[Parameters: Topic='LAND SURFACE', Term='SOILS', Variable_Level_1='CARBON']
Soil property estimates for Tunisia derived from SOTER and WISE (SOTWIS-Tunisia, ver. 1.0)Entry ID: SOTWIS_Tunisia
Abstract: This datasets describes a harmonized set of soil property estimates for Tunisia. It has been derived from the 1:1 million scale Soil and Terrain Database for the country (SOTER_TN, ver. 1.0) and the ISRIC-WISE soil profile database, using standardized taxonomy-based pedotransfer (taxotransfer) procedures.
The land surface of Tunisia, covering some 164,150 km2, has been characterized in SOTER_TN ... using 250 unique SOTER units. Each map unit consists of up to four different soil components. In so far as possible, each soil component has been characterized by a regionally representative profile, selected and classified by national soil experts (see Dijkshoorn et al. 2008). Conversely, in the absence of any measured legacy data, soil components were characterized using synthetic profiles for which only the FAO-Unesco (1988) classification is known.
Soil components in SOTER_TN have been characterized using 100 profiles of which 44 are synthetic. The latter represent some 59 per cent of the territory. Comprehensive sets of measured attribute data are not available for most of the measured profiles (56) collated in SOTER_TN, as these were not considered in the source materials. Consequently, to permit modelling, gaps in the soil analytical data have been filled using consistent taxotransfer procedures. Modal soil property estimates necessary to populate the taxotransfer procedure were derived from statistical analyses of soil profiles held in the ISRIC-WISE database ― the current taxotransfer procedure only considers profiles in WISE that: (a) have FAO soil unit names identical to those mapped for Tunisia in SOTER, and (b) originate from regions having similar Köppen climate zones (n= 3566).
Property estimates are presented for 18 soil variables by soil unit for fixed depth intervals of 0.2 m to 1 m depth: organic carbon, total nitrogen, pH(H2O), CECsoil, CECclay, base saturation, effective CEC, aluminium saturation, CaCO3 content, gypsum content, exchangeable sodium percentage (ESP), electrical conductivity (ECe), bulk density, content of sand, silt and clay, content of coarse fragments (> 2 mm), and volumetric water content (-33 kPa to -1.5 MPa). These attributes have been identified as being useful for agro-ecological zoning, land evaluation, crop growth simulation, modelling of soil carbon stocks and change, and studies of global environmental change.
The soil property estimates can be linked to the spatial data (map), using GIS, through the unique SOTER-unit code; database applications should consider the full map unit composition and depth range.
The derived data presented here may be used for exploratory assessments at national scale or broader (< 1:1 000 000). They should be seen as best estimates based on the current, still limited, selection of soil profiles in SOTER_TN and data clustering procedure ― the type of taxotransfer rules used to fill gaps in the measured data has been flagged to provide an indication of confidence in the derived data.
