Water Features on Topographic Maps

Topographic maps are a prime source of information for planning the improvement of man's environment with respect to water. In order to utilize the tremendous amount of hydrologic information shown on these maps, the water resources planner must know what maps are available and how to interpret the map portrayal of water features. The paper explains how various features are shown and how to interpret features that are subject to change because of seasonal conditions, construction of dams, reclamation of swamps, and changes in stream courses. The classes of water features discussed include streams, lakes, ponds, reservoirs, canals, aqueducts, ditches, springs, wells, glaciers, and coasts. Methods of improving the means of presenting hydrologic information on maps are considered, with specific reference to orthophotomaps. Applications of special types of photography such as color infrared, and the use of orbiting satellites as vehicles for sophisticated sensors are mentioned.