 |
| Titel |
Sediment yield and connectivity in a gullied sandy catchment |
| VerfasserIn |
Ana Lucía, José Francisco Martín-Duque, Jonathan B. Laronne, Miguel Ángel Sanz-Santos |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250097387
|
| Publikation (Nr.) |
 EGU/EGU2014-12963.pdf |
|
|
|
|
|
| Zusammenfassung |
| Badland areas are considered to have high connectivity of sediment at the catchment scale;
however, little is known about processes occurring in gullies and badlands developed in
sands. This type of gullies is quite common in the Central-Eastern Iberian Peninsula and is
associated with historic mining. The sandy badlands also appear in both abandoned and
traditionally reclaimed mines, generating on- and offsite environmental effects. Our aim is to
quantify the rates of the different processes occurring in the sandy gullied catchments,
as well as their coupling and connectivity at a catchment scale. This may allow
application to improve reclamation practice in mines and quarries located in sandy
materials.
The study site is a small (1.32 ha) gullied catchment, the Barranca de los Pinos, which is
located in the Northern Piedmont of the Guadarrama Mountains (Central Spain). The
catchment area has been divided into Homogeneous Response Units (HRUs) attending to the
dominant active process . The sediment produced in the different HRUs has been
monitored by a variety of methods: repeat Terrestrial Laser Scanning of high gradient
slopes, closed microplots in low gradient slopes and automatic (Reid type) slot
bedload samplers and siphon samplers to monitor suspended sediment transport in the
channel.
During the 2010-11 monitoring period the sediment yield due to gravitational movements
in high gradient slopes varied from 20 to 200 kg m-2y-1. In the low gradient slopes
the splash and non-concentrated runoff generated 0.1 - 6 kg m-2y-1,while the
channel yielded 7.44 ± 1.08 kg m-2y-1 with a very high proportion (>70%) of
bedload.
Despite the difficulties of extrapolating and comparing the results obtained at different
spatial and temporal resolutions, annual patterns of erosion and transport of sediments
within the sandy gullied catchments have been identified. These confirm that the
transport of sediment in this catchment is limited by the capacity of flow events to
transport sand and not by the supply of sand. This is interpreted as a tendency towards
landform stabilization. Detailed study of the areas acting as sinks or temporary
storage areas is required, as well as further understanding of the processes interacting
with vegetation that has been colonizing the gullied area during the last decades. |
|
|
|
|
|
|