Review of measurement and quantification of surface microtopography
Zhu Liangjun, Zhang Guanghui
（1.School of Geography, Beijing Normal University, 100875, Beijing, China；
2.State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation,
Chinese Academy of Science and Ministry of Water Research, 712100, Yangling, Shaanxi, China）
Abstract： Surface microtopography, as the basis of quantification of surface roughness, is closely related to dynamic changes of soil erosion, hydrological process simulation and the soil erosion process modeling. At present, techniques used to quantify surface microtopography can be divided into two categories, contact and non-contact measurement. The former consists of pins, chain and GPS-RTK methods, while the latter includes ultrasonic, infrared sensor, structured lighting laser scanner, laser scanner based on distance measuring, 3D laser scanner and close-range photogrammetry. In first instance, a comprehensive review of the principle, merits and demerits and applications of all techniques is given in this paper. The next part is a brief introduction of often-used indices for water erosion research, which are based on statistical, geostatistical, fractal and multifractal models. Finally, two major conclusions are drawn. First of all, GPS-RTK, structured lighting laser scanner, 3D laser scanner and close-range photogrammetry will continually contribute to the measurement of microtopography at millimeter to centimeter scale and the research of multiscale surface roughness characteristics, while the pins method will be still widely used in field test because of its simplification and convenience. However, based on the measurement techniques, more efforts should be made in generating an integrated technological process of measurement, quantification and model application in soil erosion models. Besides, by considering spatial anisotropy and heterogeneity of surface roughness, it is essential to develop a new and uniform quantification method for describing microtopography.
2013, Vol. 11 
