The Horsens city and its suburbs is the project area for this action, covering the possibilities of infiltration of surface water in urban development areas throughout the municipality’s urban development areas.
For the purpose of mapping the infiltration potential in urban development areas, areas will be mapped with high-precision geophysics, which may show in detail the upper 5 to10 meters of the ground surface, see Figure 50 and Figure 51. In connection with the geophysical mapping, supplementary manual drillings up to 1 to 5 meters depth will be carried out, describing lithology and grain size analyses in detail.
As an extension of the geophysical mapping, infiltration tests cf. Figure 52 are made with different clay types found in urban development areas. The aim is to carry out field studies to a sufficient degree, making it possible to perform a quantitative (statistical) clarification of the individual soils’s infiltration capabilities. The results of the executed infiltration tests form the basis for examining to what extent there exists a quantitative correlation between the geological descriptions and the soils’ infiltration capabilities.
Similarly, the resistivity measurements from the geophysical mapping will be compared with the results from the infiltration tests, to ascertain whether a quantitative correlation exists between the deposits’ electric resistivity and the infiltration capabilities. Based on the soil types’ different infiltration capabilities, it will be possible to produce a detailed infiltration potential map for urban development areas.
Action C23.1 includes:
- Quantitative (statistical) clarification of the individual soil’s infiltration capabilities. By finding a quantitative correlation between the individual soil type and their infiltration capabilities, results can be immediately transferred to similar areas, for example, with the use of a soil type map.
- Quantitative correlation between the geological descriptions from the drillings and the soils’
infiltration capabilities. By finding a quantitative correlation between the geological descriptions from drillings and the soils’ infiltration capabilities, stakeholders and municipalities have the opportunity in the future to be able to express whether the area’s infiltration capabilities are valid based on new and existing descriptions from drillings.
- Quantitative correlation between the soils’ electrical resistivity and infiltration capabilities. By finding a quantitative correlation between the soils’ electrical resistance and their infiltration capabilities, stakeholders and municipalities are in the future able to carry out geophysical mapping and thus gain an overview of the area’s infiltration potential.
- Production of a detailed infiltration potential map for urban development areas. In connection with the preparation of a infiltration potential map, a number of guidelines will be written, which describe how the map is made and which data are necessary.
- The creation of a professional knowledge base for the municipalities’ formulation of best practices and guidelines for local management of precipitation in urban development areas. Reports on best practices and guidelines that describe how data shall be used and interpreted. The results will be reported to other municipalities and stakeholders with similar challenges on an ongoing basis, so that experience from the project can be passed on and widely dispersed.
Where: Horsens city and suburbs is project area. However, the methodology developed is relevant for all C2C CC partners. The project area covers approx. half of a total of 490 ha, where Horsens has designated development areas for new homes. See Figure 53.
When: January 2017 – December 2018
It is planned that action C23.1 will be executed over the first two years (2017-2018)