 |
| Titel |
Spectroscopy as a diagnostic tool for urban soil |
| VerfasserIn |
Anna Brook, Daniella Kopel, Lea Wittenberg |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101505
|
| Publikation (Nr.) |
 EGU/EGU2015-663.pdf |
|
|
|
|
|
| Zusammenfassung |
| Anthropogenic urban soil are the foundation of the urban green infrastructure, the green
net quality is as good as each of its patches. In early days of pedology urban soil
has been recognized with respect to contamination and the risks for human health
but in study performed since the 70s, the importance of urban soil for the urban
ecology became increasingly significant (Gómez-Baggethun and Barton 2013). Urban
soils are highly disturbed land that was created by the process of urbanization. The
dominant agent in the creation of urban soils is human activity which modifies the
natural soil through mixing, filling or by contamination of land surfaces so as to
create a layer of urban soil which can be more than 50 cm thick (Pavao-Zuckerman
2008).
The objective of this study is to determine the extent to which field spectroscopy methods
can be used to extend the knowledge of urban soils features and components. The majority of
the studies on urban soils concentrate on identifying and mapping of pollution mostly heavy
metals. In this study a top-down analysis is developed – a simple and intuitive spectral feature
for detecting the presence of minerals, organic matter and pollutants in mixed soil
samples. The developed method uses spectral activity (SA) detection in a structured
hierarchical approach to quickly and, more importantly, correctly identify dominant
spectral features. The developed method is adopted by multiple in-production tools
including continuum removal normalization, guided by polynomial generalization, and
spectral-likelihood algorithms: orthogonal subspace projection (OSP) and iterative spectral
mixture analysis (ISMA) were compared to feature likelihood methods (Li et al.
2014).
Results of the proposed top-down unmixing method suggest that the analysis is made
very fast due to the simplified hierarchy which avoids the high-learning curve associated with
unmixing algorithms showed that the most abundant components were coarse organic matter
12% followed by concrete dust, plastic crumbs, other man made materials, clay and other
minerals.
The major part of the mineralogical composition was dominated by Montmorillonite and
Kaolinite as is it expected to be in the Mount Carmel soils. Pyroxene and Olivine are
also typical to the mineralogy of the Mount Carmel were there are several known
magmatic eruption areas of Scoria and Basalt. There is a high frequency of Actinolite
(Ca2(Mg,Fe)5(Si8O22)(OH)2), Amphibole family (2.5%) that is typical to metamorphic
rocks that are not to be found in the Mount Carmel region. Some of the mineral
found in the analysis is of marine origin like Syngenite (K2Ca(SO4)2(H2O)) and
Blodite (Na2Mg(SO4)24(H2O)) as the area was created under the Mediterranean Sea
and is still influence by it. None of the endmembers were detected only once, the
lowest frequency was 4 times for Cyanide-Cadmium (Cd(CN)2) and Andalusite
(Al2SiO5).
The results of the soils pH, measured electrometrically and the particle size distribution,
measured by Laser diffraction, indicate there is no big different between the samples particle
size distribution and the pH values of the samples but they are not significantly different from
the expected, except for the OM percentage which is significantly higher in most
samples.
The suggested method was very effective for tracing the man-made substances, we could
find concrete and asphalt, plastic and synthetic polymers after they were assimilated, broken
down and decomposed into soil particles. By the top-down unmixing method we did not limit
the substances we characterize and so we could detect unexpected materials and
contaminants.
Gómez-Baggethun, Erik and David N. Barton. 2013. "Classifying and Valuing Ecosystem
Services for Urban Planning." Ecological Economics 86: 235-245.
Pavao-Zuckerman, M. A. 2008. "The Nature of Urban Soils and their Role in Ecological
Restoration in Cities." Restoration Ecology 16 (4): 642-649.
Li, Lijun, Peter E. Holm, Helle Marcussen, and Hans Christian Bruun Hansen. 2014.
"Release of Cadmium, Copper and Lead from Urban Soils of Copenhagen." Environmental
Pollution 187: 90-97. |
|
|
|
|
|
|