From the achievements made in the field of geological disaster monitoring instruments in recent 10 years, the following are selected as representatives.
1. Multi-parameter acquisition and transmission instrument for geological disasters
Aiming at the present situation of domestic geological disaster monitoring industry, based on the advantages and disadvantages of various working modes widely used in the field of geological disaster monitoring at home and abroad, a multi-parameter acquisition and transmission instrument for geological disasters is developed. The sensors that can be connected include pull rod displacement sensor, pull rope displacement sensor, magnetostrictive displacement sensor, ground sound sensor, rainfall sensor, water content sensor, mud level sensor, tilt sensor, etc. Through the combination of these sensors, it can be used to monitor landslide, debris flow, collapse, land subsidence and other fields respectively. The collected data is transmitted to the back-end data monitoring center server by TCP/IP through the GPRS network of China Mobile for display and storage. If there is no GPRS signal on site, data can be transmitted by SMS via Beidou satellite. The system block diagram is shown in figure 1, and the physical object is shown in figure 2.
Figure 1 Block diagram of multi-parameter acquisition and transmission instrument for geological disasters
Main technical indicators:
1) sampling mode: timing acquisition, remote setting of acquisition time;
2) Analog input channels: 4 channels;
3)A/D resolution: equivalent to 16 bits;
4) Digital input and output channels: rainfall switch input and alarm switch output;
5) Working temperature:-30 ~ 50℃;
6) Transmission mode: China Mobile GPRS or Beidou satellite short message;
7) Power supply voltage: DC 12V, AC /DC dual-purpose power supply.
Fig. 2 Host and supporting sensors of geological disaster multi-parameter acquisition and transmission instrument
2. Landslide early warning extensometer and crack alarm
These two instruments are mainly used to monitor the changes of cracks, and when they reach the preset alarm threshold, they send out evasive alarm, which can replace manual patrol and be used to monitor landslides, ground subsidence or house cracks. The working principle of landslide early warning extensometer is shown in Figure 3, the working principle of crack alarm is shown in Figure 4, and the real object is shown in Figure 5.
Fig. 3 schematic block diagram of landslide early warning extensometer
Main technical indicators:
1) monitoring range: landslide early warning extensometer 0 ~ 1000 mm, crack alarm 0 ~1000 mm;
2) Monitoring accuracy:1mm;
3)A/D resolution: equivalent to 16 bits;
4) Alarm sound pressure: landslide early warning extensometer 105dB, crack alarm100db; ;
5) Power supply voltage: the landslide early warning extensometer is 12V alkaline battery, and the crack alarm is 3V alkaline battery.
On the basis of using the alarm, the landslide early warning extensometer adds the function of remote alarm by using the wireless switch module, and the host computer installed in the residential area can receive the alarm signals sent by multiple landslide early warning extensometers, as shown in Figure 6.
Fig. 4 principle block diagram of crack alarm
Fig. 5 Landslide early warning extensometer and crack alarm
3. Distributed conductance geological disaster monitoring device
The invention is mainly used for seawater intrusion monitoring. By collecting the conductivity values of well fluids at different depths in seawater intrusion observation wells, and determining the boundary of salty and fresh water according to the conductivity values and the depth of the wells where the electrodes are located, the monitoring of geological disasters such as seawater intrusion can be completed conveniently, quickly and accurately.
The distributed conductivity geological disaster monitoring device consists of a host computer, cables and distributed measuring electrodes. 30 measuring electrodes are arranged in the observation well, and the electrode spacing is 1m, and each electrode is connected to the digital output pin of the host computer through a relay. The host computer controls 30 relays to turn on and off 30 electrodes in turn after a predetermined time. The data collected by AD is stored in the memory of the upper computer, and the monitoring effect is shown in the form of curve in the subsequent processing. See Figure 7 for the system block diagram, Figure 8 for the working opinions and Figure 9 for the physical objects.
