Task and deployment of national geological disaster investigation and planning

According to different purposes, serving different fields, and adopting different precision, the national geological disaster investigation work is fully deployed from three levels: point, line and area (Figure 6. 1).

6.3. 1 Continue to complete the national geological disaster survey in mountainous and hilly areas (1:110,000).

By 2008, the survey of geological disasters in 6.77 million square kilometers of mountainous and hilly areas in China will be completed in an all-round way, the monitoring and prevention system of geological disasters will be established in an all-round way, and disaster prevention plans will be drawn up to fundamentally and effectively protect people's lives.

(1) Main tasks

1) under the guidance of the principle of "people-oriented", find out the distribution of geological disasters or hidden dangers and make geological disaster zoning;

2) Through investigation, comprehensively analyze the causes, occurrence conditions and hazard characteristics of geological disasters, and delineate the areas prone to geological disasters;

3) Actively serve local governments in disaster reduction and prevention, and assist local governments to establish and improve the geological disaster monitoring system combining group and specialty;

4) Carry out information integration and comprehensive research, study the influence of different inducing factors on geological disasters in geological disaster-prone areas, study the theories and methods of determining the critical value of geological disasters induced by various inducing factors, especially the relationship between rainfall and geological disasters in mountainous areas, study the theories and methods of geological disaster prediction and early warning, explore more effective means of geological disaster prevention and control, and improve the ability of geological disaster prediction and early warning;

5) Through investigation, the archives of hidden danger points of geological disasters are established, and the geological disaster information system is established.

(2) Work deployment

Geological disaster investigation area is a mountainous and hilly area where sudden geological disasters develop, and counties (cities) are the basic units to carry out investigation work. At present, the mountainous and hilly areas and their transitional zones in China cover an area of 6.77 million km2, accounting for 1583 counties (cities). According to the plan, by 2005, the land and resources survey of 700 counties (cities) will be completed, covering an area of about 2.08 million square kilometers.

In 2004 ~ 2005, the geological hazards survey in 84 counties (cities) was completed.

From 2006 to 2008, 4.69 million square kilometers of geological disasters in 883 counties (cities) were investigated, and a comprehensive monitoring system for monitoring and prevention of geological disasters was established.

6.3.2 Carry out1:50,000 ~1:250,000 plain geological disaster survey.

In plain areas, a geological disaster survey of1∶ 50,000 ~1∶ 250,000 was carried out in view of geological disasters such as land subsidence, ground fissures and ground collapse. Before 2008, the geological disasters in the Yangtze River Delta, North China Plain and Wei Fen inland basin will be investigated * * *1610000km2; Before 20 10, geological disasters in Songnen Plain, Liaohe Basin and Pearl River Delta have been investigated139,000 km2.

6.3.3 Geological hazard investigation of1∶ 50,000 shall be carried out in important economic zones, major engineering zones and areas with high risk of geological hazards.

From 2006 to 20 10,1:/kloc-0 was carried out in 14 geological disaster-prone area (area dominated by sudden geological disasters/0.5 million km2, area dominated by slow geological disasters/200,000 km2), six major engineering areas and important economic zones.

(1) Main tasks

1) Prepare the Technical Requirements for Geological Hazard Investigation of1∶ 50,000;

2) Formulate "1∶ 50,000 geological disaster risk assessment methods and standards";

3) Carry out geological disaster investigation in 14 large area and 6 key engineering areas1∶ 50,000, carry out risk zoning and put forward prevention suggestions;

4) Establish a survey database.

(2) Work deployment

In 2006-2007, geological disasters were investigated in the loess plateau, eastern Gansu, southern Qinghai, Qinba Mountain area, eastern Sichuan and western Hubei, Yangtze River Delta, North China Plain, West Route of South-to-North Water Diversion Project, West-to-East Gas Transmission Project and Baocheng Oil Pipeline (1∶ 50,000) to the west of Luliang Mountain.

From 2008 to 20 10, geological disasters were investigated in Xiangxi-Qianxi area, eastern margin of Qinghai-Tibet Plateau, Hengduan mountain area, alpine valley area in southeast Tibet, Liaodong-Beishan area in Beijing, Wei Fen area, Jianghan area, and Sino-Russian oil pipeline, Senninglan natural gas pipeline and Hanchuan natural gas pipeline (1∶ 50,000).

