The challenges of collating legacy data for digital mapping of Nigerian soils

Digital soil assessments and beyond contains papers presented at the 5th Global Workshop on Digital Soil Mapping, held 10-13 April 2012 at the University of Sydney, Australia. The contributions demonstrate the latest developments in digital soil mapping as a discipline with a special focus on the use of map products to drive policy decisions particularly on climate change and food, water and soil security. The workshop and now this resulting publication have better united formerly disparate subdisciplines in soil science: pedology (study of the formation, distribution and potential use of soils) and pedometrics (quantitative and statistical analysis of soil variation in space and time). This book compiles papers covering a range of topics: digital soil assessment, digital soil modelling, operational soil mapping, soil and environmental covariates, soil sampling and monitoring and soil information modelling, artificial intelligence and cyber-infrastructure, and GlobalSoilMap. Digital soil assessments and beyond aims to encourage new mapping incentives and stimulate new ideas to make digital soil mapping practicable from local to national and ultimately global scales

Solum depth spatial prediction comparing conventional with knowledge-based digital soil mapping approaches

Solum depth and its spatial distribution play an important role in different types of environmental studies. Several approaches have been used for fitting quantitative relationships between soil properties and their environment in order to predict them spatially. This work aimed to present the steps required for solum depth spatial prediction from knowledge-based digital soil mapping, comparing the prediction to the conventional soil mapping approach through field validation, in a watershed located at Mantiqueira Range region, in the state of Minas Gerais, Brazil. Conventional soil mapping had aerial photo-interpretation as a basis. The knowledge-based digital soil mapping applied fuzzy logic and similarity vectors in an expert system. The knowledge-based digital soil mapping approach showed the advantages over the conventional soil mapping approach by applying the field expert-knowledge in order to enhance the quality of final results, predicting solum depth with suited accuracy in a continuous way, making the soil-landscape relationship explicit

GlobalSoilMap: Toward a Fine-Resolution Global Grid of Soil Properties

Soil scientists are being challenged to provide assessments of soil condition from local through to global scales. A particular issue is the need for estimates of the stores and fluxes in soils of water, carbon, nutrients, and solutes. This review outlines progress in the development and testing of GlobalSoilMap—a digital soil map that aims to provide a fineresolution global grid of soil functional properties with estimates of their associated uncertainties. A range of methods can be used to generate the fine-resolution spatial estimates depending on the availability of existing soil surveys, environmental data, and point observations. The system has an explicit geometry for estimating point and block estimates of soil properties continuously down the soil profile. This geometry is necessary to ensure mass balance when stores and fluxes are computed. It also overcomes some limitations with existing systems for characterizing soil variation with depth. GlobalSoilMap has been designed to enable delivery of soil data via Web services. This review provides an overview of the system's technical specifications including the minimum data set. Examples from contrasting countries and environments are then presented to demonstrate the robustness of the technical specifications. GlobalSoilMap provides the means for supplying soil information in a format and resolution compatible with other fundamental data sets from remote sensing, terrain analysis, and other systems for mapping, monitoring, and forecasting biophysical processes. The initial research phase of the core project is nearing completion and attention is now shifting toward establishing the institutional and governance arrangements necessary to complete a full global coverage and maintaining the operational version of the GlobalSoilMap. This will be a grand and rewarding challenge for the soil science profession in the coming years.JRC.H.5-Land Resources Managemen