Overview and Prospect of the Development of Hydrogeology

Hydrogeology is a relatively young natural discipline, it is people in the continuous utilization of groundwater resources, as well as the fight against groundwater hazards in the process of gradual development. With the development of production, hydrogeology only became an independent discipline in the 20th century in the 20s to 30s.

China is one of the earliest countries in the world to utilize groundwater, as early as 5,000 years ago, it was known to drill wells to obtain water. About 3,000 years ago, China's agriculture has been considerable development, about the use of groundwater has been a lot of records. The pre-Qin "hit the soil song" said: "sunrise and work, sunrise and rest, drilling wells and drink, plowing and eat." It shows that there was already the knowledge of drilling wells to utilize groundwater. 2500 years ago, our ancestors already knew how to use various signs of soil and plants to search for groundwater and deduce the depth of the groundwater and the quality of the water. In the Qin Dynasty, in Zigong, Sichuan Province, people used bamboo tools in the hard bedrock to cut wells more than a hundred meters deep to take brine to cook salt, which is the world's earliest artesian wells, artesian wells utilized 1500 years earlier than in France. Facts fully illustrate that China's ancient working people in the production practice has accumulated a wealth of knowledge of groundwater.

In foreign countries, hydrogeology was first developed in Europe. 17th century, the rise of capitalism in Europe, the new relations of production strongly promote the forward development of productive forces, the industrial revolution in the 18th century 60's, but also promote the development of science and technology, so far, people through a wide range of experiments and observations, about the formation of groundwater, the theory of movement, as with all the natural science Theories about the formation and movement of groundwater, like all natural sciences, were gradually established. Until the beginning of the 20th century, due to the development of modern natural science, so that hydrogeology developed into a comprehensive discipline.

After the founding of New China, with the recovery of the national economy and the first five-year plan, hydrogeology put forward urgent requirements. Such as the new and expanded city water supply, mine drainage, and some water conservancy project construction of many hydrogeological problems. To this end, our country in the five or six years after the founding of new China, the rapid establishment of hydrogeological disciplines, trained the first generation of hydrogeologists in new China. With the development of construction, this team continues to grow and develop. The majority of hydrogeologists carried out scientific research on groundwater in conjunction with various construction projects in China, such as the formation conditions of groundwater, water quantity evaluation and water quality research, long-term observation of groundwater dynamics, etc. By the beginning of the 1960s, China's hydrogeology had become one of the most popular disciplines in the world. To the early 1960s, China's hydrogeologists in the formation of groundwater, groundwater movement, groundwater chemistry and underground hot water and other aspects of the study have a lot of ideas for the city, industrial and mining enterprises, agriculture, railroads and other water supply, mines and engineering construction and other areas of the drainage, a lot of water conservancy and hydroelectricity construction, hydrochemical mineral prospecting, etc., to provide hydrogeological information to ensure the development of the various sectors of the national economy. In the early 1970s, the hydrogeological work in mountainous areas was especially strengthened, and investigations and researches on fissure water and karst water were carried out, and the theory of geomechanics was widely applied to the work of water searching, which contributed to the census and exploration of groundwater in mountainous areas. In addition, regional hydrogeological surveys at different scales have been carried out throughout the country, and since 1995, a special plan for finding water in the northwestern region and a plan for poverty alleviation in the poor karst mountainous regions of the southwestern part of the country have been carried out, while in 2001 and 2002, the Emergency Groundwater Survey Project for the Severely Water-Scarce Areas in the Western Region and the Demonstration Groundwater Survey Project were implemented, respectively. "During the Tenth Five-Year Plan, a new round of groundwater potential investigation was carried out throughout the country, and a spatial database of the country's major groundwater systems was established. With the emergence of problems such as shortage of water resources and environmental degradation, China has carried out groundwater resource management since the mid-1980s. At present, groundwater resource management has evolved from purely hydraulic modeling to economic management modeling and joint groundwater and surface water dispatching management modeling.

In terms of hydrogeological research methods and technical means, in the 1950s, some countries with developed science and technology generally adopted modern means to study hydrogeological problems, and there appeared successively computational means such as electric network simulation and numerical simulation, etc. In the 1960s, isotope technology began to be used to solve certain hydrogeological problems. Subsequently, mathematical geological methods and remote sensing (RS) technology have also been introduced into hydrogeology. In recent years, geographic information system (GIS), a computer software system that can effectively handle a large amount of spatial information, as well as global positioning system (GPS) technology, have been gradually and widely applied to hydrogeological work. The means of hydrogeological research is developing in the direction of diversification and synthesis, and the application of new theories and technologies will make the hydrogeological research move towards informatization and digitization.

In summary, hydrogeology, marked by the establishment of Darcy's law in 1856, has developed rapidly in 150 years. Regarding the development trend of contemporary hydrogeology, Zhang and others put forward the following views:①Transfer of core subjects: water search hydrogeology→resource hydrogeology→ecological environment hydrogeology. ② Expansion of research field: localization of aquifer → whole aquifer → groundwater system → hydrological system → ecological environment system → technical-social system. (iii) Change of research objectives: from local problems to global issues, from current problems to long-term sustainable development issues, from solving specific production problems to constructing a coordinated and virtuous cycle of groundwater system, hydrological system, geo-environmental system and ecosystem between human and nature. (4) Expansion of research content: from the study of water quantity of groundwater to the study of water quantity and quality; from the study of groundwater in a narrow sense (saturated zone water) to the study of groundwater in a broad sense (including saturated zone water and water in the air-bearing zone), and even the study of the groundwater circle. (5) The change of research idea: the research on the regularity of the phenomenon can no longer satisfy the needs, and it is required to strengthen the proportion of process and mechanism research from the perspective of the formation of life. (6) Multidisciplinary cross-penetration becomes the mainstream: the pure hydrogeology in the traditional sense is dying out, and the cross-penetration of groundwater science with other natural sciences and social sciences, and the multidisciplinary way of studying and dealing with the problems are becoming the mainstream. (7) service mode change: hydrogeology service object greatly expanded, the service mode has changed a lot, how to make hydrogeological work results into productivity, has become a major issue that needs to be resolved.

Review questions

1. hydrogeology research object, what is the task?

2. How is the role of hydrogeology in the construction of national economy? Why should the students of hydrogeology-related majors master the basic theoretical knowledge and skills of hydrogeology?

3. Try to explain the functions of groundwater.