Songnen Plain is one of the working areas deployed by China Geological Survey to investigate and evaluate groundwater resources and their environmental problems in the main plain basins in northern China. It is undertaken by Shenyang Institute of Geology and Mineral Resources, with the participation of College of Water Resources and Environment of Jilin University, Heilongjiang Geological Survey Institute and Jilin Geological Survey Institute. The working period is from 2003 to 2005.
The work makes full use of new technologies and methods such as remote sensing, computer, information technology, isotope technology, model technology, etc., and gives full play to the technical advantages of multi-discipline and multi-means and Industry-University-Research's joint work. On the basis of investing a lot of physical workload, we will carry out systematic and in-depth investigation and research.
The research results systematically collate the previous data and work results, establish the groundwater numerical model and geological structure model in Songnen Plain for the first time, realize the visualization of geological structure and the digitalization of groundwater flow, and lay the foundation for groundwater dynamic evaluation and optimal management of groundwater resources; In this study, the early warning theory is applied to the study of groundwater pollution for the first time, the framework of groundwater pollution early warning system is put forward, the groundwater pollution evaluation early warning system is established, and the prediction of groundwater pollution evolution is realized. 270 groups of isotope samples were collected, and the recharge, diameter, discharge and regeneration mechanism of groundwater were studied by isotope technology. Based on the groundwater system, the groundwater resources are re-evaluated, and the changes of recharge, diameter and discharge conditions of groundwater in recent 20 years are deeply analyzed. More than 2400 water samples were collected from aquifers with different depths for laboratory analysis, and the present situation of groundwater quality was systematically evaluated, and the changing trend of water quality was analyzed. The environmental geological problems related to groundwater and their changes in recent 20 years are deeply analyzed and studied. The results reflect the changes of ecological environment during the rapid economic development in recent 20 years, which provides an important basis for evaluating groundwater resources and protecting the ecological environment. Through the work, the spatial database of groundwater resources and its environmental problems in Songnen Plain has been established, which has built a good working platform for hydrogeology and environmental geology in the future. Finally, some suggestions and countermeasures are put forward for the rational development and utilization of groundwater resources in Songnen Plain and the safety of water supply in major cities.
1. The numerical model and geological structure model of groundwater flow in Songnen Plain are established.
Based on GMS (groundwater modeling system) software, the geological structure models of the whole region and cities and counties are established for the first time, and the arbitrary cutting and spatial visualization of geological sections are realized. Based on the geological structure model, the structure and boundary conditions of aquifer system are summarized, and a hydrogeological conceptual model is established. The numerical model of groundwater flow simulation in the study area is generalized as a heterogeneous, isotropic and unstable flow mixed model of porous phreatic water, pore confined water and pore fissure confined water, and the mathematical models of groundwater are established respectively. Through flow coupling, the numerical model of groundwater based on the whole basin is established. The actual groundwater level data is used to identify and verify the model, and the identification and verification effect is good, and the established water flow model is reliable. Based on the identified and verified numerical model of groundwater flow, the changes of groundwater flow field in 20 10 and 2020 under the given mining scheme are predicted, and the changing trend of groundwater flow field in Songnen Plain in the future is given.
2. The groundwater pollution early warning system has been established and developed.
This work applies the early warning theory to the study of groundwater pollution for the first time, puts forward the idea of groundwater pollution early warning system, and establishes the framework of groundwater pollution early warning system. Based on GIS component development technology and groundwater pollution early warning model, a groundwater pollution early warning system which can run independently from GIS platform is developed, and the groundwater quality in Qiqihar city is evaluated and early warned. The system can carry out water quality evaluation, water quality prediction, aquifer inherent vulnerability evaluation, pollution source load risk calculation, pollution risk evaluation and pollution early warning analysis in the study area. The system has established mathematical models such as fuzzy comprehensive evaluation, neural network, grey model and time series analysis. It has spatial analysis functions such as buffer analysis, superposition analysis and spatial interpolation, and can draw isolines and isosurface of spatial data. The evaluation results can be expressed in various forms, such as graphs, tables and composite graphs formed by their combination.