(3) Basic information of each district

1) Sudden geological disaster investigation area:

A. the landslide and debris flow area in the loess plateau west of Luliang Mountain. The loess joints in this area are well developed and have strong collapsibility, which is a landform of ridges, hills and beams. In rainy weather, the critical rainstorm intensity required to cause landslides is low.

B. Longdong and Qingnan landslide and debris flow areas. The elevation of West Qinling is 2500 ~ 4500m, and the relative elevation difference is 1000 ~ 2000m, which belongs to the middle and high mountain terrain. Rock mass types are mainly metamorphic rock series and carbonate rock series. There are clastic rocks and loess in Xili basin and Huicheng basin. The annual precipitation is generally 600 mm.

C. landslide and debris flow area in qinba mountain area. A strongly uplifted folded mountain range. Stratigraphic rocks are mainly metamorphic rocks and magmatic rocks, with a small area of loess in general. Crack development. The annual rainfall is between 800 ~1200mm.

Landslide and debris flow areas in eastern Sichuan and western Hubei. The area is dominated by Zhongshan landform with steep slopes and deep valleys. The strata exposed from Paleozoic to Mesozoic are mainly sedimentary rocks, mainly carbonate rocks and carbonate rocks mixed with clastic rocks. The average annual rainfall is between 1200 ~ 1800 mm. Landslides and mudslides frequently occur in western Hunan and western Guizhou. The landform in this area is high, medium and mid-mountain, and the terrain is highly cutting. There is abundant precipitation. The rocks are mainly carbonate rocks and clastic rocks with developed faults.

Fig. 6. 1 National Geological Hazard Survey Plan

Fig. 6. 1 National Geological Hazard Survey Plan

F. Landslides and collapses in the eastern margin of the Qinghai-Tibet Plateau. This area is dominated by mountains and Zhongshan. Metamorphic rocks and magmatic rocks are widely distributed, mainly clastic rocks and carbonate rocks. The structure is complex. From north to south, there are many structural systems such as latitudinal, Cathaysian, meridional, zigzag and Xinhua Gorge, with dense active faults, which are also within the distribution range of the famous north-south seismic belt in China. The annual precipitation is between 600 ~ 1400 mm.

G. Hengduanshan landslide collapse area. The terrain in this area is high in the north and low in the south, mainly from high mountains to Zhongshan, with strong terrain cutting. The lithology is complex, with a large area of clastic rocks, carbonate rocks, metamorphic rocks and magmatic rocks, and the bedrock is soft and hard. Zigzag structure and meridional structure are reconnected and compounded, and active faults are dense, which belongs to the distribution range of western Yunnan seismic belt. The annual precipitation is between 400 mm and 2000 mm, increasing rapidly from north to south, and the vertical zoning of climate is also obvious.

H. Landslides, collapses and mudslides in alpine valleys in southeastern Tibet. It belongs to the lower reaches of Yarlung Zangbo River, with tributaries such as Nianqu and Palong Zangbo River, and is a concentrated distribution area of marine glaciers in China. Due to abundant precipitation, high temperature, fast glacier movement and strong melting, there is a lot of rainfall in summer and autumn. River valleys are mostly developed along active fault zones, with steep terrain on both sides, broken rock strata, especially rich glacial deposits, and strong seismic activity in the adjacent areas.

First, Liaodong-Beijing Beishan debris flow area. This area is mountainous, with high mountains and steep slopes, deep valleys and narrow valleys. Metamorphic rocks and magmatic rocks are widely distributed. Because the east and south slopes face the sea, there is abundant rainfall and heavy rain. The earthquake activity is strong. Geological disasters are frequent, wide in scope, large in scale and heavy in disaster. Debris flow in gully is mainly large and medium-sized debris flow. The debris flow disaster site is124,000, and the debris flow density is 7.9/100km2, resulting in 1300 deaths and direct economic loss of1200 million yuan. There were many group mudslides in 1950, 1969, 1972, 1976 and 1977 in Beishan, Beijing, resulting in 2 13 deaths.

