Today in P6 we started reviewing the water cycle and Perth's waterways. Some boys were absent due to choir rehearsals so I have put lots of the links and information below. Due to the Swan River being a topic covered across Term 3 and Term 4 we have broken the test up into two. The first test which will be conducted this term will focus on the water cycle, Perth's water sources, taking care of our waterways (pollution), how nutrients get into our waterways and water as a solid/liquid/gas.
Boys are being given vocabulary checklists and "I can do" checklists for this Unit. We will go through in class what terms and knowledge they need for this particular upcoming test. There are also some great vocabulary words down below to help.
THE WATER CYCLE:
What Is the Water Cycle?
Water is continuously circulated through a global cycle powered by
the sun and the rotation of the earth. With exposure to the sun and the
wind, water evaporates from the ocean as vapour and condenses into
clouds. Given the right conditions, it then precipitates as rain, hail
or snow. Some of this water returns to the atmosphere through
evaporation or transpiration by vegetation; some flows back to the sea
in streams and rivers; some is stored in lakes; and some infiltrates
into the ground, where it may be stored, or through which it moves
slowly to be discharged, eventually, back into the sea.
How We Use the Water Cycle
We use the natural water cycle to meet our needs for water. In
Australia we are a ‘thirsty’ nation: the spread of population, the
development of our cities and towns and water-based recreational
activities have all combined to create an increasing demand for water.
Water is supplied from the natural cycle, and water utilities make sure
that the water reaching our homes is safe to drink. After water is used,
water utilities treat it before it is returned to the water cycle. It
is everyone’s responsibility to ensure that water sources, whether or
not they are used for drinking water, do not become polluted, as they
are all part of the water cycle.
PERTH WATER SOURCES:
Traditionally Perth has relied heavily on our dams as a water source.
With our drying climate we can no longer rely on dams or other
traditional sources like lower security groundwater. Because of
declining rainfall and streamflows, dams traditionally used to supply
our Perth customers will be used less as a metropolitan water source and
will take on a bigger role as storage reservoirs. Water produced from
sources, such as deep groundwater and desalination, will be transferred
into our dams for storage and distributed out to customers in periods of
higher demand. This will help ensure climate independent, year round
water provision.
Water Corporation uses dams to move water around, including supplying
towns in the Goldfields and Agricultural areas through the Goldfields
Pipeline. In recent years more southern dams have been connected. This
provides greater flexibility and security to Perth and the South West,
as it allows towns access to a wider range of water sources.
Positive rainfall and streamflow trends in some northern areas of our
state mean many towns in the Pilbara and Kimberley regions will continue
to be supplied by traditional surface water and groundwater sources.
Water Corporation wants to provide a sustainable water supply in the
face of strong state population and industry growth, and dwindling
surface and shallow groundwater supply. The plan is to do this by
becoming climate resilient. This requires a balance of reducing water
use, increasing the amount of water we recycle, and developing new water
sources.
Water Corporations goals for 2030 are:
- Reduce water use by 15%. By working with households, businesses and communities to reduce water use and leaks.
- Increase water recycling in Perth to 30%. Increase the use of recycled water for parks, gardens and in industry.
- Develop up to 100 gigalitres of new water sources. Desalination
is an important new source as well as groundwater replenishment and
secure groundwater sources.
NUTRIENTS IN OUR WATERWAYS:
Our rivers and estuaries are under increasing pressure from land use
change, altered aquatic habitat, competition from exotic species,
changes to flow regime, pollution and a changing climate.
Eutrophication (high concentrations of nutrients) can be either
natural or caused by human impact. When humans alter the landscape by
clearing vegetation there may no longer be enough vegetation around
rivers and estuaries to absorb excess nutrients before they enter these
waterways. This problem is exacerbated by the addition of extra
nutrients onto the land in the form of fertilisers and animal manure and
by changing the types of plants present.
What are nutrients?