Fig. 6 Landslide early warning extensometer with wireless alarm function
Fig. 7 Block diagram of distributed conductance geological hazard monitoring device
Fig. 8 Schematic diagram of distributed conductance geological disaster monitoring device.
Fig. 9 Distributed conductivity geological disaster monitoring device
Main technical indicators:
1) conductivity monitoring range: 500μ s/cm ~ 0.3s/m;
2) Measurement accuracy:1%;
3) Power supply: DC 12V, AC /DC dual-purpose power supply;
4) Working environment temperature:-5 ~+40℃;
5) Maximum control range of electrode: 24m.
4. Debris flow monitoring, analysis and early warning device
Figure 10 Block diagram of debris flow monitoring, analysis and early warning device
Figure 1 1 Debris Flow Monitoring, Analysis and Early Warning Device
It is the key to carry out the study of debris flow early warning and obtain accurate and reliable data. The monitoring, analysis and early warning device of debris flow is designed according to the main parameters of debris flow characteristics. The frequency of the debris flow geo-acoustic signal is low, and its dominant frequency is much higher than other frequency components (environmental noise), which provides favorable conditions for us to detect and identify the signal. The intensity (amplitude) of debris flow geo-acoustic signal is directly proportional to the debris flow scale, and the scale can be determined through the collection and analysis of debris flow geo-acoustic data, and early warning can be carried out according to the scale. By collecting and analyzing the intensity, frequency range and duration of debris flow ground sound, we can preliminarily find out the activity characteristics, distribution law and development trend of debris flow ground sound, provide effective prevention and early warning technical scheme, promote the improvement of debris flow disaster prevention and control ability, and provide technical support for geological disaster monitoring and early warning. See figure 10 for the system block diagram and figure 1 1 for the physical object.
Main technical indicators:
1)A/D resolution: equivalent to 12 bits;
2) Sampling interval:10 ~ 50μ s;
3) frequency band:1~ 500 Hz;
4) gain of program-controlled amplifier: 5 ~ 1000 times program-controlled and adjustable;
5) Number of channels: 3 sensor signals, using MSD bus protocol;
6) Working environment temperature: 0 ~+40℃;
7) power supply: DC 8 ~ 28V, AC /DC dual-purpose power supply.
5. Distributed geological disaster monitoring acquisition and transmission instrument
At present, the geological disaster monitoring instruments developed and applied are mainly connected with the front-end sensors through cables. The main disadvantage is that wiring is difficult and the number of connected sensors is limited, which is not suitable for monitoring environment with complex terrain and many monitoring points. The distributed geological disaster monitoring, acquisition and transmission instrument adopts IEEE802. 15.4 protocol in the physical layer and MAC layer, and ZigBee protocol in the network layer, which reduces power consumption, simplifies routing algorithm, effectively increases the number of sensors, and has great advantages over wired mode. See figure 12 for the block diagram of the instrument system and figure 13 for the physical object.
Figure 12 Block diagram of distributed geological disaster monitoring, acquisition and transmission instrument
Main technical indicators:
1)A/D resolution: equivalent to 16 bits;
2) Networking scale: 1 host, 10 collector;
3) Wireless fidelity: 780MHz, mesh network topology conforming to ZigBee specification;
Figure 13 Distributed Geological Disaster Monitoring, Acquisition and Transmission Instrument
4) Collector power supply: 3.6V battery;
5) Mainframe power supply: DC 12V, AC /DC dual-purpose power supply;
6) Working environment temperature: -20 ~+40℃.
6. Geological disaster monitoring and prevention and early warning information management system
Geological disaster early warning information management system includes stand-alone version, B/S version, publicity website and C/S (three-dimensional) version. The stand-alone version of the system is developed based on VB+MapObject component development mode, and the map format is shp format, which is mainly used for the input and management of basic information of group prevention and treatment. The software is shown in figure 14.
