Reply to comment of Legates et al.

In the previous comment, Legates et al. express concern about the statistical reliability of the positive runoff–temperature relationship presented by Labat et al. We are grateful for this opportunity to respond to these concerns. As Legates et al. correctly points out, the effect of temperature on runoff is a complex relationship, which involves precipitation, evaporation, anthropomorphic affects, among others. As such, the effect of increased temperature on runoff is strongly dependent on the identity of the watershed of interest. For example, a watershed located in a glaciated region, such as Iceland, exhibits a strong positive correlation between runoff and temperature, whereas a watershed located in a arid climate, such as the Sahara desert, exhibits a negative correlation; often there is no run off at all during the summer months in such watersheds

Evidence for global runoff increase related to climate warming

Ongoing global climatic change initiated by the anthropogenic release of carbon dioxide is a matter of intense debate. We focus both on the impact of these climatic changes on the global hydrological cycle and on the amplitude of the increase of global and continental runoff over the last century, in relation to measured temperature increases. In this contribution, we propose an original statistical wavelet-based method for the reconstruction of the monthly discharges of worldwide largest rivers. This method provides a data-based approximation of the evolution of the annual continental and global runoffs over the last century. A consistent correlation is highlighted between global annual temperature and runoff, suggesting a 4% global runoff increase by 1 C global temperature rise. However, this global trend should be qualified at the regional scale where both increasing and decreasing trends are identified. North America runoffs appear to be the most sensitive to the recent climatic changes. Finally, this contribution provides the first experimental data-based evidence demonstrating the link between the global warming and the intensification of the global hydrological cycle. This corresponds to more intense evaporation over oceans coupled to continental precipitation increase or continental evaporation decrease. This process finally leads to an increase of the global continental runoff

Les monts de Pardailhan : étude hydrodynamique et hydrochimique des sources karstiques de Poussarou et Malibert (Montagne Noire-Hérault)

L'étude hydrogéologique des Monts de Pardailhan a permis de définir les régimes d'écoulement des principaux cours d'eau et sources de cette région. L'analyse hydrodynamique des deux principales sources karstiques, Poussarou et Malibert, a montré grâce à l'utilisation de différentes méthodes (débits classés, corrélogrammes) que ces sources ont des régimes d'écoulement différents. L'étude hydrochimique a confirmé cette différence de comportement à l'exutoire. (Résumé d'auteur

Role of formate in methanogenesis from xylan by CELLULOMONAS sp. associated with methanogens and DESULFOVIBRIO VULGARIS : inhibition of the aceticlastic reaction

Different methanogenic defined mixed cultures, including CELLULOMONAS sp. strain ATCC21399 as a hydrolytic and fermentative bacterium, were used to show that methane production could proceed from larchwood xylan as well as from cellulose. Via the different mixtures of bacteria used, the role of formate is described. It is shown that formate inhibits methanogenesis from acetate by pure cultures of aceticlastic methanogens. (Résumé d'auteur