DIFFERENTIATING SOIL PHYSICAL-PROPERTIES FROM MULTIPLE BAND DOQ DATA

The purpose of this study was to investigate the use of color infarare d-digital orthophoto quadrangle (CIR-DOQ) data in differentiating amon g surface soils of similar properties and to identify the CIR-DOQ spec tral band most useful in estimating selected soil properties, The CIR- DOQ data were generated by scanning four 9 x 9 in CIR aerial photograp hs at a uniform pixel sampling grid of 25 microns, resulting in 2 m of ground sample resolution, Correlation, regression, and discriminant a nalyses were used in analyzing the data, The overall accuracy of the C IR-DOQ data in differentiating the surface soils was 62.8%. AU three o f the CIR-DOQ bands were important in differentiating the surface soil s, Significant correlations were found among the CIR-DOQ data and soil s variables studied; however, the amount of variance explained was qui te low, The prediction equations for estimating soil properties accoun ted for less than 35% of the variability in the data, The low percenta ges can be attributed to the season of the year and climatic condition s that existed when the CIR photographs were taken, These conditions h ad a profound impact on the spectral quality of the photographs and, t herefore, the quality of data recorded by the scanner. It was conclude d that even though the spatial resolution of the CIR-DOQ data is super ior to most digital spectral data used today, the spectral quality is inadequate for differentiating among surface soils and for generating mathematical equations for predicting soil properties.