Types of water demand

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Types of water demand

  1. 1. Received on Marks Comments: FACULTY OF APPLIED SCIENCES Bachelor of Science (Hons.) Environmental Technology EVT 423 HYDROLOGY AND WATER RESOURCES TITLE: TYPES OF WATER DEMAND Prepared by: Bil. Name ID Group 1 MUHAMMAD RAHIMI BIN SATAR 2012427054 AS2291A 2 MOHD SHUKRIE JR BIN SUKUR 2012234764 AS2291A 3 MOHD MUHAIMIM BIN ABD RAZAK 2012207434 AS2291A 4 MUHAMMAD ELIYA BIN KHAIRUDDIN 2012827504 AS2291A 5 MOHD MUSTAQIM BIN MADZKI 2012819318 AS2291A Lecturer’s Name: Mdm Nurazura Normal
  2. 2. INTRODUCTION Water Demand is equivalent to water use which is volume rate of flow that is applied to some beneficial purpose. We use large amounts of water each day, as water serves many different purposes. We use water to drink, to do the dishes, to take a shower, to flush the toilet, to cook diner and form any other purposes. But water is not only used for domestic purposes, humans also use water in the industries and in agriculture. In agriculture water is mainly used to water crops, but in the industries it serves many different purposes. It can serve as an ingredient of a product we produce, but it can also be a part of the whole production process. Water can be used to cool substances in the production process, for transportation and conditioning of raw materials, for boiling or cooking, for flushing, as a cleaning agent and for product transport by shipping. Water is very important for life. We need water to drink, to wash our hands, to cook, to water plants and many other things. What other important uses for water do we have? Without water, the plants would die and people and animals would go thirsty. Did you ever wonder why water was so important? But nowadays, people do not realize the important of water not only to human but to all creatures on earth. Water is important to creature because with water it can survive us to still alive and give strengthen to us. As world population is constantly growing, the demand of water increases each and every day. The demand of water is the amount required for a given purpose, for example liter per person per day, or mm per crop. The demand can be present or future, and it can be actual (related to an available infrastructure) or potential (assuming full infrastructural development and no raw water shortage). The serviceable (part of the) demand is limited both by infrastructure and raw water availability. A distinction can be made between consumptive demand (for households, industries and agriculture), and non-consumptive demand (for habitat preservation, fisheries, navigation, and salinity control at the river mouth). A similar but slightly different distinction can be made between in-stream demand and off-stream demand.
  3. 3. A common characteristic of water demand in urban areas worldwide is its relentless rise over many years, and projections of continuous growth over coming decades. The chief influencing factors are population growth, together with changes in lifestyle, demographic structure and the possible effects of climate change. The detailed implications of climate change are not yet clear, and anyway will depend on global location, but must at least increase the uncertainty in security of supply. This is compounded by rapid development, creeping urbanization and, in some places, rising standards of living. Water Use: • In-stream use 1. Hydropower 2. Waste transport & treatment fish and wildlife habitat 3. Navigation 4. Recreation 5. Aesthetic appreation • Withdrawal use 1. Thermoelectric cooling 2. Irrigation 3. Domestic 4. Industrial 5. Commercial 6. Livestock 7. Mining
  4. 4. TYPES OF WATER DEMAND: Types of water demand Domestic Demand Industrial Demand Public Demand 1. Domestic Demand: Water that supplied to a residential households, both interior use and exterior use known as domestic demand or domestic use. The demand of water is made up authorized consumption by domestic and non-domestic consumers and water losses. Domestic consumers use water within the household or drinking, cooking, bathing, washing of clothes and utensils, sanitary blocks, private vehicles, personal hygiene cooking and cleaning, and outside the dwelling for cleaning patios, irrigating gardens, filling ponds and swimming pools and washing cars. Domestic consumers include households that are not connected to the distribution mains but rely on collecting their supply room standpipes and public taps located in the street. Non-domestic consumption comprises industrial, commercial, institutional and agricultural demand legitimately drawn room the distribution mains. This category also includes legitimate public use for irrigating public parks and green areas, street cleaning, flushing water mains and sewers and for fire-fighting. Domestic consumption is influenced by many factors including, the class of dwelling, number of people in the household, changes in household income, ablution habits, culture, religion, differences in climate including seasonal variations and the number and capacity of water fittings installed.
