Dalat is anxious in the rainy season

Rescuers search for victims of a landslide that caused a house to collapse in Tay Ho alley on the evening of November 19.

Special geological structure

Since the beginning of the year, the Lam Dong Provincial Hydrometeorological Station has continuously issued warnings about heavy rains, along with warnings of flooding and especially landslides. Data shows that the rainfall in Da Lat sometimes reaches 70 - 100 mm/24 hours, even peaking at over 140 mm/24 hours during the peak season from August to October. There are nearly 200 rainy days a year, even a record 206 days, causing the already weak and poorly cohesive soil and rocks to become saturated and prone to landslides. This is the external factor that awakens potential dangers underground in the Lam Vien highlands. The concern is not only on the mountain passes, but is evident even in the residential areas that have been formed for many years in Da Lat and are increasingly crowded.

According to the in-depth analysis of the Lam Dong Geographic Book (old), the engineering geology of the Da Lat urban area is divided into 3 groups. Of which, the group of medium mountain tectonic - erosion zones, distributed mainly in the high mountains in the North, the East slope of Da Lat and Prenn Pass, is assessed as "not suitable for the construction of civil works, industrial works, power lines, pipelines". Geological experts only recommend the construction of roads or small irrigation works in these areas.

Those scientific warnings have been verified by painful reality in recent times. After continuous heavy rains, weak geological areas such as Dang Thai Than, Dong Da, Hoang Hoa Tham and Tuyen Lam Lake have continuously experienced incidents such as falling trees, landslides, house collapses, and slope collapses, even causing loss of life and property. There have been deaths, injuries, and property damage due to slope landslides in Xuan Truong Ward - Da Lat. A slope landslide buried two people on the afternoon of August 12. Most recently, on the evening of November 19, a landslide occurred on the road leading to Tay Ho Alley, causing soil to fall on a resident's house, injuring a little girl.

Spontaneous slope "matrix"

Rapid urbanization and complex mountainous terrain have created a picture of unsystematic construction in Da Lat today. To have land to build houses, for a long time, decades ago, people and organizations were quite arbitrary in leveling, filling land, and building embankments. It is worth mentioning that this process in the past took place without strict management and lacked regulations suitable to each terrain feature in each area.

In the past, when population density was low, small houses had little impact. But as land values increased, the need for larger houses led to increasingly high slopes on hilly areas. More importantly, drainage systems - a vital factor in minimizing the risk of landslides - were often overlooked. Many residential areas on the edge of forests today do not have wastewater collection systems. As a result, slopes easily become "time bombs" ready to collapse at any time during heavy, prolonged rains.

Faced with the recent complicated developments and serious consequences, the provincial and ward authorities have continuously issued documents directing the strengthening of inspection, review, and prevention of landslides and slopes. Construction management, especially regulations on slope construction, are also regulated and managed more strictly. However, in reality, these directives have not been able to completely prevent landslides.

It is time for geological notes and notes to not just be lines of text in books, but to become the foundation for all development and planning decisions so that the city of thousands of flowers, Da Lat, is truly a livable, safe and sustainable place for both residents and tourists.

Source: https://baolamdong.vn/da-lat-thap-thom-mua-mua-404108.html