II.

Physical Geography

North Carolina, 29th in size among the 50 states, has a total area of 139,391 sq km (53,819 sq mi), including 10,256 sq km (3,960 sq mi) of inland water. Its maximum dimensions are 809 km (503 mi) from east to west and 301 km (187 mi) from north to south. The state’s mean elevation is about 210 m (700 ft).

A.

Natural Regions

Largely on the basis of its topography and landforms North Carolina is often divided into three natural regions, or physiographic provinces: the Atlantic Coastal Plain, the Piedmont, and the Blue Ridge (or Mountain) province.

The Atlantic Coastal Plain makes up about 45 percent of the state (see Coastal Plain). It is a low, flat to gently sloping plain that tilts slightly seaward. Much of the region is less than 75 m (250 ft) above sea level. The western margin is marked by the Fall Line, in actuality a zone where the rivers descend over small waterfalls and rapids from the ancient, harder rock of the Piedmont to the more easily eroded sands, clays, and shales of the Atlantic Coastal Plain. At the Fall Line the land of the Coastal Plain rises in some places to elevations of 120 m (400 ft). The Coastal Plain is actually a series of broad, very flat terraces or steps, which are bounded on their western edges by abrupt rises in elevation that represent ancient beach ridges. The easternmost of these terraces are poorly drained in places, giving rise to large swampy areas or “pocosins,” an Algonquian word meaning “swamp on high ground.” The Great Dismal Swamp is one of these pocosins. Others are Holly Shelter Swamp and Green Swamp. The river valleys in the eastern Coastal Plain were flooded by a rise in sea level since the end of the last period of glaciation, creating the broad sounds and rivers, which are called estuaries.

Most of the Atlantic Coastal Plain has a sandy surface, and solid rock is very deep below many layers of sediments. Marsh grass and water-tolerant trees cover the wetter areas. Pine forests occupy the better-drained sandy sections.

The seaward part of the Atlantic Coastal Plain, extending from 50 to 130 km (30 to 80 mi) inland, is usually referred to as the Tidewater. Marshes, swamps, and lakes cover wide areas. The irregular shoreline has numerous bays and sounds that penetrate westwardly into the Coastal Plain. Sand dunes are numerous near the shore in many places. Low narrow sandbars, called barrier islands, enclose quiet lagoons, or sounds, and provide long stretches of attractive beaches. The outermost barrier islands are called the Outer Banks, which enclose the large body of water known as Pamlico Sound. At three locations along the coast—Cape Hatteras, Cape Lookout, and Cape Fear—the sandbars project far out under the Atlantic Ocean, creating dangerous shoals that are hazards to shipping. Just offshore from Cape Hatteras are the treacherous Diamond Shoals, site of hundreds of shipwrecks. This coast is nicknamed the “Graveyard of the Atlantic.” North Carolina’s coastline measures 484 km (301 mi). The tidal shoreline, which includes islands, bays, and river mouths, stretches for 5,432 km (3,375 mi).

The inner portion of the Atlantic Coastal Plain is somewhat higher in elevation and much better drained than the outer Coastal Plain. The gently rolling surface and light sandy soils have helped mold it into a leading agricultural region. In its southwestern part, near the South Carolina border, is found the Sandhills, a hilly area of ancient beach sand dunes with heights up to 180 m (600 ft) above sea level. This area is known for its peach orchards and for its winter golf resort areas.

North Carolina’s Piedmont is about the same size as the Atlantic Coastal Plain, comprising about 45 percent of the state’s area (see Piedmont Plateau). Lying between the Coastal Plain and the Appalachian Mountains, this rolling to hilly transitional region ranges from 150 m (500 ft) above sea level in places on its eastern border to as much as 460 m (1,500 ft) in the west.

The mountain region of North Carolina occupies about 10 percent of the state. It is part of the southern portion of the Appalachian Mountain province, which extends from New England in the north to Alabama in the south. In the southern part of the Appalachian system, the easternmost mountain ridge is called the Blue Ridge. The Blue Ridge province attains its greatest width, height, and ruggedness in the area along the North Carolina-Tennessee border. In places the boundary between these two states follows the crest of the mountain ridges. The region is divided into a number of smaller mountain ranges. The easternmost range is specifically called the Blue Ridge, while along the western margin lie several ranges, including the Unaka Mountains and the Great Smoky Mountains. Several ranges, such as the Black Mountains and the Plott Balsam Mountains, connect the easternmost and westernmost ranges, enclosing lower-lying basins and valleys. The Asheville Basin, in the French Broad Valley, is the most significant.

