Air contamination caused by human activity

: 4/14

SURFACE WATERS: Major riversTennessee; Tombigbee, with its main tributary, the Black Warrior; Coosa and Tallapoosa, which join to form the Alabama; Mobile, formed by the joining of the Alabama and the Tombigbee;

Chattahoochee. Major artificial lakesPickwick, Wilson, Wheeler, and Guntersville, on the Tennessee River; Lay, Mitchell, Weiss, and Jordan, on .the Coosa; Martin and Thurlow, on the Tallapoosa; Holt Reservoir on the Black Warrior.

CLIMATE: TemperatureJuly average, about 27C (80F) statewide. January average, about 7C (44F) in north, 12C (53F) in south. PrecipitationRainfall average, 1,350 mm (53 in); varies from 1,320 mm (52 in) in north to 1,730 mm (68 in) along the coast. Growing seasonVaries from about 200 days in north to 300 days in south.

Natural Resources

Leaders of the state like to say that Alabama has more natural resources than any other area of its size in the world. These resources include soils, minerals, forests, and water.

Soils. Alabama may be divided into several major soil areas. Along the Coosa and the Tennessee rivers, there are valleys called limestone valleys. The soils in these valleys are mainly red clay loams. They were formed by the weathering of limestone rock. The soils of the Appalachian Plateau are mainly sandy loams. Red sandy loams and clay loams cover much pf the Piedmont Plateau. The soils of the Gulf Coastal Plain were formed from sediment laid down in the oceans that once covered the plain. Most of these soils are sandy loams or clay soils.

Long years of growing cotton and corn lowered the fertility of Alabama's soils. The abundant rainfall also caused the topsoil to be washed away. In many places, especially in the Piedmont Plateau and the Black Belt, farms are now planted in grasses to improve the soil and provide pasture for cattle.

Forests. About 60 per cent of all the land of Alabama is forested. Many kinds of trees are found, but the soft pine is the most common. It is also the most valuable for wood pulp, which is used for making paper. The pine forests grow mainly in the central and southern parts of the state.

To improve worn-out soils, farmers have developed many tree farms for future harvest. Paper companies, farmers, and the government all help in a continuing program of reforestation.

Minerals. Most of Alabama's minerals are in the northern half of the state. Coal and iron ore are found in the Appalachian Plateau and in the Ridge and Valley Region. One of the largest deposits, or fields, of coal is the Warrior field. It extends through all of Walker County and parts of Fayette, Tuscaloosa, and Jefferson counties. Some of the best beds of iron ore are in the Birmingham area.

Limestone occurs in the Tennessee Valley and in the Ridge and Valley Region, as well as in areas of the Gulf Coastal Plain. Marble is found in Coosa and Talladega counties.

Petroleum is the most important mineral of the Gulf Coastal Plain. It has been found in the extreme southwestern counties. There are important salt deposits north of Mobile. Henry and Barbour counties, as well as other parts of the state, have deposits of bauxite, a claylike mineral from which aluminum is obtained.

POPULATION

TOTAL: 3,893,888 (1980 census). Density29.6 persons to each square kilometer (76.7 persons to each square mile).

GROWTH SINCE 1820

Year Population Year Population

1820 127,901 1920 2,348,174

1860 964,201 1960 3,266,740

1880 1,262,505 1970 3,444,354

1900 1,828,697 1980 3,893,888

Gain Between 1970 and 198013.1 percent

CITIES: Fifteen of Alabama's cities have a population of more than 25,000 (1980 census).

Birmingham 284,413 Prichard 39,541

Mobile 200,452 Florence 37,029

Montgomery 177,857 Bessemer 31,729

Huntsville 142,513 Anniston 29,523

Tuscaloosa 75,211 Auburn 28,471

Dothan 48,750 Phenix City 26,928

Gadsden 47,565 Selma 26,684

Decatur 42,002

: 17/09/2007