River Improvement so far
River improvement has taken place for the purpose of water conservancy and farmland reclamation. There are various types of river improvement, but in general the one which has taken place at Kushiro region was to straighten the river. This approach is very effective to lower the groundwater level and as a result of it, aridification of those area has been encouraged. Right figure shows an example of typical river improvement, which were taken place at Kayanuma area, midstream of Kushiro river.
However due to the hastened current velocity and concreated river channel, this type of river improvement would give negative effect to aquatic lives. In addition, it is recently advocated that river improvement ruin the nature beauty. |
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Comparison of before/after river improvement. (Put mouse on the figure to see "after" improvement) |
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