The Four Major Rivers Restoration Project can be described as mutually beneficial enterprise. After scraping out deposits on river bed to prevent flood and customary inundation, we do farmland remodeling using dredged soil from the work. That has an effect of prevention for inundation by raising the ground which had been frequently damaged because of lower than the level of river. Dredged soils gained from the Four Major Rivers Restoration Project up until now exceeded 100 million m2, and those are to be used to raise the existing agricultural grounds through strict inspection under the Soil Environment Preservation Act.
Inundation-prone riparian farmland in need of measures
Clues for resolution are to be found just around its question. When a doctor treats a patient, only accurate diagnosis can result in accurate prescription. That's why to grasp the exact state is very important.
Having longed for increasing product of food with even limited land area, it somehow successfully contributed in self-efficiency of rice that creating many paddies around the riparian area. However, those riparian paddies almost belong to flood-prone area. In this rainy season of august, keyword of 'inundation' ranks high on web search directory.
Climate in Korea can be characterized with 'localized torrential downpour' in summer. At the point of view from soil, erosion by heavy rain is something chronic to worry about every summer. Additionally, in case that particle of soil in water inflow to large river so to get lose its velocity, accumulated sediment cause higher river bed than the level of adjacent farmland. In pedological point of view, riverside soils contain much sand ingredients so that is suitable to utilize for dry field rather than rice paddy. However, as rice is the suitable and durable for inundation-prone condition of location, ironically it is inevitable to use the area as rice paddy because of not pedological but locational condition.
To improve these areas prone to flood, government has run the drainage enhancement works with investing budget annually. The targeted area is much of 232,000 ha, and as of 2009, 62.6% were completed but still left 87,000 ha.
Raises low-lying farmland and its utilization coefficient
There are active farm remodeling enterprises to improve agricultural environment; to raise the riverside lowland farming ground utilizing dredged soil out of Four Major Rivers Restoration Project; to rearrange farmlands in better shape and quality; to solve the problem of habitual inundation; to improve agricultural infrastructure resulting in increasing coefficient of utilization.
How to switch to high income crops is meaningful because of structural conversion for farmland
Conjuring up the situations after this works, several validities could be drawn easily. First, it is possible that permanent prevention for seasonally repeating inundation. Second, not to say this work, facilities maintenance is essential. The timeworn agricultural infrastructure facilities are to be replaced into new ones. Third, due to agricultural environment improvement, alternation land usage between dry field and rice paddy came to be possible, in some cases; high-tech farming and large-scale agricultural complex could be developed.
At this point, I would like to add one more thing. At present, Korea is one of biggest agricultural products importation countries, despite oversupply with rice. Even at this time government grapples with problem of stock rice. This work of farmland remodeling would contribute to switch to high-income crops, at the same time; balance in rice supply in government level would be stabilized at all. It can be said that significant meaning lies on the fact that not by huge budget consuming policy but by just remodeling-level work we can reform the whole structure of arable lands.
Out of concern for deliberate work, as pedologist, I hope that field workers and interested party do not fail to refill the precious original fertile surface soil after mounding with dredge soil.
Written by LEE Seung-Heon, senior researcher & deputy director, a doctor of agriculture, soil environment technologist / Korea Rural Community Corporation
