What are the ways to obtain geological and hydrological data?

Remote sensing is a new technology developed on the basis of aerial photography, which was developed in the early 1960s. Started for aerial remote sensing, since 1972, the United States launched the first land satellite, marking the beginning of the era of space remote sensing. After decades of development, remote sensing technology has been widely used in resources and environment, hydrology, meteorology, geology and geography and other fields, and has become a practical and advanced space exploration technology.

Remote sensing uses remote sensors to detect the characteristics of ground objects from the air. According to the principle that different objects have different responses to the spectrum, it is of great significance to recognize various ground objects on the ground. That is to say, remote sensors on flying objects such as airplanes, spaceships and satellites above the ground are used to collect ground data and obtain information from them, and ground objects can be identified through recording, transmission, analysis and interpretation.

The main features of remote sensing technology are:

1. A wide range of data can be obtained. The flying height of aerial photography plane used for remote sensing is about 10km, and the satellite orbit height of land satellite is about 9 10km, which can obtain a wide range of information in time. For example, a Landsat image can cover more than 30,000 square kilometers. This kind of image showing the macroscopic scene is extremely important for analyzing the earth's resources and environment.

2. The speed of obtaining information is fast and the period is short. Because the satellite orbits the earth, it can get the latest information of various natural phenomena passing through the region in time, so as to update the original information or carry out dynamic monitoring according to the changes of old and new information, which is incomparable to manual field measurement and aerial photogrammetry. For example, Landsat 4 and 5 can cover the earth once every 16 days, and NOAA meteorological satellites can receive images twice a day. Meteorological satellites acquire images of the same area every 30 minutes.

3. Access to information is less restricted by conditions. There are many places on the earth, where the natural conditions are extremely bad and it is difficult for human beings to reach, such as deserts, swamps and mountains. Using remote sensing technology, especially space remote sensing, which is not limited by ground conditions, can obtain all kinds of valuable information conveniently and timely.

4. There are many ways to get information, and there is a lot of information. According to different tasks, remote sensing technology can choose different bands and remote sensing instruments to obtain information. For example, visible light can be used to detect objects, and ultraviolet, infrared and microwave can also be used to detect objects. Using the different penetrability of different wave bands to objects, we can also obtain the internal information of ground objects. For example, the microwave band can also work around the clock in the depths of the ground, under the water, under the ice water body and under the desert.

Use:

First, the application of remote sensing in resource investigation

Remote sensing can play a great role in resource investigation, especially in natural resources investigation. In recent years, a lot of work has been done and fruitful results and considerable benefits have been achieved. Mainly in the national economic construction of agriculture, forestry, geology and mineral resources and water conservancy construction and other departments.

Application of (1) in agriculture and forestry

The application of remote sensing in agriculture and forestry is mainly in the investigation and monitoring of agricultural and forestry land resources, land use status, agricultural and forestry diseases and insect pests, soil drought, salinization and desertification, as well as crop monitoring and yield estimation, forest resources inventory and so on. In recent years, work has also been carried out in pasture resources, short-term and medium-term agricultural and forestry disasters, agricultural water resources and wildlife ecological environment investigation, and achieved results.

Remote sensing has been widely used in the investigation of land resources and soil. Remote sensing has accelerated the investigation progress, and the accuracy and quality of the work have also been greatly improved. For example, using 560 Landsat images, China completed the analysis, measurement and statistics of 15 land use types in only two years, providing basic data and related maps of land use in the whole country and provinces.

Crop yield estimation is the best example of comprehensive application of remote sensing in agriculture. Since 1974, the United States, the former Soviet Union, Argentina, China, Japan, India and other countries have carried out yield estimation of different crops in different ranges. The accuracy of the United States' estimation of the world wheat yield has reached more than 90%, and it has been extended to the yield estimation of more than eight crops such as corn and soybean. From 1983 to 1986, China conducted a large-scale winter wheat yield estimation experiment in Beijing, Tianjin and Hebei, with an accuracy rate of over 90%.

Remote sensing is also widely used in forestry. For example, the comprehensive remote sensing survey of the "Three North" shelterbelt completed in China in recent years. The type, distribution, area and preservation rate of existing shelterbelts were completed in the investigation of the first phase of the "Three North" afforestation project, covering most of the northwest, northern North China and northeastern northwest, with a total area of 6.5438+0.28 million square kilometers. Quantity, quality and distribution of grassland; Investigate the types, distribution, quantity and utilization of land resources. More than 200 remote sensing thematic series maps were provided, and the resource and environment information system of the whole region was built, which laid the foundation for grasping the present situation of shelter forest areas and further development planning of forest areas.

(ii) Applications in geology and mineral resources

The application of remote sensing in geology and mineral resources is mainly manifested in basic geological work, mineral geological work, and comprehensive geological survey of engineering geology, seismic geology and disaster geology. Remote sensing has become an advanced working method and an important method for geological and mineral investigation and research.

