Soil Clay Content Mapping Using a Time Series of Landsat TM Data in Semi-Arid Lands

Remote Sensing

Marouen Shabou²  Bernard Mougenot²  Zohra Lili Chabaane³  Christian Walter⁴  Gilles Boulet²  Nadhira Ben Aissa³  Mehrez Zribi²  Clement Atzberger¹ 

[1] CESBIO/UMR 5126, 18 av.Edouard Belin, bpi 2801, F-31401 Toulouse Cedex 9, France;;CESBIO/UMR 5126, 18 av.Edouard Belin, bpi 2801, F-31401 Toulouse Cedex 9, France; E-Mails:;Rural engineering, water and forest department, INAT/University of Carthage, 43, Avenue Charles Nicolle 1082 Tunis-Mahrajène, Tunisia; E-Mails:;Agrocampus Ouest, INRA, UMR 1069 SAS, 65 rue de st Brieuc- CS 84215, F-35042 Rennes Cedex, France; E-Mail:

关键词: topsoil clay content;    Landsat TM;    MID infrared index;    soil maps;    TerraSAR-X radar data;   

DOI  :  10.3390/rs70506059

来源: mdpi

【 摘 要 】

Clay content (fraction < 2 µm) is one of the most important soil properties. It controls soil hydraulic properties like wilting point, field capacity and saturated hydraulic conductivity, which in turn control the various fluxes of water in the unsaturated zone. In our study site, the Kairouan plain in central Tunisia, existing soil maps are neither exhaustive nor sufficiently precise for water balance modeling or thematic mapping. The aim of this work was to produce a clay-content map at fine spatial resolution over the Kairouan plain using a time series of Landsat Thematic Mapper images and to validate the produced map using independent soil samples, existing soil map and clay content produced by TerraSAR-X radar data. Our study was based on 100 soil samples and on a dataset of four Landsat TM data acquired during the summer season. Relationships between textural indices (MID-Infrared) and topsoil clay content were studied for each selected image and were used to produce clay content maps at a spatial resolution of 30 m. Cokriging was used to fill in the gaps created by green vegetation and crop residues masks and to predict clay content of each pixel of the image at 100 m grid spatial resolution. Results showed that mapping clay content using a time series of Landsat TM data is possible and that the produced clay content map presents a reasonable accuracy (R² = 0.65, RMSE = 100 g/kg). The produced clay content map is consistent with existing soil map of the studied region. Comparison with clay content map generated from TerraSAR-X radar data on a small area with no calibration point revealed similarities in topsoil clay content over the largest part of this extract, but significant differences for several areas. In-situ observations at those locations showed that the Landsat TM mapping was more consistent with observations than the TerraSAR-X mapping.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.