Lake retention timeLake retention time (also called the residence time of lake water, or the water age or flushing time) is a calculated quantity expressing the mean time that water (or some dissolved substance) spends in a particular lake. At its simplest, this figure is the result of dividing the lake volume by the flow in or out of the lake. It roughly expresses the amount of time taken for a substance introduced into a lake to flow out of it again. The retention time is particularly important where downstream flooding or pollutants are concerned.
Cucurbita pepoCucurbita pepo is a cultivated plant of the genus Cucurbita. It yields varieties of winter squash and pumpkin, but the most widespread varieties belong to the subspecies Cucurbita pepo subsp. pepo, called summer squash. It has been domesticated in the Americas for thousands of years. Some authors maintain that C. pepo is derived from C. texana, while others suggest that C. texana is merely feral C. pepo. They have a wide variety of uses, especially as a food source and for medical conditions. C.
ChironomidaeThe Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species superficially resemble mosquitoes, but they lack the wing scales and elongated mouthparts of the Culicidae. The name Chironomidae stems from the Ancient Greek word kheironómos, "a pantomimist". This is a large taxon of insects; some estimates of the species numbers suggest well over 10,000 world-wide.
Zebra musselThe zebra mussel (Dreissena polymorpha) is a small freshwater mussel. The species originates from the lakes of southern Russia and Ukraine, but has been accidentally introduced to numerous other areas and has become an invasive species in many countries worldwide. Since the 1980s, the species has invaded the Great Lakes, Hudson River, and Lake Travis. The species was first described in 1769 by German zoologist Peter Simon Pallas in the Ural, Volga, and Dnieper Rivers.
River ThamesThe River Thames (tɛmz ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the River Severn. The river rises at Thames Head in Gloucestershire and flows into the North Sea near Tilbury, Essex and Gravesend, Kent, via the Thames Estuary. From the west it flows through Oxford (where it is sometimes called the Isis), Reading, Henley-on-Thames and Windsor.
Lake BaikalLake Baikal (baɪˈkɑːl,_-ˈkæl ; Ozero Baykal ˈozjɪrə bɐjˈkaɫ; Baigal dalai) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the Republic of Buryatia to the southeast. With of water, Lake Baikal is the world's largest freshwater lake by volume, containing 22–23% of the world's fresh surface water, more than all of the North American Great Lakes combined. It is also the world's deepest lake, with a maximum depth of , and the world's oldest lake, at 25–30 million years.
Aral SeaThe Aral Sea (ˈærəl ) was an endorheic lake lying between Kazakhstan to its north and Uzbekistan to its south which began shrinking in the 1960s and largely dried up by the 2010s. It was in the Aktobe and Kyzylorda regions of Kazakhstan and the Karakalpakstan autonomous region of Uzbekistan. The name roughly translates from Mongolic and Turkic languages to "Sea of Islands", a reference to the large number of islands (over 1,100) that once dotted its waters.
Caspian SeaThe Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, west of the broad steppe of Central Asia, south of the fertile plains of Southern Russia in Eastern Europe, and north of the mountainous Iranian Plateau of West Asia. It covers a surface area of (excluding the highly saline lagoon of Garabogazköl to its east), an area approximately equal to that of Japan, with a volume of .
Mississippi RiverThe Mississippi River is the primary river, and second-longest river, of the largest drainage basin in the United States. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The main stem is entirely within the United States; the total drainage basin is , of which only about one percent is in Canada.
United StatesThe United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America and consisting of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations.
