Karst; Hydrogeology; Paleoclimate; Climate change; Natural hazards; Floods; Spring; Cave; Sediments; Speleothems; Stalagmites; U/Th dating; Hydraulics; Time-series
BartoloméMiguel, BenitoG., LuetscherMarc, Badules-IglesiasJ., Pérez-VillarG., EdwardsR.L., MorenoA. (2021), The potential of Ojo de Valjunquera cave (NE of Iberia) sediments for paleoflood reconstructions, in Cuaternario y Geomorfología
, 35(3-4), 11-28.
Bartolomé Miguel, Sancho Carlos, Benito Gerardo, Medialdea Alicia, Calle Mikel, Moreno Ana, Leunda Maria, Luetscher Marc, Muñoz Arsenio, Bastida Joaquín, Cheng Hai, Edwards R.L. (2021), Effects of glaciation on karst hydrology and sedimentology during the Last Glacial Cycle: The case of Granito cave, Central Pyrenees (Spain), in CATENA
, 206, 105252-105252.
Luetscher Marc (2021), L'impact climatique sur les grottes et le karst - perspectives de spéléologues
, 71(1), 100-106, Stalactite, La Chaux-de-Fonds 71(1), 100-106.
Luetscher Marc, Moseley Gina E., Festi Daniela, Hof Florian, Edwards R. Lawrence, Spötl Christoph (2021), A Last Interglacial speleothem record from the Sieben Hengste cave system (Switzerland): Implications for alpine paleovegetation, in Quaternary Science Reviews
, 262, 106974-106974.
Floods represent one of the most significant natural hazards affecting communities worldwide. Although there is a general understanding that, in the Alpine region, flood frequency may increase under climate change scenarii, the natural variability of hydrological systems combined with the lack of sufficiently long records makes the analysis of hydrological extremes, and therefore rare events, difficult. This is particularly true for flash-floods in karst terrains, where a sudden rise in the hydraulic head may temporarily reactivate inactive emergences, sometimes located tens of kilometres away from the main recharge area. This project aims at reconstructing extreme floods from well preserved cave records. Because, they are preserved from surface erosion processes speleothems have emerged as a promising archive for the reconstruction of paleofloods on short and long time-scales. Applying an original approach combining modern hydrological process studies with speleothem paleoclimate science we want to investigate 1) how the hydraulics of selected karst systems responds to extreme precipitation events; 2) whether extreme flood records from singular caves are reproducible on a regional scale, and 3) to which extent changes in paleoflood frequencies and magnitudes can be associated with climate changes.Based on detailed cave surveys, we will model the hydraulics for 5-10 selected cave sites using pipe-flow solutions and calibrate our results against empirical head data acquired over the last 25 years. This calibration will be extended to include extreme floods identified microscopically and geochemically from detrital layers incorporated in speleothems. U-series dating of pristine calcite layers will provide the age control to determine the return period of singular events. By establishing a direct link between the hydrological response of a karst system and the transport and incorporation of sediments into speleothems we will provide, for the first time, a quantitative approach for the interpretation of speleothem paleoflood layers. The estimates of aquifer recharge triggering flash-floods will contribute to a better understanding of the synoptic climatology. Our results will serve as a basis for predictive modelling of the karst hydrology under contrasted climate scenarios with the ultimate objective to provide a methodology to predict flush floods from meteorological forecasts. The results anticipated from this research will provide original information about the hydrological transmissivity and maximal discharges anticipated under contrasting climate scenarios. By supporting the identification of sporadic karst emergences, our data will provide a basis for discussing local and regional maps of natural hazards with policy makers and stakeholders. Elaborating on these results, we will be in position to propose a detailed methodology for predictive modelling of karst discharges based on meteorological data. Besides contributing to the management of flood risks, this research is also relevant for groundwater abstraction strategies which aim at minimizing sedimentary loads. The main outcomes of this project will thus be implemented in teaching activities and dedicated public outreach towards local communities relying on karst water resources.