8 
Figure 3 
rehabilitation of the damaged cities. Later a number of additional cities were 
mapped by the Project to fulfill specific needs for planning and for engineering 
studies for flood control and highway location. Figure 3 shows a portion of the 
aerial photography and mapping of the City of Concepcion. 
MOSAICS 
The decision to provide photo-mosaics of the Project area, rather than com 
pile topographic or planimetric maps, was reached because the need for a map base 
was immediate and monies for the production of more detailed maps would not be 
available. 
It was recognized that photo-mosaics would have inherent errors of relief and 
tilt displacements. However, through the use of a sufficient control and the 
employment of proven mosaic making methods, reliable mosaics were prepared. These 
mosaics proved valuable for the accurate delineation of property, soils, land use 
and land capability boundaries.