Groundwater exploration in Ordos basin

(1) Introduction to the results

1. It is the first time to find out the total amount of groundwater resources in the whole basin and its development and utilization potential.

The total recharge resources of groundwater in the basin are 654.38+0.05 billion m3/a, and the recoverable resources are 5.8 billion m3/a. At present, the exploitation amount is 654.3.8+0.654.38+0.05 billion m3/a, and the exploitation potential is 4.7 billion m3/a. The areas with great exploitation potential mainly include karst groundwater in the eastern and southern edges of the basin and Cretaceous groundwater in the northwest. In these areas, there is a potential groundwater enrichment area 18, and the groundwater source area 16 1 has been found. After preliminary assessment, the water supply capacity of the water source area can reach 2.2 billion m3/a.

According to the regional economic development plan, by 20 10 and 2030, the total water demand in Ordos basin will be 7.2 billion m3/a and 9 billion m3/a respectively. The total amount of water resources available in the whole basin is 654.38+004 million m3/a, including 4.6 billion m3/a of surface water and 5.8 billion m3/a of groundwater. Through the analysis of supply and demand balance, it is considered that the total amount of water resources in the basin can basically meet the short-term and medium-term planning water demand of the energy base through further exploration and evaluation, overall planning and scientific allocation of the designated centralized water supply source areas.

2. The formation and evolution of groundwater in the basin have been found out, and a series of internationally recognized scientific and technical problems have been solved.

The three-dimensional geological structure digital model of the whole basin and the Cretaceous aquifer structure digital model are established for the first time. The formation mechanism and circulation mode of karst groundwater and Cretaceous groundwater around the basin are found out, and the formation age and renewal rate of groundwater with different depths in Cretaceous thick aquifer are quantitatively revealed. The groundwater database and spatial information system in Ordos Basin are established, which realizes the effective management of geographic information, basic geology, hydrogeology, geophysical exploration and remote sensing information, and provides a digital platform for the rational development, management and environmental protection of groundwater resources.

3. Obtained a large number of measured data, which provided important geological basic information for regional economic and social development.

For the first time, the massive measured data of basic geology and hydrogeology in the whole basin were systematically obtained. The results of the project are being widely used in the economic and social development planning of Shaanxi, Gansu, Ningxia, Mongolia, Shanxi and other provinces (regions). The people's governments of Shaanxi Province, Gansu Province, Inner Mongolia Autonomous Region and Ningxia Hui Autonomous Region have increased capital investment in groundwater exploration and further improved the level of water source exploration. During the implementation of the project, through the combination of exploration and mining, more than 0/00 wells were drilled for the local area, with a cumulative output of 330,000 cubic meters per day, which solved the drinking water problem of nearly 570,000 people in more than 20 towns, hundreds of villages and some factories and mines in five provinces (regions) of Shaanxi, Gansu, Ningxia, Mongolia and Shanxi.

4. Explore a set of organizational forms of major projects and train a group of outstanding talents.

The project organized geological survey teams from five provinces (regions) of Shaanxi, Gansu, Ningxia, Mongolia and Shanxi, and more than 500 scientific and technical personnel from 17 unit including famous domestic professional colleges, and adopted cross-regional, multidisciplinary and multi-arm joint research to apply the latest theories and technical methods of groundwater exploration to groundwater exploration in Ordos Basin, so that the scientific and technological level of the project reached the international leading level. Explore a set of multi-unit, multi-disciplinary integration, international cooperation, and local government cooperation in the organization and operation of major planning projects. Through the combination of Industry-University-Research and cooperation with famous foreign research institutions, a group of technical backbones and leading talents who can undertake major projects have been trained, which has laid a talent foundation for groundwater exploration in other large river basins in China. At present, 2 monographs have been published; Published 50 papers, including 2 foreign papers, 2 papers included in SCI and EI, and 2 core journals1paper; Academic exchanges at international and domestic academic conferences have reached more than 10 times; Trained 16 doctoral students and 27 master students.