The general elevation within the mountains varies from 600 to 1,200 m (2,000 to 4,000 ft), with valleys considerably lower. Many peaks are considerably higher; 50 exceed 6,000 ft (equivalent to 1,829 m). Mount Mitchell in the Black Mountains, 2,037 m (6,684 ft) high, is the highest point not only in the state but also in the entire eastern United States east of the Black Hills of South Dakota.

B.

Rivers and Lakes

The drainage divide in North Carolina follows the Blue Ridge range on the eastern margin of the mountain region. This is called the “Eastern Continental Divide.” West of this divide, rivers drain into the Mississippi River through the Tennessee River and other tributaries of the Ohio River. The French Broad, the largest, and the Little Tennessee flow into the Tennessee River. The New River flows into the Kanawha River of West Virginia which in turn flows into the Ohio River.

Most of the state’s rivers flow southeastward across the Piedmont and the Atlantic Coastal Plain. In the mountains and in the Piedmont they are relatively swift-flowing streams. In places the rivers have cut valleys 60 m (200 ft) or more below the upland surface. Major rivers and their tributaries provide good drainage, and excellent sites to use the rivers to generate electricity are numerous. Most rivers have developed falls or rapids where they cross the Fall Line from the Piedmont into the Atlantic Coastal Plain and become sluggish as they wend their way across the flatter Coastal Plain. Floodplains are wide and river swamps are common.

The Cape Fear River, one of the principal rivers in the state, begins in the Piedmont and flows southeastward as a stream laden with yellow muds and silts until it converges with a large backwater tributary known as the Northeast Cape Fear River. From the junction point of these two rivers at Wilmington, a broad estuary is formed that flows south to empty into the Atlantic Ocean at Smith Island just west of Cape Fear. The Neuse and Tar-Pamlico rivers flow into different arms of the Pamlico Sound. The Roanoke, Chowan, Perquimans, and Pasquotank rivers enter Albemarle Sound. The New River (which is a different river from the New River in the Blue Ridge province) empties into Onslow Bay. The Yadkin-Pee Dee, Catawba, Broad, and Waccamaw rivers originate in North Carolina and reach the ocean through South Carolina.

North Carolina’s few large natural lakes are in the outer Coastal Plain. Lake Mattamuskeet, near Pamlico Sound, is the largest. Lake Phelps, nearby, is second in size. Lake Waccamaw, near the South Carolina border, is the state’s third largest lake. Of the numerous swamps, the Great Dismal Swamp, astride the North Carolina-Virginia border, is the best known.

C.

Floods and Flood Control

The rivers of the Atlantic Coastal Plain flow through broad flat valleys and sometimes can cause damaging floods to large areas. Flooding in the mountains and the Piedmont, however, is restricted more to the immediate stream valleys. The early spring is usually the flood season, but hurricanes in the late summer and autumn can sometimes cause tremendous flood damage both along the coast and in the river valleys of the Piedmont and mountains.

Most of the dams and reservoirs on the Yadkin, Catawba, Roanoke, and other North Carolina rivers play a double role of hydroelectric power production and flood control, although some dams are used for power generation or for flood control only. By far the largest reservoir is Lake Norman, on the Catawba River, completed in 1964. Others include Lake Tillery, Badin Lake, High Rock Lake, and Wilkesboro reservoir on the Yadkin River, and John L. Kerr Reservoir and Lake Gaston on the Roanoke River. Fontana, Nantahala, and Cheoah reservoirs, in the west, are Tennessee Valley Authority (TVA) multipurpose dams for both flood control and power.

D.

Climate

North Carolina has a humid subtropical climate, with precipitation in all seasons and few temperature extremes.

D.1.

Temperature

In January temperatures average 4° to 7°C (40° to 45°F) in most areas, except in the mountains, where the range is from 1° to 3°C (34° to 38°F). There cold raw weather lasts much of the winter. In the Coastal Plain and the Piedmont, cold spells are brief. On the highest peaks, January averages are well below freezing and heavy snowfalls occur. July temperatures range from an average of about 20°C (about 68°F) in the mountainous regions to as high as 27° C (80°F) in the Coastal Plain. Hot days are common at lower elevations, and temperatures occasionally rise into the upper 30°s C (lower 100°s F). Summers are cooler in the mountains.

D.2.

