Transcript Impacts of UrbanN & IndustN on Agri in ZD

Impacts of Urbanization and Industrialization
on Agriculture in Zhujiang Delta (ZD)
Dr. Ng Sai Leung (伍世良)
Department of Geography and Resource Management
The Chinese University of Hong Kong
September 2001
Outline
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Introduction
Agriculture in ZD
Urbanization and Industrialization
Impacts on ZD’s Agriculture
Zhujiang
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Zhujiang (珠江, in Chinese, means Pearl
River) is named because of the Pearl Rock
(走珠石, a red Cretaceous sandstone
exposure located at Guangzhou).
Zhujiang is not a single river, but a river
network.
3 major rivers and 8 outlets (三分河道,
八分河口)
ZD is a compound delta (複合三角洲)
Zhujiang and Agriculture
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Zhujiang Delta has a total area of 453,000 km2.
3/4 of land is flatland with fertile soil and
sufficient supply of fresh water.
Traditionally, it is the most important and one
of the ten most important grain production
areas in in Guangdong province and China.
Zhujiang Delta has experienced remarkable
economic growth since 1978.
Significance of Agriculture in ZD
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Whether or Zhujiang Delta can sustainably
develop, agriculture plays a vital role.
Agriculture is of importance to 20 million
people in the region not only in the sense of
providing foods and grains but also in
offering job opportunities.
Agriculture is important in terms of
environment and ecology.
Favourable factors to agriculture
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Climate
Soil
Arable land
Natural ecology
River network
Location
Climate
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Subtropical monsoon maritime climate (plently
precipitation and >10oC the accumulative
annual temperature is greater than 7500oC).
Long cropping season and multiple cropping (3
seasons for rice and the 4th for bean, 三造稻四收
荳).
Guangdong and Hainan are two only regions in
China, which can produces tropical crops.
Soil
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The deposits of the delta are generally 2040m in thickness.
Sediments are rich in organic substances
(about 0.6 million tones per year).
Long soil formation period enables to
accumulate nutrients.
Arable land
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Zhujiang has a discharges approx. 7 times of Yellow
River. Sediment content is 0.13-0.34kg/m3, total
loading is 85 mill ton.
The coast extends 100 m outward every year,
translating into a total area of 15 thousand hectares.
More than 0.3 million hectares have been recreated
from reclamation since 1949.
Because of large river discharge, salt content in soil
can be removed quickly and easily.
Natural Ecology
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Terrestrial habitats because of
topography
Estuary habitats because of
sedimentation
River networks
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High accessibility of Zhujiang River
provides fast and convenient
transportation for the region. There are
many advantages:
 Cut
down the cost of transportation
 Reduce damages of grain and crops
 Maintain the freshness of produces
Location
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Close linkage with Hong Kong and Macau in
terms of culture, economics and technology
A large outlet for agricultural produces.
Characteristics of agriculture in ZD
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Fragmented
Intensive
Integrated
Special techniques: tidal irrigation,
ecological dyke ponds, etc.
Landuse in Guangdong
Landuse types
Area
(X mill ha)
% of total
area (1993)
Arable land
107
17.15
Orchard
Woodland
Grassland
Residential area
32
264
26
51
5.10
42.30
4.22
8.12
Transportation
Water body
Others
11
73
60
1.77
11.69
9.65
Total
624
100.00
Paddy field (水田)
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Mainly for cultivating paddy rice (about 80%) and sugar
cane (about 10%).
Sustain three crops a year. Cultivation sequence is ricerice-vegetables (or rest) or rice-sugar cane rotation.
Series of paddy field align along the coast-inland transact:
 Xiantian (saline field, 鹹田), shatian (sand field, 沙田
), weitian (reclaimed field, 圍田), langtian (field on
the hill, 塱田), tungtian (field on the basin, 垌田) and
hangtian (stony field, 坑田).
Only two crops (paddy rice) are allowed in low productive
fields, e.g., saline field.
Dry field (旱田)
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Distribute over plateaus and undulating
with an elevation of 1-40m, slope is
relatively steep (5-15o).
Parent materials are usually granite or
reddish siltstone.
Difficulty in irrigation and soil erosion are
main concerns.
Orchard (菜地)
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Including land for vegetables and fruits.
They are not large in area, usually <100
acres They are usually scattered at the
fringes of cities and market towns.
“Four fruits of Lingnan 嶺南四果” are
tangerine, banana, pineapple and lychee.
Woodland
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Original subtropical monsoon evergreen
broad-leaved forest has almost disappeared.
Secondary forest (characterized by pines and
shrubs) is the dominant type now.
Small pieces of Fung Shui woodland can be
found in remote villages.
Wind break can also found in coastal areas
while mangrove found in mudflats.
Grassland
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Grassland is a relatively primitive
ecological habitat.
It is an “artifact” of human disturbance.
Natural grasslands are found at hilly areas
and low hills.
Artificial grasslands developed in recent
years, mainly for cow and fish feeds are
scattered over the dyke pond area.
Dyke pond (基塘)
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The excavated soils are used to construct the
dykes.
Dikes are usually 0.5-4m in height, ponds are
30m in width and normally 100m in length.
According to area of dyke, proportion of dyke to
pond can be classified into: 3:7, 4:6 (commonest)
and 7:3.
Dyke ponds which are classified based on the
dominant crop grown. There are 4: mulberry,
sugar cane, fruit, and miscellaneous.
Tidal flat
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Tidal flat is shallow beach at coastal area,
it mainly located at Humen, Jiaomen,
Hengmen, Modaomen.
According to the sediment size, it can be
classified into sand beach, muddy beach,
grass beach and mangrove area. Sand
beach can be found at the river month
while other three can be found adjacently.
Impacts of Economic on Agriculture
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Loss of arable land
Pollution
Structural transformation
Loss of arable land
Year
Population
(million)
Arable
land
(mill acre)
Less
than
(mill
acre)
Less
than
1984
(%)
Arable land
per head
(acre)
1984
1987
1990
1991
1992
1993
17.528
18.488
19.560
19.926
20.221
20.854
14.02
13.51
12.90
12.70
11.88
10.71
-0.52
1.12
1.33
2.15
3.32
-3.7
8.0
9.5
15.32
23.64
0.80
0.73
0.66
0.64
0.59
0.51
Environmental problems
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Over-emphasis on economic growth,
failure in central policy planning and
ignorance of environment
3 wastes: water, air and solid pollution
Point source vs non-point source pollution
Ecological degradation: habitat loss,
pollution and human disturbance
China’s accession to WTO
Structural transformation
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Manpower
Market economy
Decline in grain production
Rise of economic crops.
Three “highs” (三高農業)
Shrinkage of grain production
Year
1984
1986
1988
1990
1992
1993
Population
Food
(million) production
(t)
17.528
18.134
18.829
19.560
20.221
20.854
6313387
5703224
5703224
6174022
5983278
4311932
Less
than
1984 (t)
Less
than
1984
(%)
Food
production
per head
(kg)
-603762
610163
139365
794138
2001450
-9.6
9.7
2.2
12.6
31.7
360
315
303
316
273
207
Development of Zhujiang Delta
~ End ~