(2) Technical features

Based on the theories and technical methods of large-scale basin groundwater exploration at home and abroad, a set of theories and technical methods of large-scale basin exploration and evaluation are adopted, which are supported by GIS and database, from geological investigation to geophysical data interpretation to hydrogeological drilling verification, three-dimensional geological modeling to isotope and hydrochemical analysis, groundwater system division to groundwater numerical simulation, etc.

The whole exploration work should be combined with Industry-University-Research, special research and comprehensive evaluation, and multi-disciplinary and multi-method comprehensive means should be adopted to fully absorb and introduce foreign new technologies and methods of groundwater exploration and strengthen international technical cooperation and exchange. At the same time, in the exploration work, especially in the hydrogeological drilling work, we should combine the local needs as much as possible, strive to improve the level of exploration and research, and give play to economic and social benefits. The specific technical scheme is as follows:

1. Remote Sensing Interpretation of Hydrogeology in Ordos Basin

Based on the principle of surface energy balance system (SEBS), the quantitative remote sensing technology is used to estimate the surface evaporation in the basin. Combined with the study on the variation law of vegetation index in this area, the reasonable groundwater ecological water level is determined.

2. Study on 3D visualization geological model of Ordos Basin.

Based on the existing spatial data (including 12930 km seismic profile, 1956 coalfield oil drilling and logging data, and the latest 203 hydrogeological borehole data), the three-dimensional geological structure model, Cretaceous sand body spatial distribution digital model and visualization model of the whole basin are established by using sedimentary basin analysis technology and three-dimensional visualization technology, which quantitatively and intuitively represent the spatial geological structure and different periods of the current basin. It lays a geological foundation for three-dimensional numerical simulation of groundwater and evaluation of groundwater resources in Ordos Basin.

3. In-situ experimental study on rainfall infiltration intensity and evaporation intensity of groundwater level.

A hydrogeological in-situ test site was established in Wushenqi, Ordos, to carry out in-situ test research on precipitation infiltration and evaporation intensity of groundwater level, and systematically study the temporal and spatial variation characteristics of meteorological elements and their responses to groundwater and ecosystems. The evaporation intensity of water surface with different salt content is studied, and the relevant hydrogeological parameters of water migration in vadose zone and groundwater resources evaluation are obtained. The dynamic mechanism of water migration and transformation in vadose zone is revealed.

4. Study on the mechanism of groundwater circulation in Cretaceous.

Using the packer fixed depth stratified sampling equipment and testing technology assisted by the International Atomic Energy Agency, the fixed depth groundwater level of the aquifer with the thickness of 1000m was measured, isotope and hydrochemical samples were collected in layers, and the groundwater stratified pumping test was carried out, which provided key technical support for identifying the hydrogeological characteristics of the aquifer, obtaining key hydrogeological parameters and revealing the chemical evolution and circulation law of groundwater.

5. Study on karst development law and rational development and utilization of groundwater in Ordos Basin.

Under the guidance of system theory, using the theories of geology, karst and hydrogeology, field investigation, indoor and outdoor experiments, hydrochemistry and isotope, GIS and other methods are adopted. Based on the karst theory, the characteristics of karst development are systematically summarized, and the characteristics of different karst groundwater systems and water circulation modes are summarized. This paper analyzes the medium structure types, groundwater recharge and discharge conditions, hydrochemical and isotopic characteristics, groundwater dynamics and its influencing factors, and the evolution law of karst water resources, delineates the water sources with development and utilization prospects, and evaluates the recharge resources, exploitation resources, fresh water resources and groundwater quality of karst groundwater according to groundwater systems and subsystems.

6. Study on numerical model of Cretaceous groundwater flow in Ordos Basin.

With the support of GSLIB, T-PROGS, GMS and other simulation software, a three-dimensional numerical model of Cretaceous groundwater with an area of 13.2 1 10,000 km2 is established, and a hydrogeological structure model and a spatial distribution model of permeability parameters are established by geostatistics. A simulation model of groundwater flow, hydrochemistry and groundwater age of 14C is established by selecting typical sections. SEBS model is used to calculate phreatic water evaporation and its distribution, and environmental remote sensing method is used to analyze the evolution law of vegetation index and evaluate groundwater resources and ecological environment function.

