Harmonized World Soil Database in SWAT Format

The Food and Agriculture Organization of the United Nations (FAO) and the International Institute for Applied Systems Analysis (IIASA) combined the available regional and national soil information with the data already contained within the 1:5,000,000 scale FAO-UNESCO map, into a new comprehensive Harmonized World Soil Database (HWSD_v121). This map has a resolution of about 1 km (30 arc seconds) and consists of a 30-cm topsoil layer, and a 70-cm subsoil layer. The soil variables provided in the Harmonized World Soil Database (2009) and FAO/UNESCO Soil Map of the World included soil texture (%sand, %silt, %clay), organic carbon, pH, and EC. However, from a hydrological point of view, we are in need of parameters such as bulk density, water storage capacity, and hydraulic conductivity for different soil layers. Hence, we have used various pedotransfer functions from the literature to estimate the soil parameters needed in a Soil and Water Assessment Tool (SWAT model). The associated SWAT2012.mdb and lookup table is available at 2w2e GmbH website. The link to the database: https://www.2w2e.com/home/GlobalSoilHws