(Beijing Municipal Bureau of Land and Resources)
In 2009, at the annual meeting of 2 1 geological history, Lu published a paper "Science and technology have profoundly changed the face of geological exploration in Beijing". This paper describes the great influence of ten geological technologies on geological prospecting in Beijing. These ten geological technologies are: ① the obvious power of geophysical and geochemical exploration technology; (2) Breakthrough in prospecting technology; ③ Remote sensing technology is refreshing; ④ Computers play an important role in all aspects of work; ⑤ Comprehensive methods play a great role in regional dispatching; ⑥ Adopting new theories to improve the level of geological research; ⑦ Water conservancy environmental geological work broadens the field of geological work; ⑧ The exploration and development benefits of underground hot water are good; Pet-name ruby shallow geothermal energy and heat pump technology are being vigorously promoted; Participating in multi-parameter stereoscopic geological survey has created a new situation.
The article in 2009 only briefly introduced the top ten geological technologies. This paper will focus on the first item, the outstanding achievements of Beijing geophysical and geochemical exploration technology.
As we all know, before the founding of New China, the geological exploration in China was very backward, and few people engaged in geological work. The working methods and means are very simple. Geological work depends on those three big pieces (hammer, compass, magnifying glass), and nothing else. Therefore, in the early days of the founding of New China, geophysical and geochemical exploration was a blank situation; Therefore, the adoption of geophysical and geochemical exploration methods has brought new exploration means to geological work.
Beijing attaches great importance to new geophysical and geochemical technologies. Since the 1950s, dozens of departments and units, such as geology and mineral resources, petroleum, metallurgy, hydropower, coal, aerospace, construction, nuclear industry, armed police gold, State Seismological Bureau, Hebei Geological Bureau and Beijing Geological Bureau, have invested in geophysical and geochemical exploration in Beijing. Beijing Geological Bureau has also set up a professional geophysical and geochemical exploration team, which has undertaken most of the work.
Geophysical and geochemical exploration in Beijing consists of seven aspects: ① regional geophysical exploration (including aerial geophysical exploration, regional gravity survey, regional electric sounding survey, regional surface magnetic survey and geophysical and geochemical exploration in regional geological survey); ② Geophysical exploration of mineral resources; ③ Hydrogeogeophysical exploration; ④ Geothermal geophysical exploration; ⑤ Archaeological geophysical exploration, engineering geophysical exploration and environmental geophysical exploration; ⑥ Geophysical exploration in the well; ⑦ Geophysical exploration of deep structures.
In 60 years of geological work, geophysical and geochemical exploration methods have been widely used in Beijing, with outstanding results. It is divided into the following ten aspects.
First, it has promoted the development and changes of regional adjustment.
In the late 1950s and early 1960s, Beijing launched the first round of large-scale1:50,000 regional adjustment. At that time, there was only one geological observation method, and the method was single. It usually takes four years to complete a map. In 1980s, geophysical and geochemical techniques were widely used in the second round of1:50,000 regional survey, and a lot of geological information was obtained. In particular, remote sensing technology makes it possible to conduct multi-image joint investigation, which enlarges the working area (generally 2-3 images) and speeds up the work progress. It is reported that the geophysical exploration team of Beijing Geological Exploration Bureau has worked in Qinglong Bridge, Qingshui, Yanhecheng, Zhoukoudian and Changping successively 1 1 maps, collected and sorted out the previous geophysical and geochemical data, conducted a general survey and evaluation of aeromagnetic anomalies and regional geochemical exploration in the maps, made necessary work, compiled maps of geophysical and geochemical exploration results and submitted independent geophysical and geochemical exploration reports.
According to the survey, the initial joint survey of two maps (Changping and Xiaotangshan) in the second round of regional survey takes an average of 2 to 5 years to complete one map. With experience, the speed of map joint survey is accelerated, and it takes more than one year to complete a map on average; Three maps were jointly surveyed, and one map was completed in an average of more than half a year. Joint debugging has greatly changed the slow pace of regional dispatching work and achieved good, fast and many tasks.
