
comprehensive understanding of their strengths and weaknesses to help inform
decisions on the most appropriate irrigation systems for different agricultural
scenarios.
The objective of this comparative analysis is to contribute to the improvement of
water management practices in agriculture, promoting sustainability, and ensuring
food security. Through detailed descriptions, technical specifications, and practical
applications of each irrigation method, supported by visual aids and real-world
examples, this study seeks to offer valuable insights into irrigation engineering. By
the end of this assignment, readers will be better equipped to make informed
decisions regarding the selection and implementation of irrigation systems,
ultimately enhancing agricultural productivity and resource efficiency.

Irrigation methods
Irrigation methods are adopted to ensure crops receive water efficiently,
maximizing storage in the root zone while minimizing water loss. The four general
methods are:
1. Surface Irrigation: Water flows over the soil surface.
2. Subsurface Irrigation (Subirrigation): Water is applied below the soil
surface.
3. Sprinkler (Overhead) Irrigation: Water is sprayed over crops like rain.
4. Drip (Trickle) Irrigation: Water is delivered directly to the root zone of
plants.
Surface Irrigation Methods
In surface irrigation, water is allowed to flow over the soil surface from a supply
channel. To ensure high efficiency:
 Fields are divided into plots or strips for uniform irrigation.
 Water is discharged at the highest level to flow down by gravity.
 Runoff and deep percolation are avoided.
 The size of the water stream is controlled.
Type of Surface irrigation methods:
1. Wild flooding irrigation
2. Border or border strip irrigation
3. Check or check basin irrigation
4. Basin irrigation
5. Furrow irrigation
Wild or Uncontrolled Flooding Irrigation
Wild or uncontrolled flooding irrigation involves applying water to the field from
supply ditches without any levees to guide the flow. Here are some key points as
per the attachment:
 Description: Water is brought to the field through permanent supply
ditches. Secondary ditches are then used to distribute water across the field.
Once the water leaves these ditches, it flows freely across the field without
any attempt to control its flow by means of levees.
 Spacing: The ditches are generally spaced 20 to 50 meters apart, depending
on various factors such as slope, soil texture, and the types of crops being
grown.
 Usage: This method is largely practiced when irrigation water is abundant
and inexpensive. It's particularly suitable for closely spaced crops, pastures,
and fields with steep or irregular topography where other flooding methods
are not feasible.
Advantages
1. Low Initial Cost: Minimal land preparation is required.
2. Ease of Application: Water application is straightforward and inexpensive.
3. No Skilled Labor Needed: It doesn't require skilled labor for
implementation.
Disadvantages
1. High Labor Requirements: Generally, more labor is needed compared to
other methods.
2. Water Loss: There can be excessive water loss through runoff and
percolation.
3. Low Efficiency: The efficiency of water application is typically low.
4. Uneven Wetting: It can result in non-uniform wetting of the land.
5. Variable Crop Growth: Crop growth and yield can be poorer in higher and
lower spots of the field due to improper irrigation.
Border or Border Strip Irrigation Method
In the Border or Border Strip Irrigation method, the field is divided into strips, which
are generally 10 to 20 meters wide and 100 to 400 meters long, separated by low
levees called borders. Here are the key points:
 Water Flow: Water is turned from the supply ditch into these strips, flowing
slowly towards the lower end and wetting the soil as it advances. When the
water reaches the lower end of the strip, the supply is turned off.
 Field Leveling: Strips are level between the borders so that the advancing
sheet of water covers the entire width uniformly. The longitudinal slopes of
the strips are usually between 0.2% to 0.4%.
 Suitability: This method is suitable for soils with moderately low to
moderately high infiltration rates and for irrigating closely-spaced crops such
as wheat, barley, fodder crops, and legumes. It is not suitable for crops like
rice which require standing water.
Advantages
1. Uniform Distribution: Achieves uniform water distribution and high
application efficiency if properly designed.
2. Labor Efficiency: Can be managed with low labor requirements.
3. Ease of Operation: Simple and easy to operate.
Disadvantages
1. Land Preparation: Requires precise land grading and preparation, which
can be costly.
2. Conveyance Losses: High potential for water loss in open field channels if
not managed properly.
3. Layout: Borders may be laid either along the general slope of the field
(straight or down-the-slope borders) or across the general slope (contour
borders).
Water is often applied through earthen ditches or lined concrete pipes with riser
intervals. The advancing sheet of water is influenced by the soil's infiltration rate
and the strip's width. High infiltration rates necessitate high discharge rates to
spread water rapidly, while low infiltration rates require smaller ditches to avoid
surface runoff losses.
Check or Check Basin Irrigation Method
In the Check or Check Basin Irrigation method, the field is divided into several
relatively level plots called checks, which are surrounded on all four sides by low
levees. Here’s a summary based on your attachment:
Description:
 Field Layout: The field is divided into smaller plots, each surrounded by
levees to form basins or checks. These basins can vary in size, from 0.02 to
0.8 hectares.
 Water Application: Water is applied to one basin at a time, quickly filling it
to a predetermined level before moving on to the next. The water is allowed
to infiltrate the soil while standing in the basin.
Suitability:
 Suitable for both permeable and less permeable soils. In highly permeable
soils, water is quickly spread to minimize percolation losses, while in less
permeable soils, water is held longer to ensure adequate penetration.
 Ideal for crops that can withstand temporary flooding, such as rice.
Types of Check Irrigation:
 Rectangular Check Method: Used in relatively uniform and gentle slopes
