Valley

A valley is a low area between hills, often with a river running through it.

In geology, a valley or dale is a depression that is longer than it is wide. The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys. Most valleys belong to one of these two main types or a mixture of them, (at least) with respect to the cross section of the slopes or hillsides.

Valley terminology

A valley in its broadest geographic sense is also known as a dale. A valley through which a river runs may also be referred to as a vale. A small, secluded, and often wooded valley is known as a dell or in Scotland as a glen. A wide, flat valley through which a river runs is known in Scotland as a strath. A mountain cove is a small valley, closed at one or both ends, in the central or southern Appalachian Mountains which sometimes results from the erosion of a geologic window. A small valley surrounded by mountains or ridges is sometimes known as a hollow. A deep, narrow valley is known as a cwm (also spelled combe or coombe). Similar geological structures, such as canyons, ravines, gorges, gullies, and kloofs, are not usually referred to as valleys. See also: "chine". A valley formed by erosion is called an erosional valley; a valley formed by geologic events such as drop faults or the rise of highlands is called a structural valley.

Gila River

The Gila River (/ˈhiːlə/; O'odham [Pima]: Keli Akimel or simply Akimel, Quechan: Haa Siʼil) is a 649-mile (1,044 km)tributary of the Colorado River flowing through New Mexico and Arizona in the United States. The river drains an arid watershed of nearly 60,000 square miles (160,000 km²) that lies mainly within the U.S. but also extends into northern Sonora, Mexico. Indigenous peoples have lived along the river for at least 2,000 years, establishing complex agricultural societies before European exploration of the region began in the 16th century. However, Euro-Americans did not permanently settle the Gila River watershed until the mid-19th century.

During the 20th century, human development of the Gila River watershed necessitated the construction of large diversion and flood control structures on the river and its tributaries, and consequently the Gila now contributes only a small fraction of its historic flow to the Colorado. The historic natural discharge of the river is around 1900 cfs, and is now only 247 cfs. These engineering projects have transformed much of the river valley and its surrounds from arid desert to irrigated land, and supply water to over five million people that live in the watershed.

Gila River Valley

The Gila River Valley is a multi-sectioned valley of the Gila River, mostly in Arizona. The Gila River forms in western New Mexico and flows west across southern-eastern, south-central, and southwestern Arizona; it changes directions across the state, and defines specific areas and valleys. The central portion of the river flows on the southern Phoenix valley region-(where Phoenix, in the Salt River Valley joins the Gila River Valley), and the final sections in southwestern Arizona form agricultural, irrigated smaller valleys within the Gila River valley, (for example Dome Valley, Mohawk Valley, and Hyder Valley).

Two mountain ranges are named for the Gila River: the Gila Mountains (Graham County) bordering the Gila River valley, northeast of Safford; the Gila Mountains (Yuma County) border the Gila River valley before the Gila River joins its confluence with the Colorado River; that range is east of Yuma and the Fortuna Foothills.

References

River Valley

A river valley is a riverine valley.

Geography

Schools

See also

Gila

Gila may refer to:

Animals

Geography

People