2) Investigation area of mild geological disasters:

A. the Yangtze river delta region. The Yangtze River Delta includes Shanghai, Suzhou, Wuxi, Changzhou, Zhangjiagang, Jiangyin, Nantong, Yancheng, Qidong, Dongfang, Dafeng, Hangzhou, Jiaxing, Huzhou, Ningbo and Wenzhou. The Quaternary in the Yangtze River Delta is 200 ~ 300 m thick, and its lithology is mainly fine, silty sand, muddy clay and sandy clay. Confined aquifers are widely distributed, with thicknesses ranging from ten meters to hundreds of meters. The Yangtze River Delta is the area with the earliest land subsidence and the most serious damage and loss. The area south of the Yangtze River with accumulated subsidence exceeding 1 1,000 mm is about 300km2, and the area exceeding 000 mm is nearly 1 1,000 km2, and the area is connected together. The total loss was nearly 350 billion yuan, of which the direct economic loss exceeded 20 billion yuan.

B. North China Plain. North China Plain, including the plains of Beijing, Tianjin, Hebei, Shandong, Henan and other provinces (cities), covers an area of 654.38+04,000 km2. It is the most developed region in politics, economy, science and technology and culture in China, and it is also one of the most competitive economic regions. Due to the long-term over-exploitation of groundwater, the North China Plain has become the most serious area of groundwater over-exploitation in the world, and it is also the area with the largest area of groundwater falling funnel, the largest area of land subsidence and the most complicated types, especially in the Beijing-Tianjin-Hebei-Shandong area. Land subsidence directly leads to the loss of ground elevation resources in the coastal low plain area of North China Plain, which in turn leads to the subsidence of railway subgrade and the aggravation of storm surge disaster. Due to the influence of flood discharge, the ground accumulated water for a long time and the factory building was flooded; Due to uneven ground settlement, buildings are damaged and large-scale municipal infrastructure is destroyed; Due to land subsidence, many geological disasters such as ground collapse and ground fissures have been caused. Due to land subsidence, the more the local economy develops, the greater the disaster loss, which restricts the sustainable development of social economy. At the same time, the sea level rise caused by global temperature rise and land subsidence always threatens the survival of human beings in coastal areas of estuaries, including low-altitude areas in North China Plain. Therefore, large-scale land subsidence poses a serious threat to the safety of local people's lives and property, and has become one of the important factors restricting the sustainable development of local economy.

C. Wei Fen region. The ground fissure zone in Wei Fen Basin starts from Baoji at the southern foot of Liupanshan Mountain in the east along Weihe River, reaches Xi 'an to fenglingdu in the north, and reaches Linfen and Taiyuan along Fenhe River in the northeast to Datong, with a width of about 1000km and a length of about1000 km. Land subsidence mainly occurred in Xi and Taiyuan in Guanzhong basin, Shaanxi Province. The faulted basin was formed under structural control. Active faults are mainly east-west, northeast-east and northeast. Loose sediments are widely distributed in basins (valleys), mainly quaternary lacustrine sediments and loess accumulation. Loess has weak-strong collapsibility. The aquifer is divided into two layers, that is, the upper part is phreatic water and the lower part is generally confined water. The confined water head is generally several meters, and some reach tens of meters. Ground fissures in Yuci City have damaged 8 1 building, seriously damaged 18 roads, and caused direct economic losses of 1, 3 1.5 million yuan.

There are 10 large ground fissures in Datong city, with a total length of more than 34.5km, which have caused buildings to be destroyed, roads and bridges, underground pipelines to be cracked and railways to be distorted, resulting in direct economic losses of156.5 million yuan. The area of Xi 'an 1995 with accumulated subsidence exceeding 200mm is145.5km2. The ground subsidence center of Taiyuan City is located in Jinyang Lake and Wu Jiabao, with the maximum subsidence of 3700mm and economic loss of tens of millions of yuan.

