Monitoring NDVI of North Korea using NOSS AVHRR data
exploring the possibility of early warning system of agricultural production
Result
Fig. 3. is a map of Korea Peninsula. We assume low fat area is almost agricultural land in North Korea.
Fig. 3. Map of the Korea Peninsula
(conic projection)
(Copyright © Teikokushoin Co., Ltd.)
Fig. 4 and Fig. 5. is the NDVI image of Korea in Aug of 1992 and 1997. The data of 1992 have some noses in the northern part of the Korea Peninsula. Except these noises, we can see some changes, which indicate the decline of NDVI value, in the low fat area of North Korea. (darker area corresponds lower NDVI area on the gray scale). On the other hand, it seems that in South Korea almost all area maintains approximately the same NDVI value. (It should be noted that the NDVI values are low because of clouds in the east of South Korea.)
Fig. 4. NDVI image of Korea Aug/1992 (Mercator projection)
Fig. 5. NDVI image of Korea Aug/1997 (Mercator projection)
Conclusions and Future Prospects
In North Korea, relative higher NDVI values are observed in 1992 rather than in 1997,
while South Korea almost all area keeps the same values approximately. We can conclude NDVI data from AVHRR data can be used for detecting relatively large-scale decline of agricultural production. The problem remained to be solved are
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how to prevent geometric correction errors in case of its is hard to capture coastal lines for GCP's due to cloud over.
- how to calibrate fluctuations of NDVI values by observational time.
- how to remove occasional noises and clouds.
As we have mentioned the severity of these problems almost seem to depend on the data.
The following are further perspectives.
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By comparing with the images of Landsat, we will check how accurate this
observation from AVHRR data is.
- Based on this case study in North Korea, we will explore the possibilities of anticipating the crisis of food shortage using a satellite data on the real-time basis.
References
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PaNDA Committee, 1993, PaNDA operation manual, PaNDA Committee.
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1997. FAO/WFP crop and food supply assessment mission to the Democratic People's Republic of Korea, FAO Global Information and Early Warming System on Food and Agriculture World Food Program SPECIAL ALERT NO. 1275/06/97.
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JARS, 1996. Wakariyasui remote sensing system and geographic information system, JARS : 166-167. (in Japanese)
