Hawkesbury-Nepean River Environmental Monitoring Program

More documents

Recommendations

Info

a relatively poor fit to the data (explaining less than 20% of the variance in the data). This summary therefore indicates both the direction of the (non-linear) trend in time and the explanatory power of the model for a specific water quality variable at a specific site. A graphical example of the measured data and the results of the modelled time trends are provided in Figures 5.7, 5.8 and 5.9. Figure 5.7: Time series plot of chlorophyll-a levels at North Richmond Figure 5.8: Non-linear time trend in chlorophyll-a levels at North Richmond, modelled using GAMs. Values on the y-axis represent partial residuals; Time = 1 on the x-axis corresponds to 1/1/1984; Time = 8614 is 1/8/07 20 Hawkesbury Nepean River Environmental Monitoring Program: Final Technical Report
Figure 5.9: Chlorophyll-a levels over time at North Richmond, showing GLM and GAM predicted values. Records of flow for the Grose River commenced on 19/11/87, so earlier records for chlorophyll-a could not be modelled when this co-variable was included in the model. General conclusions • GLM and GAM modelling were generally in agreement with the results of comparisons with ANZECC/ARMCANZ guideline levels (see Comparison of Water Quality with ANZECC/ARMCANZ (2000) Guidelines above). • Phosphorus levels (both total and filterable) have generally been declining throughout most of the river system (with perhaps the exception of the uppermost site considered: Maldon Weir — site N92). Phosphorus levels downstream of Penrith STP (e.g. at N53) remain elevated compared with those in many other areas in the system. • Nitrogen levels have declined at many sites throughout the river system. Exceptions to this are Sharpes Weir (downstream of West Camden STP) and Wallacia Bridge (sites N75 and N67), where nitrogen levels (particularly inorganic nitrogen levels) appear to be increasing (e.g. see Figure 5.10). Despite many decreasing trends in nitrogen levels, nitrogen levels often remain above ANZECC/ARMCANZ guideline levels throughout the river system. Hawkesbury Nepean River Environmental Monitoring Program: Final Technical Report 21
Page 1 and 2: Hawkesbury-Nepean River Environment
Page 3 and 4: CONTENTS: BOOKLET Summary..........
Page 5 and 6: Summary Adaptive management require
Page 7 and 8: 1. Introduction The Hawkesbury-Nepe
Page 9 and 10: • local government • other stak
Page 11 and 12: Sackville that have been the site o
Page 13 and 14: Long-term monitoring sites A review
Page 15 and 16: including algal blooms. This presen
Page 17 and 18: Figure 5.1: Long-term sampling site
Page 19 and 20: General observations from these gra
Page 21 and 22: Figure 5.4: Smoothed trend lines fo
Page 23 and 24: are also highly variable in terms o
Page 25: Water quality trends using statisti
Page 29 and 30: al. (1999, 2004). Sydney Water rout
Page 31 and 32: N95 Edge Samples N95 Riffle Samples
Page 33 and 34: quality and macroinvertebrate commu
Page 35 and 36: Figure 6.6: Principal components an
Page 37 and 38: Figure 6.8: Average SIGNAL-SG score
Page 39 and 40: Sites upstream and downstream of da
Page 41 and 42: Figure 6.10: Multidimensional scali
Page 43 and 44: Temporal trends in AusRIVAS-based a
Page 45 and 46: Trends in periphytic diatom communi
Page 47 and 48: species did not appear in searches
Page 49 and 50: the average percentage abundances (
Page 53 and 54: . Figure 6.18: Sampling sites for f
Page 55 and 56: Hypseleotris were caught only much
Page 57 and 58: Figure 6.23: Length frequencies of
Page 59 and 60: Figure 6.24: Chlorophyll-a, total c
Page 61 and 62: Figure 6.26: Temporal differences i
Page 65 and 66: Figure 6.30: Temporal differences i
Page 67 and 68: (e.g. Merismopedia, Phormidium) hav
Page 69 and 70: Macrophytes Large aquatic plants pl
Page 71 and 72: • Two species of weeds, Gymnocoro
Page 73 and 74: ecord for the unregulated Colo Rive
Page 75 and 76: River has changed in the recent pas
Page 77 and 78:
Maheshwari B.L., Walker K.F. and Mc
Page 79 and 80:
Department of Environment and Clima
show all

Hawkesbury-Nepean River Environmental Monitoring Program

Create successful ePaper yourself

Delete template?

Save as template?