More than 40 years have passed since James E.Hackett, a scholar of Illinois Geological Survey, wrote an article on urban land planning in 1964. His view that "environmental geology is a new method to study and use geology to achieve a harmonious and perfect state" has gradually faded out, but the term "environmental geology" has been used to this day, and the name of a new discipline has been adopted by geologists.
For decades, the discussion on the definition and connotation of environmental geology has never stopped.
In 1968, W.J.Wayne thinks: "In the urban center and the area near the city, human environmental geology becomes more important. Urban geology has become synonymous with environmental geology. " P.H.Moser pointed out in 1969: "Environmental geology is a discipline that uses the principles of geology, hydrogeology, engineering geology, geophysics and related disciplines to study the surrounding environment of human beings and make more effective use of natural resources." P.T.Flawn pointed out in 1970: "Environmental geology is to study the whole range of human land use, including cities, rural areas and the original areas to be developed in the future, including the location and development of natural resources, the influence of waste disposal, block movement and tectonic movement on buildings, and the subtle changes in the composition of geotechnical materials on human health." Edwarda in the 1980s. Keller expounded seven basic concepts (viewpoints) about environmental geology in his book Environmental Geology, and pointed out that "when we explore the nature of environmental problems, the importance of interdisciplinary nature of environmental geology is obvious. Most projects are complex, including many different aspects, which can be summarized into three categories: physics, biology, human utilization and human interests. " Since then, he further clarified in 1998 that "environmental geology is an applied geology, which mainly studies all aspects of the interaction between human beings and the natural environment".
At the same time, China scholars also expressed their views on the connotation of environmental geology. In 1980, Liu Dongsheng and Wan pointed out: "Environmental geology is a discipline that studies the interaction between human activities and geological environment, a branch of geology and an integral part of environmental geology." In 1983, Zhong pointed out: "Environmental geology is a comprehensive geological discipline that applies the basic principles of geology, studies the interaction between human engineering economic activities and geological environment, predicts the occurrence and development law of natural and man-made geological processes, and thus formulates plans, measures and schemes for transforming, utilizing and protecting the geological environment, so as to prevent or mitigate geological disasters and protect and improve the quality of geological environment." 1995 Chen mengxiong clearly pointed out in the article "theoretical basis and research field of environmental geology": "environmental geology is a new branch of geological science and belongs to the category of applied geology. It is a highly comprehensive marginal or comprehensive discipline, focusing on the relationship between man and land and the relationship between geological science and environmental science. " Zhang Zonghu proposed in 199 1 that environmental geology should be a subject to study the interaction between human technological activities and geological environment. In addition, scholars such as Li Erong, Zhu Dakui, Pan Mao, Duan, Xu Zengliang, Dai Tagen and Ha Chengyou have also written articles or expounded some insightful views in the textbooks, which are not introduced here.
Scholars who hold the above views come from many fields, including scholars and experts engaged in theoretical research and engineering technology or technology management departments; There are people who have environmental science and geological geography, especially hydrogeology and engineering geology. Their views basically reflect the current understanding and mainstream of environmental geology in academic circles at home and abroad. It should not be ignored that there are also objections in academic circles. For example, G.B. oakeshott (1976) thinks that environmental geology is an absurd term, saying that "all geology is environmental". Although these voices are not loud, they also reflect from another side that some concepts and terms need to be further improved in the process of environmental geology absorbing nutrients from other disciplines. Even among the scholars who agree, there are some differences. One of the outstanding problems is whether environmental geology is an applied or engineering discipline and whether it has the basic characteristics of scientific and technological integration. This problem will be discussed in the third part of the introduction. This paper only focuses on the research topics of environmental geology, which is the consensus of the above viewpoints.
(B) the research theme of environmental geology
The theme of environmental geology research can be summarized in one sentence, that is, to study the relationship between man and geological environment, including: ① the significance and influence of geological background, geological process and its process on human beings; (2) Geological basis and sociological problems of geological environment changes caused by human activities; ③ How to coordinate the relationship between man and geological environment.
1. Geological background, geological process and its significance and influence on human beings
In the relationship between man and land, the significance and influence of geological environment on human beings can be understood from the following two aspects:
(1) Geological environment is the provider of resources.
Geological resources include land resources, water resources, mineral resources and landscape resources. They are the necessary material basis for human survival and development.