  5. 5. The requirement of water for domestic animals is also included in this demand. In other towns or cities, the domestic consumption of water under normal condition is taken as 135 litters/day/capita. In develop countries; the water demand is very high due to their advanced life style. It is estimated that 8% of worldwide water use is for household purposes. Basic household water requirements have been estimated by Peter Gleick at around 50 liters per person per day, excluding water for gardens. Drinking water is water that is of sufficiently high quality so that it can be consumed or used without risk of immediate or long term harm. Such water is commonly called potable water. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard even though only a very small proportion is actually consumed or used in food preparation. I. Residential: Water used by residential households, both interior uses (faucets, toilets, showers) and exterior uses (car washing, lawn watering) II. Institutional Use: water use by facilities such as hospitals and schools III. Commercial Demand: Water use for drinking and sanitary purposes by employees and customers, as well as for special water needs (examples: cooling, washing, ice making, ornamental fountains) In modern day, water is essential to people’s daily lives. Without water, restaurants could not supply meals or even clean up after the meals, cars would go unwashed, and fires could be disastrous, with no means of dousing the blaze. Commercial demand includes water demand in commercial centre like office buildings, hotels, restaurants, shopping centre, cinema houses, motor garages, laundries, green parks, recreational fields, and golf courses rely on water to keep the grass and soil moist and healthy. Roadways would become dirty and grimy in the absence of any water-based cleaning program. Offices would grind to a halt with no water available for drinking and bathrooms, and office buildings, stores, and public and private centers would also be dark places without the water necessary to generate electricity for lighting. The water for these and other commercial uses comes from the surface and from underground (groundwater) sources. The extent to which a community uses a surface or a groundwater source depends on which source is more abundant in the particular area. For
  6. 6. example, the drier central portions of the United States and Canada do not have as much surface water as the eastern and western coasts. In the prairies, wells that reach down to tap underground water sources are more common than in coastal regions such as California. Some of the water that is used for commercial purposes can be reused. The water used in a car wash is one example. Another example is the water that is applied to golf courses. Surface water that is obtained from a lagoon (shallow body of water cut off from a larger body) can be suitable for keeping a golf course lush and green. Other commercial water uses, such as drinking water, demand water that is free of chemicals and harmful microorganisms. Fresh and salt water is also home to many living creatures that are harvested by humans. Whether for sport or as a business, fisheries are completely dependent on water. 2. Industrial Demand: Water has a wide range of uses in industrial processes. It may be incorporated into a product such as food and drinks; for wash down, concrete batch mixing; and a variety of other purposes. Industrial water use includes water used for the industrial processes such as fabrication, processing, washing and cooling, mining, hydropower generation and thermal electric power generation. Many industries use potable water when lower quality water would be adequate for their purposes. Some industries use recycled water from their own site or treated effluent from the sewage treatment plant, in their manufacturing processes, but currently this is only a minor component of total industrial use. Industrial water use varies significantly from city to city. Industrial use is falling as industries become more efficient. Major industrial users are of reclaimed water are power plants, oil refineries, and manufacturing facilities where water is required principally for cooling purposes. Water quality, especially total dissolved solids, chlorides, and dissolved oxygen, is specific concern because of potential scaling or corrosion in piping systems and heat exchangers. Residual organic matter may also contribute to biological growths in heat exchangers and cooling towers. Additional treatment may be necessary at the point of use depending on the water quality requirements for the specific industrial process. Other important considerations include matching supply for the
  7. 7. specific industrial process. Other important considerations include matching supply with demand, system reliability, and disposal of cooling tower blow down. Industrial demand for water can be divided into four categories: I. Cooling water demand that usually abstracted direct from rivers or estuaries and returned to the same with little loss. It is not normally taken from the public supply except for some supplies to water cooled air conditioning systems for commercial and office buildings. II. Major industrial demand consumption greater than 1000 m3/day for example for papermaking, chemical manufacturing, production of iron and steel and oil refining. Large capacity water supplies tend to be obtained either from private sources or a ‘raw water’ supply pro-vided by the water utility. The raw water is distributed through a public non-potable network or a dedicated pipeline to the industry and may receive disinfection treatment to reduce the health risk to people who could come into contact with it. The user would normally treat the water to the quality required for his processes including additional treatment and ‘polishing’ where the supply is derived from a potable supply. Non-potable supplies are always reported separately from the ‘public’ water supply in statistics. III. Large industrial demand which is factories using 100–500 m3/day for uses such as food processing, vegetable washing, drinks bottling and chemical products. These demands are often met from the public supply. Generally the supply receives additional treatment on site to meet process requirements. IV. Medium to small industrial demand which are factories and all kinds of small manufacturers using less than 50 m3/day, the great majority taking their water from the public supply. 