امكان سنجي داده هاي ماهواره اي به منظور مطالعه خصوصيات خاكهاي مناطق خشك (برآورد رنگ خاك)

Remotely sensed data evaluation on soil spectral properties in arid regions

One of the apparent characteristics of soil is color which shows high correlation with soil characteristics and spectral reflectance. Soil color is identified using visual comparison of sample and colored chips of Munsell color charts .In arid regions due to the prolonged sunny days, low soil moisture, sparse vegetation cover and close relation between land units and soils, there is an ideal condition for application of remote sensing data especially for study of relation between satellite data and color of surface features. The soil color and the most effective factors on color and spectral reflectance of soil are explained in brief. Color composite images produced from TM7, TM4 and TM2 as red, green and blue respectively used in order to choose sample sites. The 20 sample sites were chosen based on resample 3><3 pixels (90x90 m). In each site, the soil surface conditions and the munsell color of the soil surface were investigated in the field. Some physico-chemical properties of soil samples were also determined in the laboratory. The results of this study indicates that munsell notation of hue, value and Chroma are significantly correlated to the visible bands of Landsat (TM) data. From this study it may be concluded that visible reflectance of Landsat can be used to estimate soil color, if very precise result is not expected .More investigation are necessary in order to improve the obtained results.