Assessing and Managing Soil Quality with Geodata: The IQS Project

Abstract

Despite its soil protection regulation, ongoing land sealing and soil loss have continued over the past three decades and Switzerland lacks a comprehensive soil map. Soil quality is affected by land use which is challenging to map because it may change on the short-time, and also soil functions are controlled by soil properties that are not necessarily taken into account in soil map**, such as organic matter content. Moreover, stakeholders seldom integrate soil information in their projects, since the data is scarce and the soil awareness is poor. To address these challenges, we developed a user-oriented framework assessing the soil functions based on expert predictions from land use, which are corrected with available soil data. The framework was applied to estimate soil quality in the Morges region. It takes into account all available digital information such as land-use layers, aerial imaging, geological maps etc. to split the area into polygons of predicted soil quality associated with an estimated accuracy, and integrates in a second step all available information on the soils, such as soil analysis, soil depth, polluted sites etc. Two complementary tools based on open-source software allow refining the estimated scores of the polygons and simulating the impact of development projects on soil quality. A semi-automated process was implemented to model input parameters and generate maps. Workshops involving experts, decision-makers, and soil specialists from the region allowed to improve and validate the soil map** and the interface. The framework, named IQSM, allows to generate and update maps inexpensively, this can be replicated in any Swiss location. The open-source methods and the user-oriented interface raised a strong interest among stakeholders.