National Mapping for Urban Areas

The need for topographic mapping with increasing scales and more detail has grown steadily since the inception of the national program. As a result, a mapping scale which began at 1:250,000 has evolved into the present 1:24,000 basic scale. The Geological Survey is exploring the need for general-purpose maps at a larger scale that might help solve the environmental problems of urban areas. The Urban Mapping Coordination Group (five Federal bureaus) is also working towards this goal. A study completed by the System Development Corporation provided valuable related information and statistics. To ascertain how the functions of city agencies can be better served by maps and cartographic data, the Geological Survey recently conducted a study of map use in the District of Columbia government. Also beneficial to urban use is the Survey's development of the orthophotomap and a rapid method of map revision called interim revision. Although the Geological Survey is pledged to continue its primary program – to provide standard-quadrangle topographic coverage at 1:24,000 scale – it will also continue to assess the need for an urban series of general-purpose maps at a larger scale.