A propensity index for surface runoff on a karst plateau
<p>Karst aquifers are an important water resource, but are particularly vulnerable to pollution due to the typically short residence times. As the rainwater runs off on the surface it may collect contamination from faeces and other sources, before infiltrating the surface. It is therefore impo...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-11-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://www.hydrol-earth-syst-sci.net/22/6147/2018/hess-22-6147-2018.pdf |
| Summary: | <p>Karst aquifers are an important water resource, but are particularly
vulnerable to pollution due to the typically short residence times. As the
rainwater runs off on the surface it may collect contamination from faeces
and other sources, before infiltrating the surface. It is therefore important to understand
the spatial distribution of the frequency of surface runoff in karst areas.
This paper proposes a new field-mapping method for the ability of the
landscape to produce and convey surface runoff. The mapping method is based
on (i) prior spatial information (e.g. geological map, terrain model), (ii) a
visual assessment from a distance at the landscape scale (e.g. traces of
surface runoff) and (iii) local data collection in the field (e.g. soil
moisture, grain size distribution). The focus on variables that can be
assessed from a distance in the landscape makes the method suitable for
mapping larger areas than traditional field mapping. The mapping method is
developed and tested for the 60 km<span class="inline-formula"><sup>2</sup></span> Hochschwab area in Austria. The
field mapping is used to specify a surface runoff propensity index which is
tested against the spatial distribution of observed sink holes in the area.
The mapping indicates that, in the study region, runoff occurs much more
frequently in the poorly karstified dolomitic areas than in the limestone
areas that are highly karstified. On dolomites, low permeable soils or debris
prevail, often resulting in a permanent surface drainage network. On
karstified limestone, sometimes overlaid by debris, surface runoff only
occurs through infiltration excess at high rainfall intensities. Overall the
analyses suggest that the mapping method is suitable for efficiently and
reliably identifying spatial patterns of the ability of the landscape to
produce and convey surface runoff in karst areas.</p> |
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| ISSN: | 1027-5606 1607-7938 |