River Wharfe fisheries monitoring report - summer 2001

This is a report on monitoring carried out in 2001 specifically in relation to effects of flows and abstractions on fisheries in the River Wharfe. The monitoring is a continuation of that started in relation to the Time Limited Abstraction Licences in 1996 and required by the new licences granted in 1999. It gives information regarding fish populations at a range of sites in the River Wharfe and also two tributary sites. It also gives recommendations for future investigations in relation to both Time Limited Licences and general broader issues.

River Leith fluvial aufit. Final project report

This is the River Leith fluvial audit: Final project report produced by Lancaster University in 1998. Freeze cores extracted from the upper and lower ends of River Leith illustrate that the bed is highly compacted in the downstream reach. Fine material is locally derived from bedrock at depths of only 32 cms into the bed and in one core fine material is 66% of the extracted core. Levels of fines that are believed to be detrimental to fish are put at 20 to 30%. Reduced flow and stream power from water abstraction may lead to a greater infiltration of fine material if gravels are not regularly flushed through with flood flows. Infiltration of fine material can lead to river bed compaction and concretion. A small abstraction may have no effect on the morphology of a river if the reduced discharge is within the normal range of flows experienced. However if the impact on flows is small it is still possible that fine sediment problems will develop progressively and the effects may not be noticed for several years.

An analysis of river flows in relation to the catching of salmon by anglers [River Lune]

The problem of the Lancashire River Authority is one of deciding the river flow which will meet the requirements of the water engineer in his endeavour to secure water for the public and industry, demands of fish populations, and the needs of anglers. This report analyses salmon catch data from anglers in the River Lune (north west England) and relates it to flow range. The years 1956-1967 are covered.

Influence of climatography on rainfall thresholds for initiation of debris-flows on the California coast [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Since 1986, the U.S. Geological Survey and National Weather Service have operated a warning system for debris flows triggered by severe rainstorms in the San Francisco Bay region. The NWS tracks storm systems as they approach the region, forecasts precipitation, and observes rainfall with a network of radiotelemetered rain gauges (ALERT). The USGS also monitors ALERT data and compares the observed and forecast rainfall to thresholds for debris-flow initiation. Both groups jointly assess debris-flow hazards and issue public advisories when rainfall conditions reach or approach critical levels.