The Department of Water Resources (DWR) is responsible for managing and protecting California’s water resources. DWR works with other agencies to benefit the State’s people and to protect, restore and enhance. Guard leadership, news, history, Family Action Office, and job opportunities. Includes links to Pennsylvania National Guard units and State veteran's homes. Water - Wikipedia. Water in three states: liquid, solid (ice), and gas (invisible water vapor in the air). Clouds are accumulations of water droplets, condensed from vapor- saturated air. Its chemical formula is H2. O, meaning that its molecule contains one oxygen and two hydrogenatoms, that are connected by covalent bonds. Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure; but it often refers also to its solid state (ice) or its gaseous state (steam or water vapor). It also occurs in nature as snow, glaciers, ice packs and icebergs, clouds, fog, dew, aquifers, and atmospheric humidity. Water covers 7. 1% of the Earth's surface. On Earth, 9. 6. 5% of the planet's crust water is found in seas and oceans, 1. Antarctica and Greenland, a small fraction in other large water bodies, and 0. Less than 0. 3% of all freshwater is in rivers, lakes, and the atmosphere, and an even smaller amount of the Earth's freshwater (0. Evaporation and transpiration contribute to the precipitation over land. Large amounts of water are also chemically combined or adsorbed in hydrated minerals. Safe drinking water is essential to humans and other lifeforms even though it provides no calories or organicnutrients. Access to safe drinking water has improved over the last decades in almost every part of the world, but approximately one billion people still lack access to safe water and over 2. Approximately 7. 0% of the freshwater used by humans goes to agriculture. Much of long- distance trade of commodities (such as oil and natural gas) and manufactured products is transported by boats through seas, rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is a good solvent for a wide variety of chemical substances; as such it is widely used in industrial processes, and in cooking and washing. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, and diving. Chemical and physical properties. States. Water is a liquid at the temperatures and pressures that are most adequate for life. Specifically, at normal atmospheric pressure of 1 bar (0. Pa, 1. 4. 5 psi), water is a liquid between the temperatures of 2. K (0 . Increasing the pressure slightly lowers the melting point, which is about . This effect is relevant, for example, to ice skating, to the buried lakes of Antartica, and to the movement of glaciers. Wind definition, air in natural motion, as that moving horizontally at any velocity along the earth's surface: A gentle wind blew through the valley. High winds were forecast. The Energy Story is a general introduction to energy. Chapters explore renewable energy, fossil fuels, electricity, circuits and many other things. Global water distribution. For an estimated explanation of where Earth's water exists, look at the chart below. By now, you know that the water cycle describes the movement of Earth's water, so realize that the chart and table. Since 1981, family owned and operated Northern Tool + Equipment has become an industry leader, offering expertly chosen generators, pressure washers, heaters, power tools + more! Official municipal site includes information about city services, departments, meetings, events, and the community. This effect is important in, among other things, deep- sea hydrothermal vents and geysers, pressure cooking, and steam engine design. At the top of Mount Everest, where the atmospheric pressure is about 0. At very high pressures (above 2. Water also differs from most liquids in that it becomes less dense as it freezes. The maximum density of water is 1,0. A regional utility that supplies electric power and energy services to Georgia businesses and residents. Subsidiary of Southern Company. Humans, and other animals, have developed senses that enable them to evaluate the potability of water by avoiding water that is too salty or putrid. Water vapour is essentially invisible as a gas. Through a thickness of 1. The color becomes increasingly stronger and darker with increasing thickness. The refraction index of ice (1. Polarity and hydrogen bonding. Impact from a water drop causes an upward . Water is a good polar solvent, that dissoves many salts and hydrophilic organic molecules such as sugars and simple alcohols such as ethanol. Most acids dissolve in water to yield the corresponding anions. Many substances in living organisms, such as proteins, DNA and polysaccharides, are dissolved in water. Water also dissolves many gases, such as oxygen and carbon dioxide . Many inorganic subtances are insoluble too, including most metal oxides, sulfides, and silicates. Because of its polarity, a molecule of water in the liquid or solid state can form up to four hydrogen bonds with neighboring molecules. These bonds are the cause of water's high surface tension. The capillary action refers to the tendency of water to move up a narrow tube against the force of gravity. This property is relied upon by all vascular plants, such as trees. They also explain its exceptionally high specific heat capacity (about 4. J/g/K), heat of fusion (about 3. J/g), heat of vaporization (2. J/g), and thermal conductivity (between 0. W/m/K). These properties make water more effective at moderating Earth's climate, by storing heat and transporting it between the oceans and the atmosphere. Electrical conductivity and electrolysis. Pure water has a low electrical conductivity, which increases with the dissolution of a small amount of ionic material such as common salt. Liquid water can be split into the elements hydrogen and oxygen by passing an electric current through it . The decomposition requires more energy input than the heat released by the inverse process (2. J/mol, or 1. 