Chen Mengxiong

Ministry of Land and Resources, Beijing, P.R.C.

Abstract: Knowledge on the development and utilization of groundwater had a long history in ancient China. However, the use of geologic science for studying the underground water began only in the 1920s to the 1940s of the last century. Hydrogeology as a branch of geological science was actually started and established in the 1950s after the founding of new China. Five periods may be subdivided during the different decades of the past 50 yeas. The decade of the 1950s is the period characterized by the development of regional hydrogeology; while the 1960s is the period of agricultural hydrogeology. In both the two periods, the development of hydrogeology was much influenced by the basic conceptions or theories of the scientists of the former Soviet Union. From the 1970's to the 1980's, the main feature was the development of environmental hydrogeology and quantitative hydrogeology (water-resources hydrogeology). During that time, it was evident that the exchange of experience and information as well as the international cooperation with the western countries pushed forward the rapid advancement of the hydrogeological science in China.

Key word: traditional hydrogeology; current hydrogeology; regional hydrogeology; agricultural hydrogeology; environmental hydrogeology; quantitative hydrogeology; information hydrogeology.

Introduction.

Hydrogeology as a branch of geologic science was actually initiated and established in the 1950s after the founding of new China. The hydrogeologic science gained great progress in line with the rapid development of economic construction. According to the changes of the main aspects, five periods may be discerned during the past 50 years: (1) the period of regional hydrogeology of the 1950s, (2) the period of agricultural hydrogeology of the 1960s, (3) the period of environmental hydrogeology of the 1970s, (4) the period of quantitative hydrogeology of the 1980s, and (5) the period of information hydrogeology of the 1990s. In the early stage, the new idea of modem hydrogeology was introduced to China from the former Soviet Union, while in the later stage international exchange has become common, especially the cooperation with western countries has caused rapid advancement of the hydrogeologic science in China. This paper intends to give a brief account of the major events and main aspects of the development of hydrogeologic science in the different periods.

Period of Regional Hydrogeology (1950s)

This is the period of initiation of modern hydrogeology. This period was characterized by setting up of new organizations and beginning of nation-wide regional hydrogeologic surveying and mapping all over the country. The Bureau of Hydrogeology and Engineering Geology was set up under the Ministry of Geology in 1955, which was responsible for the investigation and research work of groundwater resources of the whole country. It cooperated with related sections of water conservancy and urban reconstruction or industrial sectors in groundwater exploitation for agriculture and industry. All the provincial bureaus set up their own hydrogeology teams to undertake their tasks. To coordinate the prospecting works, three research units were set up, including the Institute of Hydrogeololgy and Engineering Geology in Zhengding(1956), the Institute of Technology and Methodology of Hydrogeology and Engineering Geology in Baoding(1960), both in Hebei Province, and the Institute of Karst Geology in Guilin, Guangxi Zhuang Autonomous Region(1970s). These units are principally engaged in scientific research. In respect of education, five geologic colleges had established the department of hydrogeology and engineering geology to train specialists in that field.

During this period, many Soviet experts visited China as part of intergovernmental cooperation. Therefore basic conceptions or theories, standards or regulations and methodologies for hydrogeologic investigation were introduced or originated from the former Soviet Union. A hydrogeologic map of China in the scale of 1:3,000,000 was compiled and published in 1958, which is the first nation-wide hydrogeologic map in China. The nation-wide hydrogeologic mapping had promoted the development of regional hydrogeology. A lot of articles or monographs were published, such as<The Regional Hydrogeology of China>published by the Geological Publishing House in 1958.

Period of Agricultural Hydrogeology (1960s)

In the early 1960s, North China suffered a bad drought which lasted for several years. In order to overcome the drought, the main task turned from regional hydrogeology to agricultural hydrogeology including reclamation hydrogeology for developing well-irrigation. Much specialized prospecting works had been accomplished for the exploitation of groundwater and the improvement of saline soil as well as the control of swamps, especially in North China. Experiences also were accumulated in water exploration in mountainous regions and pasture lands. A great number of hydrogeologic maps in the scale of 1:50,000-1:100,000 were completed for agricultural water supply or other purposes, which provided a scientific basis for the rational arrangement of groundwater use. In order to meet the needs of agriculture, small scale maps of large areas, such as the hydrogeologic map series of Huang-Huai-Hai Plain and Songliao Plain(1:1,000,000) were compiled and published in the early 1960s on the basis of reconnaissance survey. This was the first group of small scale map series published in China.

