The birth of modern surveying and mapping occurred in the 1920s, when airborne cameras were used to produce photographic maps. This type of mapping has been carried to even greater sophistication today, through the use of mapping satellites that now circle the globe. Likewise, recent developments in three-dimensional computer modeling have given engineers the ability to generate terrain models of the land by converting coordinate data graphically.
Cartography, the science of mapmaking, remains an important component of surveying and mapping. Cartographers prepare maps and charts from data gathered by physical surveys, aerial photography, and the more sophisticated technologies such as remote sensing, which uses various forms of radar. The products of cartographers include topographic maps showing the elevation and major physical features of the land surface; nautical and aeronautical charts; meteorological maps; city maps; political maps of countries; and atlases. Clearly, the preservation of accuracy and detail throughout the entire process is the most critical element in producing maps. Extremely precise surveying techniques are obtained through the use of precision drafting instruments, cameras, computers, printers, and plotters. Civil engineers practicing cartography develop expertise in many areas, including geography, design, even art. By converting numerical and physical data into maps, these engineers perform a critical service for aircraft and ship pilots, truckers and other motorists, as well as for government, corporate, and scientific users.
Surveying is primarily concerned with the determination of boundaries of real property, and with the precise location of route alignments. Surveyors also plot out and subdivide geographic areas, and prepare deed descriptions for conveying ownership of parcels of land. The civil engineer involved in surveying prepares maps with drafters and cartographers, showing natural and human-made features on the land and water surfaces in a given area, and property boundaries. The surveyor's work is vital to the establishment of state and local boundaries for the definition of townships, range, and sections.
Engineering surveys provide the data used by engineers in planning, locating, designing, and constructing physical facilities. Among the basic data used in design are the horizontal and vertical locations of natural features of the land surface, and the location of human-made features. These features are then depicted through the development of cross-sectional and profile views showing the elevation and character of the ground surface along lines established for design and construction purposes. Civil engineers are responsible for the layout of structures to be built, the measurement of quantities of materials used in construction, and often do the actual surveys of mines, quarries, and other excavation activities.
Just as with mappers, today's surveyors are heavily involved with computer applications. Indeed, the common image of the surveyor in the field taking measurements with a tripod-mounted transit is becoming outdated. Much of the modern field equipment is computer driven or uses computers in field data acquisition and storage. There is also a natural link between the surveyor and CAE/CAD (computer-aided engineering, design, and drafting) in that quite often surveying data gathered onto disks, CDs, or tapes in the field are processed into maps and charts by computer without anyone ever putting pencil to paper.
Currently, about one in twenty of the civil engineers working in the United States is involved in the practice of surveying or mapping.
GEOTECHNICAL ENGINEERING
Another rapidly growing specialty group within the field of civil engineering is geotechnical engineering. Engineers in this field are responsible for determining the characteristics of the soils and rocks at a given construction site or along the route of a highway or other transportation facility. Geotechnical engineers apply the principles of mechanics to the natural soil and rock materials that are found on project sites. They develop designs for foundations to support bridges, industrial buildings, and other structures. They also develop excavation techniques and construction methods for tunneling, pile-driving, and similar works.
These engineers also conduct the exploration and testing of the geologic materials that will be the foundations of structures or form the construction materials for embankments for highways, railroads, dams, levees, and floodwalls. In doing so, geotechnical engineers work closely with engineering geologists to detect possible weaknesses in the soils and rocks at particular sites, and with designers to match the characteristics of the soils and rocks found at the site of proposed facilities.
Today, an estimated one in ten civil engineers working in the United States is a geotechnical engineer.