3. Using isotope technology to study groundwater recharge and regeneration mechanism.
In this study, 2 16 groups of hydrogen, oxygen and carbon isotopes were selected, and the formation and evolution of groundwater were analyzed according to the groundwater system and the existing research results of regional geology, lithofacies palaeogeography, hydrogeology, environmental geology and isotopes. Based on the stable isotope characteristics of hydrogen and oxygen in precipitation, river water and groundwater, the zoning characteristics of recharge area and its relationship with groundwater are determined. Using radioactive tritium and radioactive carbon of precipitation and groundwater, the circulation depth and range of groundwater in different aquifer systems are analyzed to judge whether there is ancient water or deep circulating water recharge; According to the changes of hydrochemistry, hydrogen and oxygen isotopes and radioactive carbon along the streamline, the possible recharge source, retention time, groundwater flow mode and spatial distribution characteristics of groundwater are determined. According to the isotopic and chemical information of precipitation, river water and groundwater, the recharge, runoff and discharge mechanism of groundwater are determined.
4. The groundwater resources are evaluated and the conditions of recharge, diameter and discharge are changed.
On the basis of field investigation, a series of hydrometeorological data are used to evaluate groundwater resources, and the changes of groundwater recharge, runoff and discharge conditions in recent 20 years are analyzed. Taking the groundwater system and the administrative districts of cities and counties as units, the groundwater resources were evaluated by water balance method, analytical method and numerical simulation method respectively. More than 2,400 water samples were collected from aquifers with different depths for laboratory analysis, and the present situation of groundwater quality was systematically evaluated by various methods. Compared with the existing water quality monitoring data, the changing trend of groundwater quality is analyzed, and the hydrochemistry and water quality evaluation maps of different aquifers are compiled.
5. The research on environmental geological problems related to groundwater is carried out, and the changing trend of environmental geological problems is analyzed.
Based on the satellite photos of mid-1980s and 2000 ~ 200 1 year, the present situation of land desertification, salinization and wetland distribution in Songnen Plain was interpreted, and its development trend was compared and analyzed. Using the spatial analysis function of GIS, the changes of land desertification, salinization and wetland in recent 20 years were quantitatively studied. The scope and amplitude of regional groundwater level decline are basically found out, and the development trend of groundwater level decline funnel in Harbin, Daqing, Qiqihar and Changchun is analyzed.
6. The spatial database of groundwater resources and its environmental problems in Songnen Plain is established.
Based on the database software of groundwater resources and its environmental problems developed by China Geological Survey, the spatial database of groundwater resources and its environmental problems in Songnen Plain was established. The database contains all survey data and previous major achievements, including hydrogeological field survey, drilling data, comprehensive results of pumping test, analytical test data, socio-economic data, remote sensing interpretation, comprehensive reports and maps. There are 1886 boreholes, 2,408 groundwater quality data, 2 16 isotope test data sets, 243 1 groundwater monitoring points, 96,965,438 field records of groundwater level monitoring, 2,346 pumping well monitoring points, and165,438 comprehensive results of pumping tests. The establishment of this database not only improves the informatization level of hydrogeological data, but also lays a foundation for realizing the socialized service of hydrogeological data, and provides a working platform for the future investigation and study of hydrogeological environment geology in Songnen Plain.
Second, the scope of application and application examples
The investigation result is a deep and systematic summary of the present situation of groundwater resources and its environmental problems in Songnen Plain. The achievement has been published, which is of great significance to the sustainable utilization, protection and management of water resources and the sustainable development of local society and economy in Songnen Plain. The results of the project have been widely used in the land departments and water conservancy departments of cities and counties in Songnen Plain, which has played a basic supporting role in the later investigation of groundwater dynamics, the construction of groundwater monitoring network and the investigation of groundwater pollution in Songnen Plain.
Third, promote the transformation mode.
Conference exchange, project cooperation, consulting services, etc.
Technical support unit: Shenyang Geological Survey Center of China Geological Survey.
Contacts: Zhao Ailin and Wang.
Mailing address:No. 1 Huanghe North Street, Huanggu District, Shenyang.
Postal code: 1 10034
Tel: 024-62606 139
E-mail :syxiaoguang@yahoo.com.cn