In recent years, flash floods and landslides have been common phenomena in mountainous areas, resulting in serious consequence for citizens, possessions and ecosystem. Despite the small scale, it is difficult to predict exactly when they take place. Therefore, prevention and control of such nature disasters are totally challenging.

   1.  Small scale – significant damage

      According to the report by The Central Steering Committee, from 2000 to 2015, there were 250 flash floods, landslides negatively affecting urban areas, causing 646 people to be lost, almost 351 people to be injured, over 9,700 buildings to be collapsed, more than 100.000 flooding, severely damaged houses. Over 75,000 hectares of rice fields and flower crops were submerged hundreds of hectares of crop-land were decimated a large number of traffic, irrigation and economic works got remarkably impaired the total loss got up to over 3,300 billion Vietnam dongs.

     Flash floods, landslides often take place in: Lao Cai, Ha Giang, Lai Chau, Son La, Cao Bang, Bac Kan, Yen Bai, Nghe An, Quang Nam, Ha Tinh, Kon Tum, Gia Lai, Dak Lak, Binh Thuan.

   2.  Causes of these disasters:

-          External factors: heavy rainfall, storm surges, slope angle, climate, weathering, water content, vegetation, overloading,... 

-          Human impacts: 

+ Unstable and uncontrolled land clearing

+ The burden of mineral exploitation and infrastructure projects to drainage system.

+ Land reclamation for buildings blocking the flow of the water.

+ Demographics' lack of awareness of disaster prevention when facing floods.

+ Ineffective campaigns, governmental agencies? light supervision.

  3.  Urge for creating maps of areas of flashing floods and landslides:

     Since 2006, the proposal for zoning and warning of the rate of landslides has been carried out in mountainous areas in Vietnam. The scientists have worked in 10 provinces, pointing out around 10,266 places that are prone to landslides, 2,110 of which stand a high, very high and especially high chance of damage.

     Up to now, the maps of real estate situations of landslides, geological structure and rainfall have been made for 10 Northern mountainous provinces, including Lao Cai, Yen Bai, Ha Giang, Tuyen Quang, Bac Kan, Lai Chau, Dien Bien, Son la, Thanh Hoa, Nghe An.

     Mr. Tran Tan Van, the head of the Institute of Geological and Mineral Science, said that the programme would last until 2020 maps of flash flood and landslide zoning would be created with an increasing rate, more detailed researches in order to inform the local authority and urban about the phenomena they are facing in their areas.

     'First and foremost, to decrease the chances of landslides, we need to have changes in public awareness as well as actions. Knowledge of floods, disasters must be ensured. Landslides can happen at any time after a storm. The local authority, together with the citizens, has to stay careful and cautious all the time to minimize the level of damage.'

     Although the local authority was always warned, there was still a lot of damage after the disasters, especially the 3th storm that took place in last August. It is time to call for more detailed maps for the sake of the habitants.

_____o0o_____

Reference : http://baotainguyenmoitruong.vn/moi-truong-va-phat-trien/201609/lu-quet-sat-lo-dat-quy-mo-nho-hau-hoa-lon-2732476/