2 1 century, geological survey entered a new stage. From 2003 to 2007, the subordinate units of Beijing Geological Survey Bureau (Municipal Geological Survey and Research Institute, Municipal Hydrogeological Engineering Geological Brigade, Municipal Geological Exploration Technology Research Institute and Municipal Geological Research Institute) jointly undertook the work of "Beijing Multi-parameter Stereo Geological Survey". The project is jointly funded by the Ministry of Land and Resources and the Beijing Municipal Government. The main content of the work is the urban geological problems that Beijing is facing and urgently needs to solve, and its purpose is to serve the sustainable development of the capital. The work is carried out under the guidance of geoscience theory, drawing lessons from advanced experience at home and abroad, and on the basis of fully studying and utilizing existing data, using modern exploration technology (including geology, hydrogeology, drilling, geophysical and geochemical exploration, etc.). ) has been comprehensively applied, especially drilling and various geophysical and geochemical exploration methods (table 1 ~ table 3) have been widely used, thus obtaining a large number of geological information in all aspects.
Table 1 Evolution of Geological Survey in Beijing Area
Table 2 Drilling Worksheet for Multi-parameter Stereo Geological Survey
Table 3 Geophysical exploration methods and worksheets used in multi-parameter stereo geological survey
sequential
The project team put forward the investigation idea of "three circles and three floors" three-dimensional geological structure in Beijing Plain. The so-called "three circles and three layers" three-dimensional geological structure, "three circles" means that the surface work is divided into general areas, areas within the Sixth Ring Road and key areas, and "three layers" means that it is vertically divided into Cenozoic strata, engineering construction layers (0 ~ 50m) and bedrock. Through this investigation, the spatial distribution law of stratum structure of different scales in Beijing Plain was found out. Using digital visualization technology, combining geological drilling with geological profile, the three-dimensional structural digital model of pre-Cenozoic strata, Cenozoic strata and engineering construction layer is established.
This topic includes 3 topics and 8 sub-topics.
These three topics are: ① Study on active faults and crustal stability in Beijing; ② Special geological survey in the Olympic Park area; ③ Construction of urban geological information management and service system.
These eight sub-topics are: ① Cenozoic three-dimensional geological survey of Beijing plain; ② Three-dimensional geological survey of engineering buildings in Beijing Plain; ③ 3D geological survey of bedrock in Beijing Plain; ④ Geochemical investigation of soil environment in Beijing Plain; ⑤ Investigation on the present situation of municipal solid waste treatment and geological environment of site selection in Beijing; ⑥ Geochemical investigation of groundwater environment in Beijing Plain; ⑦ Evaluation of groundwater resources potential in Beijing; ⑧ Evaluation of geothermal resources potential in Beijing.
After the work, the project report was submitted, and experts spoke highly of the multi-parameter three-dimensional geological survey report in Beijing: the overall level reached the international level, and some reached the international leading level, and the project played a demonstration role. Multi-parameter stereoscopic geological survey is a new development of geological survey.
Looking back on the course of geological survey, from 1950s to 1960s, it was a simple geological survey process, only observing and studying the surface, with emphasis on basic geology and prospecting. In the late 20th century, the research object was not limited to geology and prospecting, but the field extended outward. 2 1 century, with more means, wider vision and deeper observation. The main research is urban geological problems. The development of geological survey to multi-parameter three-dimensional geological survey stage is an objective need, the progress of science and technology, and the result of the close combination of geology and various scientific and technological means.
Second, it has made great contributions to iron ore prospecting.
Magnetic method (including aerial magnetic method and ground magnetic method) is an effective method to find iron ore. Since 1950s, Beijing * * * has conducted six systematic airborne geophysical surveys, covering the whole of Beijing, including aeromagnetic surveys1:25,000,1:50,000,1:65438+10000. From 1958 to the end of 1970s, systematic geomagnetic survey was carried out in Beijing. The magnetic survey of 1: 50,000 km2 has been completed in mountainous areas, and another1:25,000, 1: 1. Circle 265 ore anomalies, involving ferrous metals such as iron, chromium, vanadium and titanium. Three magnetic fields are divided, including 1 1 magnetic anomaly area, 8 1 magnetic anomaly group and 257 local magnetic anomalies. Among them, 28 magnetic anomalies have been confirmed by exploration or drilling, accounting for10.9% of the total number of anomalies; Among them, 22 cases have been investigated in detail, accounting for 8.5% of the abnormal number; 64 have been investigated, accounting for 24.9% of the total number of anomalies; The remaining 143 magnetic anomalies were not checked.
