Chapter 7 Environmental geoscience

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Chapter 7 Environmental geoscience

• 7.1 Characteristics, status and role of
  environmental geoscience
• 7.2 Combined system of human - earth's
  environment
• 7.3 Entirety of human - earth's environment as
  well as influence and response of each circle
• 7.4 Case study

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7.1 Characteristics, status and role of
environmental geoscience

• Study purpose master change and development
  regular of each environmental element and
  environmental system, implement to predict and
  management environmental system, and make accord
  development of human earth.
• During environmental science system,
  environmental geoscience is subject to
  comprehensively study entirety of combined system
  of human - earth's environment and correlation
  between each subsystem.
• Provide scientific basis and support for other
  subfield research, and summarize and integrate
  the results and progress of other subfield
  research.

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7.2 Combined system of human - earth's
environment
7.2.1 Combined system of human - earth's
environment (1) Weather system Weather system is
a whole system composed with underlayer
atmosphere, hydrosphere, cryosphere, biosphere,
pedosphere, superior part of lithosphere. They
have close and complex interactions between
them. (2) Air pollution in atmospheric
environment and boundary layer Atmosphere is the
most active part with the largest change in earth
system, and atmospheric sphere, one of the
subsystems in combined system of human - earth's
environment, is an important part of the human
environment.
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Atmospheric environment and air pollution
Atmospheric environment, considering atmosphere
as the media centre, is physical environment in
earth system. Generally, it points ozonosphere
and the following parts closely related to human,
especially atmospheric condition of boundary
layer Atmospheric pollution generally means
substances into the atmosphere induced by human
activities and natural processes, showing enough
concentration and reaching enough time to harm
the human body's comfort, health and welfare or
environment. Anthropogenic emissions is the main
reason resulting in air pollution, especially
local air pollution
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The classification and characteristics of air
pollutants
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Diffusion and study methods of pollutant in
atmospheric
Generalized atmospheric dispersion means the
pollutant entering into air is gradually
dispersed and diluted with wind, rapid current,
uplift, subsidence, dry and wet deposition,
chemical conversion, and other progress.Although
it benefits mitigate local air pollution, the
influence basin of pollutant will be expanded,
and the secondary pollution may be induced or the
pollution may be transferred to the soil and
water body. The research methods generally are
divided into mathematical simulation, physical
simulation of indoor fluid (such as wind-tunnel,
sink, and convection chamber simulation) as well
as field experimentation.
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(3)The value and protection of air resources
During animals breath, oxygen contained in the
fresh air is transferred into each tissue of the
body and cells by the blood and participates in
every iochemical reactions and metabolic
processes. Only in this way, the life can be
lasted.Air is the primary produceressential
substances for plant respiration and normal
physiological response. Air movement not only
promotes exchanges of material, heat and
moisture, produces all kinds of atmospheric
phenomena, provides clean wind energy for the
human, and is the important way to spread
seeds. Greenhouse effect of earth's atmosphere
greatly inhibits dramatic changes of ground
temperature, protects the organism on the earth
from the harm of cosmic rays and meteor, and
provides rich raw material for industrial and
agricultural production.
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(3) The value and protection of air resources
However, as for some area (such as city, valley
and basin), air is limited in self-purification
and dilution capacity for pollutant discharged by
mankind's activity. If the threshold value of
atmospheric environmental capacity is exceeded,
air quality will significantly get worse. In
addition to reinforcement of publicity and
education, improvement of environmental
consciousness, performance of cleaner production,
optimization of the industrial structure and
increasing the forest area (figure 7-2), legal
measures and economic instruments should be used
to protect air resource and improve air quality.
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Figure 7-2 19801995 The change of world
forest area (qouted from World
Resources Report UNDP,UNEP,WB,WRI,2002)
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7.2.2 The water environment and the marine
environment
(1)The basic types of water circulation General
circulation occur in water exchange process
between global ocean and land. Because it wildly
covers the global, it is named as general
circulation Lesser circulation occur in water
exchange process between ocean and atmosphere, or
land and atmosphere. Lesser circulation is also
named as internal circulation. The former is also
called as marine lesser circulation, and the
latter is called as land lesser circulation.
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(2)Water balance
Water balance is quantities of water cycle, i.e.
in a certain time-domain space, during the
progress of cycle and transform of moisture
content, its quantity follows law of conservation
