Pedosphere 28(6): 913--925, 2018
ISSN 1002-0160/CN 32-1315/P
©2018 Soil Science Society of China
Published by Elsevier B.V. and Science Press
Classification of soil types using geographic object-based image analysis and random forests
Andrei DORNIK, Lucian DRĂGUŢ, Petru URDEA
Department of Geography, West University of Timişoara, Timişoara 300223(Romania)
Corresponding Author:Andrei DORNIK
      There is increasing interest in developing automatic procedures to segment landscapes into soil spatial entities that replace conventional, expensive manual procedures for delineating and classifying soils. Geographic object-based image analysis (GEOBIA) partitions remote sensing imagery or digital elevation models into homogeneous image objects based on image segmentation. We used an object-based methodology for the detailed delineation and classification of soil types using digital maps of topography and vegetation as soil covariates, based on the Random Forests (RF) classifier. We compared the object-based method's results with those of a pixel-based classification using the same classifier. We used 18 digital elevation model derivatives and 5 remote sensing indices that were related to vegetation cover and soil. Using 171 soil profiles with their associated environmental variable values, the RF method was used to identify the most important soil type predictors for use in the segmentation process. A stack of rastergeodatasets corresponding to the selected predictors was segmented using a multi-resolution segmentation algorithm, which resulted in homogeneous objects related to soil types. These objects were further classified as soil types using the same method, RF. We also conducted a pixel-based classification using the same classifier and soil profiles, and the resulting maps were assessed in terms of their accuracy using 30% of the soil profiles for validation. We found that GEOBIA was an effective method for soil type mapping, and was superior to the pixel-based approach. The optimized object-based soil map had an overall accuracy of 58%, which was 10% higher than that of the optimized pixel-based map.
Key Words:  GEOBIA,landscape segmentation,soil classification,soil covariates,soil mapping
Citation: Dornik A, Drăguţ L, Urdea P. 2018. Classification of soil types using geographic object-based image analysis and Random Forests. Pedosphere. 28(6):913-925.
View Full Text

Copyright © 2019 Editorial Committee of PEDOSPHERE. All rights reserved.
Address: P. O. Box 821, 71 East Beijing Road, Nanjing 210008, China    E-mail:
Technical support: Beijing E-Tiller Co.,Ltd.