As a result, 170 million mu(1133 x10⁴ ha) of arable land were irrigated with water from wells, and the annual exploitation of underground water has reached 40 billion m³. In Hebei Province, more than 400, 000 irrigation wells have been drilled with an annual exploitation of about 10 billion m³, irrigated for more than 30 million mu (200 x10⁴ ha) by groundwater. These areas had witnessed bumper harvests for many years and consequently had become self-sufficient in cereal products.  

Period of Environmental Hydrogeology (1970s)

During this period, environmental hydrogeology became the main task to meet the needs of the rapid development of urban construction. Enormous investigation works had been undertaken to facilitate water supply in large and medium-sized cities and industrial bases. Many important cities, including Beijing, Xi' an, Taiyuan, Tianjin and Shenyang are largely dependent upon groundwater supply. With the growth of urban population and the rapid development in industry, water demand greatly increased. In the urban areas, environmental problems related to groundwater frequently arise, such as excessive exploitation, water pollution, seawater intrusion, land subsidence, etc. Many monitoring stations were set up in important cities. Research works have been made to study the origin, mechanism, and basic rules of water pollution or seawater intrusion for their control or elimination. Intensified experimental tests and research on artificial recharge had been undertaken in Beijing and other cities in order to expand groundwater resources.

On the basis of studies of the mechanism, development, and frequency of land subsidence, the city of Shanghai adopted multiple measures including the reduction of water consumption, adjustment of the order of exploitation of aquifers and artificial recharge. The interrelations among groundwater output, recharge and water-table fluctuations were also studied in detail, and the subsidence of land surface in Shanghai is now being basically controlled. In order to maintain low temperature water in summer and medium temperature water in winter, the city of Shanghai has creatively developed a method of regulating groundwater storage by "winter recharge for summer use and summer recharge for winter use". This has helped not only to effectively control surface subsidence but also to take advantage of the particular thermo-preserving property of groundwater. This method has now found wide application in many cities.

Hot springs are widespread in China. Many prospecting and exploration works of the geothermal water have been undertaken in urban areas as initiated and supervised by Prof. J. S. Lee and had already obtained significant results. Prominent examples of utilization of geothermal water are in Beijing, Tianjin and Fuzhou. Geothermal water of good quality has been found in large quantities in the urban areas of these cities, and is utilized in many ways, such as medical treatment, space heating, dyeing, air conditioning, bathing, farming and side line production. Investigations of thermal water had been also developed successfully in the exploration and research of high temperature thermal fields in Tibet and western Yunnan.

In this period, regional hydrogeologic mapping mainly in the scale of 1:200,000 was basically completed in the whole country except for some high mountainous regions and desert regions. A great number of hydrogeologic maps in separate sheets and with relevant expositions have been published. Maps or atlases in various scales have been also compiled for provinces and basins according to needs of national economic construction. One of the highlights was the publication of the Hydrogeologic Atlas of the PRC in 1979 compiled by the Institute of Hydrogeology and Engineering Geology in cooperation with the provincial agencies. This atlas is a reflection of the main achievements in the research of regional hydrogeology.

Period of Quantitative Hydrogeology (1980s)

Beginning from the 1980s, the Chinese national economy entered a new period of development. An overall evaluation of groundwater resources of the country was accomplished to meet this new situation. The comprehensive assessment of water resources and environmental quality for major economic regions or river basins and important cities were the main task in this period. Besides, the study of the resources of fissure water and karst water were also emphasized. A monograph entitled<Research on the Prediction of Groundwater Resources and Environmental Problems of the Urban Areas in 2000>was published by the Management Section of Geologic Environment, Ministry of Geology and Mineral Resources in 1986.

Because of the open-door policy, intercommunications with foreign hydrogeologists, especially of the western countries, have become more and more often. Thus new ideas or techniques were introduced into our country; such as the theory of unsteady flow, new conception of groundwater flow system and sytematic engineering, electronic computer technique, mathematical modeling, isotopic technique and remote sensing, had been widely applied in hydrogeologic study and groundwater resources evaluation. Geophysical methods are also widely used for hydrogeologic prospecting. Thus it may be said that the hydrogeologic science has stepped into a new period of quantitative hydrogeology.

