CIVIL ENGINEERING DEPARTMENT

SUB- H & I Engineering

TOPIC-FLOW IRRIGATION

SEMESTER-4^TH

BY

ER. SASMITA GOCHHAYAT

(HOD,CIVIL ENGINEERING DEPARTMENT)

AY:2021-2022

FLOW IRRIGATION

INTRODUCTION :-

• FLOW IRRIGATION IS THE TYPE OF IRRIGATION IN WHICH WATER IS AVAILABLE AT A HIGHER LEVEL AS TO ENABLE SUPPLY TO THE LAND BY GRAVITY FLOW. IN FLOW IRRIGATION WATER IS SUPPLIED TO THE FIELDS THOUGH THE CANALS OFF TAKING FROM HEAD WORKS.

TYPES OF CANAL:-

*BASED ON PURPOSE -

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1. IRRIGATION CANAL�2. POWER CANAL�3. FEEDER CANAL�4.NAVIGATION CANAL

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1. IRRIGATION CANAL

A CANAL ALIGNED ALONG THE BOUNDARIES OF CULTIVATABLE AREAS IN ORDER TO SUPPLY WATER FOR THE PURPOSE OF AGRICULTURE IS SAID TO BE AN IRRIGATION CANAL.

(IRRIGATION CANAL)

��2.POWER CANAL�A CANAL CONSTRUCTED ESPECIALLY FOR THE GENERATION OF HYDRAULIC POWER IS TERMED AS POWER IRRIGATION.

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3.FEEDER CANAL��AS THE NAME SAYS, A FEEDER CANAL IS CONSTRUCTED TO FEED TWO OR MORE OTHER CANALS OR BRANCH CANALS,������

���4. NAVIGATION CANAL��

��A CANAL WHICH IS CONSTRUCTED ESPECIALLY FOR NAVIGATIONAL PURPOSES IS KNOWN AS NAVIGATION CANAL.THE WATER LEVEL REQUIRED IN A NAVIGATION CANAL IS GENERALLY A LOT HIGHER TO ACCOMMODATE LARGE SHIPS, VESSELS ETC .

(Navigation canal)

*BASED ON NATURE OF SUPPLY :-

1.INUNDATION CANAL

2.PERENNIAL CANAL

1.INUNDATION CANAL

�INUNDATION CANAL IS A TYPE OF CANAL IN WHICH WATER IS AVAILABLE ONLY DURING THE FLOOD PERIODS. THESE TYPE OF CANALS ARE TAKEN OFF FROM RIVERS TO CONTROL THE WATER LEVEL IN RIVERS DURING FLOODS. A CANAL HEAD REGULATOR IS PROVIDED TO REGULATE THE FLOW INTO THE CANAL.

2.PERENNIAL CANAL �

��A PERENNIAL CANAL IS A TYPE OF CANAL IN WHICH WATER IS AVAILABLE THROUGHOUT THE YEAR. THIS TYPE OF CANAL IS GENERALLY DIRECTED FROM A PERMANENT SOURCE OF SUPPLY WATER BODIES. SEVERAL PERMANENT HYDRAULIC STRUCTURES ARE CONSTRUCTED IN THIS TYPE OF CANAL FOR WATER REGULATION AND DISTRIBUTION. A PERMANENT CANAL CAN ALSO BE CALLED AS A PERENNIAL CANAL .

( perennial irrigation)

*BASED ON DISCHARGE

1.MAIN CANAL

2.BRANCH CANALS

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1.MAIN CANAL�

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THE MAIN CANAL TAKES OFF DIRECTLY FROM A RIVER OR RESERVOIR. IT CARRIES WATER IN LARGE AMOUNTS TO FEEDTHE BRANCH AND DISTRIBUTARY CANALS. DUE TO CONVEYING OF VERY HIGH DISCHARGE THROUGH THE MAIN CANALIT IS NOT RECOMMENDED TO DO DIRECT IRRIGATION FROM IT.

2.BRANCH CANAL �

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THE BRANCH CANAL TAKES OFF FROM MAIN CANALS AT REGULAR INTERVALS. THESE CANALS SUPPLY WATER TO MAJOR AND MINOR DISTRIBUTARY CANALS. THE DISCHARGE OF THE BRANCH CANAL IS GENERALLY OVER 5 M/SEC. IN THE CASE OF BRANCH CANALS ALSO, DIRECT IRRIGATION IS NOT RECOMMENDED UNLESS THEIR WATER CARRYING CAPACITY IS VERY LOW.��

ADVANTAGES & DISADVANTAGES OF INUNDATION IRRIGATION

ADVANTAGES :-�1. IN THIS SYSTEM, NO HYDRAULIC STRUCTURE IS CONSTRUCTED.�2. IN THIS SYSTEM, THE MAINTENANCE COST ISLOW.

3. THE WATER CARRIED BY THE CANAL CONTAINS FINE SILT WHICH IMPROVES THE FERTILITY OF THE LAND.�4. THE CANALS RUN IN RAINY SEASON ONLY, AND IN OTHER SEASONS THE CANALS REMAIN PRACTICALLY DRY. SO, THERE IS NO POSSIBILITY OF WATER-LOGGING. DISADVANTA

DISADVANTAGES:-

1. AS THERE IS NO CONTROL OVER THE FLOW OF WATER OVER IRRIGATION MAY SPOIL THE�CROPS.�2. THE SUPPLY OF WATER IS UNCERTAIN. 3. IT IS NOT APPLICABLE IN RABI SEASON.�4. THE HEAD OF THE CANAL MAY BE DAMAGED DURING FLOOD. 5. IN CASE THE RIVER CHANGES ITS COURSE, THE WHOLE SYSTEM IS TO BEABANDONED .

6. SILTING IS THE MAIN PROBLEM WHICH INVOLVES RECURING CLEANING EXPENDITURE.�

THANK YOU