Remote sensing images have a wide field of vision, objectively and truly reflect various geological phenomena and their relationships, and vividly reflect the spatial relationship between regional geological structures, which provides extremely favorable conditions and foundations for cross-regional and even global regional geological research. For example, in recent years, the research on the extension and strike of the Yarlung Zangbo River deep fault zone, the demonstration of the extension and strike of the Tan fault zone, and the revision of the1∶ 40,000 China structural system map are all based on the new understanding and new discoveries of remote sensing images, which have solved some problems that have been debated for a long time or are difficult to solve conventionally in the geological field. Remote sensing provides a basis for geologists with different academic viewpoints and promotes the development of geology.

The application of remote sensing in mineral geology has made many achievements and won unanimous praise. For example, the Xiaoqinling gold ore field is divided into 1030 linear structure, 138 ring structure and 1000 ancient mining caves by remote sensing geological survey method in China's geological and mineral system. According to the results of geochemical and geophysical exploration, the 13 prospect area is put forward. After inspection, 22 gold-bearing quartz vein zones and altered structural zones have been found, and 3 gold deposits have been seen, all of which lasted only one year. Another example is: Coalfield Corporation delineated 17 coal-bearing basins on the western slope of Daxing 'anling in Northeast China by using remote sensing geological method, among which 4 were newly discovered, with an additional reserve of 54 billion tons. There are countless similar examples, and remote sensing geological method has become an important method in mineral geological work.

As a modern means, remote sensing is also widely used in comprehensive geological surveys such as engineering geology, seismic geology, hydrogeology and disaster geology. Only during the period of 1980- 1985, the remote sensing geologist of the Ministry of Geology and Mineral Resources made the 13 project to evaluate the stability of large projects and studied four major landslides. The Remote Sensing Center of the Ministry of Geology and Mineral Resources has carried out color and side-looking radar imaging flights between Chongqing and Yichang in the Three Gorges of the Yangtze River. According to the obtained data, the engineering geological interpretation and analysis of the Three Gorges reservoir area are carried out in detail, and the shape, formation mechanism and development trend of Xintan slope are analyzed in detail, which provides the basic information for the construction of the Three Gorges Project for the country.

Based on the extensive application and remarkable benefits of remote sensing in geological and mineral surveys, the geological prospecting departments in China have successively set up professional remote sensing application and scientific research institutions, and the number of remote sensing geological teams has also been expanding, with many achievements, showing the bright development prospects of remote sensing in geological and mineral resources.

(3) Application in hydrology and water resources

The application of remote sensing in hydrology and water resources, such as water resources investigation, watershed planning, soil erosion investigation, ice and snow monitoring, coastal zone and shallow sea topography investigation in Haikou, marine investigation and research, can play an important role. Especially in the desolate areas where human footprints are difficult to reach, remote sensing technology can become an effective means of hydrological and water resources investigation. For example, in the past 300 years, the Qinghai-Tibet Plateau in China has experienced more than 150 explorations and discovered more than 500 lakes. In recent years, the use of aerial photos and satellite images for interpretation has not only corrected the location of these lakes, but also supplemented more than 300 lakes not marked on the ground survey or map.

Remote sensing images, especially infrared remote sensing images, are very beneficial to identify aquifers, judge water-filled faults and find out the location of water-rich areas. For example, in the Hawaiian Islands, the United States discovered more than 200 underground fresh water dew points by infrared remote sensing, thus solving the island's demand for fresh water. China has carried out aerial thermal infrared remote sensing experiments in Dalian, and found 22 fresh water springs with no historical records in coastal areas. Through the analysis of these springs, the underground fresh water discharge area is determined, which provides an important way to solve the drinking water source for people and animals in coastal areas.

The use of remote sensing images for coastal investigation, suspended sediment transport in estuaries and inshore waters and marine environment monitoring, such as measuring seawater temperature, salinity, water depth, ocean currents, waves and tides, can play an important role and is of great significance to ocean development. In particular, remote sensing images can provide large-scale, realistic, multi-level, all-weather, objective and true information, provide a basis for marine research and guide marine fishery production.

Second, the application of remote sensing in environmental monitoring and assessment and fighting against natural disasters.

(A) the application in environmental monitoring

Remote sensing mainly uses large-scale images provided by remote sensing to monitor air pollution, water pollution, land pollution and marine pollution. Because the information provided by remote sensing is fast, timely, true, objective and vivid, we can know and master the location of pollution sources, the nature and dynamic changes of pollutants, and the impact of pollution on the environment in real time, thus providing a basis for timely protection or diversion measures and environmental assessment. For example, the Hydrological Law Team of the Ministry of Geology and Mineral Resources cooperated with the Geological Remote Sensing Center to investigate and study the current situation of water pollution from Suzhou estuary to Wudaokou in the lower reaches of the Yangtze River. They used aerial thermal infrared scanning images to identify 29 abnormal points and drew an interpretation map of river pollution of about 25 kilometers. They also carried out aerial infrared monitoring of seawater pollution in coastal ports and offshore platforms from Dalian in the north to Hainan Island in the south, which provided a basis for the law enforcement of the State Oceanic Administration.

