Eine Untersuchung zur Anwendbarkeit optischer Verfahren in der Rauhigkeitsmessung von Bodenoberflächen : Ein Beitrag zur Methodenentwicklung

Oldenburg

2001

S. 121-122

4 Abb., 2 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200126282

The goal of this thesis (diploma) was to characterize the roughness from soil surfaces beam and to manufacture the connection to the shadow surface portion with defined lightangle of incidence. Roughness measurements are among other things needed for a better understanding of the protective function of a rough surface of soils in relation to wind - and water erosion. The investigations were at first three manually produced soil surfaces, which itself showed different characteristics in their roughness (very rough, means rough, light rough), in their texture, content of organic substance and the soil colour. In an angle of 17° these soils were artificially lit up, in order to enter the shadow surfaces evident from it photographically and to classifiy their shadow surface portions by picture handling programs. Subsequently, additional accomodation of a fourth soil surface took place in the field under natural lighting conditions with the same work procedures. From all the four soil surfaces the roughness was recorded with a laser relief meter. Those won elevator values served here on the one hand for a three-dimensional representation of the surfaces, and on the other hand for the calculation and representation of artificial shadow surfaces, which served the comparison with the shadow surface portions classified before. Parallel to this, a view took place from positive and negatively influencing factors, which could affect the picture handling. The statistical view of the roughness - and shadow structures took place through calculation of the external heterogeneity. Additionally, a view of the middle heights, the minimum and maximum heights, and the standard deviations took place as well as the frequency distribution of the elevator values in defined classes of the roughness structures. The dissolution of the roughness measurement with the laser relief meter for this of 2x2 mm, for this selected, was sufficient for the characterisation of the roughness structure, and could even still reduced to (= 4x4 mm). The evaluation of the Shadow surface portion is however mandatory necessary to achieve high resolution. The result of these investigations is a close exponential connection between the roughness of the soil surfaces and the shadow surface portion; it can always be always closed in the reversal conclusion by the shadow surface portion on the roughness. For the evaluation of soil surfaces outside of the examined roughness area, resuming investigations would still have to follow.