7. Research on Groundwater Information System in Ordos Basin

Based on ArcGIS, the spatial database of Ordos Basin is established, which can effectively manage five categories of data: geographic information, basic geology, hydrogeology, geophysical exploration and remote sensing interpretation, and develop related data analysis function modules. Using Visual Basic language, integrating ArcGIS, GoCAD, GMS, Sufer, Grapher and Aquachem, the three-dimensional query of geospatial information is realized. The spatial information database system of model information management, information query and information exchange based on ArcGIS has established a good platform for the visualization and mutual access of geospatial information.

Second, the scope of application and application examples

(1) Scope of application

1. Scope of application of technical methods

With the support of GIS and database, a set of exploration evaluation theories and technical methods in great basin are adopted, including geological survey → geophysical data interpretation → hydrogeological drilling verification → 3D geological modeling → isotope and hydrochemical analysis → groundwater system division → groundwater numerical simulation, etc. It can be applied to the main basins in the northwest of China.

2. Application scope of groundwater exploration results in Ordos Basin

The exploration results of groundwater resources in Ordos basin can be used as the geological basis for further exploration of groundwater resources in the basin.

(ii) Application and effectiveness

1. The application and effect of the project achievements.

Application of (1) in the social and economic development planning of the country and related provinces (regions)

The results of the project have strong practicability, which not only provides macro-decision-making basis for the social and economic development planning of the country and relevant provinces (regions), but also directly provides valuable underground water sources for local economic construction and people's lives, and solves the urgent needs of some areas with serious water shortage.

(2) Application in the planning and construction of national energy base.

The project has proved the total amount of groundwater resources in the basin and its development and utilization potential, and delineated 18 groundwater enrichment area and 16 1 water source. The cumulative water supply capacity of water sources has reached 2.2 billion cubic meters per year, and some water sources have been transformed and applied by the local government. The people's governments of Shaanxi, Gansu and Inner Mongolia Autonomous Region cooperated with the Ministry of Land and Resources respectively and jointly invested/kloc-0.08 million yuan to further explore and evaluate some water sources, which provided water resources guarantee for the planning and construction of national energy bases.

(3) Application in water supply of large national enterprises.

Through the transformation of achievements, it has effectively promoted the development of local economy. China Shenhua Group's "Coal to Oil" project is a national key construction project approved by the National Development and Reform Commission. Whether the project can run normally depends on the degree of water resources security. The exploitable groundwater resources of Haole Baoji Water Source discovered by the project exploration reach 80,000 m3/d, which has started to supply water to the plant area, ensuring the normal operation of national key projects. At the same time, three karst water sources were found in Qipanjing Town, Etuoke Banner, which is seriously short of water, basically solving the water problem of Inner Mongolia district-level industrial parks, making the town's GDP increase from less than 6 million yuan in the past to 3.4 billion yuan in 2004, and earning 50 million US dollars from exports. It is estimated that by 20 10, the industrial output value will reach 10 billion yuan, and the foreign exchange earned by export will reach 10 billion US dollars.

(4) Application in safe drinking water for urban and rural residents.

In the process of project implementation, combined with the needs of local residents' safe drinking water and economic construction, seepage wells, radial wells and vertical shafts were used to take water, and development models under different hydrogeological conditions were established. Combining exploration and mining, more than 0/00 wells were drilled in the local area, with a total output of 400,000 m3/d, which solved the problem of safe drinking water for nearly 570,000 people in more than 20 towns and hundreds of villages, and made important contributions to improving people's living conditions in the old revolutionary base areas and ethnic minority areas, promoting local economic development and strengthening national unity.

2. Application example of achievement transformation

(1) The northern Shaanxi Energy and Chemical Industry Base in Ordos Basin has carried out groundwater exploration.