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Data Set Citation
Dataset Originator/Creator: Niels H. Batjes
Dataset Title: Soil property estimates for Tunisia derived from SOTER and WISE (SOTWIS-Tunisia, ver. 1.0)
Dataset Series Name: SOTWIS
Dataset Release Date: 20100131
Dataset Release Place: Wageningen
Dataset Publisher: ISRIC - World Soil Information
Version: ver. 1.0
Data Presentation Form: ArcGis 9.x and MSAccess tables (zipped)
Other Citation Details: http://www.isric.org/isric/Webdocs/Docs/ISRIC_Report_2010_01.pdfOnline Resource: http://www.isric.nl/isric/CheckRegistration.aspx?dataset=62
Start Date: 1963-01-01Stop Date: 2004-12-31
Horizontal Resolution Range: 10 km - < 50 km or approximately .09 degree - < .5 degree
AGRICULTURE > SOILS > CALCIUM
AGRICULTURE > SOILS > CARBON
AGRICULTURE > SOILS > CATION EXCHANGE CAPACITY
AGRICULTURE > SOILS > ELECTRICAL CONDUCTIVITY
AGRICULTURE > SOILS > NITROGEN
AGRICULTURE > SOILS > ORGANIC MATTER
AGRICULTURE > SOILS > SOIL SALINITY/SOIL SODICITY
AGRICULTURE > SOILS > SOIL BULK DENSITY
AGRICULTURE > SOILS > SOIL CLASSIFICATION
AGRICULTURE > SOILS > SOIL DEPTH
AGRICULTURE > SOILS > SOIL HORIZONS/PROFILE
AGRICULTURE > SOILS > SOIL PH
AGRICULTURE > SOILS > SOIL TEXTURE
AGRICULTURE > SOILS > SOIL WATER HOLDING CAPACITY
AGRICULTURE > SOILS
LAND SURFACE > SOILS > CALCIUM
LAND SURFACE > SOILS > CARBON
LAND SURFACE > SOILS > CATION EXCHANGE CAPACITY
LAND SURFACE > SOILS > ELECTRICAL CONDUCTIVITY
LAND SURFACE > SOILS > NITROGEN
LAND SURFACE > SOILS > ORGANIC MATTER
LAND SURFACE > SOILS > SOIL SALINITY/SOIL SODICITY
LAND SURFACE > SOILS > SOIL BULK DENSITY
LAND SURFACE > SOILS > SOIL CLASSIFICATION
LAND SURFACE > SOILS > SOIL DEPTH
LAND SURFACE > SOILS > SOIL HORIZONS/PROFILE
LAND SURFACE > SOILS > SOIL PH
LAND SURFACE > SOILS > SOIL TEXTURE
LAND SURFACE > SOILS > SOIL WATER HOLDING CAPACITY
LAND SURFACE > SOILS
Quality The data set's lineage is described in:
Batjes NH 2010. Soil property estimates for Tunisia derived from SOTER and WISE (SOTWIS-Tunisia, ver. 1.0). Report 2010/01, ISRIC – World Soil Information, Wageningen (41 p. with data set)
Access Constraints ISRIC kindly requests that you send us two reprints of any publication that uses data received from ISRIC - World Soil Information. This will help us to determine the type and level of use of the data we distribute.
Use Constraints Materials developed by ISRIC are copyrighted, all rights reserved. Reproduction and dissemination of such materials for educational or non-commercial purposes are authorized without any prior written permission from the copyright holders provided the source is fully acknowledged. Reproduction of materials for resale or other commercial purposes is prohibited without prior written permission of the ... copyright holders. Applications for such permission should be addressed to: Director, ISRIC - World Soil Information, PO Box 353, 6700 AJ Wageningen, the Netherlands or by e-mail to email@example.com.
ISRIC requests you to acknowledge use of our data; this will allow us to gauge the interest and usefulness of our services. Please refer to the dataset documentation for suggested form of acknowledgement and correct citation.
Data Set Progress
Distribution Media: zip files, on-line
Distribution Size: 4 MB zipped, 14 MB unzipped
Email: niels.batjes at wur.nl
ISRIC - World Soil Information (World Data Center for Soils) P.O. Box 353
Postal Code: 6700 AJ
Country: The Netherlands
1) Batjes NH 2010. Soil property estimates for Tunisia derived from SOTER and WISE (SOTWIS-Tunisia, ver. 1.0). Report 2010/01, ISRIC – World Soil Information, Wageningen (41p. with data set)
2) Dijkshoorn JA, van Engelen VWP and Huting JRM 2008. Soil and landform properties for LADA partner countries (Argentina, China, Cuba, Senegal and The Gambia, South Africa and Tunisia), ISRIC Report 2008/06, FAO, Rome, and ISRIC - World Soil Information, Wageningen (28 p. with dataset)
Creation and Review Dates
DIF Creation Date: 2010-02-22
Last DIF Revision Date: 2011-09-12