The main components of land resources are rocks and soil. Soil is the object of agriculture, forestry and animal husbandry. It is a parent material formed by weathering of rocks and a loose matrix formed by biochemical processes. Its formation process is closely related to internal and external dynamic geological processes. Internal dynamic geological processes can lift underground strata to the surface and provide soil-forming materials. External dynamic geology plays a key role in the final formation of soil, on the one hand, it determines the formation speed and maturity of soil; On the other hand, it changes the texture and distribution of soil through the erosion, transportation and accumulation of water and wind, thus affecting the yield of crops and the structural characteristics of plant communities. In addition, the surface and underground space are both attached objects of artificial buildings, and land planning and urbanization development are carried out in this space. Therefore, they are also an important function of land resources and geological background.
Generally accepted, water resources mainly refer to surface water and groundwater. In the long run, non-gravity water in soil and active water in near-surface atmosphere may become the objects of utilization. No matter what kind of water is brought into the hydrological cycle, its formation and distribution are not only related to atmospheric activities, but also topography, landforms, strata and geological structures will affect the quantity, quality and temporal and spatial distribution of water resources, especially groundwater.
Mineral resources, including metallic minerals, nonmetallic minerals and fossil fuels, can be regarded as direct products of geological processes. Some are formed under the internal dynamic geological action; Some of them are related to external dynamic geological processes; There are also the results of the comprehensive action of two geological processes.
The landscape resources here mainly refer to the natural geological relics and natural landforms that have the value of geoscience research and can be visited by people. They are also the products of geological processes.
Some people think that these resources can be divided into renewable resources and non-renewable resources according to the balance between their formation speed and human consumption speed. In fact, this division is not absolute, but reflects people's thinking about the relationship between people and resources. For example, when the soil fertility rate is higher than the soil nutrient consumption and soil erosion rate, the land suitability is sustainable. On the contrary, the land develops in the direction of impoverishment, desertification or rocky desertification and loses its use value. Another example is water resources. When the development and utilization amount is less than the runoff of the basin, the hydrological cycle can continuously supplement the consumed water and make it inexhaustible. If it is over-exploited, water resources will be less and less. Because of this, some people classify the above two kinds of resources as renewable resources, while others think that they are renewable resources within a certain use limit, and they are non-renewable resources beyond the limit. Mineral resources are formed in a long geological history. Due to the continuous geological cycle, the mineralization process is still going on, but it takes tens of thousands of years or even longer to complete this process, such as coal and natural gas, which is obviously in an "overdraft" state compared with the speed of human exploitation. Another consideration is that the evolution of the earth and the change of geological environment are irreversible processes. As far as a particular area is concerned, once the mineral resources are exhausted, they will not be regenerated in that area. Therefore, mineral resources are generally regarded as non-renewable resources.
If the above-mentioned resource renewability considers the balance of quantity, then landscape resources pay attention to the uniqueness of form. Its formation is closely related to geological processes, and it is a landscape "fragment" left by a specific geological evolution process in a specific time and space. Once destroyed, it is difficult to repair, and it is almost impossible to find a similar scene. Therefore, it is generally classified as non-renewable resources.
(2) Geological environment is the home of human beings.
The shallow geological environment on the earth, especially on the land surface, is the place where human beings live, multiply, live and engage in various production activities, and is the home of human beings.
In this space, geological processes are very active and never stop. The erosion, transportation and accumulation of water, wind and gravity drive the movement of rocks, water and salt, so that the surface materials on the surface are in the process of continuous redistribution, and the surface morphology is reshaped again and again. At the same time, tectonic movements, magmatic activities, earthquakes, etc. It can also release the material and energy deep in the earth to the surface, turn the sea into mulberry fields and turn mountains into lowlands. Some large-scale orogeny will also cause climate and ecological changes.
Some environmental effects caused by geological processes are beneficial to human beings, providing a unique living place for human beings and promoting the development of human beings from the primitive civilization of eating and drinking blood and choosing aquatic plants to the modern civilization of large-scale industrial production; Some will also bring harm and disaster to mankind. Earthquakes, volcanoes, sea level rise and desertification not only lead to the disappearance and annihilation of some splendid ancient civilizations on the earth, but also cause losses to people's lives and property, and even make rich land unfit for human habitation. Whether human beings like it or not, geological processes and geological processes have always been with us. From this perspective, the history of mankind is not only a history of struggling with nature, but also a history of learning how to use and respect nature.