The effect of magnetic survey is very obvious, the prospecting clues are prominent, and there are clear abnormal manifestations on the map, which is of great help to prospecting. Up to now, the distribution, occurrence and scale of iron ore in Beijing have been basically ascertained, with proven reserves of 10× 108 (1 large ore, 22 medium ore and 20 small ore). The proven reserves over the years rank 1 1 in China. Magnetic data not only give clear clues for prospecting, but also show a lot of information about iron ore itself.
Taking Miyun Shachang Iron Mine as an example, ① there are aeromagnetic and geomagnetic anomalies in the mine; ② Magnetic anomaly data show that the mining area is syncline structure; ③ No.Ⅱ abnormal zone shows concealed ore. It is confirmed by drilling that all the information is correct. The structure of Shachang iron mine area is indeed a syncline structure, and there is indeed a concealed mine in No.2 anomaly. Therefore, the reserves of the mining area have greatly increased, from more than 30 million tons (medium-sized) to 1.4× 108 tons (large-sized).
Third, I'm looking for a gold mine.
In the 1960s and 1970s, Beijing launched a large-scale gold survey. Although great efforts have been made, the effect is not obvious, only some small mines have been discovered. This situation continued until the mid-1980s. Later, by summing up the experience and lessons of prospecting, we reflect on the guiding ideology, theory and method of prospecting. Correct thinking, firm confidence, and vigorously adopting comprehensive means and methods, especially geochemical exploration methods, have created a new situation in ore prospecting.
1. Discovery of Yangshuxia gold deposit in Huairou
1987, during the regional survey of1:50,000, the regional survey team of Beijing Geological Survey conducted geochemical exploration under poplar trees and conducted inspection and sampling in the controlled molybdenum mine tunnel. It is found that the grade of gold ore is high, so it is found that the iron hat in this area is a gold ore body dominated by gold. Then, the institute officially started the exploration work here. By the end of 1989, it was found that the gold reserve of this mine was 4.8t (close to the medium-sized mine).
2. The discovery of Detiangou gold deposit in Huairou.
In the early 1990s, the team of Beijing Geological Survey 10 1 and the geophysical and geochemical exploration team of Beijing Geological Survey jointly formed a survey team to investigate the geophysical and geochemical anomalies in Detiangou to Qifengcha area. 232 geochemical samples were collected and exposed on the surface, which roughly delineated the mineralization range and preliminarily delineated the scale of No.2 ore body. Later, geochemical secondary halo and primary halo profile measurement, induced polarization profile, electrical logging and borehole geophysical exploration tests were carried out. The combination of geology and geophysical and geochemical exploration has finally determined a medium-sized gold deposit with a gold reserve of 5.09 tons.
The discovery of these two gold deposits is a major breakthrough in gold prospecting in Beijing, which is the result of regional adjustment and the combination of geology and geophysical and geochemical exploration, in which geophysical and geochemical exploration has played an important role.
Fourth, show the power of finding water.
China is a country with a serious shortage of water resources, and all parts of the country are trying to dig wells to find water. Years of work have proved that hydrogeological exploration has become an important method of geophysical exploration. At present, this method has been widely used in water exploration all over the country, and the effect is remarkable. Through the combination of hydrogeology and hydrogeology, a large amount of groundwater (1982 and 1987) was found in Beijing, and the water resources were calculated and evaluated twice. Therefore, the total exploitable groundwater resources is 26.33× 108m3, which plays an important role in ensuring the safety of water supply in the capital.
During the 1960s and 1970s, hydrological geophysical prospecting mainly served for drought-resistant water supply in suburban farmland, and large-scale (1: 2000 or 1: 1000) hydrological geophysical prospecting was carried out in Changping, Mentougou and Tongxian. In 1980s,1:50,000 hydrogeological exploration was mainly carried out, and the main methods were electrical profiling, electrical sounding and electromagnetic sounding.
