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Abstract:
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Reason of the recurrence of the historical flash flood (with cycle of 70 years) in 2002 in Ha Tinh province is determined based on the results of analysis of the relation between 3 elements: Thien (the weather), Dia (geomorphological and geological characteristics), Nhan (human activities). The human activities in recent years, such as destroying the forest, making new roads... had increased the intensity of the flash flood. The interaction between form of Ngan Sau River valley and raining efficient blasts caused big raining and made Ngan Sau river become a hight raining navel. Huong Son, a district of Ha Tinh province, locates nearby the position of flood exit from Ngan Sau River entering Ca River, so it was damaged most heavily by flash flood in 2002.
In the future, if the flash flood happens again, the form of flood will be basically similar to flood in 1934 and 2002. In order to mitigate the flash flood, it is necessary to recover the forest and move inhabitants from the way of flow to safety places. |