About
This is the official webpage of the international
WORKING GROUP ON DIGITAL SOIL MAPPING (WG-DSM)
Digital Soil Mapping is the creation and the population of a geographically referenced soil databases generated at a given resolution by using field and laboratory observation methods coupled with environmental data through quantitative relationships.
The Working Group operates under the auspices of the Commissions on Soil Geography (C1.2) and Pedometrics (C1.5) of the International Union of Soil Sciences (IUSS)
Chair: Neil McKenzie, CSIRO Land and Water, Australia
Secretary: Florence Carré, European Commission, Joint Research Centre, Italy
Webmaster: Thorsten Behrens, Institute of Geography, University of Tübingen, Germany
Information about the IUSS Commissions on Soil Geography and Pedometrics
Commission 1.2 – Soil Geography
Chair: Douglas Miller, Earth and Environmental Systems Institute, The Pennsylvania State University, USA
Soil geography is a study of the soil cover and its many morphogenetic attributes as a function of climate, geology, relief, vegetation, human activities, and history (natural and anthropogenic). It is that component of the division that serves as a vehicle to transfer soils knowledge gained in C 1.1, especially as it impacts ecosystem sustainability, food security, land carrying capacity, human health, and the global biosphere. Different types of maps, at different scales, represent soil distribution covers of significance to these utilitarian priorities and the field of soil science as a whole.
Commission 1.5 – Pedometrics
Chair: Murray Lark, Rothamsted Research Harpenden Hertfordshire, United Kingdom
By pedometrics the Commission means the application of mathematical and statistical methods for the study of the distribution and genesis of soils. The goal of pedometrics is to achieve a better understanding of the soil as a phenomenon that varies over different scales in space and time. This understanding is important, both for improved soil management and for our scientific appreciation of the soil and the systems (agronomic, ecological and hydrological) of which it is a part. For this reason much of pedometrics is concerned with predicting the properties of the soil in space and time, with sampling and monitoring the soil and with modelling the soil’s behaviour. Pedometricians are typically engaged in developing and applying quantitative methods to apply to these problems. These include geostatistical methods for spatial prediction, sampling designs and strategies, linear modelling methods and novel mathematical and computational techniques such as wavelet transforms, data mining and fuzzy logic.
BACKGROUND TO DIGITAL SOIL MAPPING
With the great explosion in computation and information technology has come vast amounts of data and tools in all field of endeavour. This has motivated numerous initiatives around the world to build spatial data infrastructures aiming to facilitate the collection, maintenance, dissemination and use of spatial information. Soil science potentially contributes to the development of such generic spatial data infrastructure through the ongoing creation of regional, continental and worldwide soil databases, and which are now operational for some uses e.g. land resource assessment and risk evaluation.
Unfortunately the existing soil databases are neither exhaustive enough nor precise enough for promoting an extensive and credible use of the soil information within the spatial data infrastructure that is being developed worldwide. The main reason is that their present capacities only allow the storage of data from conventional soil surveys which are scarce and sporadically available.
The main reason for this lack of soil spatial data is simply that conventional soil survey methods are relatively slow and expensive. Furthermore, there is a worldwide crisis in collecting new field data in general which leads some to be very pessimistic about future developments in conventional soil surveying. Others believe technologies, such a hand-held field spectrometers, will come to the rescue.
To face this situation, we think that the current Spatial Soil Information Systems have to extend their functionalities from the storage and the use of digitised (existing) soil maps to the production of soil maps ab initio. This is precisely the aim of digital soil mapping, which can be defined as the creation, and population of spatial soil information systems by the use of field and laboratory observational methods coupled with spatial and non-spatial soil inference systems.
The development of digital soil mapping methods has been a growing activity for the past decades. It is moving inexorably from the research phase of the early 1990’s to production of maps for regions, catchments and whole countries. Moore’s Law is a scaling law developed in the 1970’s, stating that electronic device feature sizes would decrease by a factor of 0.7 every three years or the processing power of microchips doubles every eighteen months. Although this empirical law has attracted various kinds of critics, this prediction has proven to be accurate enough that it has become well-established within the computer and information technology industries. Because digital soil mapping is underpinned by information technology one might speculate a relationship between the size of DSM project that might be tackled and time. Taking data on the number of pixels described or predicted from the earliest projects up until the present day we can observe an exponential growth with time. The fitted line describes a ten-fold increase every 7.1 years, or a doubling in the number of pixels every 26 months – slightly slower than Moore’s law. The scaling model predicts that we should be able to have a 10-metre resolution digital soil map of the world by 2040, but we must not sit back and believe it will just happen!
This evolution is contemporaneous with the increasing development of spatial data infrastructures which provide more and more exhaustive mapping of soil-forming factors e.g. DTM, remotely sensed images. Meanwhile, the classical toolbox for observing and characterising soils in the field (codified observations of auger hole and pits and laboratory chemical analysis) is more and more integrated within GIS thanks to new tools such as GPS or PDA observation forms. It is also complemented with new field observation techniques able to hasten and objectify the collection of soil data e.g., geophysics and visible-NIR spectrophotometry. In parallel, a body of research work in geographical Information science heralds the evolution from classical raster or vector GIS, tools limited to the collection and storage of all kinds of spatial data, to more sophisticated systems able to represent more complex spatial models, and to embed spatial reasoning procedures such as inductive learning, or hierarchical reasoning. Therefore, a perspective now exists to integrate in modernised GIS packages all the computational work on digital soil mapping which has been done so far outside the framework of simple raster or vector GIS. In this perspective, we feel it is timely to develop a general intellectual and operational framework for digital soil mapping which can integrate the recent developments in numerical soil mapping techniques in the light of the knowledge on soil cover which has been accumulated for a century or so by soil surveyors.
Within this framework, the needs of national agencies responsible for soil surveying and production of soil maps and soil-related maps should be considered. Another aspect pointing to the linkage to related topics and commissions is the internationalisation of soil classification – namely the WRB. This topic seems to be important especially important in Europe for applied digital soil mapping, because almost every country has its own classification system.
The working group sees the realization of digital soil mapping worldwide as its key goal. We are aware in order to achieve this we need a focused group of scientists willing to discuss and collaborate, and willing to help others in capacity building.