For example, from1March, 1982 to1May, 1990, the Beijing Geological Exploration Bureau successively carried out electrical profiling and electrical sounding work on the 6422km2 Beijing plain. This work redraws the geological map of bedrock in the plain area, which not only improves the basic geological research in Beijing plain area, but also delineates the Quaternary water-rich area in the survey area according to the Quaternary electrical characteristics. Such as Yongding River alluvial fan and ancient river water-rich area, Dashi River alluvial fan and ancient river water-rich area, Suihe River alluvial fan and ancient river water-rich area, Chaobai River ancient river water-rich area, etc. The alluvial fan, alluvial fan skirt and ancient river channel are also divided, and the distribution map of Quaternary water inflow in Beijing Plain (10 ~ 100 m) is compiled. These results provide a basis for regional hydrogeological condition evaluation, farmland water conservancy construction, well location selection and water inflow calculation.
Beijing has a large mountainous area, and many places are short of water resources, making it difficult for people and animals to drink water. Since the 1960s, all units under the Beijing Geological Exploration Bureau have been sending people to the mountainous areas for technical guidance, searching for water and drilling hundreds of wells for the countryside. Among them, hydrogeological exploration is also an important exploration method.
Fifth, it plays a unique role in geothermal exploration.
Geophysical exploration plays an extremely important role in geothermal exploration and determination of geothermal well location.
There is no record of geothermal exploitation and utilization in the history of Beijing urban area. In the early 1970s, Beijing Hydrogeological Engineering Company conducted a geothermal survey under the guidance of Minister Li Siguang. It became an instant hit, and the underground hot water with the temperature of 30 ~ 50℃ was successively extracted from Beijing Oxygen Plant, Tiantan Park and Beijing Railway Station, and the geothermal anomaly area of about 30km2 was initially delineated.
Then, after 40 years of exploration, four geothermal anomaly potential zones were identified in the plain area, including 10 geothermal fields, with a total area exceeding 1400km2. The prospective reserves of geothermal energy (Grade E) are calculated, which is equivalent to 8926.38+03× 104t standard coal.
Geothermal resources are buried deep underground, and the role of naked eye observation is greatly limited. The main methods of geothermal investigation are geothermal geophysical exploration, including geophysical and geochemical exploration methods, which are used to delineate geothermal zones and thermal storage uplift areas.
Up to now, the development and utilization of geothermal energy in Beijing has achieved remarkable results, with about 160 geothermal wells and more than10 normal wells. The exploitation amount of underground hot water is controlled below 1000× 104m3, which is mainly used for heating, bathing, medical treatment, aquatic products, aquaculture, greenhouse planting, leisure and health care, drinking mineral water, tourism, etc., and plays a good role in attracting investment and earning foreign exchange.
In recent years, the micro-motion sounding technology, namely Rayleigh wave method (sounding 3000m), has been adopted in geothermal exploration, which overcomes the defect of shallow depth of electric sounding (sounding 1600m). One of the advantages of this method is that it can be applied to the environment of big cities, which solves the problem that the conventional geophysical prospecting method is difficult to construct because of overpopulation, dense buildings, busy traffic and serious industrial interference, and provides a more effective means for urban geothermal exploration.
The fretting sounding technology (1992) was first applied to Fengtai World Park. At that time, there was no reference to geothermal well data in this area, and only 1600m was measured by electrical sounding, which was not enough to determine the buried depth of thermal reservoirs. Later, Rayleigh wave method was used to infer that the buried depth of Jixian system was about 2000 m m, and drilling confirmed that the roof of this layer was 1940m, which was very consistent with the prediction result of Rayleigh wave method. Finally, a geothermal well with a depth of 2500 meters and a water outlet temperature of 69℃ was drilled.
200 1, Beijing Geological Survey Institute launched "Study on Deep Geothermal Exploration of Integrated Geophysical Exploration System (Combination) in Beijing Area". The investigation shows that "gravity, magnetic method, DC resistivity sounding, fretting sounding, CSAMT and MT are suitable for geothermal exploration in Beijing, and the application effect is good".