Period of Information Hydrogeology (1990s)

In order to provide a great quantity of hydrogeologic records and data for establishing models, it is necessary to establish related information search system and data base. As a result of study on the data management system in recent years, groundwater resources data management system in Henan Province and groundwater balance test and monitoring data processing system were developed by Henan General Environ-hydrogeologic Station. They are running normally. Shanxi General Environ-hydrogeologic Station has also established groundwater regime data base (GWD) management system in Shanxi Province, which could input, revise, inquire, count and process the regime data, as well as print report forms and draw figures. The data base and data management system are also established in many other cities such as Qinhuangdao, Shijiazhuang, Xinxiang, etc.

On the basis of geographic information system (GIS), study on specialist decision system for the urban water resources and environment management is being carried out in China. As a result of study on information data base, knowledge base, inference-interpretation system and knowledge gaining system, a current specialist decision system for urban water resources-environment management could be established. The complicated systematic engineering of water resources-environment management could be computerized and automated. A technical tool easy for operation could be provided to the department of urban water resources management. Using this tool, one could not only carry out real time analysis, process simulation and information output for the state of water resources, but also realize optimal decision for water resources management.

Study on information system has become one of necessary and important topics of water resources research. It includes data management system, regime monitoring information system, remote sensing information system, development of specialist decision system, and application of 3-dimensional GIS to model study, etc. Hydrogeology is gradually developing towards information hydrogeology, in which water resources management and protection become the main objects.

Major Events of International Exchange and Cooperation

Since the middle of the 1970s, normal international scientific exchangs have been resumed and advanced, especially with the western countries. Among foreign hydrogeologists or delegations visiting China, the most important was the French hydrogeologic delegation under the leadership of Dr. G.Castany. This was also the first hydrogeologic delegation visiting China from a western country.

In this period many foreign scholars visited China and gave lectures in related colleges or institutes. Among them, Dr. G. B. Engelen, Professor of Free University of the Netherlands, gave a series of lectures on groundwater flow system. Dr. J.Soveri of Finland on environmental hydrogeology, Dr. K.D.Clampe from Germany on compilation of hydrogeologic map. Many research projects were accomplished in cooperation with foreign specialists, such as the study of the mathematical model on the land subsidence of Shanghai in cooperation with Belgian scientists, the program "Groundwater resources evaluation of the Huang-Huai-Hai Plain" in cooperation with the UNDP, the study of the model of karst water in Guilin in cooperation with French hydrogeologists, and the exploration and utilization of geothermal water in Beijing-Tianjin region in cooperation with the UN experts.

Meanwhile, China has joined some important international organizations in 1980s and became a country member of the International Association of Hydrogeologists (IAH) and the International Association of Hydrological Science (IAHS). The China National Committee for IAH and of IAHS were established. Chinese hydrogeologists have visited many foreign countries and attended international symposiums including the IAH Congress and the Scientific General Assembly of IAHS. Many papers in the proceedings of these symposiums have been translated and published in Chinese. Moreover, some important international meetings were organized successfully in China, such as the 21th Congress of IAH and the Symposium on Karst Hydrogeology held in Guilin in 1988, and the Symposium on Hydrological Basis for Water Resources Management held in Beijing in 1990.

In addition, Chinese hydrogeologists have also joined some working groups of the scientific projects of the International Hydrological Program (IHP) of UNESCO, e. g. project A2.8 "Developments in the Analysis of Groundwater Flow Systems" and project 11. la " Side Effects of Water Resources Management". The results of these projects have been already published by IAHS. Through the active collaboration between Chinese and foreign institutions, academic intercommunications have been successfully conducted in China.

Conclusion

It is evident, since the middle of the 1970s, the government began to execute the reform and open policy , normal international scientific or technique exchange and cooporation have been resumed and advanced especially with the western countries, such as the Germany, Holland, France, England, Finland and Belgium. A lot of new theories and techniques were introduced into or country greatly promoting the advancement of the hydrogeological science of China. This is an important turning point from the stage of traditional hydrogeology stepped into the stage of current hydrogeology.

In conclusion, the history of the development of hydrogeologic science in China may be subdivided into four stages, including ancient China. In the recent 50 years, it could be divided into two stages and five periods according to the development of its branches of learning. The former stage (1950s-1970s) is called the stage of traditional hydrogeology, the latter (1970s-1990s) ---- the stage of current hydrogeology.