Relating Color Tone of Color Aerial Photograph to Some Characteristics of Soils and Utilization of Arable Land

Abstract

Relationship between the color of color aerial photograph determined by micro multi photometer MMP IID and the results of soil survey was investigated using the color aerial photograph taken in the northern part of Yokohama City on November 1972.
In paddy areas mainly consisted of muck soils, high correlation was recognized between the color components such as dominant wavelength, brightness, and the occuring depth of gleyed muck horizon affecting the humidity of surface soil. But no correlation was found between color and occurring depth of muck horizon.
Grades of humus content of bared upland soils are directly interpreted from the degree of darkness of color aerial photograph, which is difficult to interprete from panchromatic aerial photograph.
Fallow paddy fields are easily differentiated from paddy field by its high chromatic yellowish color owing to the withered weeds. Moreover, the chroma of fallow paddy field appears to change to higher and become to more rough textured with the increase of fallowing years.
Main vegetables in upland field in this season, such as radish, carrot, spinach, pe-tsai, mustard, welsh onion, lettuce, give a characteristic color on the photograph respectively.
To identify the wetness of paddy soils in lowland areas, it seemed most suitable to take aerial photograph at the time with little or no rain for at least several days before photographing as early as possible after the harvest.