Development of Remote Sensing
in China : Status and Future
Zou Xintie
National Remote Sensing Center of China
Abstract
The increasing needs for natural
resources and environmental management have significantly promoted the
development of remote sensing technology direction of application, basic
research, system development. Several national projects in remote sensing
field are described. Finally, this paper discusses the further development
of remote sensing in China.
Remote Sensing has become an important
tool for Resource and Environment Management in China
China is a
developing country covering last territory of 9.6 million square km with
diverse land scope type ranged from coast, zone to plain, desert, plateau
and high mountains. It has also about 1.1 billion population. The country
is confronted with two problems: how to utilize more reasonably the very
limited resource for better standard living of the people, and how to do
with the environment degradation in the country. The main resource and
environment problem in china are identified as follows,
Degradation and decrease of land resource
The area of
land damaged by soil erosion in China is over 1500, 000 sq. km. Especially
the Loess Plateau with are of 600,000 sq. km contains soil erosion area of
430,000 sq. km and 300,000 valleys longer than 1 km, from which huge
volume (1.6 billion tons/yr) of silt is dumped into the yellow river. Soil
erosion and unreasonable use of land have caused rapid decrease of
agricultural land.
Deforestation
The percentage of
forest coverage in the country has shown the trend of decrease. It has
caused deterioration of ecological environment especially in the northern
region of the country, for example, expansion of desertification area and
serious soil erosion. Since 50’s the decertified land has expanded with a
speed of average of 1,500 sq. km/y. The total area of decertified land in
china has reached about 1000,000 sq km as 11% of the country’s territory.
For example, only in northern china, more than 334,000 sq. km is being
affected by decertification process. Desertification are also threatening
other regions of country.
Natural disaster
Disaster,
such as flooding, forest, fire, lands lode, mud-rock flow, and earthquake
has caused enormous losses of property and life of people in the country.
Most resources and environment problems mentioned above are
results of excessive human activities in china’s long history. To protect
the environment we are living n, we urgently need to clarify situation and
dynamic changes of spatial distribution and quality of resource and
environment. No doubt, remote sensing is an effective means to answer
these questions with quick response. The principle for remote sensing
development in China has been formulated as that, applications of remote
sensing technology must be geared to urgent needs in social and economic
development of the country. In this connection, several projects of remote
sensing application and technology of national importance have been
organised and carried on. Thousand of universities are involved to the
projects.
Recent Development of Remote Sensing
Projects of Remote Sensing and GIS Application for
Resources and Environment Management
- Integrated remote sensing inventory of the Three-North forest
shelter belts
The Three-North implys the region which composed of
three sub regions: north-east, north, and north-west of China and covers
above 3.89 million sq. km as for almost 40 percent of the country’s
territory. The ecological environment in this region is quite sensitive
with serious problems of soil erosion and desertification. The purpose
of this project is to inventory forest and land resources in the region,
mation system for regional planning, and evaluate the impact of forest
shelter belts constructed on ecological environment based on the
inventory. Three levels of thematic maps with scales of 1:10,000,
1:500,000, and 1:1500,000 including landuse map, forest type map, grass
type map and land suitability map will be produced. A typical country
was selected as the test area for evaluation for capabilities of
different types of remote sensing data such as TM, MSS, SPOT, and aerial
IR images of different tasks before overall investigation started. This
project has been carried on jointly by researchers from institutes of
Ministry of Forestry and Chinese Academy of sciences (CAS), and
universities.
- Investigation of soil erosion in the Loess plateau
The project is
to use multi-level remote sensing information for producing maps of
landuse and soil erosion intensity of this region, and put forward a
proposal for controlling soil erosion and planning of the region. A
geographical information system is a very important content of this
project. Many scientists from institutes of CAS, Ministry of
Agriculture, and Universities have involved to this project.
- Exploration of mineral deposits
Several mine prospective areas
have been found, such as gold, coal, oil and gas, by scientists of CAS
and Ministry of Geology and Mineral Exploration using satellite and
airborne remote sensing images integrated with geochemical and
geophysical data. Researchers are intending to use new airborne remote
sensors, such as fire-split infrared scanner, for mineral exploration,
and some remarkable results have obtained in the Xinjiang Autonomous
Region.
- Forest fire monitoring
Both the meteorological satellite
center and the remote sensing ground station in Beijing received NOAA
and TM Images of the Daxingnagling forest north-east part of China to
monitor and evaluate the current status ad development trend of the
fire for making correct decision in fire-fighting. It has proven that
remote sensing is very helpful in forest fire fighting.
- Flood monitoring
Satellite remote sensing information has been
applied to monitoring flooding of the Laiohe River, the Nenjiang River
in Northeast China, Yellow river and Yangtze River. The Meteorological
satellite with fast cycle time show obvious advantages for flood
monitoring. We also use aerial SAR remote sensing for all weather
monitoring the flood of rivers, transmit image data to headquarter of
flood-fighting in Beijing by communication satellite and microwave
communication links, and build an information system to calculate area
of indundated land, and to estimate the loss caused b the flooding. A
flooding control system for the Yellow River, including flood
forecasting, monitoring, management of river bed and dykes, and
alarming sub-systems, is under development.
