Search results

AbstractThis paper suggests that the relative salt (sodium chloride) dilution method should be more widely used for the routine measurement of stream discharge, and has been written to increase awareness of the technique among flow‐gauging practitioners. Recent improvements in instrumentation have increased accuracy and simplified practical application, making the method better suited (in many circumstances) than the more widely used alternatives. The paper (a) reports on a field study to evaluate the performance of a portable dilution‐gauging flowmeter, and (b) considers the environmental issues which are associated with the method. The review reveals that the use of salt (in the quantities typically required) is unlikely to have any significant ecological impact, and argues that environmental concerns are founded upon little scientific basis.

ABSTRACTUrban watercourses are potential hazards because of their rapid flow changes, poor water quality and contaminated sediments. This study is a preliminary field investigation into fine sediment‐associated metal contamination and its transport dynamics in a highly urbanised catchment in West Yorkshire, UK. Spatial and temporal changes in the concentration of channel‐bed sediment‐associated metals are investigated, and the fluxes of selected suspended sediment‐associated metals, during an extreme high flow event, are determined. Channel‐bed sediments were more contaminated at the most heavily urbanised sites. Data suggest that contaminated bed sediments could accumulate and possibly become increasingly contaminated between high‐flow events, prior to being flushed from the system. Fluxes of contaminated suspended sediments were very high at the peak of the high flow event. The spatial and temporal dynamics of contaminated fine sediment which were identified in this study could inform planners with regard to future monitoring strategies.