6. Play a key role in detecting the deep crustal structure in Beijing.
After the Tangshan earthquake, the Geophysical Exploration Center of China Seismological Bureau and other units carried out a lot of artificial seismic sounding work in North China. This work reveals for the first time that the deep structure of the crust and upper mantle in Beijing area has the basic characteristics of vertical stratification and horizontal block. The crustal velocity structure in Beijing and its adjacent areas can be roughly divided into two parts: the upper crust and the lower crust (Xu Xiwei, 2002). The upper crust includes sedimentary caprock and its underlying crystalline basement, and its thickness changes little. The general trend is that it is thinner in the southeast and thicker in the northwest. Sanhe and Baodi 20 ~ 2 1 km, 22km near Beijing and 23 ~ 24 km in Zhangjiakou. The lower crust is also composed of two layers, and its thickness gradually increases from southeast to northwest. Near Tianjin in the southeast, the lower crust is 10km thick, and Zhangjiakou in the northwest is the thickest 19km.
The analysis of crustal velocity structure and Moho surface three-dimensional structure of artificial seismic sounding profile shows that the velocity structure of different geological structural units in Beijing and its adjacent areas is obviously different, which can be divided into Huabei fault block, Yanshan fault block, Taihang fault block, Shanxi fault basin and other blocks with different velocities. The contact zone between different blocks is often the change zone of various geophysical data (such as crustal thickness, gravity and magnetic field characteristics, etc.). Among them, Zhangjiakou-Bohai structural belt and Taihang piedmont fault zone are the two most obvious deep structural variation zones in the region. These two deep structural variation zones are closely related to current seismic activity.
Crustal structure is closely related to seismic activity. In Beijing and its adjacent areas, the spatial distribution of seismic activity and main seismic zones is consistent with the variation of crustal thickness and the extension of structural zoning boundaries reflected by regional gravity and magnetic fields. Such as the Zhangjiakou-Bohai fault zone in the northwest, the Taihang piedmont fault zone in the northeast, and several northeast structural zones in the North China Plain. According to research, in these zones, earthquakes mostly occur near the gravity and magnetic anomaly step zone, at the junction of positive and negative anomalies, at the intersection of gravity and magnetic anomaly zones in different directions or at the turning point of anomaly zones. These places are often the contact zone between magnetic basement and weak magnetic basement, or the transition zone between basement uplift and depression, or the change zone of crustal thickness, accompanied by the development of deep faults.
Seven, give the soil a comprehensive "physical examination" of the capital's modern agriculture to take off.
For decades, geologists in many units in the capital have cooperated with regional surveys or mineral exploration to carry out geochemical exploration. In the 1980s, the geophysical and geochemical exploration team of the Bureau of Geology and Mineral Resources conducted a survey of sediments in the mountain area1:200,000 water system. A1:50,000 soil environmental geochemical survey was carried out in Beijing together with the Institute of Geochemical Exploration of the Ministry of Geology and Minerals. Twenty-two elements and indexes such as copper, arsenic, lead, cadmium, zinc, chromium, nickel, mercury and fluorine were quantitatively analyzed, the abundance and deficiency of soil nutrients and nutrient elements and the enrichment law of harmful elements in main crops were found out, and some remarkable abnormal areas were identified and evaluated. In addition, the eco-agricultural geology in Yanqing County and Daxing District was investigated and evaluated.
Agriculture in the plain area is the key area of agriculture in the city. In 2006-2007, Beijing Geological Exploration Institute carried out a large-scale (6400km2) soil environmental geochemical survey and evaluation for the first time, which basically found out the overall situation of soil environmental quality in the plain area, classified and evaluated its safety, summarized the influencing factors, changes and evolution trends of urban ecosystem and farmland ecosystem, and provided scientific basis for urban environmental protection, pollution control and rational crop planting.
Eight, the investigation of land and resources to provide a basis for urban planning.
Remote sensing technology is an important means of airborne geophysical exploration. Since 1980s, Beijing has vigorously promoted the application of remote sensing technology in all aspects of geological work, with remarkable results. With regard to the achievements of remote sensing, we should especially mention "830 1 Project". "830 1 Project" is a comprehensive aerial remote sensing survey in Beijing. It is a major project jointly organized by the Ministry of Geology, the Ministry of Urban and Rural Construction and Environmental Protection and the Beijing Municipal Government, with 4 1 project. This work was completed by the Remote Sensing Center of the Ministry of Geology and Beijing Geological Exploration Bureau from 1983 to 1986. The project has achieved fruitful results, with 23 achievements filling the gaps, 2 reaching the international advanced level, 7 reaching the international equivalent level, and 14 reaching the domestic advanced level. The project won the first prize of National Science and Technology Progress Award.
