A Hydrophysical Database to Develop Pedotransfer Functions for Brazilian Soils: Challenges and Perspectives

Abstract

Access to soil hydrological data is vital for hydrology projects and for supporting decision-making in issues related to the availability of food and water and the forecasting of phenomena related to geomechanics. Brazil is a country of continental dimensions and has accumulated a significant body of soil information, holding a prominent position in tropical soil science. Nevertheless, a database with hydrophysical information on Brazilian soils has not been compiled so far, whereas much information is registered and analyzed. In this study we discuss the potential for the development of a Brazilian hydrophysical database and pedotransfer functions (PTFs). We present on metadata the measurement methods of soil hydrophysical attributes and the characteristics of the sites where these soil properties were determined. Statistical analyses were performed to characterize the dataset according to the metadata-based data structure. A total of 8,983 datasets contains soil water retention information associated with physical or chemical properties. Besides these, 1,253 datasets with data on saturated hydraulic conductivity coupled with water retention information are also available. The results of this study suggest that it is possible to develop a representative hydrophysical database for Brazilian soils that covers most of Brazil's federative states, with a substantial volume of data and homogeneous with respect to the methods of measuring soil properties. This creates excellent prospects for PTFs development, especially for estimating water retention, at a national scale. The challenge in the development of the Brazilian soil hydrophysical database is the refinement of the dataset model that can encompass the wide range of available information and can provide answers to queries of interest to different types of users of soil information. Considering the size of the Brazilian territory, it would be of interest that the database development become a joint effort of government agencies, universities and commercial enterprises.