Suggestions of Passage from Open Channel to Tube Custom Configuration - Assignment Example

Number Subject Name Lecturer’s Name Law Due date Date Submitted Implications of Conversion from Open Channel to Pipe System Distribution Introduction Irrigation is the man made supply of water on to land to assist and help in the production of crops, vegetables and fruits. In most of the times, the water source and the farm are in two distant and different places. The situation is made worse in cases of large – scale irrigation that requires a lot water to be supplied on the farm. There is therefore the need for a water delivery system. The water delivery system is the conduit through which water is transported from its source to the intended destination. There are two main water delivery systems. One is called the open channel water distribution system. The second is called the piped water distribution system. The water delivery system is important as it can determine the total productivity of the farm. A good water delivery system will ensure on time water delivery, efficient water use, maximum land utilization, and optimum production (Allan, 1999). Open Channel Water Distribution System Open channel water system is characterized by the use of a liquid surface known as a free surface. Open channel system is composed of either two of channels. One is artificial channels. These channels are made by man. They are constructed in a regular manner and take a cross – section shape throughout. They are prismatic channels of flow. This means that they do not widen or narrow along the length of the channel. Examples of open channel water systems include; irrigation canals, drainage ditches and navigation canals. The second channels are natural channels. From their name, they are no man – made. They do not come in a regular shape. They nor prismatic and the can widen or get narrower along the length of the channel. The material that is used in their construction is likely to change severally. The roughness of the surface also changes with time, distance and elevation. Examples of natural systems are rivers, creeks and floods In an open channel system, velocity is nil at the side and the bott0om of the channel. This is as a result of the no – slip condition. Velocity is at its maximum at the midline of the free surface of the channel. In many of the times, the velocity of the water varies in the steam wise direction. The flow of the water in an open water channel is in 3D. The flow of water in an open channel system is propelled by gravity or potential energy. Piped Water Distribution System Pipe flow is another method of conducting water through a channel. Pipe flow does not use a free surface. The flow of water in a piped system is propelled by hydraulic pressure. There exists no atmospheric pressure in a piped system. The flow cross section in a p-piped system is known and is fixed. The velocity of the water does not vary within the channel and is deduced from continuity of the flow of water. The pipe system ensures the maximum utilization of land, energy and water savings. There is less disruption of normal activities during the installation of pipes. Pipes are generally safety, environment friendly and provide flexibility in water delivery. The water supplied through the piped system is of high quality as it can be screened as it gets into the pipes. The negatives that come with the piped system include the high costs involved and a higher earthquake risk. In instances where conversion of open channel system is taking, there is the possibility of disruption to farming activities. It is also likely that there will be loss of biodiversity and the environmental habitat during the conversion. Ashburton Lyndhurst Irrigation Limited, New Zealand The Ashburton Lyndhurst Irrigation Limited was started as an open channel system to supply water for the border dyke flood irrigation. The irrigation scheme caters for up to 228 shareholders who have control of over 24,522 hectares of farm land. After some length of operations, the scheme started posting losses. A study was carried out on the losses and the weak link identified as the open channel system used in the supply of water. The main causes of the losses were evaporation, seepage, over supply and travel time of the water. In an effort to stem down the losses, the study proposed the change from an open water system to a piped channel system. The proposal was supported by 98% of the shareholders and the decision was made. The open channel system had a coverage area of about 400 hectares and the loss of water in this area was more than 20%. The shareholders approved a $8 million project to start a piped water system in the farm. Three open water channels were closed and in their place, 31 km of polythene pipe of between 1000mm to 160mm diameter. The piped system has been designed to operate at a rate of 2000l/sec, the water allocation of the farm is 1600l/sec. this allows for flexibility in water supply and leaves room for possible expansion of the farm. The funds for the project were acquired through a 30 year bank loan and the sale of water shares that is now possible with the piped system (Enrique & Luciano 2005). The benefits that come with the piped channel system are many and varied. The piped channel has enable water saving. The scheme has recorded a 20% saving in water. This result is very much possible as there is no evaporation, no seepage, no delivery time and better control of water delivery. The piped channel has led to an increase in the amount of area irrigated.an additional 550 hectares can now be irrigated with the piped system. The farm has also benefitted from the piped channel as there is increased power savings, water is screened before entering the pipes and the system is designed for the maximum utilization of water. The scheme has seen drastic improvements after the conversion from open water system to piped channels. These improvements are followed by more output and profitability. Harvey Water, Western Australia Harvey Water is a private cooperative that seeks to promote regional economic development in Western Australia. It is located approximately 100 kilometers south of Perth. The Cooperative takes water from seven dams through an open channel system. The open channel system has led to delivery losses of up to 30 per cent of the water delivered. The loss takes place as the water moves from the dams located in the hills to the farms located on the coastal plains. It is caused by seepage, channel fill, leaks and end of system losses. The largest dam in the project is Wellington Dam