3. Public Demand: Public water supply refers to water withdrawn by public and private water suppliers and delivered to users. Public water suppliers provide water to domestic, commercial, and industrial users, to facilities generating thermoelectric power, for public use, and occasionally for mining and irrigation. The Standard Industrial Classification (SIC) code for this category is 4941. A public water supply is a public or private water system that provides water to at least 25 people
  8. 8. or has a minimum of 15 service connections. Examples of public water-supply systems include those that serve cities and towns, military bases, apartment complexes, and large mobile home parks. Water supplied by municipalities and other public entities for public park, golf course, swimming pool and other recreational areas, municipal building, fire fighting, public work such as street cleaning, sewer flushing and water system flushing. It includes the water requirement for public places such as public sanitary blocks, parks, swimming pools. The water demand for this purpose is considered as 5% of the total consumption of water in the town or city. The water-use activities in the public water-supply category include water withdrawal from ground and surface water; in stream conveyance to and from reservoirs and canals; consumptive use, as evaporation during open storage or conveyance; raw and finished water storage; purchases from other public water suppliers; treatment; and distribution to other public water suppliers and to various users. Human requirement is summarized as given below:
  9. 9. One example of public demands is fire demand. In the case of any outbreak of fire in busy areas of town or city, sufficient quality of water may not be available for fire-fighting from the surface source such as ponds, ditches, open wells, etc. again these source may not exist within busy areas of town and city. Hence, requisite amount of water for fire-fighting should always be kept stored in underground reservoirs in specific place and fire hydrants should be established in main pipe lines at an interval of about 100 m to 150 m. in the event of fire, the fire brigade pump is connected to the fire hydrant and the jet of water is thrown under high pressure over the fire. Firefighting, hydrant-testing and sewer flushing generally consume an insignificant quantity, when expressed as an average daily demand. The number of occupants in a household can have a significant effect of water use. water demand within a community can vary due to a numbers of factors:  Time of day and day of week  Climate and season of the year  Type of community (residential or industrial and the economy of the area  Dependability and quality of the water  Connection to a sewer system or to individual onsite wastewater treatment and disposal system  Condition of water system(leakage/loses)  Water conservation/demand management
  10. 10. CONCLUSION As a conclusion, water demand is equivalent to water use which is volume rate of flow that is applied to some beneficial purpose.There are three basic categories of water demand which are domestic, public and industrial. As world population is constantly growing, the demand of water increases each and every day. Thus, Simple techniques can be used to reduce the demand for water. The underlying principle is that only part of the rainfall or plants take up irrigation water, the rest percolates into the groundwater, or is lost by evaporation from the surface. Therefore, by improving the efficiency of water use, ad by reducing its loss due to evaporation, we can reduce water demand. There are numerous methods to reduce such losses and to improve soil moisture. Some of them are listed below: (a) Soil covered by crops, slows down run-off and minimizes material evaporation losses. Hence, fields should not be left bare for long period of time. (b) Ploughing help to move the soil around and consequently, it retains more water thereby reducing evaporation. (c) Shelterbelts of trees and bushes along the edge of agricultural fields slow down the wind speed and reduces evaporation and erosion. (d) Planting of trees, grass and bushes breaks the force of rain and helps rain water penetrate soil.
  11. 11. Reference Lawrence digman, S. (1993). Physical Hydrology, published by Prentice-Hall, New Jersey. U.S.A. Nagarajan, R. (2005). Water Conservation, Use and Management for Semi-arid Region, published by Capital Publishing Company, New Delhi, India. Jr. Warren Viessman and Hammer M. J. (2004). Water Supply and Pollution Control, published Pearson, Prentice Hall, U.S.A. Metcalf and Eddy. (2007). Water Reuse Issues, Technology, and Applications, Mc Graw Hill, U.S.A. N.N.Basak. (2007). Environmental Engineering, published by McGrill-Hill, U.S.A. GemaLuque. (2010). The Demand For Public WaterSupplies, last viewed October 21,2012 retrieved from: http://www.scribd.com/doc/59293044/The-Demand-forPublic-Water-Supplies Hydrology (ENV 188) Note.

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