Field Prediction and Potential Monitoring of Cassava Production
in Nakhon Ratchasima
3. Analysis and Results
3.1 Relieves of Kiyomizu cliff-surface stone Buddha in Kagoshima-ken
The target cliff area extends for 20 meters high and 400 meters long. About two hundreds of relieves were carved on the cliff surface from the thirteen century. Relieves that are called "three Sanskrit words" and "the five-storised pagoda" are selected in this study. They are carved outdoors and directly affected by sunbeams. The surface temperature change gives the difference of about twenty degrees twenty degrees centigrade in winter. Table.2 shows environmental parameters at the tome of data acquisition.
Table.2 Environmental parameters at the time of data acquisition in Kiyomizu
| |
Three Sanskrit words |
The five-storied pagoda |
| Date |
1994.02.02 |
| Thermal video |
JTG-4230 |
| Distance (M) |
80 |
10 |
| Time |
7:15 |
11:39 |
8:55 |
14:30 |
| Air temperature(°c) |
8.5 |
11.3 |
9.0 |
11.1 |
| Humidity (%) |
68 |
62 |
58 |
55 |
(1)The case of "three Sanskrit words"
Thermal images of "three Sanskrit words" were taken from the opposite side of the river far from about 80 meters. This cliff has an irregular surface. The relief was carved at about 13 meters high.
The subtracted thermal image is shown in Photo.1 and the weathering distribution map is shown in Figure.4 as the reference. This map was made by the photo interpretation and the size survey. Large temperature change areas on the upper cliff face to the southwest, because the surface that the flaking and covering splitting areas indicates larger change than another areas in the upper area of the cliff. The lower side of the cliff is hidden by trees except the center of the lower area. In this center area, the large change area is flaking and is covered by splitting.
Photo 1 The subtracted image of "three Sanskrit words"
Figure 4 The weathering distribution map of "three Sankrit words"
(2)The case of "the five-storied pagoda"
"The five-storied pagoda" is carved on the stone of 10 meters high. This relief faces to the east. The surface of the relief makes the shade after the noon. The subtracted thermal image and the distribution map are shown in Photo.2 and Figure.5 each other. The surface temperature change was smaller than the case of "three Sanskrit words". As small river flows near the relief, the stone carved the relief is apt to be percolated by the ground water. However the lower area of the relief indicates large temperature change than the upper. This lower side corresponds to the area that is covered by splitting and flaking area.
Photo 2 The subtracted image of "the five-storied pagoda"
Figure 5 The weathering distribution map of "the five-storied pagoda"
3.2 The relief of "Moto-machi stone Buddha" in Oita-ken
The relief of "Moto-machi stone Buddha" was carved in the eleven century. The relief is inside of the shrine and is not affected by sunbeams. As the inner air temperature change are not large, the surface temerature change of relieves are smaller than the case of "three Sanskrit words" in Kiyomizu. Table.3 shows environmental parameters at the observation time.
Table.3 Environmental parameters at the observation time in Moto-machi
| |
The relief of Buddha |
| Data |
1995.02.16 |
| Thermal video |
JTG-5700 |
| Distance (m) |
3 |
| Time |
6:24 |
10:13 |
14:37 |
19:20 |
| Air temperature (°c) |
2.1 |
9.5 |
10.7 |
8.1 |
| Humidity (%) |
73 |
50 |
45 |
60 |
The relief is weathered by the flaking and the deposition of the chloride. The water condition in the relief related to the deposition. The chloride deposits with the evaporation activity from the surface of the relief.
As four images were used in this case, the method of the addition operation was carried out for
the analysis of the relief. The added image and the distribution map of the weathering are shown in Photo.3 and Figure.6each other. The left earlobe, the jaw and and right bosom show the large surface temperature change. There are the weathered or repaired area. The area from the jaw to the lower lip will be in danger of flaking off in the near future. The nose and the cuff of the right hand show the large difference of the temperature change, because projections and edges of the object rise the surface temperature in a daytime. Although these areas do not indicate the weathering, they may be weathered in future.
Photo 3 The added image of "Moto-amchi stone Buddha"
Figure 6 the weathering distribution map of "Moto-machi stone Buddha"
4. Conclusion
It was conformed that the method by using thermal infrared video images was effective for the prosirvation of the weathered stone relics. Advantages of this method are as follows.
- The target is not destructed by this method.
- It can display an untouchable place like a high cliff.
- The weathering condition is able to be objectively estimated.
- It is possible to map the two-dimensional distribution of the weathering.
Notices of this method are indicated as follows.
- Thermal images are affected by meteorological environments.
- Edges or projection of the object tend to change the surface temperature largely.
To relax the effect of (a), it is necessary that images are taken in a same day as possible. On the case of (b), it is better that the surface from is checked when thermal images are taken, and the pronominally study is done before the analysis.
Acknowledgments
The authors are grateful to Prof. Nishida for the useful advice. Sigeeyuki Tohyama and Ryuichiro Egawa always gave helpful comments during this analysis.
References
-
Saito, K and Y.Yamano(1995), The Use of Thermal Images for the Preservation of Relieves of Buddha on a cliff, Journal of the Japan Society of Photogrammetry and Remote Sensing, vol.34 no.1, pp.2-3.
- Inoue, M., J Kanmura, K. Saito, Y. Yamano, S. Tohyama and K. Nishida (1995), An Examination on Weathering Condition Analysis of Cliff-surface Stone Buddha Images by Using Thermal Infared Sensor, Reports of the Symposium of Preservation Techniques for historicsites ,international
society for soil mechinics and Foundation Engineering, pp. 47-52.
