e2af1672-ab22-4fdf-909f-81fb586268dc dataset Data infodesk ISRIC - World Soil Information data@isric.org 2021-07-14T11:51:38 ISO 19115:2003/19139 2003/Cor.1:2006 4326 EPSG SOTER-based soil parameter estimates (SOTWIS) for Upper Tana river catchment, Kenya 2011-02-01 e2af1672-ab22-4fdf-909f-81fb586268dc This harmonized set of soil parameter estimates for the Upper Tana river catchment, Kenya. The data set was derived from the 1:250 000 scale Soil and Terrain Database for the Upper Tana (SOTER_UT, ver. 1.1; Dijkshoorn et al. 2011) and the ISRIC-WISE soil profile database, using standardized taxonomy-based pedotransfer (taxotransfer) procedures. The land surface of the Upper Tana, Kenya, covering some 18,900 km2, has been mapped in SOTER using 191 unique SOTER units. Each map unit may comprise of up to three 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. 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_UT have been characterized using 146 profiles consisting of 109 real and 37 so-called synthetic profiles. The latter were used to represent some 18% per cent of the study area. Comprehensive sets of measured attribute data are seldom available for most profiles (109) collated in SOTER_UT, 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 (43) identical to those mapped for the Upper Tana in SOTER, and (b) originate from regions having similar Köppen climate zones (n= 5745). 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 (less than 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. Niels Batjes ISRIC - World Soil Information Senior Soil Scientist PO Box 353 Wageningen 6700AJ Netherlands niels.batjes@isric.org https://files.isric.org/public/thumbnails/sotwis/SOTWIS_UT.jpg calcium carbon cation exchange capacity electrical conductivity nitrogen organic matter bulk density soil profiles pH salinity texture water holding capacity nutrients Soil science Stratum Africa East-Africa Kenya Tana river Region Attribution 3.0 International (CC BY 3.0) 250000 geoscientificInformation 1972-11-01 2003-03-01 36.6 38.4 -1.2 0.3 zip https://files.isric.org/public/sotwis/SOTWIS_UT.zip WWW:DOWNLOAD-1.0-ftp--download Download https://isric.org/projects/harmonized-continental-soter-derived-database-sotwis WWW:LINK-1.0-http--related Project webpage https://isric.org/sites/default/files/isric_report_2010_07b.pdf WWW:LINK-1.0-http--related Report 1) Batjes NH 2011. Soil property estimates for the Upper Tana river catchment, Kenya, derived from SOTER and WISE (ver. 1.1). Report 2010/07b, ISRIC – World Soil Information, Wageningen, vi + 37 p. with data set, https://isric.org/sites/default/files/isric_report_2010_07b.pdf 2) Dijkshoorn JA, Macharia P, Huting J, Maingi P and Njoroge C 2011. Soil and and terrain conditions for the Upper Tana river catchment, Kenya (Ver. 1.1), ISRIC Report 2010/09b, Kenya Agricultural Research Institute (KARI) and ISRIC – World Soil Information, Wageningen, pp 35 + data set. 3) Batjes NH, Al-Adamat R, Bhattacharyya T, Bernoux M, Cerri CEP, Gicheru P, Kamoni P, Milne E, Pal DK and Rawajfih Z 2007. Preparation of consistent soil data sets for SOC modelling purposes: secondary SOTER data sets for four case study areas. Agriculture, Ecosystems and Environment 122: 26-34, http://dx.doi.org/10.1016/j.agee.2007.01.005 4) Immerzeel W, Huting JRM, Mantel S, Van Lynden G, Maingi P, Muchena F and Kamoni PT 2007. Green and blue water resources and assessment of soil and water management scenarios using an integrated modelling framework, IIED, SEI, IFAD, SADC, LEI and ISRIC, Wageningen.