The Three Gorges Water Control Project on the Yangtze River is a large-scale project with complex technology and great economic and social benefits. However, the construction of the Three Gorges Dam on the main stream of the Yangtze River will have a far-reaching impact on its ecology, environment and society. Therefore, in the systematic study of the impact of the Three Gorges Project on the ecological environment and its countermeasures, as well as in the field investigation, the comprehensive analysis method of remote sensing is adopted, which gives full play to the role of remote sensing in the environmental demonstration and information storage of the Three Gorges Project. Many remarkable achievements have been made in environmental background investigation, environmental evolution analysis and environmental dynamic monitoring in the reservoir area, which provide reliable data and basis for scientific decision-making of the Three Gorges Project in China.

In recent years, China has monitored and evaluated the urban environment of Changchun, Taiyuan, Beijing, Tianjin, Guangzhou and other large and medium-sized cities by using aerial remote sensing, which indicates that the application of remote sensing in environmental monitoring in China is developing in a broader and deeper direction.

(b) Combating natural disasters.

Natural disasters refer to disasters brought by environmental anomalies or sudden changes to human life and survival. In recent years, remote sensing technology has made many important achievements in disaster prediction and has become a powerful tool and means to predict natural disasters.

At present, meteorological satellites have entered operational operation, forming a multi-level forecasting network, which has played a very important role in disastrous weather monitoring, weather analysis and forecasting, meteorological research and so on. The successful development and successive launch of China's Fengyun-1 and Fengyun-2 meteorological satellites indicate that China's meteorological forecasting technology has developed from single, short-term and small-scale forecasting to comprehensive, medium-and long-term and large-scale accurate forecasting. It provides reliable data for the accurate prediction of drought, flood, landslide, debris flow and diseases and insect pests in China, and provides reliable basis for taking disaster reduction measures.

Forest fire has always been one of the important disasters that threaten forestry construction. As early as 1970s, China carried out aerial remote sensing-forest fire detection experiment. At an altitude of 3000 meters, the fire source of 0. 1 m2 on the ground can be found by thermal infrared sensor. 1May, 987, in the great forest fire in Daxinganling, Heilongjiang Province, remote sensing played an important role in accurately determining the location, scope and spreading trend of the fire source, providing timely and accurate fire information for extinguishing the fire, monitoring the development of the fire, evaluating the fire loss after the disaster and restoring and rebuilding the plan, and achieved remarkable social and economic benefits.

In recent years, multi-temporal remote sensing data and geographic information system technology have been used for comprehensive investigation and study of soil erosion in the Loess Plateau. Using the global positioning system (GPS) technology, we can monitor the movement of the crust and its plates, conduct geodynamics research on a large scale, explore the mechanism of earthquakes, and make medium and long-term earthquake predictions. Using multi-temporal large-scale aerial remote sensing images combined with meteorological forecast data and ground exploration to investigate and monitor landslides and debris flows to ensure the safety of key projects and railways; And using long-distance satellite communication technology to improve the timeliness and accuracy of disaster prediction, and provide basis for disaster relief and decision-making. , has made great achievements and significant progress.

Third, the application of remote sensing in regional analysis and construction planning

Remote sensing image is a true and objective record and image display of the landscape in a certain area of the surface. Geographical area analysis also makes full use of this feature and advantage of remote sensing images and becomes an important aspect of remote sensing application in geography. For example, the early remote sensing experiments in Tengchong, Changchun, Xinjiang and the middle and lower reaches of the Yangtze River in China, as well as the comprehensive remote sensing investigation of the Loess Plateau and the "Three North" shelterbelt in recent years are all based on regional analysis. In the application of regional analysis of remote sensing, China has formed certain characteristics and entered the advanced level in the world.

In recent years, with the upsurge of urbanization and urban construction, urban remote sensing is in the ascendant. Urban remote sensing can provide basic information of urban development, such as urban land use status, urban land use analysis, urban environmental monitoring and evaluation, urban layout structure analysis, urban road traffic analysis, urban population analysis and urban ecological analysis, and serve urban construction planning and decision-making. For example, the "Beijing Aerial Remote Sensing (830 1 Project)" jointly organized and implemented by the Beijing Municipal Government, the Ministry of Geology and Minerals and the Ministry of Urban and Rural Development started its remote sensing flight from 1983 to 1986, and it was used in urban environmental geology, urban construction, agricultural water conservancy construction, ecological environment, image maps, cultural relics and ancient buildings, etc.

