Learn how plants respond to higher atmospheric CO2 concentrations

How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Extreme Floods of Southern France
Sheffer, N.A., Rico, M., Enzel, Y., Benito, G. and Grodek, T. 2008. The palaeoflood record of the Gardon River, France: A comparison with the extreme 2002 flood event. Geomorphology 98: 71-83.

The authors introduce their study by noting that "during the past few years, Europe has experienced extraordinary flooding," and they say that "in southern France, the Gardon River experienced an extreme flood during the 8th-9th of September 2002," which was "larger than any known historical flood on record in this catchment."

What was done
Working in two caves and two alcoves of a 1600-meter-long stretch of the Gardon River, where it flows through a gorge with steep banks of flood terraces and exposed rocky cliffs, Sheffer et al. analyzed geomorphic, sedimentologic and hydrologic data associated with both historical and late Holocene floods, which they hoped would provide a longer and better-defined perspective on the subject.

What was learned
The Spanish and Israeli researchers report that stratigraphic and hydraulic modeling data indicate that "at least five floods of a larger magnitude than the 2002 flood occurred over the last 500 years," all of which took place, as they describe it, "during the Little Ice Age." In addition, they write that "the Little Ice Age has been related to increased flood frequency in France (Guilbert, 1994; Coeur, 2003; Sheffer, 2003; Sheffer et al., 2003a,b; Sheffer, 2005), and in Spain (Benito et al., 1996; Barriendos and Martin Vide, 1998; Benito et al., 2003; Thorndycraft and Benito, 2006a,b)."

What it means
Sheffer et al. conclude that "the extraordinary flood of 2002 was not the largest in the basin" of the Gardon River. And their findings and those of many others, both in France and elsewhere, suggest that the really huge European floods of the past few centuries occurred during colder rather than warmer times, which relationship is just the opposite of what the world's climate alarmists claim to be the case.

Barriendos, M. and Martin Vide, J. 1998. Secular climatic oscillations as indicated by catastrophic floods in the Spanish Mediterranean coastal area (14th-19th centuries). Climatic Change 38: 473-491.

Benito, G. and Thorndycraft, V.R. 2005. Palaeoflood hydrology and its role in applied hydrological sciences. Journal of Hydrology 313: 3-15.

Benito, G., Machado, M.J. and Perez-Gonzalez, A. 1996. Climate change and flood sensitivity in Spain. Geological Society Special Publication 115: 85-98.

Benito, G., Diez-Herrero, A. and de Villalta, M. 2003. Magnitude and frequency of flooding in the Tagus river (Central Spain) over the last millennium. Climatic Change 58: 171-192.

Coeur, D. 2003. Genesis of a public policy for flood management in France: the case of the Grenoble valley (XVIIth-XIXth Centuries). In: Thorndycraft, V.R., Benito, G., Barriendos, M. and Llasat, M.C. (Eds.), Palaeofloods, Historical Floods and Climatic Variability: Applications in Flood Risk Assessment. CSIC, Madrid, Spain, pp. 373-378.

Guilbert, X. 1994. Les crues de la Durance depuis le XIVeme siècle. Frequence, periodicite et interpretation paleo-climatique. Memoire de maitrise de Geographie. Universite d'Aix-Marseille I, Aix-en-Provence.

Sheffer, N.A. 2003. Paleoflood Hydrology of the Ardeche River, France. A Contribution to Flood Risk Assessment. M.Sc. Dissertation, The Hebrew University of Jerusalem, Israel.

Sheffer, N.A. 2005. Reconstructing the paleoclimate record using paleoflood hydrology as a proxy. Fifth Conference on Active Research, CARESS 2005. The Weitzmann Institute of Science, Rehovot, Israel.

Sheffer, N.A., Enzel, Y., Grodek, T., Waldmann, N. and Benito, G. 2003a. Claim of largest flood on record proves false. EOS: Transactions, American Geophysical Union 84: 109.

Sheffer, N.A., Enzel, Y., Benito, G., Grodek, T., Porat, N., Lang, M., Naulet, R. and Coeur, D. 2003b. Paleofloods and historical floods of the Ardeche River, France. Water Resources Research 39: 1376.

Thorndycraft, V.R. and Benito, G. 2006a. Late Holocene fluvial chronology of Spain: the role of climatic variability and human impact. Catena 66: 34-41.

Thorndycraft, V.R. and Benito, G. 2006b. The Holocene fluvial chronology of Spain: evidence from a newly compiled radiocarbon database. Quaternary Science Reviews 25: 223-234.

Reviewed 8 October 2008