Soil information system as part of a municipal environmental information system

 The objectives of the interdisciplinary pilot project "Development of a municipal environmental information system" in Hannover encompassed the development, modification and improvement of data acquisition methods and methods for describing the environment on the basis of this data, as well as methods for evaluating the data as a basis for measures affecting the environment taken by the community. The subproject "Urban Soils" had the following two main objectives: (i) development of a data acquisition method for soils in municipal areas and a method for evaluating this data, and (ii) development of methods for making this information available to local government in the form of a "soil information system" for urban areas. To achieve these objectives, the following work was carried out: (1) a factor analysis to determine which factors affect the soil in an urban area; (2) study of methods for mapping soils in cities; (3) development of a concept for a soil information system; and (4) evaluation of environmental problems of the municipality using the soil information system. Data acquisition was done in two steps: First, soil-relevant data was selected, standardized, digitized and stored in an alphanumeric and a graphic database for a factor analysis. By intersection of the eight information levels, the factors affecting the soil were determined for the city of Hannover (200 km²). To test the hypothesis that the results for one site can be transferred to another site with the same combination of factors, 43 test sites typical of urban land use were selected. These test sites were mapped in a way to fulfill geostatistical requirements; physical and chemical analyses of the soils were made. A prognosis of soil distribution and properties was made on the basis of the factor analysis. and compared with the actual conditions. Concurrent with the pedological research, a prototype soil information system was developed. The system consists of databases, a methodbase, a geometrical tool, and a control system. Alphanumeric data is stored in a relational database, the geometric data in ISAM files. Methods for determining soil parameter values were selected and tested for their applicability. Using the pedological data and the soil information system, information can be obtained about soil conditions in Hannover as well as about soil processes (e.g. infiltration rates) and interaction with the atmosphere, hydrosphere, etc. This information can be obtained in the form of thematic maps and statistical representations, which can be used by decision-makers at the municipal level. Received: 3 September 1994 · Accepted: 19 December 1995