- Other Applications
Some projects on applications of remote
sensing to estimation of wheat production, forecasting for ocean
fi-shery, inventory of cost zone have been conducted.
Development in Remote Sensing and GIS Technology
- Development of Remote Sensors and High Altitude Airborne Remote
Sensing System
Sensing data acquisition we are establishing the
operational high altitude airborne remote sensing system. Some new
developed remote sensors are installed on the plane for applications.
The system is equipped with :
Aerial photographic
camera
Multiband Photographic Camera
Multisepctral Scanner with 19
spectral bands
0.48-0.52 0.52-0.54
0.54-57 0.57-0.61
0.61-0.65
0.65-0.69
0.69-0.73 0.73-0.77
0.77-0.81 0.81-0.85
0.85-0.89
0.89-0.93
1.01-1.05 1.04-1.01
1.55-1.75 1.04-1.08
1.55-1.75
2.08-2.35
8.0-12.5 (um)
Thematic
multispectral scanner with channel centers:
1.660 2.035 2.087 2.143
2.200 2.255
2.500 2.280 2.300 2.330 2.380 2.450 (um)
Synthetic Aperture Side looking Radar (SAR)
with ground resolution of 10m and multi-polarizations, action width of
105km, and mapping width of 35 km. real Aperture side looking radar
Multiband Microwave Radiometers UV and IR Dual Channel scanner Airborne
Spectroradiometer.u
Some sensor
systems, such as Laser Altimeter/Bathymeter, Laser Stimulated
Flourmeter, and Imaging Sepctrcometer with 71 channels, are under
development.
- Development of Image Processing system and GIs software
Systems
Several image processing software systems and GIs software
systems have been developed by institute and universities, as follows
DIPNET 890
image processing station, which can be
used for general image processing, thematic and statistic mapping, multi
data image analysis, developed by the Research Institute of Surveying
and Mapping.
GEO UNION
a general GIs software system
with Chinese and English versions of user interface based on IBM PC/AT
and compatible micro computers, consisting of data digitization and
editing manipulating (polygon based overlay, merge, map join, clip, and
select), inquiry linked with an ORACLE DBMS, map drawing and DTM
processing. The system is developed by the Institute of Geography of CAS
and Department of Computer Science, Beijing University. Recently it has
been applying to forest resource management and evaluation of impact of
forest shelter on ecological environment in the Three-North region.
PURIS GIS software system based on IBM PC / AT compatible
microcomputer developed by institute of remote sensing technology and
application, Beijing university. SYSTEM-W Image Data Bank system
supported by VAX computers and developed by information processing
center, Beijing university SODAMS Software System for Digital Automatic
Mapping developed by the Wuhan Technical university of Surveying and
Mapping. Prospects for the future of Remote Sensing
Development
The applications and technology of remote sensing in
China has got remarkable progress in the past years. But we have noticed
that, sensing technicians and administrations. The main thing is how to
bring the advantages of remote sensing technology in dynamic monitoring
and quantitative analysis into full play, and to meet quickly the
requirement of administration for data and schemes. In this point, we
understand that, at present, remote sensing technology is facing the
challenge of applications. Here two problems have been recognized :
development of operational remote sensing systems from data acquisition,
preprocessing, to analyzing an mapping is urgently required: and basic
research on mechanism, of transmission and imaging of remote sensing
information is also an important phase in development of remote sensing
technology inadequacy in basic research has been hindering the
establishment of efficient analysis models and data processing methods,
and then limiting the progress of remote sensing application in depth.
Encounted with the increasing resource and environment problems,
we have planned in development of remote sensing for the next five or more
years.
- To establish an operational system for real time remote sensing
monitoring, estimation and assist decision making of large scale
disaster, such as flooding, forest and grassland fire, draught. The
system will use multi level remote sensing data systematically while
applying synthetically GIS, and other new technologies, such as
satellite communication, GPs and artificial intelligence.
- To expand the applications of microwave remote sensing and other
effective remote sensor systems while addressing to basic research and
development of new sensors.
- To carry out the global environment programme using remote sensing
technology, for which international cooperation is necessary
- To prepare the establishment of the system of application of the
Chinese resource satellite.
There is no doubt that, remote
sensing has shown its great potential for resource and environment
management. But as we know, its capability is limited just because of the
nature of the information capture. In development of remote sensing we
must very clear on this based on deep basic research.
Space is a
common resource of mankind. We have similar resource and environmental
problems in the world today. Share of experience in development of remote
sensing application and technology is beneficial to scientists and people
of countries in the Asian region and in the world. For this reason we
believe that enhancement of international cooperation is very important to
us. China has developed cooperation relationship in remote sensing field
wit many countries including taking joint research projects, holding
regional and international seminars, workshops and training courses and
exchanging scientist. We will continue to promote and expand the
co-operation relationship.
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