2024-03-28T23:12:20Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1148112018-09-20T13:06:45Zcom_10261_65com_10261_8col_10261_318
White, Sue
García-Ruiz, José María
Martí Bono, Carlos Enrique
Valero-Garcés, Blas L.
Errea, M. P.
Gómez-Villar, Amelia
2015-05-07T08:04:00Z
2015-05-07T08:04:00Z
1997
Hydrological Processes 11 (14): 1797-1812 (1997)
0885-6087
http://hdl.handle.net/10261/114811
10.1002/(SICI)1099-1085(199711)11:14<1797::AID-HYP605>3.0.CO;2-7
1099-1085
On the evening of the 7 August 1996 an intense storm occurred over the Arás catchment near Biescas in the central Pyrenees. Eighty-seven people were killed as a result of the subsequent flood, which hit a campsite located on the alluvial fan at the outlet of the 18·8 km2 catchment. This paper presents the main results of a hydromorphological study of the event. The Betés subcatchment received the most intense rainfall, estimated at somewhat in excess of 250 mm, which resulted in a peak flow from this tributary of 300 m3 s−1. Just downstream from the Betés river junction, flow in the main channel reached 400 m3 s−1, increasing to around 500 m3 s−1 further downstream. Rainfall in the larger Aso tributary was less intense, and in the head reaches flow remained within-bank, representing a one in two-year return period event. Flow from this tributary did not exceed 100 m3 s−1, indicating that the Betés subcatchment supplied some 75% of the flow from just 28·7% of the catchment area. The extreme flows caused the collapse of a series of sediment trap dams in the Arás channel downstream of the Betés junction. This resulted in the addition of 68 000 m3 of sediment to an already disastrous event. Data from other rain gauges in the area showed both the extremely local nature of the event, and the problems of return period analysis for such storms, whose peaks are rarely observed at gauges. Together with the high geomorphological risks of the zone, this leads to the conclusion that a new method of spatial and temporal risk analysis is required for infrastructure planning. © 1997 John Wiley & Sons, Ltd.
eng
closedAccess
extreme events
sediment transport
discharge estimation
hydromorphological disaster
Alluvial fans
Central Pyrenees
The 1996 Biescas campsite disaster in the Central Spanish Pyrenees, and its temporal and spatial context
artículo