5. 9 MJ/kg). Sound travels long distances in water with little attenuation, especially at low frequencies (roughly 0. B/km for 1 k. Hz), a property that is exploited by cetaceans and humans for communication and environment sensing (sonar). The formation of stars is accompanied by a strong outward wind of gas and dust. When this outflow of material eventually impacts the surrounding gas, the shock waves that are created compress and heat the gas. The water observed is quickly produced in this warm dense gas. According to the researchers, the . Based on models of the formation and evolution of the Solar System and that of other star systems, most other planetary systems are likely to have similar ingredients. Water vapor. Water is present as vapor in: Atmosphere of the Sun: in detectable trace amounts. Scientists believe liquid water is present in the Saturnian moons of Enceladus, as a 1. The Earth is located in the habitable zone of the solar system; if it were slightly closer to or farther from the Sun (about 5%, or about 8 million kilometers), the conditions which allow the three forms to be present simultaneously would be far less likely to exist. Water vapor and carbon dioxide in the atmosphere provide a temperature buffer (greenhouse effect) which helps maintain a relatively steady surface temperature. If Earth were smaller, a thinner atmosphere would allow temperature extremes, thus preventing the accumulation of water except in polar ice caps (as on Mars). The surface temperature of Earth has been relatively constant through geologic time despite varying levels of incoming solar radiation (insolation), indicating that a dynamic process governs Earth's temperature via a combination of greenhouse gases and surface or atmospheric albedo. This proposal is known as the Gaia hypothesis. The state of water on a planet depends on ambient pressure, which is determined by the planet's gravity. If a planet is sufficiently massive, the water on it may be solid even at high temperatures, because of the high pressure caused by gravity, as it was observed on exoplanets Gliese 4. The Antarctic ice sheet, which contains 6. Earth, is visible at the bottom. Condensed atmospheric water can be seen as clouds, contributing to the Earth's albedo. Hydrology is the study of the movement, distribution, and quality of water throughout the Earth. The study of the distribution of water is hydrography. The study of the distribution and movement of groundwater is hydrogeology, of glaciers is glaciology, of inland waters is limnology and distribution of oceans is oceanography. Ecological processes with hydrology are in focus of ecohydrology. The collective mass of water found on, under, and over the surface of a planet is called the hydrosphere. Earth's approximate water volume (the total water supply of the world) is 1,3. The majority of water on Earth is sea water. Water is also present in the atmosphere in solid, liquid, and vapor states. It also exists as groundwater in aquifers. Water is important in many geological processes. Groundwater is present in most rocks, and the pressure of this groundwater affects patterns of faulting. Water in the mantle is responsible for the melt that produces volcanoes at subduction zones. On the surface of the Earth, water is important in both chemical and physical weathering processes. Water, and to a lesser but still significant extent, ice, are also responsible for a large amount of sediment transport that occurs on the surface of the earth. Deposition of transported sediment forms many types of sedimentary rocks, which make up the geologic record of Earth history. Water cycle. The water cycle (known scientifically as the hydrologic cycle) refers to the continuous exchange of water within the hydrosphere, between the atmosphere, soil water, surface water, groundwater, and plants. Water moves perpetually through each of these regions in the water cycle consisting of following transfer processes: evaporation from oceans and other water bodies into the air and transpiration from land plants and animals into air. Most water vapor over the oceans returns to the oceans, but winds carry water vapor over land at the same rate as runoff into the sea, about 4. Tt per year. Over land, evaporation and transpiration contribute another 7. Tt per year. Precipitation, at a rate of 1. Tt per year over land, has several forms: most commonly rain, snow, and hail, with some contribution from fog and dew. Dew usually forms in the morning when the temperature is the lowest, just before sunrise and when the temperature of the earth's surface starts to increase. A mathematical model used to simulate river or stream flow and calculate water quality parameters is a hydrological transport model. Some water is diverted to irrigation for agriculture. Rivers and seas offer opportunity for travel and commerce. Through erosion, runoff shapes the environment creating river valleys and deltas which provide rich soil and level ground for the establishment of population centers. A flood occurs when an area of land, usually low- lying, is covered with water.
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