2. Changes in geological environment caused by human activities and their impacts on human beings.
As a population in the biological world (primitive man), man is the product of the evolution of the earth to a certain stage. Humans regard water, rocks, soil and other organisms as the material basis for their survival and development, and at the same time transform the surrounding rocks, soil, water and biological conditions through labor. This relationship between man and nature is the objective background of the formation of the concept of geological environment. It can be said that the geological environment only existed after the appearance of human beings. Without human beings, there would be no geological environment, and the evolution of geological environment is bound to be closely related to human activities.
With the progress of science and technology, human beings have moved from primitive nomadic civilization to farming civilization and modern industrial civilization. In this process, the ability of human beings to intervene and use the geological environment has become increasingly powerful, and the benefits obtained are also very rich. However, with the rapid expansion of the scope and intensity of human activities, its negative aspects are gradually exposed. Over-emphasis on people's initiative, exaggeration of people's ability to control nature and neglect of people's passivity and dependence in front of nature have led to the abuse and misuse of scientific and technological means, which is one of the important reasons for the imbalance between people and land and the endless geological and environmental problems in recent decades.
Geological bodies are always in the process of development and evolution, and have their natural evolution laws driven by natural forces. When the role of human beings reaches a certain level and becomes a new geological force that cannot be ignored, the situation will change, and the evolution of geological bodies will be determined by both natural and human forces. Although human beings get what they want in the process of activities, the environmental cost is also very amazing.
According to some data, by the end of the 20th century, the magnitude of artificially moved geotechnical materials in the world has been 4-5 times higher than that of natural processes. A large number of excavation and spoil have changed the original stress state of topography and shallow rock and soil in many areas, and even induced frequent geological disasters such as collapse, landslide and debris flow. Take Fujian Province, China as an example. Up to 200 1, 803 landslides and 329 collapse points have been identified in the whole province, of which 87% and 84% are related to manually moving geotechnical materials, which is enough to show the great influence of human activities. Secondly, excavation or waste of rock and soil will cause soil loss or burial, and the quantity and quality of cultivated land will decrease obviously. At present, hundreds of thousands of hectares of cultivated land are occupied by urban and rural construction and tens of thousands of hectares of land are destroyed by coal mining every year in China. Coupled with other reasons, the cultivated land in China is reduced by about 1.45 million hectares every year. In recent 40 years, the total amount of cultivated land reduced in China is equivalent to one French, two British or four Japanese countries. There are 666 counties in China, which are below the warning line of 0.8 mu (about 667m2) per capita arable land stipulated by FAO. This situation will seriously threaten China's food security.
Excessive exploitation and utilization of water resources will also affect the quality of geological environment, and may also indirectly affect land hydrology and ecological processes. In 2004, the total water resources in China was 24 1.30× 1.08 m3, and the annual water supply was 5548× 1.08 m3, accounting for 23% of the total water resources, which was still within the safe water use range. At present, the common international standard is that the utilization rate of water resources should not exceed 25% ~ 40% of the total, otherwise there will be resource shortage and ecological environment problems, but this boundary has long been broken in many areas. For example, at present, the water controlled by the surface water storage project in Hebei Plain has accounted for more than 70% of the river runoff, the groundwater exploitation is close to119×108m3/a, accounting for 124% of the groundwater recharge resources, and the cumulative consumption of water storage resources has reached 350× 108m3. Due to the serious imbalance between natural water production capacity and artificial water intake intensity, the groundwater dynamic field, hydrochemical field, temperature field and stress field have all changed, which eventually leads to the increasingly prominent geological and environmental problems such as river drying up, water quality deterioration, land subsidence and cracking, seawater intrusion and ecological degradation.
Driven by short-term economic interests, excessive disorderly development and utilization of resources will inevitably lead to disorder of geological environment, and even lead to unexpected ecological imbalance and disasters. Macro-changes in geological environment are irreversible. If human beings lose the ability of foresight and self-control, while enjoying the immediate benefits, the resulting environmental deterioration is paving a road of no return for human beings. As RachelCarson, an American marine biologist, pointed out in his book Silent Spring, it is not the enemy's activities that keep the life of this victimized world from being revived, but people themselves harm themselves. This philosophy is also applicable to the thinking of the relationship between man and land.
