Regional-scale ecological soil evaluation

Soil is a vital component of the ecosystem. Despite its little depth of only a few decimeters it fulfils a great variety of functions. As the development of soil is a very slow process, the destruction of soil means a permanent loss of these ecological functions. Therefore soil protection ought to be a paramount topic on all levels of spatial planning. But effective implementation of soil protection requires information processed into a practically usable form, first of all a differentiated evaluation of soil functions. A lack of practice-oriented soil information is one of the main reasons for the present neglect of soil related issues despite years of effort towards soil protection. The proposed soil evaluation will be carried out through a set of rules that define the combination of basic soil parameters (e.g. texture, bulk density, ...) to complex soil features or soil qualities (e.g. available field capacity, kf- value, cation-exchange capacity) and soil functions (e.g. soil as filter and buffer for harmful substances as groundwater protection). The final output of the procedure are extensive information on medium-scale (1:25.000 to 1:100.000) about local soil`s performance regarding its ecological functions. The results can already be used as input for planning measures on various levels. In addition, the subsequent combination of these results with requirements of planned forms of land use provides valuable decision-support not available so far. Not only the suitability of local soils for intended forms of land use is assessed but also the - negative - effects on soil functionality caused by different soil utilizations. For an area-wide evaluation the quality of available soil data is varying. While detailed soil data exist for most agricultural areas and forests (land taxation results, soil maps, forest soil maps, data bases such as BORIS) hardly any soil data is available for settled areas and high-mountain regions. For these areas soil information either has to be derived from secondary data or interpolated from point data if available. Thus one major work step of the proposed project will be the development and improvement of methods to join existing soil information and supplement missing parts from secondary data sources. The actual soil evaluation based on these input data can be carried out on different levels of precision depending on the varying data quality. The project aims at combining existing and developing new standards and algorithms on a scientific basis to facilitate soil evaluation in a comprehensible and practical way. The developed procedure will be tested in a larger region showing a variety of both natural preconditions and anthropogenic impact. Evaluation results and their presentation are oriented towards the needs and demands of regional and local planners and will contribute to making a better consideration of soil features in spatial planning activities possible.

Soil is a vital resource for human life. It is exposed to various threats among which sealing and pollution are dominant in Central Europe. Effective soil conservation is only possible if a legal framework exists and is applied in spatial planning. Soil science has to contribute soil data and evaluation algorithms, differentiated regionally and in terms of content, to meet planners` requests. One major aim of the present project is an improvement of this information transfer in Austria. Soil evaluation is exemplified in three test areas in Tyrol. The most important findings of the project are: (i) Sophisticated evaluation methods are proposed for various levels of detail to allow the most adequate combination of existing soil data on different planning levels and scales. (ii) Existing algorithms for soil evaluation can be adapted to the Austrian soil taxonomy. (iii) Digital soil mapping approaches in areas lacking comprehensive soil data proved to be insufficient mainly due to the small-scale variations inherent to alpine areas. (iv) Available soil data from various sources are difficult to merge (e.g., soil map and land taxation map) and show certain flaws, as verifications in the field revealed. (v) In Austria planners` interest in soil conservation and therefore the demand for information on soil is still low. Based on the review and assessment of existing data as well as field data from several mapping campaigns a guidebook shows how soil information can be used to evaluate soil and apply the results in daily practice. One chapter of the guidebook is dedicated to the rough assessment of diffuse soil contamination from different sources. Practicability is significantly improved by a newly developed computer tool for an automated execution of the evaluation process. Both computer tool and guidebook facilitate soil evaluation in spatial planning. In the near future this approach shall be compared to solutions developed in other Austrian federal states and contribute to further improvement of an effective implementation of soil conservation measures in Austria.