Figure 14 Single-machine software of geological disaster group monitoring, prevention and early warning information management system
The B/S version of the system is developed based on the network, and the secondary development function of SuperMap is.net Platform of SuperMap Company is applied. Through the network, the management functions such as real-time query of monitoring data, management of group monitoring and prevention system, data entry according to authority, two cards and one table entry and query of group monitoring and prevention are realized, which greatly facilitates the management of disaster points and group monitoring and prevention points by local managers. The software is shown in figure 15.
The monitoring information network of geological disaster group monitoring and prevention is a website developed for the research and development of group monitoring and prevention technology, the achievement display of demonstration projects and the promotion of instruments. The website publicizes the main achievements of the project and the importance of geological disaster monitoring through news, project overview, instrument introduction and popular science. It is planned to realize unified publicity of geological disaster monitoring in the future. The software is shown in figure 16.
Map 15 B/S version of geological disaster group monitoring and prevention early warning information management system software
Figure 16 Website Software of Geological Disaster Monitoring, Prevention and Early Warning Information Management System
The C/S version (3D) is developed on the basis of the previous B/S version. Based on the three-dimensional geographic information component of iTelluro, the system realizes the integrated management of geological disasters, early warning plans, group monitoring and prevention and monitoring information in three-dimensional environment. Based on the plug-in secondary development interface, customized services such as prevention and control decision-making and comprehensive management can be quickly realized. The software is shown in figure 17.
Map 17 C/S version of geological disaster group monitoring and prevention early warning information management system software
Second, the scope of application and application examples
The application of 1. demonstration area
Figure 18 Multi-parameter Acquisition and Transmission Instrument for Geological Hazards in Shuifu Railway Station
Figure 19 Distributed geological disaster monitoring and acquisition transmitter installed in Daguan Vocational Middle School
The instruments developed above have been applied in Zhaotong demonstration area of Yunnan Province. Three sets of geological disaster multi-parameter acquisition and transmission instruments were set up in Shuifu County to monitor the parameters of rainfall, displacement and water content (figure 18). 150 landslide early warning extensometer, 300 crack alarms and 3 sets of debris flow monitoring, analysis and early warning devices were installed in Shuifu County, Yanjin County and Daguan County. Install a set of distributed geological disaster monitoring, acquisition and transmission instrument in Daguan Vocational Middle School (Figure19); Distributed conductivity geological hazard monitoring device has been used to monitor seawater intrusion in Nandaihe, Hebei Province and Changyi, Shandong Province (Figure 20); The geological disaster early warning information management system has been applied in Zhaotong City, Yunnan Province. The topographic maps and image maps of the main counties in Zhaotong City, Yunnan Province have been edited, and 882 disaster points and 8 professional monitoring points have been recorded.
Fig. 20 Distributed conductivity geological disaster monitoring device installed in Nandaihe, Hebei Province.
2. Promotion and effect
1) During the post-earthquake reconstruction work in Wenchuan in 2008, 5,000 sets of landslide early warning extensometers and 85,000 sets of crack alarms were produced for the Wenchuan disaster area (Figure 21); In the post-earthquake reconstruction of Yushu, Qinghai, 40 sets of landslide early warning extensometers were installed; In Anxian County, Sichuan Province, Zhaotong City, Yunnan Province, the early warning and forecasting was successful four times (Figure 22).
Figure 2 1 shows the production and assembly of 90,000 sets of crack alarms, landslide early warning extensometers and supporting equipment in Wenchuan disaster area.
Figure 22 Alarm materials
2) Multi-parameter collection and transmission instruments for geological disasters were installed in Kangding, Sichuan (Figure 23), 2 in Liangzi landslide in Fengdian, Zhongjiang County, Sichuan Province (Figure 24), 73 in Zhouqu post-disaster recovery and reconstruction planning area (Phase II) (Figure 25), and 16 in monitoring and demonstration of important hidden dangers of geological disasters (Figure 26).
3) Six sets of debris flow monitoring, analysis and early warning devices have been installed in the Shentan and Mentougou mining areas in Huairou, Beijing (Figure 27), and nine sets have been installed in Kangding, Sichuan (Figure 28), all of which are working normally at present.
