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Oceanography / Meteorology
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Investigation on Tidal Land Reclamation in Korea Using Satellite Image Data
1.1 Coming in and going out of fish through the locks.
Many fish go up a river from sea to return to sea from river mouth n certain season. This fishways are often attached to an enclosure dike as necessary facilities. However, it was confirmed that fish of a particular species rushed to the locks and went up the river in Yangasangan stage-3. The phenomenon was recorded by a vidgo-camera and television latter. The particular type of fish seemed to be attar ached because some water quality component (small) of the water flowing from upper stream spreaded over the sea surface when the locks were operated. Based on this experience, the locks are operated positively at appropriated Limes now to let particular types of fish go up the river of retrn in the area.
1.2 Cultivation of the drained land y by farmers
In Yangasangan projects Stage 3-1, the enclosing dike of Yangan Ho was completed in 1991 and the salt water in the bottom layer of the upstream desalted lake was drained by gate operation and desalting conduits. The link canal from Yangasangan estuary dam has also been completed permitting a gradual desalting of the lake and the mean salt concentration decreased to 1,700 ppm. A August 1996.The inside water level has been maintained lower than the outside water level(between 0.02 and -1.45)resulting in draining of all the lands which had once been tidal flats although polder dike, irrigation and drainage canals, or roads inside the area have not been touched officially yet. However, because the salt concentration decreased in the past 5 year and the lands which had been tidal flats were desalted by rainfall, the inhabitants in the vicinity of the area have consolidated the land arbitrarily without permission and started cultivation of rice and others by constructing irrigation canals. According to the field office, tempo ration farm lands consolidated by the inhabitants will be reconstructed once the official land consolidation and construction of drainage pump system and polder dikes these are started.
In Yangasangan Project Starge 3-2, the enclosing dike of Keum Ho was completed in 1993. Here drain bottom slat water and maintaining the inside water level lower than the outside have also operted. However the cancentration of Keum Ho Lake has Lake has not decreased below 17.000 ppm because only small river basin is providing fresh water flowing into the reservoir and the link canal to yangan Ho lank is incomplete.
The present state and future plan of Saemankeum comprehensive tideland reclamation project3)
This is the project which has been planned and put into practice regimentation experiences and results of the water area reclamation projects over several projects over several decades in the past to deal with land and water demands in recent years in Korea. The project plan prepared in 1989 was finally put into practice in 1991 after much meandering.
Fig. 1 Shows the conceptional drawing at completion. A period of 14 years is estimated for the whole project; 8 years for construction of water-use facilities including sea dikes and 6 years for construction of roads and bridges inside the drained land, establishment of irrigation and drainage canal networks and consolidation of land. The main facilities include the sea dike extending over 33 km, which is longer than the length, 32.5 km, of the enclosing dike for Zuyderzee, the Netherlands4), and 40,100 ha of land in total comprising 18,900ha of land for agriculture and fish cultivation, 11800 ha of desalted, reservoir, and 9,400 ha urban and industrial lands. Resort land for tourists and settlers acreage have also been integrated. Since lack of water is predicted if inflaming Mankyon river and Donjin river where the only water resources, construction of a 16-km link canal to Kumgang estuary dam being constructed in the north adjacent to the project area is planned to integrate excess water of some 450 million m3 to be developed for agriculture, industry urban life and resort project.
Figure 1 Land use plan of Saemankeum comprehensive tideland reclamation
On Gogunsan Islands off shore of the project area, construction of port facilities, resort facilities and new piers has been planned and construction of a railway connecting these facilities and Seoul passing thought the adjacent Kunsan city is coming within the range. Provided that this kind of social basis is developed in this project area, the area will play the role of an advance base building up the west coast era. Fig. 2 shows the state of progress of the construction works as far as 4.7 km of the section 1 of the enclosing dike in August, 1996. Construction of the drainage gate of Dongjin river is planned here.
Figure 2 Radial gate will be constructed where joint place between section 1 and section 2 of closing dike.
2. Application of satellite image data
Fig. 3 shows the map of whole Korea. The large -scale projects mentioned above are developed in the areas including Mokpo and Kunsan. The 3 frames show the areas covered by the satellite images, shown Figs. 4,5 and 6, respectively. Table -1 shows he satellite image data of our possession applicable to these areas.
Figure 3 Total map of Korea and covering areas by SPOT-XS, SPOT-PN, and Landsat TM.
Table 1 List of Satellite Data applicable to Study areas
| No | Objective area mission | obs.data | pass-row |
| 1 | Saemankeum | MOS-11993.02.02 | 29.70E |
| 2 | Saemankeum | SPOT-XZ | 1993.10.08 | 304-278 |
| 3 | Saemankeum | SPOT-PN | 1993.08.23 | 304-278 |
| 4 | Yangasangan | Landsat-3 | 1979.07.05 | 124-36 |
| 5 | Yangasangan | MOS-1 | 1993.02.02 | 29-71E |
| 6 | Yangasangan | Landsat-TM | 1992.09.22 | D116-036 |
| 7 | Yangasangan | Landsat-TM | 1994.09.28 | D116-036 |
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