of mass, and the difference of water revenue and
expand must be equal to variable quantity of
water-retention in this area (or water body).
Water cycle is the natural phenomenon which
objective exist on the earth, water balance is
the inherent law of water cycle.
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Figure 7-3 world hydrological cycle
process (according to Moore, repaint in 1996)
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(3)Water pollution or water auto-purification
When pollutant into rivers, lakes, oceans or
groundwater, and other water body, its content is
exceeds self-cleaning ability of the water body,
which makes physical, chemical nature or
biological components of water quality and bottom
material of the water body change, and then
reduces useful value and use function of the
water body. Therefore, it is called water
pollution. After pollutant enters into the water
body, with the complex physical, chemical and
biological actions, the concentration of
pollutant is reduced. After a period, the water
body will be recovered to the situation before
pollution. This phenomenon is called as automatic
depuration of water body.
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Automatic depuration of water body can be divided
into three kinds of depuration models according
to its mechanism Physical depuration the
progress of the concentration of pollutant
reduced with mixing, dilution, diffusion,
evaporation, precipitation of pollutant in the
water body.Chemical depuration pollutant
migrate in water body with simple or complex ions
or molecules state, and the changes of chemical
property, morphology, or valence happen, which
makes water quality produce changes of chemical
property, while not participates in biological
action Biological depuration during the progress
of biology metabolism, the concentration of
environmental pollutant and toxicity are reduced,
even disappear with biologic absorption and
degradation.
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(4)Ocean environment and oceaninteraction of
air, ocean, and land
Ocean environment Continuous water areas wildly
exist on the earth is generally called ocean, and
its area occupies 70.8 of the total area of
earth's surface. The formation of seawater has a
relationship with overall evolution of the
material on the earth. Generally speaking,
seawater is the production under the venting
action of internal material on the earth, i.e.
water vapor and other gas are discharged
continuously from the internal earth with lava
activity and volcanism.
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Interaction of ocean and gas
a. Quantity of heat exchange. The ocean transport
energy to air with convection, conduction
(sensible heat), evaporation (latent heat), heat
radiation, and other forms, this is a progress of
discharge entropy. Its result is to make movement
of the atmosphere over the ocean constantly
changing and form a variety of weather
phenomena.b. Quantity of motion exchange. On the
surface of ocean-gas, quantity of motion exchange
mainly shows provide momentum by wind stress, and
then waves and ocean currents are formed, leading
to large-scale energy and mass transfer c.
Material exchange. Moisture exchange implemented
by evaporation and atmospheric water is the main
process of material exchange on the surface of
ocean-gas.
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Ocean-land interaction
a. Material exchange. Stream flow into the ocean
will carry sediment from the land into the sea.
Meanwhile, nutrients and pollutants in the land
such as N2, P, and other compounds will be
discharged into the ocean. b. Momentum exchange.
In the littoral zone alternating of ocean and
land, marine abrasion exists by wave impact makes
rock collapse. c. Sea-level change. Because
global climate is warming, seawater expanding,
field ice in polar region and glacier thawing in
continent results in sea level rising
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(5)Effect of ice and snow underlying surface on
climatic change
Ice and snow covering has a significant impact on
global climate and environment. Because ice and
snow have high surface reflectivity, the
absorption of solar radiation on underlying
surface is greatly reduced. Ice and snow has
lower thermoconductivity, which can weaken
vertical conduction of heat quantity in the
medium under ice and snow. Glacier is the product
of climate and topography. However, it has a
strong impact on climate and topography. Amount
of precipitation in glacierized mountain area is
often higher than that of unglacierized mountain
area.
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7.2.3 Status and role of other layers
(1)Relation between lithosphere and mankind
survival and development Lithosphere is the
outermost layer of the earth composed by all
kinds of rocks, and its vertical structure
contains olivinite on the top of petrosphere and
upper earth's mantle. It is the source of a large
number of mineral resources and a variety of
fuels, which are essential for the soil and life,
and has a close relationship with survival and
development of the human. For quite a long time,
80 of the raw materials and 90 of the energy
required for human society are from the
lithosphere
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(2)Environmental effect of changes of soil
environment and land cover Soil means
loosened surface layer, located in land surface
of the earth with certain fertility and the
ability of growing plants, and is the product by
combined effects of rocks, topography, climate,
biology, time and human activities, and other
soil-forming factors. Soil fertility is the
ability of soil supplying and coordinating of
nutrition factor and environmental condition for
plant growing. Soil environment is located in