According to the results of this project, the Shaanxi provincial government cooperated with the Ministry of Land and Resources, and invested 25 million yuan to carry out the project of "Groundwater Exploration in Northern Shaanxi Energy and Chemical Industry Base of Ordos Basin", which systematically found out the total amount, geographical distribution, utilization status and development and utilization potential of groundwater resources in the area north of 38 north latitude of Northern Shaanxi Energy and Chemical Industry Base. After investigation and verification of 33 water sources, the total recoverable resources of 930 million m3/a ... 30 places reach the accuracy of Grade B, and the total recoverable resources of Grade B reach 769 million m3/a, which can be used as the basis for the construction drawing design of water sources. The accuracy of the three places reaches Grade C, and the total recoverable resources of Grade C are 654.38+0.34 billion m3/a, which can be used as the basis for the preliminary design of the water source. There are 20 new proven water sources, 8 new B-level water sources, and the B-level resources are 654.38+84 million m3/a; Three new C-level water sources and1100,000 m3/a C-level resources are added. Nine water sources were upgraded from Grade C to Grade B, which increased the resources of Grade B by 227 million cubic meters/year ... check13 Class B water sources, and the recoverable resources were 359 million cubic meters/a.

(2) Explore the groundwater resources in Yulin City.

The results of this project provide a material basis for the exploration of groundwater resources in Yulin City. According to the results of this project, Yulin invested 1 100 million yuan, and Xi 'an Geological Survey Center launched the "Exploration and Evaluation Project of Groundwater Resources in Yulin City", which identified the spatial distribution of groundwater resources, identified the regional groundwater resources and development and utilization prospects, and delineated four groundwater enrichment areas and water sources with water supply prospects. It provides a basis for the construction of energy and chemical base and the exploration of groundwater resources in Yulin city.

(3) Carry out groundwater exploration in Inner Mongolia Energy Base of Ordos Basin.

According to the results of this project, the Ministry of Land and Resources cooperated with Inner Mongolia Autonomous Region to deepen the project results, and jointly invested 38 million yuan to carry out the "Groundwater Exploration Project of Inner Mongolia Energy Base in Ordos Basin", which identified the spatial distribution of groundwater resources, identified the regional groundwater resources and development and utilization prospects, and found and delineated 13 groundwater enrichment area and 44 water sources with water supply prospects. A comprehensive hydrogeological survey was carried out in the 10 groundwater enrichment area, and the recoverable resources of Class C groundwater of 834,000 m3/d were submitted. Twenty-two water sources for further exploration were newly discovered, including 5 large ones and 7 medium ones/kloc-0, which provided water supply guarantee for the construction of energy base.

3. Application prospect

Application of (1) exploration technology

From "geological survey → geophysical data interpretation → hydrogeological drilling verification → 3D geological modeling → isotope and hydrochemical analysis → groundwater system division → groundwater numerical simulation", a set of exploration evaluation theories and technical methods in great basin are summarized. It provides technical reference and guidance for groundwater exploration in large basins in northwest China.

(2) Application of exploration technology achievements

The geological structure and aquifer types of the whole basin are systematically identified, and the three-dimensional geological structure digital model and Cretaceous aquifer structure digital model of the whole basin are established. For the first time, the total amount of groundwater resources in the basin and its development and utilization potential were identified, 18 super-large groundwater enrichment areas were discovered, and 1 groundwater source areas were delineated, including 42 large-scale water sources, which provided water source guarantee for the construction of national energy base.

With the construction of national energy base and the further development of groundwater resources, the application prospect of this achievement is broader. It provides theoretical and technical basis for the implementation of groundwater exploration projects in Shanxi and Weibei energy bases in Shaanxi Province.

Third, promote the transformation mode.

Publicity, conference exchange, project cooperation, technical training, technical consultation, on-site service, etc.

Technical support unit: Xi Geological Survey Center of China Geological Survey.

Contact: Hou, Zhang Mao Province.

Mailing address: No.438 Youyi East Road, Xi, Shaanxi Province

Postal code: 7 10054

Tel: 029-8782 1944

E-mail: xazms@ 126.com, xahgc @163.com.