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- 1. Irrigation Engineering ID-601 3(2-1) Prof. Dr. Muhammad Arshad Engr. Kashif Mehmood
- 2. Course Contents • Introduction: Definition, necessity of irrigation, water resource and irrigation system of Pakistan, Indus Basin Treaty, water budget of Pakistan • Water Requirement of Crops: Functions of irrigation, preparation land for irrigation, crop period, base period, duty and delta, relationship between duty and delta, factors affecting duty, depth and frequencies of irrigation, Kharif-Rabi ratio, optimization of irrigation water, irrigation efficiency, uniformity coefficient, consumptive use of water, effective rainfall, net irrigation requirements, gross irrigation requirement, estimation of consumption use, Blaney Criddle, Hargreaves Methods, assessment of irrigation water charges • Methods of Irrigation: Classification of irrigation methods, factors affecting the choice of irrigation methods, surface methods, sub-surface irrigation methods • Hydraulic Structures: Introduction: Dams, weirs, and barrages. Classification of dams, Gravity dams, Forces acting on a gravity dam, Modes of failure, Principal and shear stresses, Stability analysis, Elementary profile of a gravity dam, Practical profile of a gravity dam, Limiting height of a gravity dam, Profile of high masonry gravity dam. • Water conveyance structures: Introduction: Canals, distributaries, minors, and water courses. , Basic definitions, alignment of canal, water distribution system, required canal capacity, seepage losses, empirical formula for channel Losses, channel section for minimum seepage losses. • Design of irrigation channels: Design of stable channel, regime channels, Kennedy’s theory, Lacey’s theory, estimation of transported sediment, bed load equations, design procedure for unlined non-erodible irrigation channel, maintenance of irrigation channels
- 3. Practicals • Study of characteristics of various irrigation structures in the near by area. • Design and layout of a canal for a given command. • A field visit to canal irrigation system and structures. • Design of outlets. • Computer aided design of a watercourse for a command area. • Sampling and measurement of sediments in canal water.
- 4. Recommended Books • Irrigation Engineering & Hydraulic Structures by Santosh Kumar, Garg, 10th revised Edition, 1993 • Irrigation & Water Power Engineering by Dr. B.C. Punmia, Dr. Pande B.B. Lal • Siddiqui, I. H. 2003. Irrigation and Drainage Engineering. Royal Book Company, BG-Rex Centre Fatima Jinnah Road, Karachi. • Iqbal Ali. 2001. Irrigation Engineering, Oxford University Press, London. • Withers, Bruce & Vipond, S. 1980. Irrigation Design and Practice, Batsford Academic and Education Limited London. • Aisenbrey, A.J., Hayes, R.B., Warren, H.J., and Young, R.B., 1983. Design of small canal structures, USBR, Denver Colorado, USA. • Ahmad, N. and Chaudhry, G.R. 1988. Irrigated Agriculture of Pakistan, Shahzad Nazir Publisher, Gulberg-III, Lahore. • Ahmad, N. 1993. Water Resources of Pakistan, Shahzad Nazir Publisher, Gulberg- III, Lahore. • Michal, A.M. 2003. Irrigation Theory and Practice, Vikas Publishing House (Pvt) New Delhi, India.Arora, R.K. Irrigation and Water Power Engineering.
- 5. Definition: Irrigation Artificial application of water to the soil through manually or mechanically managed system for the purpose to • Supply moisture essential for plant growth • Encourage plant root development • Cool the soil and atmosphere • Create favorable condition for plant growth • Transport nutrients from soil to plant
- 6. OBJECTIVES OF IRRIGATION • To Supply Water Partially or Totally for Crop Need • To Cool both the Soil and the Plant • To Leach Excess Salts • To improve Groundwater storage • To Facilitate continuous cropping • To Enhance Fertilizer Application- Fertigation
- 7. History: Irrigation Joseph Canal (1900 b.c.) Greatest system inherited by Ramses II World’s oldest Dam (3100 b.c.) Alhazen (Aswin Dam) Community of Saba (Marib Dam) Kanates/Karez in Baluchistan Irrigation in China (Tu-kiang Dam) Western Jamuna Canal Systesm
- 8. History: Irrigation Indo-Pak • The agriculture of Pakistan mainly depends upon the irrigation water which is a critical source for sustainable and economic development of the country. • The origin of irrigation in Pakistan can be found in the pre- British time. • The objective of the colonial policy was to extend the agriculture to all the areas of Indus Basin where agriculture can boom. This would hence keep the rural population engage in agriculture, avoid conflicts, protect against drought and hence secure the colonial rule. • Available water was thus distributed among the farmers based upon the principles of equity. • After green revolution in 1960s, the colonial mantra exposed. Limited supply of water was far away less than the demand of individual farmers. Water is still being distributed among the farmers based on their land holdings.
- 9. Irrigation Engineering This involves • Conception, • Planning, • Design, • Construction, • Operation and • Management of an irrigation system. An irrigation engineer is one who has a long theoretical and practical training in planning, design, construction, operation and management of irrigation systems.
- 10. Necessity of Irrigation In areas with unreliable rainfall, watering of crops is essential. Irrigation is necessary where rainfall amount is not sufficient to meet crop water requirement. In Pakistan Average Annual Rainfall 10-14 inch Potential demand of water for Agriculture is about 70 inch
- 11. Drainage Drainage is the natural or artificial removal of surface and subsurface water from an area. An agricultural drainage system is a system by which the water level on or in the soil is controlled to enhance agricultural crop production.
- 12. Precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapour that falls under gravity. Generally, any form of moisture received on earth is called as precipitation. It includes, Rain (liquid form of precipitation) Snow (Crystalline water ice form) Hail (Irregular lumps of ice called hailstone) Sleet (Rain and partially melted Snow)
- 13. Arial distribution of rainfall zones in Pakistan Sr. No. Rainfall Zone Percent area Average annual rainfall 1 Arid 67 <10 inch 2 Semi-arid 24 10-20 inch 3 Humid 5.5 20-30 inch 4 Para Humid 3.5 >30 inch