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PC base education system for global change monitoring

Sukit Viseshsin, Yoshiaki Honda,
Shunji Murai
Institutte of Industrial Science, University of Tokyo
7-22, Roppongi, Minato-ku, Tokyo106, Japan
Tel : 03-402 6231 Ext. 2560
Telex: 02427317 KOSMUR J
Fax: 813-479-2762


Abstract
Nowadays, earth environment problem is widely interested. Since it is a global scale, it is better to monitor on the whole earth for evaluating or analyzing. However, the analyzing needs a very huge database, therefore, the expensive computer is needed.

Concerning the personal computer which is cheaper and faster than before, the personal computer should to play more role in teaching or educating in the earth environment problem.. This paper deals with the personal computer base database for global change monitoring. this database consists of GVI, Climate, topology and soil data which are prepared for the GIS system. Because for the limitation of the memory capacity of a personal computer, a magneto optical disk system and data compression are introduced. The final goal of this study is to develop a PC base system for evaluating of the potential productivity of vegetation.

Introduction
The global change of the climate is one of the most important problems for the human society, and this change can be detected from the condition of the earth's vegetation. This condition can be interpreted from GVI (Global Vegetation Index) which is produced form NOAA'S (United States National oceanic and Atmospheric Administration) AVHRR sensor ( Advanced Very High Resolution Radiation). Therefore, the seasonal GVI change pattern can be used as a tool to generate vegetation map. In combination with the other data (climate, topology, etc.) GVI is also used as a tool to monitor a change from month to month on the same area or between area and area.

Since the promotion and education on the earth environment problem is needed, personal computer is the best tool to be used because of its price. However, the monitoring on the global scale needs a huge database. The objective of this paper is to introduce a system for the global change monitoring based on a personal computer. This system is prepared to be a GIS for evaluating of the potential productivity of vegetation in the future study.

Personal computer hardware configuration
Fig. 1 shows the hardware configuration of the personal computer used for this system. The main processor is a NEC PCd-9801VM which consists of 16 - bit microprocessor as CPU, mathematical co-processor, 640 KB main memory, 256 KB graphic memory , 40 MB hard disk drive, dual 5" floppy disk drives, analog color display, mouse and a magneto optical disk ( capacity 3000MB per side).

This system introduces the magneto optical disk ( MO DISK) which is a erasable optical disk, in order to avoid the storage capacity of the personal computer. Although the 130MB hard disk drive is also available and enough to store this database, the advantage of MO DISK is the portable feature like 3.5" floppy disk.

Since the user friendly is needed. A displayed image used the easy understanding color. Therefore. The limitation of this system is that the graphic has to support the 16 colors display.




Fig. 1 Hardware Configuration
Data
A database of this system consists of :
  1. Monthly maximum value of GVI from January 1984 to December 1985. The original GVI data which indicates the weekly density and vigor of green vegetation is the resampling data of the NVI (Normalized Vegetation Index) for the whole earth ( except parts more than 75N and 55S).
  2. Monthly average value of temperature and rainfall from January 1984 to December 1985, provided by the Japanese Meteorological Agency, detected at 2344 observation stations all over the world.
  3. Global Vegetation Map which is classified using the seasonal GVI change pattern from 1983 to 1987 [2].
  4. World elevation data on the mesh size of 5 minute
  5. Maximum, minimum and average temperature and rainfall at 2344 observation stations all over the world of the record from January 1930 to December 1960.
The reason to select the information of 1984 and 1985 as sample data in this system is that the latter half of 1982 till 1984, Africa was damaged by the drought which was estimated to be the worst in this century and this drought calmed down 1985. Therefore, the difference can be clearly seen from both weather and GVI data.

Since the personal computer a limitation of data storage and data accessing time, a data compression technology is involved. Concerning the displayed image had been classified to 7 categories, it is easy to apply the " run-length" data compression method [2]. Run- length is the most simple data compression method and does not need a big amount of computing time.

Software Functions
The software which drives this system was developed under C language, NEC-DOS environment. The functions of the system are as follows:



Select an interested area ( Fig. 3 )

Select an: interested _____________________Report the information observation station ( Fig. 4) at that observation station ( Fig. 5)

Comparison the vegetation between 1984 & 1985 on the interested month ( Fig. 6)

Comparison the whole year monthly Vegetation at the interested area ( Fig. 7Z)

All the selective is invoked through a mouse on the screen menu. Fig.3 shows the first menu for selecting the interested area. The size of the area is freely assigned by the user. Fig. 4 shows the second menu after the area was selected. This displayed image composes of vegetation map, boundary line and the location of the observation stations.

Conclusion
In this paper, we have presented the implementation of a software package for global change monitoring based on personal computer. The development of the software is ongoing task to become a GIS for evaluating of the potential productivity of vegetation at the final goal.

Reference
  • William K. Pratt, Digital Image Processing , A wiley - interescience, pp. 631 - 635.
  • Yoshiaki HONDA and Shunji MURAI, " Vegetation Mapping Using Global Vegetation Index and Weather Data", 10th ACRS, Kuala Lumpur , Malaysia, 1988, PP. A-2-4-1 - A-2-4-6.