D. Jianghan area. The subsidence area of Jianghan Plain includes Jingzhou, Gongan, Shishou, Jianli, Huarong, Anxiang, Nanxian, honghu city and Yueyang. The landform type is plain, and the Quaternary loose sediment is about 170m thick, which is mainly composed of sand, gravel and clay, and sand and clay interbeds. The phreatic aquifer is undeveloped and mainly confined water. The water abundance of confined water aquifer is strong in the middle of the plain, and its edge gradually weakens. The water level is buried between 0.4 and 3.0m, which causes the deformation and damage of buildings.

3) Main project construction areas: ① West Route Project Area of South-to-North Water Transfer Project; ② West-to-East Gas Transmission Project Area; ③ along Baocheng oil pipeline; ④ along the Sino-Russian oil pipeline; (5) along the Sai Ning-Lanzhou natural gas pipeline; ⑥ along Hanchuan natural gas pipeline.

6.3.4 Carry out the geological hazard investigation of important traffic trunk lines 1: 1 10,000 ~1:50,000.

From 2004 to 20 10, the geological disaster investigation along the 25000 km railway1∶1∶ 50,000 was completed, in which the planned western railway is about16,000 km, and the double-track railway is about 0700 km, with frequent geological disasters.

Complete the investigation of geological hazards along the provincial highway 1: 1 10,000 ~1:50,000 in the mountainous area, and complete the investigation of geological hazards along the proposed1:1:50,000 expressway.

Scope of investigation on both sides along the railway: to ensure the safe operation of the railway, with emphasis on railway culverts and tunnels.

Investigation scope of both sides along the expressway: to ensure the safety of highway operation, with emphasis on highway culverts, tunnels and bridges.

(1) Main tasks

1) compile1:1000 ~1:50000 technical requirements for geological disaster investigation;

2) Formulate the method and standard of geological disaster risk assessment with the ratio of 1: 1 10,000 ~1:50,000;

3) Carry out geological disaster investigation along the 25,000km railway and1:50,000km expressway, carry out risk zoning and put forward prevention suggestions;

4) Establish a survey database.

(2) Work deployment

According to the medium and long-term traffic development plan of China, there will be 75,000 kilometers of railways in China in 2005 (western region 1.8 million kilometers), including 20,000 kilometers of electrified railways; Highway160km, including 26,000km of expressway. In 20 10, the railway will reach 80,000 kilometers, including 30,000 kilometers and 5,000 kilometers of electrified railways; High-speed railway; There are 65438+800,000 kilometers of highways, including 36,000 kilometers of expressways. Railway construction focuses on the western region.

Therefore, priority should be given to the investigation of geological disasters along railways and highways in mountainous areas, especially in western mountainous areas.

1) Railway survey and deployment.

① The planned new line in the west is about 16000km, including: the international railway passages in the northwest and southwest regions: Kashgar-Turgat section of China-Kyrgyzstan-Urumqi railway, Kunming-Hanoi section of China-Vietnam passage, Kunming-Jinghong-Mohan section of China-Laos passage and Dali-Ruili section of China-Myanmar passage; ? New passages from northwest to north China: Taiyuan-Zhongwei (Yinchuan) line and He Lin-Hami line; ? New channel from northwest to southwest: Lanzhou (or Xining)-Chongqing (or Chengdu) line; ? Convenient passages from Xinjiang to Qinghai-Tibet: Korla-Golmud Line and Longgang-Dunhuang-Golmud Line; ? Railways in the western region: Jinghe-Yining, Kuitun-Altay, Linzhi-Lhasa-Shigatse, Dali-Shangri-La, Yongzhou-Yulin and Maoming, Hepu-Hekou, Xi 'an-Pingliang, Liuzhou-Zhaoqing, Sangendalai-Zhangjiakou, Zhungeer-Hohhot and Jining-Zhangjiakou.

(2) The construction of existing railway double tracks along the line is about 7,000 km, including: Cheng Kun double track (110 km), Nankun double track (660km), Guigui double track (600km), Huai Yu double track (580km) and Ningxi double track (950km).

③ The railway with frequent geological disasters is about 2,000 km long, including baoji-chengdu railway (700km) and Golmud-Lhasa section of Qinghai-Tibet Railway (1300km).

