『Abstract
Weathering rates of base cations are crucial in critical load
calculations and assessments of sustainable forestry. The weathering
rate on a single site with detailed geological data can be modelled
using the PROFILE model. For environmental assessments on a regional
scale, the weathering rates for sites are scaled into regional
maps. The step from sites to regional level requires focus on
the spatial variation of weathering rates. In this paper, a method
is presented by which weathering rates are calculated for 25589
Swedish sites with total elemental analysis for the soil. Based
on a part of the results, a methodology for creating area covering
maps by geostatistical analysis and kriging is described. A normative
reconstruction model was used to transform total elemental analysis
to mineralogy. Information from the Swedish Forest Inventory database
and other databases were used to derive texture and other important
information for the sites, e.g. climate, deposition and vegetation
data. The calculated weathering rates show a regional pattern
that indicates possibilities for interpolation of data in large
parts of Sweden. Geostatistical analysis of an area in southern
Sweden shows different properties for different base cations.
Kriging was performed for potassium to demonstrate the method.
It was concluded that different base cations and different regions
have to be analysed separately, in order to optimise the kriging
method.
Keywords: base cations; geostatistics; kriging; mineralogy; PROFILE;
Sweden; weathering』
1. Introduction
2. Methods
2.1. The PROFILE model
2.2. Required input
2.2.1. Mineral composition
2.2.2. Mean temperature
2.2.3. Precipitation and runoff
2.2.4. Deposition
2.2.5. Base cation and nitrogen uptake
2.2.6. Base cations and nitrogen litterfall
2.2.7. Texture class and soil type
2.2.8. Moisture class
2.2.9. Soil depth and thickness of different layers
3. Results
4. Discussion
5. Conclusions
Acknowledgements
References