Water securityThe aim of water security is to make the most of water's benefits for humans and ecosystems. The second aim is to limit the risks of destructive impacts of water to an acceptable level. These risks include for example too much water (flood), too little water (drought and water scarcity) or poor quality (polluted) water. People who live with a high level of water security always have access to "an acceptable quantity and quality of water for health, livelihoods and production".
LimnologyLimnology (lɪmˈnɒlədʒi ; ) is the study of inland aquatic ecosystems. The study of limnology includes aspects of the biological, chemical, physical, and geological characteristics of fresh and saline, natural and man-made bodies of water. This includes the study of lakes, reservoirs, ponds, rivers, springs, streams, wetlands, and groundwater. Water systems are often categorized as either running (lotic) or standing (lentic). Limnology includes the study of the drainage basin, movement of water through the basin and biogeochemical changes that occur en route.
Mass concentration (chemistry)In chemistry, the mass concentration ρi (or γi) is defined as the mass of a constituent mi divided by the volume of the mixture V. For a pure chemical the mass concentration equals its density (mass divided by volume); thus the mass concentration of a component in a mixture can be called the density of a component in a mixture. This explains the usage of ρ (the lower case Greek letter rho), the symbol most often used for density. The volume V in the definition refers to the volume of the solution, not the volume of the solvent.
Water vaporWater vapor, water vapour or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Water vapor is transparent, like most constituents of the atmosphere. Under typical atmospheric conditions, water vapor is continuously generated by evaporation and removed by condensation. It is less dense than most of the other constituents of air and triggers convection currents that can lead to clouds and fog.
WaterwayA waterway is any navigable body of water. Broad distinctions are useful to avoid ambiguity, and disambiguation will be of varying importance depending on the nuance of the equivalent word in other languages. A first distinction is necessary between maritime shipping routes and waterways used by inland water craft. Maritime shipping routes cross oceans and seas, and some lakes, where navigability is assumed, and no engineering is required, except to provide the draft for deep-sea shipping to approach seaports (channels), or to provide a short cut across an isthmus; this is the function of ship canals.
Military uniformA military uniform is a standardised dress worn by members of the armed forces and paramilitaries of various nations. Military dress and styles have gone through significant changes over the centuries, from colourful and elaborate, ornamented clothing until the 19th century, to utilitarian camouflage uniforms for field and battle purposes from World War I (1914–1918) on. Military uniforms in the form of standardised and distinctive dress, intended for identification and display, are typically a sign of organised military forces equipped by a central authority.
NavigabilityA body of water, such as a river, canal or lake, is navigable if it is deep, wide and calm enough for a water vessel (e.g. boats) to pass safely. Such a navigable water is called a waterway, and is preferably with few obstructions against direct traverse that needed avoiding, such as rocks, reefs or trees. Bridges built over waterways must have sufficient clearance. High flow speed may make a channel unnavigable due to risk of ship collisions. Waters may be unnavigable because of ice, particularly in winter or high-latitude regions.
Remote controlIn electronics, a remote control (also known as a remote or clicker) is an electronic device used to operate another device from a distance, usually wirelessly. In consumer electronics, a remote control can be used to operate devices such as a television set, DVD player or other home appliance. A remote control can allow operation of devices that are out of convenient reach for direct operation of controls. They function best when used from a short distance. This is primarily a convenience feature for the user.
Properties of waterWater () is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" and the "solvent of life". It is the most abundant substance on the surface of Earth and the only common substance to exist as a solid, liquid, and gas on Earth's surface. It is also the third most abundant molecule in the universe (behind molecular hydrogen and carbon monoxide).
Scientific theoryA scientific theory is an explanation of an aspect of the natural world and universe that can be (or a fortiori, that has been) repeatedly tested and corroborated in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results. Where possible, theories are tested under controlled conditions in an experiment. In circumstances not amenable to experimental testing, theories are evaluated through principles of abductive reasoning.
