The impact of urban groundwater upon surface water - eTheses ...

MONITORING NETWORKS AND METHODS
The fieldwork programme was designed to provide more detailed information on the
groundwater/surface water quality and flow interactions at a finer scale along the study reach
and across the groundwater/surface water interface.
4.3 Surface water flow gauging.
In addition to the archive data from the gauging stations at Bescot, Water Orton and
Calthorpe, flow measurements were also undertaken on the study reach between the stations
(Figure 4.1). This was to define better the discharge accretion along the study reach and to
examine the relationship with the underlying geology (Appendix 9).
4.3.1 River discharge measurements
Discharge measurements collected during periods of dry weather flow from a series of cross
sectional profiles at intervals of several kilometres along the river were designed to assess
discharge accretion along the study reach. Sites were selected to enable easy access to the
river in areas with a relatively uniform channel profile and minimal turbulence. The
measurements were taken within the space of a single day to minimise variations due to
baseflow recession. The method was time consuming and labour intensive with a significant
travel time between sites. This limited data collection to an average of four sites in one day
per team (two people).
Flow meters of both propeller and electromagnetic type were borrowed from the School of
Civil Engineering . After initial trials the propeller type ‘Ott’ meter was found of limited use
owing to the presence of weed within the channel. An electromagnetic meter was used to
collect the majority of readings. The meter was calibrated by technicians using the School of
Civil Engineering’s flume tank.
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