Precipitation

Yearly precipitation averages 1,000 to 1,300 mm (40 to 50 in) over most of the Atlantic Coastal Plain and the Piedmont. The sheltered basins and mountain valleys receive 1,000 mm (40 in). The southern-facing slopes of the mountains in the extreme southwestern part of the state receive about 2,000 mm (80 in) due to the moist prevailing winds blowing northward from the Gulf of Mexico. Summer is the rainiest season, and autumn is generally the driest, except that near the coast, autumn can be very rainy because of tropical storms and hurricanes. Snowfall ranges from 25 to 250 mm (1 to 10 in) a year over the Atlantic Coastal Plain and the Piedmont. In the mountains annual snowfall averages as much as 1,300 mm (50 in) in places, and the snow cover can last for several weeks at a time.

D.3.

Growing Season

At the low elevations the growing, or frost-free, season is from seven to nine months long. The mountain region in the northwestern part of the state has a growing season of as short as five months.

E.

Soils

North Carolina’s well-drained mature soils belong mainly to the group known as the red-yellow podzolic soils (ultisols), that covers most of the southeastern United States. In the mountains are gray-brown podzolic soils and a few small areas of podzols, two soil types that are similar to the soils of the northeastern United States.

Most of the soils of the Atlantic Coastal Plain are light colored and of sandy texture. They are low in most elements essential to crop growth and are moderately to strongly acidic. Many of them respond to proper treatment and become quite productive for agriculture when limed and fertilized. Drainage is the major soil problem of the Atlantic Coastal Plain.

Clay and clay loam textures typify Piedmont soils, and stoniness is common. Many of the flatter upland areas and some basins have light-colored sandy and sandy loam soils. The parent material, which is derived from old deeply weathered crystalline rocks, is high in iron oxide, which gives most Piedmont soils their distinctive red color. Piedmont soils are richer in most essential elements than are most Coastal Plain soils. Some of the Piedmont’s best crop soils are derived from water-laid, or alluvial, materials on river floodplains and terraces.

Most of the mountain soils are thin, stony, and not fully developed. At lower elevations are many red-yellow podzolic soils typical of the Piedmont. In the higher parts the cooler climate accounts for gray-brown podzolic soils. The best agricultural soils are on floodplains and terraces in valleys and basins.

F.

Plant Life

Forests today cover 62 percent of North Carolina’s total area. Originally they covered the entire land area, except for grassy marshes and some bald treeless areas at high elevations. The highest proportion of forest land exists where there is little farming, in the steep mountains and the poorly-drained outer Coastal Plain.

The forests of the Atlantic Coastal Plain consist largely of southern loblolly pines and longleaf pines. Cypresses, gums, Atlantic white cedars, and other water-tolerant species are found in river bottomlands and in Coastal Plain swamps. A rare carnivorous plant called the Venus’s-flytrap is native to the swamps of southeastern North Carolina. The coastal pine forests have been cut over repeatedly, and all that remains is second-growth timber.

The forests of the Piedmont and the mountains at the time of the European settlement consisted of red oaks, white oaks, hickories, gums, yellow poplars, and other deciduous trees mixed with smaller numbers of pines. Pines predominate in some parts of the Piedmont today, but most of the region is covered by a mosaic of hardwood and pine stands. In the mountains low temperatures, a shorter warm season and abundant rainfall have favored northern species and abundant undergrowth. These species include the maple, birch, beech, hemlock, fir, and spruce.

G.

Animal Life

Although North Carolina’s wildlife has diminished over the years, it is still plentiful and varied. Land birds include quail, doves, wild turkeys, and many songbirds. Ducks and geese are plentiful near the coast. Most wooded areas have squirrels, rabbits, opossums, raccoons, foxes, and other small game. Deer are widespread. Bears are not numerous but are found in the mountains and the Coastal Plain swamps. Wild boar can be found in the Great Smoky Mountains National Park and the Nantahala National Forest. Snakes, including poisonous species such as rattlesnakes and water moccasins, are common throughout the state, and even alligators are native to the southeastern corner of the state. Most inland waters are stocked with fish, including trout, bass, bream, and perch.

H.

Conservation

Twenty divisions of the North Carolina Department of Environment and Natural Resources are responsible for aspects of environmental quality. Included are the Division of Air Quality, which monitors the quality of outdoor air (including problems such as smoke, haze, and noxious fumes), and the Division of Water Quality, which monitors the quality of surface and groundwater resources. Each of these agencies also carries out enforcement actions against violators. The Division of Soil and Water Conservation conducts programs to slow loss of topsoils, control agricultural pollution, protect watersheds, and map wetlands.

In 2006 the state had 31 hazardous waste sites on a national priority list for cleanup due to their severity or proximity to people. Some progress was being made in efforts to reduce pollution; in the period 1995–2000 the amount of toxic chemicals discharged into the environment was reduced by 29 percent.