and it provides about 40% of the required water. The dam has salinities of about 1, 100 ppm. As a result, additional water is required in the farms to create a leaching fraction (Butt et al, 1997). The Harvey Water Cooperative is working on a project to better its services. It intends to replace the open channels with pipes and also improving on the available infrastructure. The project will drastically reduce the water losses saving up to 39,000 mega liters of water. The water saved could be sold to boost the country’s water supply. The pipes will provide a pressurized water delivery system that is very low on energy costs. The system will encourage efficiency in water use in the farms and increase productivity. There will be diversification of enterprise for example the sale of water resources. Employment opportunities will be created driving regional economic growth and development. Adoption of center pivots is also an integral part in the conversion of open channels. Studies have shown that the adoption has the ability to occasion water use efficiency, negligible run – off and lead to better dairy pasture. The conversion of open channel should be complemented by advancements in border check irrigation through measuring and changing practices. Murrumbidgee Valley of New South Wales Murrumbidgee Valley consists of both horticultural and broadacre cropping farms. It is situated in the southern part of New South Wales. A recent study called the Murrumbidgee Valley Water Efficiency Feasibility Project investigated the efficiency of the water use in the farm. The report of the study concluded that the farm has the potential of saving more than 600 00 mega liters of water. This would happen by preventing water losses and maximizing the use of water delivered. The first step in this is conversion of open channels. A piped channel would prevent losses as a result of seeping, evaporation and deep percolation. In the horticultural farms, the conversion of open channel to pressurized pipes would be accompanied by the use of soil moisture monitoring technology. In the broadacre farm, the conversion of the open channels would be supported by the use of laser leveling, adoption of the center pivot, adoption of lateral move irrigation and use of surface drip irrigation (Lorite et al, 2004). The study found out that the conversion of open channels provides the greatest scope for water savings. The water saved would be sold to other buyers or reutilized in the farms to increase productivity. It also allows for greater crop diversification. The benefits brought about by this adoption require higher levels of management in order to ensure proper continuity. It is advisable for the farms to seek greater market access due to the increased production. Funding for these improvements and adoptions present a challenge to the farms. A proposal should be presented to the government and banks. The proposal should include a valuation of the public and private benefits that come with the funding of the project. The proposal also should present the proposed management of the farms and that positive change will be achieved with the project (Playa’n et al, 2000). The Turkish and Malaysian Experience The government of Malaysia is very keen in replacing the traditionally accepted open channel irrigation supply systems with the piped system. The reasoning behind this is the high costs associated with the maintenance of open channels. The open channels are also difficult to maintain. Malaysia is faced with water shortages in nationally paramount granary areas. As a result, the open channels are set aside for the piped system. The piped system is able to delivery water over long distances timely and with minimal water loss. Since the mid-1990s, there has been a progressive conversion of open channels by the Malaysian government. The Government of Turk is also leading in the conversion of open channels. The Turkish nation has mostly been using recast concrete open channel distribution systems. The reasoning of the Turkish Government is the increasing water demand in the modern country. The open channels are inflexible and cannot increase their supply to the needed areas. The open system facilitates water saving and water efficient use. Piped distribution systems provide minimal interference with above ground infrastructure for example roads that facilitate transport for the farm produce. Findings and Conclusion The conversion of open channel distribution system is accompanied by many water delivery system infrastructure and management implications. The management has to solicit funds for the conversion. Conversions are pretty expensive ventures. It includes preparation of project proposal and getting bank loans. Conversion is likely to lead to increased productivity and the management has to employ more workers and get greater market access. The management is also encouraged to acquire on the job training to keep abreast with the emerging issues and challenges that come with the conversion of open channel distribution systems. The water delivery infrastructure also comes with its own implications. One is the shift from open canal to pipes. The pipes can vary in diameter and thickness according to the needs of the farm. The piped system comes with screening of the water before it gets into the pipes to ensure its quality. The piped water delivery system also requires hydraulic pressure that will facilitate the movement of the water through the pipes. Pipes as opposed to open channels can be laid underground leaving out more land to be utilized for other purposes. The implications of the piped distribution system are both positive and negative. However, the positives greatly outweigh the negative. References Allan, T., 1999. Productive Efficiency And Allocative Efficiency: Why Better Management May Not Solve The Problem. Agric. Water Manag. 40, 71–75. Burt, C.M., Clemmens, A.J., Strelkoff, T.S., Solomon, K.H., Bliesner, R.D., Hardy, L.A., Howell, T.A., Eisenhauer, D.E., 1997. Irrigation Performance Measures: Efficiency and Uniformity. J. Irrig. Drain. Engrg. 123, 423–442. Enrique Playa and Luciano Mateos (2005) Modernization and Optimization of Irrigation Systems to increase Water Productivity. Agricultural Water Management 80 (2006) 100–116 Lorite, I.J., Mateos, L., Fereres, E., 2004. Evaluating Irrigation Performance in A Mediterranean Environment. II. Variability among Crops And Farmers. Irrig. Sci. 23, 85–92. Playa´n, E., Slatni, A., Castillo, R., Faci, J.M., 2000. A Case Study for Irrigation Modernisation: II Scenario Analysis. Agric. Water Manage. 42, 335–354 Read More