The Use of Aerial Photos in Engineering Planning
The planning of any engineering project requires information on land use, topography, soils, drainage, transportation, urban de­ velopment, and many other factors before actual location and design can be accomplished or field surveys undertaken. To obtain this preliminary information engineers surveyors, and planning com­ missions need maps. They need planimetric maps showing land use, or they need topographic maps having a contour interval of at least ten feet showing planimetric detail. Unfortunately, in numerous counties of Indiana and in the various cities of the state planimetric and topographic maps are seldom available or are obsolete. For example, of the 600 odd minute quadrangle sheets that are required for mapping the state of Indiana only about 130 maps were completed before January 1951 (10). Although 35 have been issued since that date, this great undertaking is still less than 30 per cent complete. Furthermore, the cost and time required to prepare by field survey methods the different types of maps would deplete available funds and in all probability prevent the construc­ tion of the improvement or delay it for a long period of time. In addition to the shortage of maps there is a shortage of engi­ neers for collecting and compiling information into maps. This shortage is especially felt by the county, city and state governments at a time when population is increasing; and, therefore, needs for water supply, sewage treatment, parking facilities, subdivision develop­ ment, highway development, traffic studies and other engineering studies are critical. Aerial photographs are a valuable source of basic map information to overcome the shortage of maps and also save time and money in numerous planning operations. It is the purpose of this paper to discuss the characteristics of aerial photographs and to explain their use in the planning phases of engineering projects. It is to be emphasized that aerial photographs will not eliminate
PHOTOGRAMMETRY AND ITS USES IN HIGHWAY PLANNING AND DESIGN
PHOTOGRAMMETRY MIGHT BE DESCRIBED AS THE PROCESS OF CONVERTING PHOTOGRAPHS INTO CONTOURED TOPOGRAPHIC MAPS. FORMERLY GROUND SURVEY METHODS WERE CONSIDERED THE ONLY RELIABLE MEANS OF OBTAINING ACCURATE TOPOGRAPHIC INFORMATION. IT IS NOW POSSIBLE TO DEVELOP TOPOGRAPHIC MAPS OF SPECIFIED ACCURACY BY MEANS OF AERIAL PHOTOGRAPHS WHICH ARE THEN SUBJECTED TO A SERIES OF PHOTOGRAMMETRIC PROCESSES SO THAT MAPS MAY BE DRAWN AT SCALES USEFUL IN HIGHWAY LOCATION AND DESIGN. /AUTHOR/
The Inca Occupation of the South Coast of Peru
like the others, however; it forks into several nearly parallel ravines of which the largest are Huayuri, Rio Grande-Palpa, Ingenio (called Collao in ancient times), Nasca proper (the ancient Caxamarca), Taruga, and Poroma. Due to peculiarities of the local topography, the irrigated areas in Ica and the ravines of Nasca are located inland, at the foot of the mountains, rather than at the mouths of the rivers as is more usual in Peruvian coastal valleys. No sharp natural or cultural boundary separates the valley of Chincha from the valleys of Cafiete (ancient Huarco and Runahuana), Asia, and Mala, the next valleys going up the coast to the northwest. At the other end of the area we are considering, however, there is a sharp break; beyond Yauca the Andean foothills reach out to the sea, natural conditions are quite different, and there are important differences in the archaeological picture as well. The historical sources which mention the south coast are not particularly helpful, except in so far as they provide us with a few dates. To begin with, no chronicler gives an explicit account of the political organization of the south coast at the time it came into contact with the Incas. It can, perhaps, be inferred from Cabello Balboa's statements about common policy toward the Inca invaders that there was some sort of political connection between the valleys of Mala, Cafiete, and Chincha, but the connection need have been no more than a temporary military alliance. Cabello makes no mention at all of Pisco. The valleys of Ica, Nasca, and 125