Irrigation Drainage

This textbook focuses specifically on the combined topics of irrigation and drainage engineering. It emphasizes both basic concepts and practical applications of the latest technologies available. The design of irrigation, pumping, and drainage systems using Excel and Visual Basic for Applications programs are explained for both graduate and undergraduate students and practicing engineers. The book emphasizes environmental protection, economics, and engineering design processes. It includes detailed chapters on irrigation economics, soils, reference evapotranspiration, crop evapotranspiration, pipe flow, pumps, open-channel flow, groundwater, center pivots, turf and landscape, drip, orchards, wheel lines, hand lines, surfaces, greenhouse hydroponics, soil water movement, drainage systems design, drainage and wetlands contaminant fate and transport. It contains summaries, homework problems, and color photos. The book draws from the fields of fluid mechanics, soil physics, hydrology, soil chemistry, economics, and plant sciences to present a broad interdisciplinary view of the fundamental concepts in irrigation and drainage systems design.

"Wessex Institute of Technology's Sustainable Irrigation 2012 Conference held at University of South Australia in Adelaide"--Preface.

Irrigation, as the biggest water user in most regions of the world is facing significant challenges in balancing social, economic and environmental needs for water. These proceedings of the 5th International Conference on Sustainable Irrigation and Drainage: Management, Technologies and Policies provide examples of how irrigation and drainage can become more sustainable, while acknowledging that the concept of sustainability is a goal that continues to change as our knowledge of the biophysical realities alters. In that sense moving towards sustainability is an ever evolving journey. A focus is made on the implications for improving sustainability, whether this is drainage, irrigation technologies, economic modelling, governance studies for irrigation management, reuse of water or any other aspect. Topics covered include: Irrigation management; Irrigation modelling; Irrigation systems and planning; Economic incentives; Groundwater issues; Water contamination and remediation; Drainage systems; Drainage modelling; International issues; Water reuse; Climate change effects; Water trade; Economics of irrigation; Socio-economic benefits.

This monograph provides an overview of the principles required for a service orientation in the management of irrigation and drainage systems. The material covered is designed to emphasize an area largely neglected in the irrigation and drainage management literature. The dominating philosophy underlying this book is that irrigation and drainage systems must be managed as a service business responsive to the needs and changing requirements of its customers. It is postulated that this service approach to the management of irrigation and drainage systems consitutes a key element of the startegy that is needed to improve the current level of performance of many irrigation and drainage systems worldwide. Enhanced performance of irrigation is a prerequisite if we are to face the enormous challenge of producing greater quantities of food to meet the demand of a growing population. This is particularly the case in an environment with increasing competition for water from industry and urban water users, set against mounting concerns about environmental sustainability.

The irrigated area in the Aral Sea basin totals about 7. 5 million hectare. Part of the water supplied to this area is consumed by the irrigated crop; the remainder of the supplied water drains to the groundwater basin, to downstream depressions, or back to the rivers. During its use, however, this drained part of the water accumulates salts and chemicals. The disposal of this polluted water causes a variety of (environmental) problems. If the percentage consumed water of the total water supply to an irrigated area (the so-called overall consumed ratio) can be increased, less water needs to be drained. This alleviates part of the related (environmental) problems. Further, if the overall consumed ratio for the above 7. 5 million hectare is improved, less water needs to be diverted from the rivers. Hence, more water can flow towards the Aral Sea. As mentioned above, part of the non-consumed irrigation water drains to the groundwater basin. Commonly, the natural discharge capacity of this basin is insufficient to handle this imported water. As a result, the groundwater table rises towards the land surface causing waterlogging. In (semi-)arid zones this waterlogging triggers a soil salinity problem resulting to a significant reduction in crop yields. The artificial increase of the discharge capacity, and lowering of the groundwater table, solves the soil salinity problem.

Modern Land Drainage 2nd edition is a fully revised and updated edition of the 2004 edition. Modern Land Drainage describes traditional drainage formulas (Hooghoudt, Kirkham, Donnan, Ernst, Glover-Dumm) for rainfed agriculture in the humid temperature zone. Significant parts are devoted to drainage for salinity control of irrigated land in (semi-) arid zones, and to drainage of rice land in the humid tropics. Institutional, management and maintenance aspects are extensively covered, as well as the mitigation of adverse impacts of drainage interventions on the environment. The latest computer applications for drainage design in the context of integrated water management are described (DRAINMOD, HEC, SWAP, etc.). Field surveys are executed by governments, with the aid of consultants, but rarely are the end stakeholders (i.e., farmers and general public) involved from inception to planning to execution of a drainage system. Yet, during the Operation, Management and Maintenance (OMM) phase of a water management system, they are expected to takeover, run, bear and be responsible for the costs of OMM. The book describes successful methodologies and processes to be followed for engagement of stakeholders at all levels, from government to farm, from minister to farmer, and, from beginning to end. The book covers all aspects needed for sustainable drainage. The latest survey methodologies with satellites and drones are suggested to assess cause and effect. Waterlogging and salinity are the effect of something caused most likely upstream of the drainage problem location. Hence treating the cause may be more cost-effective. Triple Bottom Line (social, environmental and financial considerations) and the water-food-energy nexus are an integral part of the drainage design process. Controlled drainage, i.e. the balance of removal and conservation of drainage water and minimising solute transport as low as reasonably achievable (ALARA principle) is extensively described. This work is intended for use both as a university level textbook and as a professional handbook; it is of particular value to professionals engaged in drainage development in the context of integrated water resources and river basin management, civil and agricultural engineers, government officials, university students and libraries.

The book is a realistic blend of basic knowledge and understanding in soil physical properties. It will enable the reader to scientifically analyze soils to develop practical and successful means of providing sufficient drainage and to develop science-based irrigation strategies. Only basic mathematical knowledge is necessary to understand and apply the proven principles covered. With limited resources that are increasing significantly in costs, the book blends the ideal concept of providing sufficient drainage and irrigation based on using soil physical properties but with financial limitations in mind. One traditional problem with many Soil Physics, Drainage, and Irrigations-based texts is the prerequisite of understanding complicated calculus-based mathematics. Although necessary for a theory-based text, our text was developed with practitioners in mind where such complicated mathematics was avoided but referenced if the reader wishes to further explore the specific topic. Another problem with many traditional texts is the lack of practical examples or case-studies allowing readers to relate their specific scenarios to similar types of situations. We have purposely included numerous examples and practical field experiences. This is especially true when many of the theoretical ideals are covered, followed by explanations of how such ideals can be applied in the laboratory and field.