Irrigation Engineering Lecture 1 PDF

8/25/2024 CENGR 4150 – Irrigation Engineering IRRIGATION ENGINEERING ENGR. JHOREENE A. JULIAN Instructor CENTRAL LUZON Department of Civil En...

8/25/2024 CENGR 4150 – Irrigation Engineering IRRIGATION ENGINEERING ENGR. JHOREENE A. JULIAN Instructor CENTRAL LUZON Department of Civil Engineering, CLSU STATE UNIVERSITY COURSE OUTLINE I. Irrigation – an Introduction II. Sources and Storage of Irrigation Water CENTRAL LUZON STATE UNIVERSITY 1  8/25/2024 INTRODUCTION The artificial application of water to land for supplementing the naturally available moisture in the root-zone soil for the purpose of agricultural production is called as irrigation. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph INTRODUCTION The artificial removal of the excess water is called as drainage which, in general, is complementary to irrigation. To keep the optimum content of water in soil, irrigation supplies water to the land where water is deficient and drainage withdraws water from the land where water is in excess. Water management is often defined as the process of integration of all the activities aimed at exploiting water in a technically and economically optimal way, but minimizing damages caused by it. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph 2  8/25/2024 INTRODUCTION The application of water to soil is essential for plant growth and it serves the following function: 1. It supplies moisture to the soil essential 5. It enables application of fertilizers. for the germination of seeds, and chemical and bacterial processes during plant growth. 6. It reduces adverse effects of frost in crops. 2. It cools the soil and the surroundings 7. It ensures crop success against short- thus making the environment more duration droughts. favorable for plant growth. 3. It washes out or dilutes salts in the soil. 4. It softens clods and thus helps in tillage operations. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph Advantages of Irrigation 1. Increase in Food Production Irrigation helps in increasing crop yields, and hence, to attain self-sufficiency in food. 2. Optimum Benefits Optimum utilization of water is made possible by irrigation. By optimum utilization, we generally, mean, obtaining maximum crop yield with required amount of water. 3. Elimination of Mixed Cropping 4. General Prosperity Revenue returns with well-developed irrigation, are sometimes, quite high, and help in all around development of the country and prosperity of the entire nation and community. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph 3  8/25/2024 Advantages of Irrigation 5. Generation of Hydro-electric Power Cheaper power generation can be obtained from water development projects, primarily designed for irrigation alone. 6. Domestic Water Supply Development of irrigation facilities in an area helps in augmenting the water supply in nearby villages and towns, where other sources of water are not available or are scarcely available. 7. Facilities of Communication Irrigation channels are generally provided with embankments and inspection roads. These inspection paths provide good roadways to the villagers for walking, cycling, or sometimes even motoring. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph Advantages of Irrigation 8. Inland Navigation Sometimes, larger irrigation canals can be used and developed for navigation purposes. 9. Afforestation Trees are generally grown along the banks of the channels, which increase the timber wealth of the country and also help in reducing soil erosion and air pollution. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph 4  8/25/2024 Disadvantages and effects of Irrigation Irrigation may contribute in various ways to the problem of water pollution. Irrigation may result in colder and damper climate. Over-irrigation may lead to water-logging. Procuring and supplying irrigation water is complex and expensive in itself. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph TWO CATEGORIES OF IRRIGATION SCHEMES 1. Surface water irrigation schemes It uses diversion and storage methods and both supplies are from rivers. 2. Ground water irrigation schemes It uses open wells, and deep and shallow tube wells to lift water from the water-bearing strata below the Earth’s surface. Choices of irrigation scheme depends on several factors: - Surface topography - Type of source available - Rainfall characteristics - Subsoil profile CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph 5  8/25/2024 SOURCES AND STORAGE OF IRRIGATION WATER 1. Surface water resources Surface water resources include the natural flowing water through the rivers and streams and the still water stored in ponds, tanks, lakes, or artificial reservoirs such as dams, barrages, and diversionary weirs. Precipitation including rainfall and melting snow act as the primary contributor to various surface water resources. a. Rivers - rivers and their tributaries and stream network constitute the major share of surface water resources. A river is a big natural water course flowing towards an ocean, a sea, an estuary, a lake, or another river. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph SOURCES AND STORAGE OF IRRIGATION WATER b. Reservoirs - a reservoir is often used to store water, which may be an enlarged lake (natural or artificial), storage pond, or impoundment from a dam. Reservoirs are created in many ways including controlling a river, or interrupting a watercourse by building an embankment, or excavated in the ground. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph 6  8/25/2024 SOURCES AND STORAGE OF IRRIGATION WATER c. Canal Irrigation - water flowing through rivers, streams, and other surface water resources can be used for irrigation directly or by diverting through canals from big reservoirs constructed for the purpose. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph SOURCES AND STORAGE OF IRRIGATION WATER d. Lakes - a lake is an inland water body with still water of considerable size. Lakes can serve as a source or termination point for rivers or smaller streams. Unlike lagoons, estuaries, or backwaters, which are part of seas or oceans, lakes are unique as they are not part of any oceans. A lake is bigger and deeper than a pond. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph 7  8/25/2024 WATER RESOURCES FOR IRRIGATION e. Ponds - a pond is also a body of still water either natural or human-made but smaller than a lake. Ponds often carry shallow water with aquatic flora and fauna. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph SOURCES AND STORAGE OF IRRIGATION WATER f. Tanks - tanks are excavated storage structures for storing water. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph 8  8/25/2024 SOURCES AND STORAGE OF IRRIGATION WATER 1. Groundwater resources Groundwater is an important life supporting resource. It is estimated that groundwater accounts for more than 95 % of all the fresh water available for use. a. Wells - a water-well is a hole made into the water bearing formation below the ground surface to extract ground water for domestic or irrigation purposes. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph SOURCES AND STORAGE OF IRRIGATION WATER b. Springs - a spring is a point on earth’ surface where groundwater from an aquifer discharges naturally as a stream like flow. Springs are usually found in mountainous regions at the toe of hill slopes, along depressions such as stream channels, and when the ground surface intercepts an aquifer. In most cases, springs form the headwaters of streams. CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph 9  8/25/2024 SOURCES AND STORAGE OF IRRIGATION WATER c. Horizontal Wells - a horizontal well can be considered as a cased spring. Horizontal wells are drilled at potential sites where springs, seeps, or traces of water are found. A horizontal rig boring is used to drill a hole and install a steel pipe casing into a mountain or hillside to tap a trapped water supply CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph SOURCES AND STORAGE OF IRRIGATION WATER 3. Conjunctive use of water Conjunctive use of water means harmoniously combining the use of water from multiple sources, for example, surface and ground water, in order to minimize undesirable physical, environmental, and economical effects of each source and to optimize the water demand-supply balance. a. Surface water and groundwater b. Conjunctive use of Rainfall and Irrigation c. Conjunctive use of Freshwater and Saline Water d. Conjunctive use of Freshwater and used Water CENTRAL LUZON STATE UNIVERSITY www.clsu.edu.ph 10  8/25/2024 THANK YOU! CENTRAL LUZON STATE UNIVERSITY 11