where checks are rectangular.
 Contour Check Method: Used in undulating areas where checks follow
contour lines. Vertical intervals between contour levees vary based on crop
type.
Advantages:
1. Adaptable Stream Size: Effective with variable sizes of water streams.
2. Versatility: Can be used across a wide range of soil types.
3. High Efficiency: High water application efficiency.
 4. Maximized Surface Water Use: Facilitates the use of surface water
efficiently.
5. Salts Leaching: Allows easy leaching down of salts from the soil.
Limitations:
1. Precise Land Leveling: Requires precise land leveling, which can be labor-
intensive.
2. Labor Requirements: Higher labor required for land preparation compared
to other methods.
3. Crop Suitability: Not suitable for crops sensitive to wet soil conditions.
Basin Irrigation Method
The Basin Irrigation method is particularly well-suited for orchard trees and other
perennial plants. Here's a breakdown based on your attachment:
Description:
 Field Layout: This method involves creating small basins or checks around
individual trees or groups of trees, typically in orchards. Under favorable
conditions of soil and surface slope, each basin may contain from two to five
or more trees.
 Water Application: Water is conveyed from the main supply ditch to the
basins through small ditches. Water can either flow sequentially through one
basin to another or be turned directly from the main ditch into each basin.
Key Features:
1. Individual Basin for Each Tree: Generally, each tree has its own basin,
although multiple trees can be grouped in one basin under certain conditions.
2. Water Conveyance: Water is either flowed through a series of basins or
directed individually to each basin from the supply ditch.
3. Flexibility: Suitable for various soil conditions and adaptable to different
terrains and slopes.
Advantages:
1. Efficient Water Use: Water is applied directly to the root zone, minimizing
evaporation losses.
2. Reduced Soil Erosion: Controlled water application reduces soil erosion.
3. Soil Moisture Control: Maintains uniform soil moisture levels around tree
roots.
4. Effective for Perennial Plants: Particularly beneficial for orchard trees and
perennial crops.
Limitations:
1. Labor Intensive: Requires labor for creating and maintaining the basins and
ditches.
2. Precision Needed: Requires precise leveling and construction to ensure
effective water distribution.
3. Not Suitable for All Crops: Limited to crops that benefit from this irrigation
method, such as trees and some perennial plants.
Furrow Irrigation Method
Furrow irrigation is a method where water is applied to the soil by running it through
narrow channels or furrows dug between crop rows. This method is particularly
suitable for row crops such as maize, potatoes, cotton, groundnuts, sugarcane,
tobacco, and vegetable crops. Here's an overview based on the attachment:
Description:
 Water Application: Water is conveyed to the field by a supply channel and
then directed into the furrows. The water infiltrates into the soil and spreads
laterally to irrigate the areas between the furrows.
 Furrow Characteristics: Furrows are typically narrow field ditches,
generally 30 to 60 cm apart, with the depth varying from 20 to 30 cm. The
spacing depends on the crop type, soil conditions, and climate.
 Furrow Layout: Furrows can be straight or curved, depending on the
topography of the field. Lengths of furrows usually vary from 4 to 30 meters.
Key Points:
1. Field Layout: Furrows are created between rows of crops or alternately after
every row.
2. Water Distribution: Water is applied to the field through the supply channel
into the furrows, ensuring even distribution along the furrows.
Advantages:
1. Efficient Water Use: Reduces water loss through runoff and deep
percolation.
2. Suitable for Row Crops: Ideal for irrigating row crops with varying water
requirements.
3. Erosion Control: The gentle slope of furrows helps control soil erosion.
Disadvantages:
1. Land Preparation: Requires careful land preparation and maintenance of
furrows.
2. Water Management: Needs efficient water management to avoid over-
irrigation or under-irrigation.
3. Labor Intensive: Involves labor for creating and maintaining the furrows.
Efficiency Improvement:
 Shorter Furrows: Reducing the length of furrows can improve irrigation
efficiency.
 Cutback Irrigation: Initially running a large stream to wet the soil quickly,
then reducing the stream size to prevent excessive deep percolation and
runoff.
Subsurface Irrigation or Subirrigation Method
Subsurface irrigation, also known as subirrigation, involves applying water below
the ground surface by maintaining an artificial water table. Here are the key points
based on the attachment:
Description:
 Water Application: Water is applied below the ground surface, which
maintains an artificial water table at a depth suitable for plant roots. Water
reaches the plant roots through capillary action.
 Soil Conditions: This method is effective in areas with an impervious subsoil
 at a depth of 2 meters or more, a highly permeable loam or sandy loam
surface soil, uniform topographic conditions, and moderate slopes.
 Delivery System: Water may be introduced through open ditches or
underground pipelines such as tile drains. The depth of open ditches varies
from 30 to 100 cm and they are spaced about 15 to 39 meters apart.
Field Layout:
 Supply Channels and Ditches: The water application system consists of
field supply channels, ditches, or trenches suitably spaced to cover the field
adequately. Drainage ditches are also included for the disposal of excess
water.
 Capillary Action: Water moves upward through the soil to reach the plant
roots, aided by capillary action.
Advantages:
1. Low Labor Cost: The labor cost for water application is very low.
2. Minimal Evaporation Loss: Evaporation loss from the soil surface is
minimized, resulting in water savings.
3. Uninterrupted Cultivation: Irrigation does not interrupt the cultivation of
fields.
Limitations:
1. Salt Accumulation: Saline and alkaline conditions may develop due to the
upward movement of salts with water.
2. Special Site Conditions: Requires rather specific site conditions to be
effective.
3. Artificial Drainage: May require artificial drainage to carry away the excess
water applied in subirrigation.