Among them, the "application of aerial remote sensing in agricultural construction planning in mountainous areas of Changping County" project was first piloted in Heishan Village of Changping District, and then carried out in the whole region, and achieved good results. We have basically found out the situation of various resources such as agriculture, forests, land and fruit trees, and obtained a lot of information about mountain water system, slope and land use. The growth status of various wild resources and fruit trees was studied, which provided an important basis for agricultural construction planning in Changping. The project was well received by the local government and won the second prize of the Science and Technology Achievement Award of the Ministry of Geology and Minerals. Since then, remote sensing technology has been further promoted and applied in agricultural construction planning in Pinggu, Yanqing and other counties, and achieved good results.
From March 2002 to February 2004, Beijing Institute of Geology conducted a comprehensive survey of land resources in Beijing by remote sensing, and completed the remote sensing interpretation of land use status, mineral resources, geological disasters and geological tourism with an area of 1.68× 104 km2. 1:65438+100000 description of environmental geological status, with an area of 3514km2; ; Interpretation1:50,000 greening around the city, with an area of1653km2; ; 1:25000 remote sensing interpretation of the comprehensive environment of the main venue of the Olympic Games, covering an area of 156km2. The above achievements have been provided to the relevant departments of Beijing for urban planning and utilization.
Nine, the geological disaster investigation and evaluation effect is remarkable.
Geological disaster is an important natural disaster in Beijing, which has brought great disasters to Beijing at all times and all over the world.
1) Beijing Institute of Geology has done a lot of research work on geological disasters in the capital by using remote sensing technology. During the period of 1989 ~ 199 1 year, Beijing Institute of Geology carried out the work of "Geological Disaster Investigation in Beijing Area". Based on the analysis of natural disaster data in Beijing over the years, the distribution status and development characteristics of major geological disasters in Beijing are preliminarily found out by using aerial photography interpretation and ground investigation. Debris flow in mountainous areas and serious ground collapse in mines; Land subsidence is most prominent in plain areas. The investigation shows that the collapse, landslide and debris flow in Beishan are more developed than those in Xishan. Through the work, the Report on Geological Disasters in Beijing was submitted, and the possible disaster areas were predicted.
1991June 10, a torrential rain fell in the mountainous area in northern Beijing, and a once-in-a-century mudslide disaster occurred in the forecast area. 1 13 gully appeared in the northern mountainous area of Huairou, causing 28 deaths and 8 serious injuries, and the direct economic loss was 265 million yuan. Subsequently, Beijing Institute of Geology investigated other mountainous counties and compiled a report (Table 4).
Table 4 results of geological disaster investigation by remote sensing technology
2) A series of investigation reports provide a basis for leaders to make decisions. 1993 the Beijing municipal government has worked out a relocation plan for the dilapidated villages in Beishan area. The municipal government allocated special funds, starting from 1993. In three years, 374 dangerous villages were relocated, with 18422 households and 6045438+0 people. Since then, the loss of life and property caused by natural disasters in mountainous areas has been significantly reduced.
3) The Beijing Bureau of Geological Exploration has formulated an emergency plan for sudden geological disasters, and set up a command and leading group (with an emergency investigation team) headed by the director and deputy director. After the sudden disaster, the emergency investigation team assembled within 30 minutes, completed the preparatory work within 1h, and went to the scene to carry out the investigation.
4) In order to cooperate with the emergency plan for sudden geological disasters, from 2003 to 2004, the Beijing Bureau of Geological Exploration and the Meteorological Bureau worked out the Implementation Plan of Meteorological Forecast and Early Warning for Sudden Geological Disasters in Flood Season in Beijing. During the period from 2004 to 2007, Beijing Geological Exploration Bureau completed more than 500 shifts of early warning and forecasting in flood season, produced early warning product 12, issued early warning information 1 1 times, and conveyed temporary geological disaster early warning information to county land and resources bureaus for dozens of times. The release of early warning and forecasting information has enhanced Beijing people's awareness of geological disasters and is conducive to the smooth progress of disaster prevention and relief work.
