Monitoring Event

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					  Event
Water
Quality

Monitoring
 ID: WQEM 0657
                                                              Regional Natural Resource Management in Queensland


                Event Summary Load Calculation
                     Tinana Creek (Bauple East) April 1988
                                                                                                              138903A
 Introduction
 This fact sheet presents Event Mean Concentration (EMC)
 sediment load estimates collected from the Tinana Creek at
 the Bauple East gauging station (Figure 1) in April 1988
 (Figure 2).

 Methodology
 Seven suspended sediment samples (Table 1) were collected
 from the gauging station GS138903A and recorded in the
 DNR archives. Discharge was assumed to be ±10% of                 Figure 1. Mary River event sampling location at Bauple
 actual flow (http://www.nrm.qld.gov.au/water/monitoring/          East
 pdf/wm_data_col_stds.pdf), although during high flows
 accuracy is likely to be poorer (David Amos, NRW Hydrog-                         200                                           70
 rapher, pers. comm.). Field replicates were not collected, so                                                           TSS
                                                                                  160                                           56
 there was no precision estimate for concentration data.
                                                                  -1




                                                                                                                                       -1
                                                                  Discharge m s




                                                                                                                                       TSS Conc. mgl
                                                                  3




                                                                                  120                                           42
 To extrapolate concentrations (mgl-1 listed in table 1) across
 the hydrograph, hourly discharge (m3s-1) was related to                           80                                           28

 the average total suspended sediment (TSS) concentration                          40                                           14
 across the hydrograph. Error margins were 2 standard errors
 around the average TSS concentration, and were propagated                           0                                           0
                                                                                  09/04/1988   15/04/1988   21/04/1988    27/04/1988
 across the hydrograph with the 10% variation in flow. The
 event load was the sum of the products of hourly discharge
 and TSS concentrations (Table 2). The EMC was calculated         Figure 2.    Sample times, discharge and TSS
 by dividing the event load by the event volume (Table 2).        concentrations of samples collected at Bauple East

                                                   Flow Event Description
 Catchment:               Mary River
                          Sub-catchment: Tinana Creek

 Location:                GS 138903A Bauple East
                          25o 49’ 19” S 152o 43’ 16” E

 Catchment Area:          9433km2, Sub-Catchmnet area 1,281 km2
                          (783 km2 upstream of the sampling point)

 Dominant Land Use:       pine forest (37%), nature conservation (21%),
 (upstream of gauge)      grazing (16%), forestry (9%), rural residency (5%)

 Event Duration:          11/04/1988 - 18/04/1988                                                 Figure 3. Cumulative rainfall during
                                                                                                  the event.
                                                                           Regional Natural Resource Management in Queensland

Results
This was a moderately large flush of a sub-catchment with relatively                                  Table 1.     Discharge and sediment
high rainfall at the regional scale (>1100mm per year), a moderate to                                 concentration data for the April 1988
low relief difference (473m), predominantly permeable soils (48.5%                                    event at Bauple East.
are kandosols), and underlying sedimentary rocks. About 76% of the
catchment upstream of Bauple is forested (eucalyptus and pine). The                                           Date/Time               Q        TSS
EMC concentration for TSS (46 mgl-1) resembled a unit discharge of                                                                  (m3s-1)   (mgl-1)
similar magnitude that flowed through Mimvale, Baffle Creek in 1988
(55 mgl-1), and was lower than was observed flowing through Ban Ban                                       10/04/1988 11:35          26.238      65
Springs in 1989 (521 mgl-1).                                                                              10/04/1988 15:45          24.357      65

                800
                                                                                                          18/04/1988 11:55          26.828      39
                700          April 1988 Event                                                             18/04/1988 11:58          12.546      23
                600                                                                                       18/04/1988 12:10          12.546      52
-1
Discharge m s
3




                500
                400
                                                                                                          20/04/1988 09:15          9.617       59
                300                                                                                       26/04/1988 09:00          6.079       21
                200
                100
                                                                                                      Table 2. Estimated load and event EMC for
                 0
                  1981             1986         1991          1996          2001           2006       the April 1988 event at Bauple East.

Figure 4. April 1988 event sampled at Bauple East in the context of
                                                                                                         Gauging        138903A
historical (mean daily) discharge
                                                                                                          station
                                                                                                         number
                                                                                                        Site Name        Bauple
                                                                                                                          East
                                                                                                        Total Event      55,677
                                                                                                        Discharge
                                                                                                           (ML)
                                                                                                        Number of             7       Lower   Upper
                                                                                                         samples                      Bound   Bound
                                                                                                         TSS Load            2.6        1.7     3.5
                                                                                                            (kilo-
                                                                                                          tonnes)
                                                                                                        TSS EMC              46         30      64
                                                                                                         (mgl-1)
                                                                                                         Maximum             181
                                                                                                           Event
                                                                                                         Discharge
                                                                                                          (m3s-1)
                                                                                                         Period of           25
                                                                                                        record (yrs)
                                                                                                         % of time           0.35
                                                                                                          that the
                                                                                                          peak is
                                                                                                        equalled or
                                                                                                         exceeded


                We would like to thank the NRM&W Hydrographic unit, Bundaberg for collecting samples and supplying data.

                To reference this information sheet:

                Esslemont, G. (2006) Water Quality Event Monitoring – Tinana Creek (Bauple East) April 1988: Event Summary
                Load Calculation (WQEM 0657) Department of Natural Resources and Water. ISBN 978-1741724240

                Produced by the National Action Plan for Salinity and Water Quality
                Queensland Water Quality State-level Investment Project

				
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Description: Monitoring Event