3. Application prospect
The destructive power of geological disasters is enormous, causing harm and destruction to human life and property and the resources and environment on which human survival and development depend. The popularization of these instruments can not only make the development unit produce good economic benefits, but more importantly, it can timely warn geological disasters and minimize the loss of people's lives and property and the damage to the environment through application. This value cannot be estimated by economic indicators. According to this mode of operation, we can give full play to limited funds and maximize social and economic benefits.
Fig. 23 Kangding site in Sichuan.
Fig. 24 Ruins of Liangzi in Fengdian, Sichuan.
Figure 25 Zhouqu Site in Gansu Province
Figure 26 Liaoning scene
Figure 27 Huairou scene in Beijing
Fig. 28 Kangding site in Sichuan.
Third, promote the transformation mode.
1. Apply for intellectual property patent protection
Debris flow monitoring, analysis and early warning device has been patented, as shown in Figure 29. The multi-parameter acquisition and transmission instrument for geological disasters, landslide early warning extensometer and crack alarm have obtained utility model patents, as shown in Figure 30 to Figure 32. The geological disaster monitoring, prevention and early warning information management system has obtained the copyright of computer software, as shown in Figure 33. The invention patents of distributed conductance geological disaster monitoring device and distributed geological disaster monitoring acquisition and transmission instrument passed the preliminary examination.
Fig. 29 Patent Certificate for Invention of Debris Flow Monitoring, Analysis and Early Warning Device
Fig. 30 Patent certificate of utility model for multi-parameter acquisition and transmission instrument of geological disasters
2. Training, publicity and communication
In the post-earthquake reconstruction work in Wenchuan, a lot of on-site training and guidance work was carried out (Figure 34); Nine technical equipment and software developed by the group monitoring and prevention project were listed as nine practical technologies for geological disaster prevention and control on behalf of the Ministry of Land and Resources in the Practical Technical Manual for Reconstruction after Rain, Snow and Freezing in South China issued by the Ministry of Science and Technology in 2008 and the Practical Technical Manual for Emergency Response to Earthquake Secondary Disasters compiled by the National Disaster Reduction Committee and the Earthquake Relief Expert Group of the Ministry of Science and Technology. In March, 2009, a publicity report was made at the National Geological Environment Work Conference, and monitoring and early warning instruments for group monitoring and prevention were exhibited. In May, 2009, a publicity report was made at the conference on prevention and control of geological disasters in Yunnan, and the installation, maintenance and application of instruments were trained. In July, 2009, the publicity materials of group monitoring and prevention instruments were distributed at the national conference on prevention and control of geological disasters in flood season. In July, 2009, he co-organized the communication training meeting of geological disaster group measurement and prevention in Zhaotong City, compiled the publicity manual of group measurement and prevention knowledge and the instruction manual of monitoring and early warning series instruments of group measurement and prevention, and recorded the publicity video program of group measurement and prevention knowledge. In September, 2009, he made a publicity report at the conference on prevention and control of geological disasters in Hebei Province, and trained the installation, use and maintenance of instruments. From June 5, 2009 to 10, he made a special report and instrument display at the National Geological Disaster Emergency Prevention Conference (Changsha). From June 5, 2009 to 10, the Ministry of Land and Resources conducted a geological disaster emergency drill in Huangshi, and these instruments participated in the drill. From June 5th to February, 2009, the Southeast Asia International Landslide Conference made a multimedia report, showed the instruments, and published the paper "Application of Low-cost Monitoring and Alarm System in China".
Figure 3 1 Patent Certificate of Utility Model for Landslide Warning Telescope
Fig. 32 Patent certificate of crack alarm utility model
Fig. 33 Copyright certificate of computer software of geological disaster group monitoring, prevention and early warning information management system
Figure 34 Installation Training Guide in Disaster Area
Technical support unit: Hydrogeological Environmental Geological Survey Center of China Geological Survey.
Contact: Zhang Qingcao Xiuding
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E-mail: zhqn123 @163.com.