Grain sizeGrain size (or particle size) is the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. This is different from the crystallite size, which refers to the size of a single crystal inside a particle or grain. A single grain can be composed of several crystals. Granular material can range from very small colloidal particles, through clay, silt, sand, gravel, and cobbles, to boulders.
Thermal pollutionThermal pollution, sometimes called "thermal enrichment", is the degradation of water quality by any process that changes ambient water temperature. Thermal pollution is the rise or drop in the temperature of a natural body of water caused by human influence. Thermal pollution, unlike chemical pollution, results in a change in the physical properties of water. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers.
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.
Lake TiticacaLake Titicaca (tɪtɪˈkɑːkə; Lago Titicaca ˈlaɣo titiˈkaka; Titiqaqa Qucha) is a large freshwater lake in the Andes mountains on the border of Bolivia and Peru. It is often called the highest navigable lake in the world. By both volume of water and by surface area, it is the largest lake in South America. Lake Titicaca has a surface elevation of . The "highest lake" claim is generally considered to refer to commercial craft. Numerous smaller lakes around the world are at higher elevations.
Great Lakes regionThe Great Lakes region of Northern America is a binational Canadian–American region centered around the Great Lakes that includes eight U.S. states, Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin, and the Canadian province of Ontario. Canada's Quebec province is at times included as part of the region because the St. Lawrence River watershed is part of the continuous hydrologic system. The region forms a distinctive historical, economic, and cultural identity.
Lake GardaLake Garda (Lago di Garda ˈlaːɡo di ˈɡarda or (Lago) Benaco beˈnaːko; Lach de Garda; Ƚago de Garda) is the largest lake in Italy. It is a popular holiday location in northern Italy, between Brescia and Milan to the west, and Verona and Venice to the east. The lake cuts into the edge of the Italian Alps, particularly the Alpine sub-ranges of the Garda Mountains and the Brenta Group. Glaciers formed this alpine region at the end of the last ice age.
