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Natural sciences

The earth and beyond

Rivers and their catchment areas

Educator section

Memorandum

Assignment 10:

1. Assignment clear in module. Assignment can lead to an exhibition of collected samples, photos and notebooks.

Follow-up visit for cleaning up is recommended.

Assignment 11:

Listen at least to Wendy Oldfield's song "Acid Rain". Learners take the lead and answer the following question:

"Which environmental issues are addressed and what solutions do we have for the problems?"

Assignment 12:

Help the learners with a framework, e.g.

  • The river as an environment wherein plants and animals can live
  • light
  • visibility
  • oxygen
  • no poison
  • protection against temperature changes
  • Life in a river (above-mentioned environment)
  • types of plants
  • types of animals
  • mutual dependence of plants and animals

Leaner section

Content

Activity: to discuss the role of rivers in nature [lo 1.1, lo 1.2]

IN THE LEARNING UNIT DEALING WITH FOSSILS WE SAW THAT THE DRY KAROO USED TO BE A MARSHLAND THAT COVERED APPROXIMATELY THREE-QUARTERS OF THE SURFACE AREA OF SOUTH AFRICA. IT IS CLEAR THAT FRESH WATER HAS PLAYED AN IMPORTANT ROLE IN THE LIVES OF PLANTS AND ANIMALS AS WELL AS PEOPLE FOR MILLIONS OF YEARS.

A RIVER IS MORE THAN WATER!

  • Rain absorbs carbon dioxide and oxygen when it travels through the atmosphere. While it travels down a mountain slope, tiny plant particles from the vegetation are also caught up in it. In this way water takes up sufficient soluble nutrients to sustain animals that live in water, as well as plants.
  • Rivers are generally endangered. The fact that people need water for survival, places a great deal of pressure on rivers to meet this need and to carry away waste material.
  • Rivers are not drainage conduits for the removal of waste: they are complex systems.
  • Different plants and animals exist along the different reaches of a river. These organisms utilise the natural materials contained in the river in the natural process of their lives. This ensures that the water in the river is purified continually. Rivers are also able to absorb much pollution.
  • This unique characteristic of rivers is largely destroyed by excessive pollution, damming up of water and canalisation.
  • The Department of Water Affairs and Forestry acknowledges that rivers are living systems that should be conserved. Healthy rivers are attractive features that provide us with water and make it possible to save money. The capacity for self-purification that is observed in rivers can make it possible to save thousands of rand that would have to be spent on building purification projects, provided that we protect this capacity.
  • Rivers need people to protect their interests and to fight for them.

River catchment areas

  • The catchment area of a river, is the area between the mountain peaks where the river has its source and the coast where the river mouth is. The area that is drained by a single river forms its catchment area.
  • The characteristic feature of any river is determined by the activities (human and natural) that take place in the catchment area. All the water that is precipitated as snow, dew, mist and rain in any particular catchment area flows together in a river. Only a very small quantity of this water is lost through evaporation.

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 6. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11079/1.1
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