3. Coordinated development between man and geological environment
Humans can't completely control nature, nor can they recreate nature according to their own wishes. The difference between man and nature is that man's activities pursue utility and purpose, while natural activities have no thought, utility and purpose, and are only governed by objective laws. Therefore, the so-called coordinated development of human-land relationship should not be understood as a process of dialogue and compromise between the two sides, but as a behavioral constraint or self-discipline requirement put forward by human beings, or as a sustainable development concept based on people's in-depth thinking about their own contemporary and long-term interests, the core of which is to follow objective laws.
Respecting objective laws is a principle that human beings must strictly abide by when dealing with nature, as well as the development and utilization of natural resources and the prevention of disasters. People's development and utilization of natural resources can achieve the expected purpose, firstly because people understand the formation and distribution law of resources, and secondly because they know how to use corresponding technical means and strategies to conform to objective laws. However, this is only one aspect of the problem. With the development and utilization activities, the original geological conditions will change due to human interference, some factors will be inhibited, while others will become more active, which may aggravate the geological environment problems or cause new problems. Through the superficial phenomenon of human activities, we can see that geological environmental problems are still caused by objective laws and have their natural basis for development. At present, the fundamental reason for the endless geological and environmental problems may be that people ignore the latter.
The multiple relationships among population, resources, environment and socio-economic development are the objective expression of the relationship between man and land. The improper mode of the four movements and the imbalance in proportion are the reasons that aggravate the contradiction between man and land. Straightening out these relationships and constructing a unified whole with benign interaction, that is, a geological environment system with coordinated development of human-land relationship, is not only the ultimate goal of theoretical research on human-land relationship, but also the eternal topic of environmental geology research.
Constructing a geological environment system with the coordinated development of man-land relationship will inevitably involve the change of ideas, the change of thinking mode and the rational use of scientific decision-making methods. To this end, we need to pay attention to the following three points.
(1) Coordination between development and utilization of geological resources and protection of geological environment
The development and utilization of geological resources is the fuse of abnormal changes in geological environment. In order to avoid the serious negative impact of the development and utilization of mineral resources, land resources and water resources on the geological environment, we must first investigate and find out the inherent regularity of geological bodies under natural conditions, then analyze or predict the reaction of geological bodies in the process of resource development and utilization and its possible adverse consequences, and accordingly put forward plans to standardize the development and utilization of resources, so as to achieve satisfactory results acceptable to both resources and the environment. In view of the fact that a large number of geological environment problems left over from China's rapid economic development in recent decades have not been solved in time, we should emphasize the importance of geological environment protection at this stage and put the comprehensive management of geological environment problems, especially the prevention and control of geological disasters, in a decisive position, instead of simply pursuing rapid economic growth. The development and utilization of resources with low added value and serious geological environment sequelae must be strictly restricted. For the engineering activities that have been run, it is necessary to realize the benign development of clean production and waste recycling as soon as possible in accordance with the requirements of the Law of the People's Republic of China on the Promotion of Circular Economy.
(2) Coordination between local geological environment and overall geological environment
The movement of rock, soil, water and gas in geological environment system is a unified whole with organic connection and mutual restriction, in which a certain element or a certain local area is strongly disturbed by human activities, and its response can affect the whole system. Some scholars call the relationship between local and whole geological environment system distance. It means that after the influence acts on a certain part of the geological environment, its consequences are manifested in the ultra-long-distance transmission of space, time and even application fields, and it produces a "domino effect" through the causal chain, which eventually produces unexpected consequences. Therefore, the evaluation of geological environment quality should not only pay attention to the analysis of the current situation of local lots, but also pay attention to its influence from far to near, enlarge the vision to the overall situation and long term, and include all possible fields as far as possible.
(3) the balance between the power to share resources and the obligation to protect the geological environment in interpersonal relationships.
Because people in different regions and industries may share the same geological environment system, once its operation pattern changes, it will involve the process of interest redistribution of different groups. If rights and obligations are not equal, it will not only aggravate contradictions, affect social stability and harmony, but also stimulate excessive development and utilization of resources driven by economic interests, resulting in chaos and disorder. Therefore, adjusting interpersonal interest relationship is one of the important ways to realize the coordinated development of human-land relationship and protect geological environment. As some scholars have pointed out, solving geological environment problems is not only the task of scientific and technological workers, but also the challenge that the whole society should jointly meet. In a sense, social reform includes the transformation of economic goals, social structure and people's consciousness, and finally realizes the balance between people's right to share resources and their obligation to protect the geological environment.