Technical Note: Determination of the SCS initial abstraction ratio in an experimental watershed in Greece

International audienceThe present study was conducted in an experimental watershed in Attica, Greece, using observed rainfall/runoff events. The objective of the study was the determination of the initial abstraction ratio of the watershed. The average ratio (Ia/S) of the entire watershed was equal to 0.014. The corresponding ratio at a subwatershed was 0.037. The difference was attributed to the different spatial distribution of landuses and geological formations at the extent of the watershed. Both of the determined ratios are close to the ratio value of 0.05 that has been suggested from many studies for the improvement of the SCS-CN method

Vertical zonation of testate amoebae in the Elatia Mires, northern Greece : palaeoecological evidence for a wetland response to recent climate change or autogenic processes?

The Elatia Mires of northern Greece are unique ecosystems of high conservation value. The mires are climatically marginal and may be sensitive to changing hydroclimate, while northern Greece has experienced a significant increase in aridity since the late twentieth century. To investigate the impact of recent climatic change on the hydrology of the mires, the palaeoecological record was investigated from three near-surface monoliths extracted from two sites. Testate amoebae were analysed as sensitive indicators of hydrology. Results were interpreted using transfer function models to provide quantitative reconstructions of changing water table depth and pH. AMS radiocarbon dates and 210Pb suggest the peats were deposited within the last c. 50 years, but do not allow a secure chronology to be established. Results from all three profiles show a distinct shift towards a more xerophilic community particularly noted by increases in Euglypha species. Transfer function results infer a distinct lowering of water tables in this period. A hydrological response to recent climate change is a tenable hypothesis to explain this change; however other possible explanations include selective test decay, vertical zonation of living amoebae, ombrotrophication and local hydrological change. It is suggested that a peatland response to climatic change is the most probable hypothesis, showing the sensitivity of marginal peatlands to recent climatic change

How can climate change be incorporated in river basin management plans under the WFD? Report from the EurAqua conference 2008

This report is based on the EurAqua conference 2008: "How can climate change be incorporated in river basin management plans under the WFD?". The conference focused on recent development in relevant EU policy, on challenges for WFD-based water management, and on the science-to-policy interface regarding adaptations to climate change impacts. This report provides recommendations for incorporating climate change considerations into river basin management plans, and identifies relevant research needs with emphasis on ecology, modelling and uncertainty.NIV

Regional relationships between basin size and runoff characteristics / Relations regionales entre la surface du bassin et les caracteristiques de l'ecoulement

ABSTRACT The effect of basin size on runoff characteristics is investigated. The maximum observed floodflow, the maximum annual constant loss, the lag time and the unitgraph peak for a certain storm duration of basins in the western and northwestern regions of Greece are increasing power functions of the basin size. These functions explain significantly the variation in the runoff characteristics. For both regions single relationships are derived for the latter two characteristics, whereas for the two former ones they vary regionally in accordance to the climatic conditions. Thus, care is needed in transferring such relationships outside the location of their derivation; besides, the transferability of the values of their parameters is doubtful. The derivation of the relationships in th

Regional relationships between basin size and runoff characteristics

ABSTRACT The effect of basin size on runoff characteristics is investigated. The maximum observed floodflow, the maximum annual constant loss, the lag time and the unitgraph peak for a certain storm duration of basins in the western and northwestern regions of Greece are increasing power functions of the basin size. These functions explain significantly the variation in the runoff characteristics. For both regions single relationships are derived for the latter two characteristics, whereas for the two former ones they vary regionally in accordance to the climatic conditions. Thus, care is needed in transferring such relationships outside the location of their derivation; besides, the transferability of the values of their parameters is doubtful. The derivation of the relationships in th