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Delaware, river, United States

(Encyclopedia)Delaware dĕlˈəwâr, –wər [key], river, c.280 mi (450 km) long, rising in the Catskill Mts., SE N.Y., in east and west branches, which meet at Hancock. It flows SE along the New York–Pennsylvan...

eutrophication

(Encyclopedia)eutrophication yo͞otrōˌfĭkāˈshən [key], aging of a lake by biological enrichment of its water. In a young lake the water is cold and clear, supporting little life. With time, streams draining i...

organic farming

(Encyclopedia)organic farming, the practice of growing plants—especially for fruits and vegetables, but for ornamentals as well—without the use of synthetic pesticides, herbicides, and fertilizers, or of raisin...

hydrology

(Encyclopedia)hydrology, study of water and its properties, including its distribution and movement in and through the land areas of the earth. The hydrologic cycle consists of the passage of water from the oceans ...

Smith, W. Eugene

(Encyclopedia)Smith, W. Eugene (William Eugene Smith), 1918–78, American photojournalist, b. Wichita, Kan. Smith is considered one of the principal masters of modern photojournalism. The distorted newspaper cover...

World Health Organization

(Encyclopedia)World Health Organization (WHO), specialized agency of the United Nations, established in 1948, with its headquarters at Geneva. WHO admits all sovereign states (including those not belonging to the U...

Adirondack Mountains

(Encyclopedia)Adirondack Mountains ădˌərŏnˈdăk [key], mountain mass, NE N.Y., between the St. Lawrence valley in the north and the Mohawk valley in the south; rising to 5,344 ft (1,629 m) at Mt. Marcy, the hi...

biological diversity

(Encyclopedia)biological diversity or biodiversity, the number of species in a given habitat. Scientists have variously estimated that there are from 3 to 30 million extant species, of which 2.5 million have been c...

Imperial Beach

(Encyclopedia)Imperial Beach, residential and resort city (2020 pop. 26,137), San Diego co., S Calif., on the Mexican border; inc. 1956. The southwesternmost city in ...

airship

(Encyclopedia)airship, an aircraft that consists of a cigar-shaped gas bag, or envelope, filled with a lighter-than-air gas to provide lift, a propulsion system, a steering mechanism, and a gondola accommodating pa...