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| Titel |
Erosion and sediment yield in Mediterranean badland areas |
| VerfasserIn |
Estela Nadal Romero, Juan Francisco Martinez Murillo, Matthias Vanmaercke, Jean Poesen |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250045969
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| Zusammenfassung |
| Badlands are usually defined as “intensely dissected natural landscapes where vegetation is
sparse or absent and which are useless for agriculture”. Badlands are characterized by
features such as the absence of vegetation, steep slopes and high density drainage
network, and hence tend to be among the most significant areas of erosion in the
world.
The main objectives of this study are to investigate the relationship between area-specific
sediment yield (SY) and contributing area (A) in Mediterranean badland areas, and to study
and discuss the effects of several possibly controlling factors of SY in badlands: i.e.
measuring methods, dominant erosion process, lithology, mean slope gradient, the
fraction of bare areas or badland areas, mean annual precipitation and mean annual air
temperature.
A database is currently compiled with 154 entries and 16 571 plot- and catchment-year
data on specific sediment yield at 87 study sites in badland areas of the Mediterranean (Spain,
France, Italy, Albania, Greece, Turkey, Israel, Morocco and Tunisia). The sediment yield data
used in this study were obtained by bathymetric surveys in reservoirs, sediment transport
measurements at gauging stations, detailed topographic surveys, erosion pins, and runoff plot
data. The results show a high variability of sediment yield. A complex A-SY relationship is
identified: for areas < 10 ha, SY is very high (mean SY = 475 t ha-1 y-1), whereas for areas
> 10 ha, SY decreases non-linearly (power law) with increasing A (mean SY =
75 t ha-1 y-1and drops from 164.5 t ha-1 y-1for 10 ha < A < 200 ha to 9.3 t
ha-1 y-1for A > 100 000 ha). The A-SY relationship observed for badlands is
different from relationships for different types of environment. Likewise, complex
relationships have been identified between the different factors (lithology, slope gradient,
annual rainfall, and mean air temperature and drainage area) and the sediment yield. |
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