Digital mapping of soil properties using geomatics: integration of GIS, GPS, and remote sensing applications

Pressure on land is a consequence of population expansion, increased food consumption, and competition between land uses. Soils play a crucial role in supporting food production and providing ecosystem services. The demand for timely and relevant soil information that can support decision-making at different scales is increasing as efforts are made to ensure sustainable use of soil resources. Digital soil mapping (DSM) has become increasingly popular in various ecosystems, including arid, semi-arid, and humid regions, as well as rangelands and forests, due to its ability to overcome associated constraints to traditional methods of soil mapping. DSM offers a more efficient way to provide soil information in terms of time and cost, while improving map accuracy and providing quantified estimates of uncertainty. DSM involves the construction of soil spatial information systems using numerical models to analyze spatial and temporal variations in soil types and attributes based on soil observations, knowledge, and associated environmental factors. The main objective of this article is to present an overview of advances in thematic soil mapping in relation to advances in remote sensing (RS). First, we provide a brief summary of common tools used in DSM. Subsequently, we discuss advances in historical soil data, environmental variables, and applications of DSM tools. Finally, we present the major developments and future perspectives suggested by existing research. In conclusion, although DSM is becoming increasingly sophisticated to meet diverse soil information requirements, there are still issues to be addressed, particularly in highly heterogeneous and human-impacted environments. These issues require the development of new methodologies and applications of the DSM.