Nutrients are elements or compounds including nitrogen, phosphorus
and organic carbon. They enter the rivers from the catchments through
drains, surface runoff and groundwater. The most common sources of
nutrients entering our rivers include fertilisers, plant matter (e.g.
grass clippings, leaves), detergents, sewage, and animal waste.
What is the problem with nutrients?
Nutrients are essential for plant growth, including algae. However
excess nutrients fuel algal blooms and can promote harmful algae. When
an algal bloom collapses, the algal cells fall to the riverbed. Here the
algal organic matter from the catchment is broken down by bacteria.
This process takes oxygen out of the water and the greater the amount of
organic matter in the system, the greater the amount of oxygen that is
removed from the water. This can result in low oxygen conditions.
Low oxygen conditions can result in nutrient release from the river
sediments, which can favour toxic algal blooms. Low oxygen conditions
and toxic algal blooms may result in fish deaths.
What can we do to help?
- Fertilise wise. Limit fertiliser application, and when needed,
apply a river-friendly variety in spring or early autumn. Never
over-water.
- Do not dispose of items in drains, as these lead to our waterways.
- Wash your car on the lawn to keep detergents out of the stormwater drainage system.
- Grow local native plants which need less water and fertiliser.
- Take your rubbish home when you are out enjoying the rivers.
- Pick up your dog’s waste and put it in a bin.
- Check with your local council where to dispose of paint, oil and chemicals.
- Use phosphorus-free detergents when washing clothes or dishes.
- Compost your leaves and grass clippings.
Key vocabulary
- Transpiration: evaporation of water from plant leaves.
- Condensation: conversion of gas to a liquid due to cooling.
- Evaporation: conversion of a liquid to a gas due to heat.
- Precipitation: water being released from a cloud in the form of rain, hail or snow.
- Cloud: a visible mass of water.
- Water Vapour: The name of water when it is a gas.
- Water Cycle: describes the continuous movement of water on, above and below the surface of the Earth
- Gigalitre (GL): a thousand million litres.
- Streamflow: amount of water flowing into dams in a year (shown in Water Corporation’s graph in GL).
- Surface water: is water collecting on the ground or in a stream, river, lake, wetland, dam, or ocean.
- Dam: a barrier constructed to contain the flow of water, usually built on a river.
- Climate change: is a significant and lasting
change in the statistical distribution of weather patterns over periods
ranging from decades to millions of years.
- Groundwater: water located beneath the ground surface in soil pore spaces and in the fractures of rock formations.
- Catchment: is an area of land where surface
water from rain and melting snow or ice converges to a single point and
joins a waterbody, such as a river, lake, reservoir, estuary, wetland,
sea, or ocean.
- Inflow: the act or process of flowing in or into
- Pollution: the act of contaminating or polluting; with unwanted substances or items (either intentionally or accidentally)
- Contaminate: make impure
- Eutrophication: the condition whereby a river or estuary has very high concentrations of nutrients present
- Nutrients: elements or compounds including nitrogen, phosphorus and organic carbon, which stimulate growth.
- Surface Runoff: is the water flow that occurs
when the soil is infiltrated to full capacity and excess water from
rain, or other sources, flows over the land.
- Biological (Bio) indicator: species that can be used to monitor the health of an environment or ecosystem.
Here is a basic youtube video that shows the process a water drop goes through in the water cycle.
http://www.youtube.com/watch?v=StPobH5ODTw
Here is the activity we did as a class in P6 today if any boys missed it and would like to complete at home. There is a great video that is at least worth watching.
http://www.watercorporation.com.au/home/teachers/lesson-plans-and-teaching-resources/lesson-plan-search/lesson-plan/?id={30F077AA-1C6A-40AC-91CA-BDAB170028EE}
Perth's Rainfall, dam storage and water supply figures. Where do we get our water supply from?
http://www.watercorporation.com.au/water-supply-and-services/rainfall-and-dams