Sprinkler or Overhead Irrigation Method

The sprinkler or overhead irrigation method involves applying water to the soil in
the form of a spray from above, somewhat resembling rainfall. This method is
adaptable to a wide range of soil types, crops, slopes, and topographic conditions.
Description:
 Water Application: Water is sprayed into the air and allowed to fall on the
crop like rain. The water is applied through a network of pipes and sprinklers
distributed uniformly across the field.
 System Components: The system includes the sprinkler, riser pipe, lateral
distribution pipe, main and submain pipelines, and a pumping plant.
Conditions Favoring Sprinkler Irrigation:
1. Porous Soil: Suitable for soils too porous for good distribution by surface
irrigation methods.
2. Shallow Soil: Effective for shallow soils where topography prevents proper
leveling.
3. Steep Slopes: Suitable for land with steep slopes and easily erodible soils.
4. Small Irrigation Stream: Ideal for irrigation streams that are too small for
effective surface irrigation.
 5. Undulating Land: Useful for undulating land where leveling would be too
costly.
6. Labor Constraints: Beneficial where labor is inexperienced or unreliable.
7. High Water Table: Effective in areas with a high water table.
Advantages:
1. Easy Water Measurement: Water measurement is easier than with surface
methods.
2. Minimal Interference: Less interference with cultivation and minimal land
loss.
3. High Efficiency: Can achieve high water application efficiency (up to 80%).
4. Frequent Applications: Allows for frequent and small applications of water.
5. Elimination of Losses: Seepage and surface runoff losses are completely
eliminated.
6. No Land Leveling: No need for land leveling.
7. Fertilizer Application: Fertilizers can be easily applied through the
irrigation water.
Limitations:
1. High Initial Cost: The initial cost of the system is high.
2. Stable Water Supply Needed: Requires a stable and adequate water
supply.
3. Wind Distortion: High winds may distort the sprinkler pattern, causing non-
uniform water distribution.
4. Evaporation Losses: In areas of high temperature and wind velocity,
significant evaporation losses can occur.
5. Water Quality: Only sand and silt-free water can be used to avoid damage
to pump impellers.
Types of Sprinkler Systems:
 Permanent Systems: Main lines and laterals are buried underground.
 Semi-Permanent Systems: Main lines are buried, but laterals are portable.
 Portable Systems: Both main lines and laterals are portable, allowing them
to move from farm to farm.

