Remote Sensing and GIs for
Urban Growth Analysis in China
Shupeng Chen, Shan Zeng, and Chuangjle Xle
Abstract
The progress of urban remote sensing and GIS in China since
the early 1980s is reviewed. The first section introduces the
early applications of remote sensing to environmental monitoring
and resources investigation, and outlines its achievements.
The second section focuses on further analysis of urban
expansion from the point of view of spatial distribution patterns
and temporal change, taking Beijing, Shanghai, and
Dongguan as examples. Urban GIS is discussed in the third
section. The regional differences of uGIS development in China
are detailed from south to north. As remote sensing and GIs
technologies develop, they will be combined for use in urban
planing and management.
Development of Urban Remote Sensing In the 20th Century
A city can be regarded as a hinged center of material flows,
energy flows, and information flows within a region. In other
words, it is a mixed complex of social and economic development,
and regional resources exploitation, continuously promoting
productivity levels and the standard of living in the
region. We may describe this as similar to the working of the
human kidney, which constantly outputs waste products and
replaces them with fresh products. Processes of urbanization
reflect not only the progress and development of regions, but
also mark regional cultures and civilizations of an epoch. Fating
rapid change and a complicated urban system, we undoubtedly
need to apply 20th century space and aerial techniques for
dynamic monitoring. Furthermore, only cities can meet the
needs of the high input-and-output talents and funds for GIs
and remote sensing applications.
In 1800, the number of urban residents represented only 2
percent of the total population of the world, while the number
had reached 10 percent by the beginning of 20th century.
Almost two-hundred years later, the urban population has
grown to over 3.2 billion, equally half of the global population,
and it increases by an average of 1,000,000 people per week.
Between 1970 and 1985, the number of people below the poverty
line in urban areas increased by 22 percent, so that the
problem was more serious for those in urban areas.
In 1993, about 330-million urban residents lived in urban
areas of 16,000 km2 in China, the numbers of urban residents
having doubled from those of the 1970s. Today there are over
660 cities with residential populations of more than 500,000.
China is both a country with a huge population and an Asian-
Pacific country with a rapidly developing economy. As urbanization
processes are being accelerated and more and more
mega-cities are appearing, the Chinese population will increase
from 1.2 billion to 1.6 billion in the 21st century. Correspondingly,
the urban population will reach 29 percent in 2020
and 47 percent in 2050 (Yang, 1996). We will then have to face a
series of environmental problems, such as a water resource crisis,
increased air pollution, and waste treatment problems. We
will have to make a series of decisions, such as construction
planning and land management. All of these situations will
stimulate the promotion of geographic information systems
(GIS) and remote sensing monitoring to deal with present and
future urban problems.
Under China's extended open-door policy and the establishment
of special economic regions, development zones, and
bonded duty zones throughout the country, regional development
in coastal areas has advanced rapidly since the 1980s.
Four highly dense urban regions have gradually formed in the
Shandong Peninsula, the Liaodong (eastern Liaoning) Peninsula,
the Beijing-Tianjing-Tangshan region, the Yangtse River
Delta, and the Pearl River Delta. Sixteen mega-cities are distributed
along 18,000 kilometers of China's coastline, including
the Special Administrative Region of Hong Kong, along with
102 large-and medium-size cities and 278 small-size towns.
Meanwhile, four huge, densely populated urban areas are scattered
along the 6,300-kilometer Yangtse River. These include
Shanghai, Nanjing, Wuhan, and Chongqing. There are, however,
few cities of such size in the wider western and middle
inland areas of China, with the exception of Zhengzhou, Xian,
and Harbin. The trend of urban distribution mentioned above
further enlarges the gap between both sides along the Tengchong-
Aihui population distribution line.
In the early 1980s, aerial and satellite remote sensing techniques
were applied to environmental monitoring, land resources
investigation, and urban planning and management in
China. Tianjin was the first city to conduct an aerial remote sensing
experiment. Land-use and land-cover maps were produced,
based on false-color infrared images. Meanwhile, environmental
quality evaluation was conducted on air, water source and
float dust, and content of sulfur dioxide through aerosol Sampling
and monitoring data of air pollution. The research results
were published in the Tianjin Atlas of Environment Quality
(Chen, 1986). This achievement had a positive effect on municipal
engineering construction projects such as pollution protection
of the Haihe River, crossroad planning, planting survival
rate, harbor deposit monitoring, and coastal zone development
with remote sensing data and maps. It also supplied a scientific
basis for the application for a World Bank loan for municipal
infrastructure construction. In 1985, NOAA AVHRR and Landsat
MSS images were used to evaluate the Ecology and Environment
in the Beijing-Tianjin-Tangshan region (Fu and Cao,
1989).