The effects of the topographic data source and resolution on the hydraulic modelling of floods were analysed. Seven digital terrain models (DTMs) were generated from three different altimetric sources: a global positioning system (GPS) survey and bathymetry; highresolution laser altimetry data LiDAR (light detection and ranging); and vectorial cartography (1:5000). Hydraulic results were obtained, using the HEC-RAS one-dimensional model, for all seven DTMs. The importance of the DTM's accuracy on the hydraulic modelling results was analysed within three different hydraulic contexts: (1) the discharge and water surface elevation results from the hydraulic model; (2)

Slackwater palaeoflood deposits were identified along two bedrock gorge study reaches of the Llobregat River, at Pont de Vilomara and Monistrol de Montserrat. The compiled palaeoflood record consists of two principal flood series: (a) a relatively complete record of low to high magnitude flood events from the last ca. 100 years and (b) evidence of the largest palaeoflood events that have occurred over the last ca. 2700 years. The longer term extreme palaeoflood record indicates that the discharge of the 1971 flood, the largest on record, was exceeded on at least eight occasions, with two periods of high magnitude flooding identified: (a) the Late Bronze Age (2500-2700 years ago) and (b) the Little Ice Age (AD 1500-1700). At Pont de Vilomara, palaeodischarge estimates of 3700-4300 m 3 /s compare to a discharge of 2300 m 3 /s for the 1971 event. Downstream at Monistrol, an estimate of 4680 m 3 /s for flood deposits dated as AD 1516-1642, and believed to be those of the AD 1617 flood, compared to 2500 m 3 /s for the 1971 flood. q

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Abundance, size, and spatial distribution of standing dead trees (snags), are key indicators of forest biodiversity and ecosystem health. These metrics represent critical habitat components for various wildlife species of conservation concern, including the Black-backed Woodpecker (Picoides arcticus), which is strongly associated with 1

This paper presents a reconstruction of the catastrophic floods of AD 1617 in Catalonia (northeast Spain). Compilation of archival data sources shows that heavy rainfall occurred from 2 to 6 November 1617 and that the resultant flooding caused severe damage throughout the region, including the destruction of at least 389 houses, 22 bridges and 17 water mills. Discharges of 2700-4500 m 3 s -1and ≤2000 m 3 s -1 were estimated from dated palaeostage indicators for the Ter and Segre rivers, respectively, whilst 4680 m 3 s -1 was calculated for the Llobregat River flood in a previous study (Thorndycraft et al., 2005). The magnitude of the 1617 floods of the Llobregat and Ter rivers exceeded the largest events of the instrumental data series (2300 and 2350 m 3 s -1 , respectively). The 1617 floods are also compared to the longer-term palaeoflood record, which shows that the largest floods in the region were associated with colder phases of climatic variability.