After Beijing, urban remote sensing has been widely developed in large and medium-sized cities in China, and the depth and breadth of its application have been improved to varying degrees. Especially with the deepening of urban remote sensing application, the establishment of urban geographic information system and its application in urban master planning and urban construction decision-making have raised the application of urban remote sensing to a higher level.

Fourthly, the application of remote sensing in global macro research.

Although the global remote sensing research has not been carried out systematically at present, it has formed a scale. However, with the development of social economy, especially a series of global problems, such as the increase of world population, resource crisis and environmental degradation, have attracted more and more attention. Global research has been put on the agenda, which is highly valued by all countries in the world, and there will be a great development.

The purpose of global research is mainly to study the lithosphere, atmosphere, hydrosphere and biosphere on which human beings depend, so as to promote the deepening of regional research and improve the global environment. Therefore, this is undoubtedly another application field in which remote sensing plays its own characteristics and advantages. Remote sensing can provide various convenient conditions for global research and promote the further development and deepening of global research. For example, the remote sensing global positioning system (GPS) can be used to monitor and study plate movements and deep faults, and to study the causes and mechanisms of ring structures; Using meteorological satellite data and other remote sensing information to carry out global meteorological research and predict world disasters; Ocean dynamics research, the distribution of solid water on the earth's surface, the advance and retreat of glaciers in the world, the monitoring and management of the world environment. Remote sensing is bound to play a greater role in global research and make greater contributions.

At present, global research has been carried out one after another, and 1992 has been designated as the International Space Year (ISY). A brand-new digital encyclopedia of global change will be published, which will explain the contribution of remote sensing to monitoring global change. China has decided to take an active part in the cooperation of the geosphere and biosphere (IGBP), the International Space Year (ISY) and the International Decade for Disaster Reduction. Undertake some projects such as global change atlas and global change electronic encyclopedia. China will contribute to global research.

V applications of remote sensing in other fields

(A) Application in Surveying and Mapping

Aerial photogrammetry has always been the main data source and important technical method in surveying and mapping, forming a complete and systematic discipline system. The development of contemporary remote sensing makes the sources of surveying and mapping data more diversified, and the accuracy and reliability of data, as well as its rapid timeliness and timely dynamics, have been greatly improved. The surveying and mapping cycle is greatly shortened; The emergence of a large number of new maps and new surveying and mapping technologies, such as image maps and digital maps, has made new changes and progress in surveying and mapping. For example, based on the images obtained by satellites launched in recent years, China has completed the compilation of the Yellow River Delta1∶ 50,000,1∶ 65438+100,000 maps, and completed the first Nansha Islands image map in China. Remote sensing can also obtain data in various areas where the climatic and meteorological conditions are complex and conventional methods are difficult to operate, filling the gap in ground operations. For example, there are nearly 5 million square kilometers of tropical rain forests in the Amazon basin of Brazil, where the land is vast and sparsely populated, and it is difficult to make routine measurements all day long. Using remote sensing side-looking radar technology, the scanning and imaging work of1∶ 400,000 radar in this area was completed in less than one year, and valuable data were obtained, which provided a basis for surveying and mapping in this area. It is common to use remote sensing images to compile various thematic maps, and to compile small and medium-sized large-scale provincial (regional), national and even continental image maps. Western European countries revised and updated the topographic map of 1∶50000 by using SPOT satellite data. With the improvement of spatial resolution, spectral resolution and phase resolution of remote sensing information, remote sensing will open up a better prospect for the development and application of surveying and mapping technology.

(2) Application in historical sites and archaeological investigation.

In recent years, with the application of remote sensing image analysis in field archaeological investigation, many important historical sites have been discovered and remarkable achievements have been made. For example, British remote sensing experts discovered the remains of ancient castles in Roman times 30 kilometers underground in London, England through computer-enhanced satellite images. China also used the information provided by remote sensing to investigate the discovery of Yuanmingyuan site, Great Wall site and Jin Dynasty ancient city in Inner Mongolia, and achieved good results. Remote sensing has brought changes to field archaeological investigation, become a powerful tool and means for archaeologists, and promoted and accelerated field archaeological work.

(3) Military application

The application of remote sensing in military affairs is self-evident. In fact, military application is the earliest and most successful application of remote sensing. Nowadays, the development of remote sensing has developed rapidly because of its successful application in the military. At present, most of the satellites launched around the earth are related to the military. The victory or defeat of today's war depends not only on the comparison of military strength (manpower and weapons), but also on accurate and reliable information acquisition, transmission and decision-making. The Falklands War between Britain and Argentina, the Middle East War and the Gulf War all fully proved the important role of remote sensing in military wars.