Successfully building a geological hazard forecasting monitoring station in Chi Linh city, Hai Duong province
Research team installs automatic monitoring station for ground settlement, dynamics and properties of groundwater in Chi Linh city
Geological disaster in Chi Linh city
Currently, the geological environment in Hai Duong province in general and Chi Linh city in particular has been constantly changing due to endogenous and exogenous processes and human activities affecting nature during the development process. Geological disasters have appeared in many places, but there is not enough actual assessment data to propose effective prevention and treatment solutions (according to information from the Department of Natural Resources and Environment of Hai Duong province). From the natural characteristics of the area, the current situation of land subsidence and cracking has demonstrated the level of influence of groundwater on the ability to deform the surface, causing instability to civil works and local infrastructure. In particular, the area of Hoang Tan ward, Chi Linh city has geological environmental conditions that are strongly affected by tectonic activities causing surface destruction, at the same time the rapid urbanization makes this area susceptible to the impact of surface subsidence disasters.
The severity of geological disasters will increase as urbanization, industrialization and population growth take place strongly in areas with unstable geological environments. One of the main driving factors causing surface subsidence is the influence of groundwater. Therefore, regular updating and processing of information on changes in the dynamics and properties of groundwater is extremely important to assess the possibility of surface subsidence.
Currently, numerous monitoring methods related to subsidence are in use. Parameters related to the dynamics and properties of groundwater such as water level fluctuations, pore water pressure, pH, temperature are important indicators in forecasting geological disasters such as surface subsidence, earthquakes, landslides and underground erosion have been conducted for decades in developed countries, but are rarely applied in Vietnam.
Research results over the past years of the Institute of Geology have determined that the Hoang Tan ward area is located within the Trung Luong active fault zone, which has developed many cracks in recent times. Typically, a series of ground cracks appeared along the fault zone in the 1970s - 1980s, with some cracks extending over 10 km. With the goal of continuing to collect actual data as a scientific basis for forecasting the impact of surface subsidence disasters and effectively supporting the planning of socio-economic development in the locality, PhD. Nguyen Viet Tien and the research team proposed and were approved by the Academy to implement the topic: "Research on the construction of an automatic monitoring station for ground subsidence, dynamics and properties of groundwater to serve the forecasting of geological disasters in the Chi Linh city area" (code: CT0000.03/20-21).
Forecasting research
In this study, the authors conducted 4 rounds of investigation to collect documents, conduct field surveys and conduct 6 geological survey boreholes in the study area. Of which, 1 borehole was installed with 2 settlement measuring systems with pore water pressure sensors and 1 borehole was installed with pore water pressure measuring equipment and groundwater pH measuring equipment. At the same time, the group collected 39 soil samples and 6 rock samples for analysis of physical and mechanical parameters and mineral composition in the laboratory.
Borehole location diagram of the research area
From the analysis results, scientists have successfully designed and installed an automatic monitoring station for ground settlement, dynamics and groundwater properties to serve the warning of surface subsidence disasters. The construction site is located on the campus of the Institute of Geology's comprehensive crack measurement station (in Hoang Tan ward, Chi Linh city, Hai Duong province). The monitoring station is linked to the Institute's existing ground crack monitoring equipment system to supplement research results to serve the warning of related geological disasters and contribute to completing the network of geological hazard monitoring stations of the Academy in the northern region of Vietnam. Also in this study, the first database on changes in dynamics and properties of groundwater was built, updated and processed information regularly according to the real-time monitoring of the system.
Image of newly installed monitoring station system
PhD. Nguyen Viet Tien shared: The automatic monitoring station system for ground subsidence and groundwater dynamics has been designed to suit the geological characteristics of the research station. The series of recorded data and variable values are consistent with reality, and the parameters show no signs of abnormality. The recorded data of the monitoring station will serve well for geological hazard forecasting in the Chi Linh city area. For online monitoring and management, the implementation team proposed adding a telephone transceiver to directly transmit data to the internet. With modern equipment, the station system will promptly collect information to assess the risk of land subsidence, effectively serving the work of natural disaster management, minimizing damage to local residents. In addition, the new system has the ability to expand the monitoring channel for other environmental quantities to become a multidisciplinary monitoring station for the locality and supplement reliable data for analysis and evaluation as a scientific basis for subsequent studies. From the achieved results, scientists hope that the monitoring station system will soon be included in the monitoring station network of VAST to effectively serve the work of forecasting ground subsidence disasters.
Translated by Quoc Khanh
Link to Vietnamese version
