746
The level has a certain relationship with TSP level.
The r of TSP and Dust, in 1980s was 0.681 (r=0.681).
It shown that TSP and Dust in air pollution have
alike sources,the pollutants which take coal pollu
tion as the representative. The windly and dry
Spring easily increases the cities Dust Pall level,
and to meet the maximum of monthly mean in the year.
Fig.4. During 1980s, the tendency of Dust level in
main cities of China.
In 1980, becouse China goverment took the matter of
desertisat ion seriously, shelterbeit engineering in
northwest of China and other environmental protec
tion were finished. These measures yield good
results on natural dust carring and diffusion. But
dust pollution is still the main content of air
pollution in China, and it's, the highest surpass
standard ratio among the four pollutants ( S02,N0x,
TSP, Dust ) in every year which is more than 90% .
Acid Rain
The early years in 1980s, the work of monitoring
acid rain was launched in part cites. In the middle
of 1980s,general survey of acid rain was carried on,
and more than two hundreds sites of national net
work for the acid rain monitoring were set up. And
the network was read justed by the end of 1980s.
In 1980s, the PH value range of acid rain in China
is 3.0 to 9.5. In some areas acid rain is very
serious, its frequency is more than 95 X and the PH
value is about 4.0.In the south of China,especially
in the southwest, the PH value are the same as the
northeast, of the USA, and a few cities in southwest
its PH value are less than the northeast of the USA.
So we ean say that some southern areas have become
one of most polluted acid rain areas in the world.
And as the enlarging monitoring frequency and area
range, and the in depth research work, it hasn't
had the proofs to show that the areas of acid rain
has enlarged and acidity has further increased in
the whole country in 1980s.
But we can see the further acidify phenomenon in
some cities. To see China's acid rain distribution,
it's more or less the same over 1980s.We occasional
ly found that it was a rare phenomenon to appear
acid rain in the northwest,and we haven't found the
further moniotoring data to show acid rain exist in
the northwest of China.
2.2 The Feature And The Regularity Of Air Pollution
The Regularity Of Years And Seasons
The result of ten years monitoring data in 1980s
shows the regularity of year changing ( see Fig.5 ):
it was the most polluted in the winter and the less
in the summer.Becouse it has smaller changes in the
season in southern cities than it in northern
cities, Coals were fewed to warm in southern of
China. So the difference between seasons emissions
is smaller in southern cities and it was proved by
the testing result on the comparison between
northern and southern, winter and summer, it shows
that in northern cities pollution level difference
between winter and summer is more obviously and
believable than the southern cities.
Fig.5. The regularrity of year changing in
Shanghai of China,1984.
Dusty pollution has a close relationship with
meteorological condition. In spring becouse of
thawing, the northern surface uncovered, dry and
no-rain,and wind always comes into being.TTie second
air pollution is the most important source of the
Dust ( dry deposition J.The data of ten years shows
that the maximum of Dust in a year is mostly in
spring ( See Table.1 ). It's the comparison of the
season-changing in cities in the year 1981-1989.
Table.1 From 1981 to 1989, percent of the highest
mean among four seasons in a year.
r
T
"H
~r
■
~T
“■)
!
item 1
winter
I spring
1
summer
1
autumn 1
1-
4
— -
4-
-4-
.. . _|
1
S02 1
79.38
j 9.50
i
2.33
j
8.79 !
I-
j_
-i-
4-
~\
f—
NOx !
H-
59.31
I 14.65
i
5.92
20.12 !
-|
1
TSP 1
47.70
i 25.91
6.79
19.60 1
f-
4-
_j
4-
-f-
. ■ -j
Dust !
_i_
26.11
! 56.28
_i_
8.35
L.
9.26 i
i
The rule of daily-change
The daily-changing of meteorological condition and
the rule of human being's production and daily life
is the main.reason of the daily-changing air pollu
tion. The.inversion layer's daily changing has a
good relationship with air pollutants concentration.
Fig.6. The daily-changing of S02 level in Beijing
of China.