Maritime and hydraulic engineering
Harbour construction and shipbuilding are ancient arts. For many developing countries today the establishment of a large, efficient harbour is an early imperative, to serve as the inlet for industrial plant and needed raw materials and the outlet for finished goods. In developed countries the expansion of world trade, the use of larger ships, and the increase in total tonnage call for more rapid and efficient handling. Deeper berths and alongside-handling equipment (for example, for ore) and navigation improvements are the responsibility of the civil engineer.
The development of water supplies was a feature of the earliest civilizations, and the demand for water continues to rise today. In developed countries the demand is for industrial and domestic consumption, but in many parts of the world—e.g., the Indus basin—vast schemes are under construction, mainly for irrigation to help satisfy the food demand, and are often combined with hydroelectric power generation to promote industrial development.
Dams today are among the largest construction works, and design development is promoted by bodies like the International Commission on Large Dams. The design of large impounding dams in places with population centres close by requires the utmost in safety engineering, with emphasis on soil mechanics and stress analysis. Most governments exercise statutory control of engineers qualified to design and inspect dams.
Power
Civil engineers have always played an important part in mining for coal and metals; the driving of tunnels is a task common to many branches of civil engineering. In the 20th century the design and construction of power plants advanced with the rapid rise in demand for electric power, and nuclear power stations added a whole new field of design and construction, involving prestressed concrete pressure vessels for the reactor.
The exploitation of oil fields and the discoveries of natural gas in significant quantities have initiated a radical change in gas production. Shipment in liquid form from the Sahara and piping from the bed of the North Sea have been among the novel developments. Vast pipelines have also been constructed in Venezuela and across the Canadian-U.S. border.
In the late 20th and early 21st centuries, demand for renewable energy increased as a climate-friendly alternative to fossil fuel use. Civil engineers have developed and installed vast solar and wind arrays in places like California, the United Kingdom, and China, and innumerable smaller constructions have been built around the world, both on land and at sea. Other sources of renewable energy include tidal and geothermal power, though their use is more geographically limited.
Public health
Drainage and liquid-waste disposal are closely associated with antipollution measures and the re-use of water. The urban development of parts of water catchment areas can alter the nature of runoff, and the training and regulation of rivers produce changes in the pattern of events, resulting in floods and the need for flood prevention and control.
Modern civilization has created problems of solid-waste disposal from the manufacture of durable goods, such as automobiles and refrigerators, produced in large numbers with a limited life, to the small package, previously disposable, now often indestructible. The civil engineer plays an important role in the preservation of the environment, principally through design of works to enhance rather than to damage or pollute. See also environmental engineering.
J. Garth Watson The Editors of Encyclopaedia Britannica