transition zone among atmosphere, hydrosphere,
lithosphere and biosphere in the environment
system of earth surface, and it is a tie
connecting inorganic and organic environment.
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Land cover means generic name of vegetation cover
and artificial cover on earth surface. Land
utilization is the external driving force of land
cover changing, while land cover also can affect
land use with feedback. The characteristics of
land cover have important effects on climate,
geochemical cycle of global biodiversity, as well
as abundance and composition of terrestrial
species.Land use and land cover change affect
regional climate with changes in surface
reflectivity, and content of greenhouse gases and
trace gases. At the same time, it affects energy
exchange, water exchange, erosion and deposition,
biological cycle and crop production, and other
main ecological processes of soil.
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(3)Relation between biosphere and compound system
of human-earth environment
Interplay and interaction of biosphere and other
layers of compound system of human-earth
environment is an important part to prompting
unceasing evolution and development of the whole
composite system. Biosphere constitutes a human
ecological environment together with soil, water
and air and other circles. With the flows and
exchange of energy and matter within and between
layers, balance and stability of earth system can
be maintained.
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(4)Relation between wisdom circle and human-earth
The main body of wisdom circle is human, while
principal character expressed by the total of a
variety of human processes and human phenomena is
sociality. Activities of human society are
associated with each other and combined into a
society as a whole. In fact, the formation and
development history of wisdom circle results from
unceasing effect and action of human social,
economic, political, cultural and technological
development on natural environmental systems, and
gradually evolves into the history of human-earth
relation.
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7.3 Entirety of compound system of human-earth
environment and influence and response between
each layer.
7.3.1 Entirety of compound system of human-earth
environment Entirety of compound system of
human-earth environment involves in interaction
of each layer. Physical, chemical and biological
processes interwork with human process, showing
entirety characteristics of organic unity of
combined system, which makes joint connection of
the whole world and region, macroeconomics and
microeconomics, as well as earth's environment
and life processes.
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7.3.2 Interaction within and between each
layer The important of interaction within each
layer is ocean-gas interaction, land-gas
interaction, and land-ocean interaction.(figure
7-3)
Figure 7-3 Important process in marine -
atmosphere - land system (according to
IGBP?-all, repaint in 2001)
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7.3.3 Intervention of human progress
The characteristic of current human activities on
surface systems reflects two aspects
?Creativity of human science and technology is
increasing. ?The scale of destruction of
ecological environment is more and more with the
regional and global characteristics. The
condition of underlaying surface decides the
distribution of solar radiation on the earth's
surface, and affects weather system. Wetlands,
forests, urban, and other surface changes are
important source of greenhouse gases of CO2, CH4
and N2O. Vegetative cover can increase solar
radiation absorbed on the earth's surface, reduce
thermal flux from the earth surface downward, and
decrease effective radiation on the earth. Once
land cover is changed, it can affect migration of
moisture interaction, erosion and deposition,
biological cycle, producing crops, and other main
ecological processes of soil, leading to a series
of ecological environment. Therefore, the
proportion of urban built-up area is large, and
it will inevitably lead to local environmental
quality decreased.
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Figure 7-4 The built-up area of some European
cities in 1995 (quoted from World Resources
Report ,UNDP,UNEP,WB,WRI,2002)
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Case study - energy cycle
Energy cycle in compound system of human-earth is
the basic power to drive all progress. In order
to keep thermodynamic equilibrium, earth-gas
system must send radiation equivalent with solar
incoming radiation. However, as for some local
area, radiation revenue and expenditure is not
balance. With the increase of latitude, the
balance of radiation becomes form positive value
to negative value. Therefore, trans-regional
energy transmission should be finished by
atmospheric circulation and ocean circulation.
During this progress, a series of energy exchange
process also exists in the interface of
atmosphere, oceans, land and ice. Besides,
triphase change progress of volcanic eruption and
water is accompanied with absorption, release and
re-distribution of energy. Energy cycle during
biogeochemical processes shows conversion of
chemical energy. Solar energy absorbed for use of
terrestrial and marine plants can maintain
synthesis, decomposition and distribution of the
product, and enter into biogeochemical cycles
with various elements.(figure 7-5)
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Figure 7-5 Energy cycle of human-land compound
system (quoted from Zhucheng, etc. Introduction
to global change,2003)
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Thank you
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