Drip or Trickle Irrigation Method

Drip or trickle irrigation is an advanced irrigation technique that is increasingly
popular in areas facing water scarcity and salinity issues. Here are the key points
based on your attachment:
Description:
 Water Application: Water is slowly and directly applied to the root zone of
the plants, minimizing losses by percolation, runoff, and evaporation.
 System Components: The system includes a head, mains, submains,
laterals, and drip nozzles (emitters).
System Layout:
 Head: Consists of a pump to lift water and produce the desired pressure
(about 2.5 atmospheres). It also includes a fertilizer tank and a filter to mix
 fertilizers with the water and remove suspended particles.
 Mains and Submains: Small-sized, flexible pipes (usually black PVC) that
are either buried or laid on the ground to carry the water from the head to
the laterals.
 Laterals: Very small-sized pipes (usually 1 to 1.25 cm in diameter) that take
off from the mains or submains. They are usually up to 50 meters long and
one lateral is laid for each row of crops.
 Drip Nozzles (Emitters): Fixed on laterals at regular intervals (about 0.5 to
1 meter), discharging water at very small rates (2 to 10 liters per hour)
directly into the root zones of the plants.
Advantages:
1. Water Savings: Significant water savings due to minimized losses by
evaporation, percolation, and runoff.
2. High Efficiency: Achieves high water application efficiency (90% or more).
3. Fertilizer Application: Fertilizers can be applied directly with the irrigation
water.
4. Weed Control: Reduces weed growth by wetting only a small area.
5. Soil Benefits: Minimizes soil crusting, soil compaction, and interference with
intercultivating.
Limitations:
1. High Initial Cost: The initial cost of installing the system is high.
2. Specialized Knowledge: Requires specialized knowledge for installation
and maintenance.
3. Water Quality: Only clean, sand- and silt-free water can be used to avoid
clogging the emitters.
4. Profitability: More profitable in areas where irrigation water is scarce and
costly, particularly in arid regions and for high-value crops.
Use Cases:
 Nurseries: Ideal for small nurseries and gardens.
 Orchards: Commonly used in orchards where individual trees or plants
benefit from targeted watering.

Assessment of Irrigation Systems

1. Surface Irrigation

Surface irrigation methods, such as wild flooding, border strip, check basin,
basin, and furrow irrigation, rely on gravity to distribute water over the soil
surface. These methods are simple and cost-effective but often result in high
water losses due to runoff and deep percolation. They are best suited for flat
fields with uniform slopes and permeable soils. However, they may not be
efficient for areas with limited water supply or uneven topography.
2. Subsurface Irrigation or Subirrigation

Subsurface irrigation involves applying water below the soil surface to

maintain an artificial water table. This method minimizes evaporation losses
and does not interfere with field operations. It is particularly effective for
areas with specific soil and topographic conditions, but it requires precise
management to avoid soil salinity issues. The initial cost and maintenance
can be high, making it less suitable for small-scale farmers.

3. Sprinkler or Overhead Irrigation

Sprinkler irrigation mimics natural rainfall by spraying water over the crops
through a network of pipes and sprinklers. This method is adaptable to
various soil types, slopes, and crop types. It provides uniform water
distribution and minimizes soil erosion. However, it is costly to install and
maintain, requires a stable water supply, and can be affected by wind
distortion and evaporation losses.

4. Drip or Trickle Irrigation

Drip irrigation delivers water directly to the root zone of plants through a
network of pipes, tubing, and emitters. It is highly efficient in terms of water
usage and reduces weed growth by wetting only the plant's root zone. This
method is ideal for areas with limited water resources and high-value crops.
However, it has a high initial cost and requires clean water to prevent
clogging of emitters.

Recommendation

Based on the assessment, drip or trickle irrigation is recommended for

regions with limited water resources, high-value crops, and the need for
precise water application. This method offers the highest water application
efficiency and minimizes losses through evaporation and runoff. It is
particularly suitable for arid and semi-arid regions, orchards, vineyards, and
vegetable crops. Despite the high initial cost, the long-term benefits in terms
of water savings and increased crop yield make it a viable investment.

Conclusion

Selecting the appropriate irrigation method depends on various factors,

including water availability, soil type, crop type, topography, and economic
considerations. While surface irrigation methods are cost-effective and simple
to implement, they may not be suitable for regions with limited water supply.
Subsurface irrigation offers efficient water usage but requires specific soil
conditions and high maintenance. Sprinkler irrigation is versatile and
effective but can be costly and affected by weather conditions. Drip irrigation,
with its high efficiency and water-saving potential, is the most suitable
method for areas facing water scarcity and for high-value crops. Investing in
drip irrigation can lead to sustainable water management and improved
agricultural productivity.