Fieldwork Activity 2
Physio-chemical water quality parameters
Complete pages 6 in the student fieldwork booklet.
Learning Intention
To process and analyse data collected on water quality in the Hawkesbury River.
Visual Observations
Use the 360 image and drone footage below to make some visual observations of the site and also fill out the human impacts section.
360 Camera Image
Canopy Film.mp4Brewongle drone footage.
Water Quality Results
Monitoring water quality parameters is an important way to assess river health. You will see a column in your data sheet for 'ANZECC Trigger values for Ecosystem Protection". These are standard measures of river health to allow you to understand if your result is in a healthy range. Think of it as similar to measuring blood pressure if you go to the doctor! ANZECC = Australian and New Zealand Environment and Conservation Council
Utilise the pictures below to collect your data for the water quality parameters in your fieldwork booklet. If you are doing a virtual excursion then you will only be able to fill out 1 group column.
Water temperature
pH - 7-14 (alkaline side of chart). Try to match all 4 colours on pH strip to the chart.
pH - 0-7 (acidic side of chart)
Dissolved Oxygen (mg/L). Match the colour of the vial to the closest sample on the chart.
Electrical Conductivity (Salinity) (ppm). Read the top number.
Turbidity - watch to see result! (<10)
The tests for phosphate and nitrate we conducted were not able to be rendered well on a photograph or video. If you look at the historic data in the spreadsheet below, you will see that these results are usually very high and well above the ANZECC trigger values.
Phosphate: 0.20
Nitrate: 0.70
Current Erosion Condition Assessment
As moving bodies of water, rivers have a great capacity to shape and change the landscape (think back to weathering, erosion and deposition from year 7). The processes by which rivers shape the landscape are referred to as "fluvial" processes and these are obvious at the study site.
Study the images below of the assessment site and complete the Current Erosion Condition survey in your fieldwork booklet.
The questions in the text below will need to be answered by you in the Conclusions and Recommendations section of your fieldwork booklet (page 10-11)
Consider how this riverbank may have been altered from its natural state. Think about the size and type of vegetation present and whether it would be the same vegetation in the past. Look at the geomorphology of the bank. Does it all look natural or have humans impacted it?
Whilst out surveying, we often see speedboats on the river. How might the wake (waves) from boats change the riverbank you can see?
Some tributaries to the Hawkesbury River have been so heavily impacted by riverbank erosion and slumping, that the rivers have become wider and shallower over time. The banks collapse and essentially fill up the riverbed with sediment. This has resulted in semi-closure of rivers. For example, the MacDonald River in Wisemans Ferry, downstream from Sackville North, was historically the main supply route for large ships to St Albans. Today, a small boat can barely pass through the second reach of the river at low tide due largely to sedimentation from riverbank degradation and the shallowing of the river.
How might we reduce this impact?