2) Highway investigation and deployment. (1) Complete the investigation of geological disasters along highways above the provincial level in mountainous areas of 200,000 kilometers1:50,000 (key areas 1: 1 10,000); (2) Complete the geological hazard investigation along the proposed 1 ∶ 1 10,000 km expressway.

6.3.5 Carry out1:110,000 ~1:50,000 key cities and densely populated areas.

From 2006 to 20 10, the geological disasters were investigated in 97 densely populated cities (cities with population above 1 10,000) and 6 mining cities in Northeast China, and the geological disasters were identified, effectively avoiding hidden dangers.

(1) Main tasks

1) completed the investigation of geological disasters in 97 national key construction cities (1:kloc-0/10,000 ~1:50,000), carried out risk assessment, and put forward reasonable suggestions on urban layout and land use;

2) Complete the investigation of geological disasters in seven mining cities in Northeast China (1 ∶ 1 10,000 ~1∶ 50,000);

3) Establish a survey database.

(2) Work deployment

By 2005, all 700 counties (cities) had completed the geological hazard survey of 1∶65438+ 10,000.

From 2005 to 20 10, a systematic survey of urban geological disasters was carried out, focusing on the Yangtze River Delta, the Pearl River Delta and the Beijing-Tianjin-Tangshan urban belt, and gradually deployed in provincial cities and important coastal cities. Promote ecological environment restoration and land reclamation projects in mining cities in northeast China, and strive to achieve obvious benefits and promote them.

(3) Investigation area

1) densely populated cities under state key construction. Cities with a population of over one million (Table 6. 1) are listed in this plan.

Table 6. 1 urban units with a population of over one million: ten thousand people

sequential

2) Mining cities. Northeast China is rich in mineral resources, and many cities have grown from small to large because of mining. Fuxin, Fushun and Anshan in Liaoning Province, and Jixi, Hegang and Shuangyashan in Heilongjiang Province are all mining cities of this type. After decades of exploitation, some cities have been faced with problems such as exhaustion of mineral resources. Even though some cities are still rich in mineral resources, they are also facing geological disasters caused by long-term mining. Ground collapse, landslide and collapse are the main geological disasters in such cities. It is of great significance to carry out geological disaster investigation in mining cities to accelerate the transformation of old industrial bases in Northeast China and promote the stable development of regional economy.

6.3.6 Establish and improve the geological disaster investigation information system.

The main goal of the construction of geological disaster investigation information system is to implement informatization in the whole process of data collection, data management and comprehensive processing of geological disaster investigation, so that geological disaster investigation can effectively and quickly apply geographic information system, satellite positioning system and remote sensing technology, improve the comprehensive processing ability of geological disaster investigation information, and realize the standardization and rapidity of geological disaster investigation data collection and comprehensive processing. The traditional working mode of geological disaster investigation will be changed into modern digital working mode, and the technical level of investigation work will be improved, which will lay the foundation for realizing the informatization of geological disaster investigation process of field collection, data transmission, data integration and information service. Geological hazard investigation system is mainly composed of field collection system and indoor desktop processing system.

Its main work content is:

1) Based on mobile computer for geological survey, PDA or tablet computer is selected to integrate GPS technology, mobile data transmission technology and geographic information system technology. According to the data model of geological disaster field investigation, the field data entry system, measuring point positioning system, data moving transmission system, field sketch drawing system and multimedia image cataloging system are established.

2) Establish a comprehensive field data management system. It provides the functions of field investigation route design, field investigation work deployment, field investigation data acceptance and field data integrated management.

6.3.7 Establish and improve the standard system of geological hazard zoning and risk zoning.

Establish1:250,000,1:1:50,000,1:110,000 geological hazard zoning and risk zoning index systems, and standardize zoning methods and expressions.

6.3.8 Improve the technical requirements or standard system of geological disaster investigation.

Improve the technical requirements for geological disaster investigation1:250,000,1:50,000, 1: 1 10,000, and form standardized technical standards for geological disaster investigation.

6.3.9 Establish a geological disaster investigation system.

Establish and improve the geological disaster investigation system, clarify the investigation period, investigation content, investigation responsibility and funding sources, and ensure the smooth development of geological disaster investigation.