Ten, widely used in geological environment investigation and evaluation, the effect is outstanding.
Geophysical and geochemical exploration is widely used in geological environment investigation, especially remote sensing technology. For example:
1) The comprehensive geological environment survey of important water sources in Beijing urban area was undertaken by Beijing Institute of Geology, which started its work in early 2002 and submitted its report in June 2003. Remote sensing technology is mainly used to interpret 1: 1 10,000 ~1:10.4 million. 1:65438+ million soil erosion survey, 3514km2; ; 1: 50000 comprehensive geological environment survey, 3514km2; ; 1:50,000 mine environment survey 63 mining areas with 3000km2；; 1: 1 10,000 key mine environment survey 4 mining areas. These works provide a basis for local governments to formulate mine planning, mine rectification and environmental management.
2) The investigation of geological environment in Miyun Reservoir and its upstream area in Beijing and the study of prevention and control countermeasures are undertaken by Beijing Geological Engineering Design and Research Institute, mainly using remote sensing technology. It started its work in March 2002 and submitted its report in February 2004. This paper mainly investigates the geological environment of Miyun Reservoir and its upstream, and finds out the number of mines, mining conditions and pollution situation in this area. This paper investigates the influence of rivers and reservoirs, geological disasters and unreasonable human activities on the environment, and puts forward practical prevention measures for related environmental factors.
3) Study on urban "heat island effect". The result of urbanization development is that the temperature of urban area is higher than that of suburbs, and the suburbs with low temperature surround the urban area with high temperature, which is called "heat island effect" in meteorology. According to the statistics of the meteorological department in recent 40 years, the average temperature in Beijing is generally 2.77℃ higher than that in the suburbs. This average data is called "heat island intensity" by meteorology. The intensity of heat island can be divided into three types, namely, weak heat island type (urban surface temperature is 2.5 ~ 4.5℃ higher than suburban surface temperature), strong heat island type (urban surface temperature is 4.5 ~ 6.5℃ higher than suburban surface temperature) and strong heat island type (urban surface temperature is above 6.5℃ higher than suburban surface temperature).
The "heat island effect" obviously affects the urban temperature, making the temperature in Beijing generally higher than that in the suburbs, and advancing the seasonal change. According to the data of meteorological department, before 2000, the time for Beijing to enter spring (in plain areas) was mostly before April 3 ~ 5 (in mountainous areas in mid-April); After 2000, the time of entering spring is mostly advanced to the end of March, 2006, 2007, 2009, and even to the middle of March.
According to historical data, the time for Beijing to enter summer is generally from May 27th to 29th. The phenological sign of entering summer is "Robinia pseudoacacia enters full bloom". 20 10 was affected by the "heat island effect", and the summer in Beijing was advanced to the middle of May (May 19).
It is reported that the global average temperature reached a new high in July of 20 10, and July was the highest month on record. The remote sensing monitoring of thermal environment in this city shows that in July, the six districts in Beijing formed an obvious heat island effect, and most areas have reached a strong "heat island" state. According to the satellite remote sensing image of July 5th 13: 58, the surface temperature in most plain areas of this city is above 48℃, among which the surface temperature in urban areas, most of Fengtai, south-central Shijingshan, east Fangshan, northwest Daxing and other counties and cities except Yanqing is above 50℃, and in a few areas it is above 54℃. But the surface temperature in most mountainous areas is below 43℃. Because most of the suburban farmland is planted with corn after harvesting wheat, the vegetation coverage rate is low, which leads to a higher average surface temperature, mostly around 48℃.
20 10 July, the load frequency of Beijing power grid hit a historical record (1666× 104kW) due to high temperature and summer heat and air conditioning operation. According to statistics, the grid load of 1/3 is air conditioning load.
The outstanding achievements in the above 10 show that geophysical and geochemical exploration is a very unique exploration method with diverse methods, wide application, obvious effect and outstanding achievements. It has promoted the rapid development and reform of geological exploration, closely cooperated with other exploration methods, improved the overall detection ability of geological exploration methods, and made more and more contributions to social and economic construction.