KOREA INSTITUTE OF GEOSCIENCE AND MINERAL RESOURCES
THE WORLD'S LEADING RESEARCH
INSTITUTE OF GEOSCIENCE
INTEGRATED TECHNOLOGY DEVELOPMENT FOR SECURING GROUNDWATER/GEOTHERMAL RESOURCES AND CONSERVING ECOSYSTEMS ACCORDING TO CLIMATE CHANGE
The National Research Council of Science & Technology (NST) of Korea has promoted the Big Issue Group Project at each research institute for the revitalization of long-term research. KIGAM selected groundwater as the subject for the Big Project, and the Groundwater & Ecohydrology Research Center created a research plan for the Big Project to develop groundwater-based fusion technology to address the climate change issue.
The final goal of the project is to develop a GEE system to cope with climate change. The GEE system is an information system integrated into the Groundwater-Geothermal-Ecosystem, refer-ring to the three components that make up the Groundwater Dependent Ecosystem (GDE). We refer to this technology as Terra-4G. Here, Terra means Earth and Big Data as the objectives of the research. In other words, it pertains to terrestrial land as the research target and Tera, the SI prefix of 1012, meaning it deals with large amounts and various types of groundwater information. In the title, 4G represents the first letter G in Groundwater resources, Global climate change, Geothermal energy, and the Geo-ecosystem. Through the de-velopment of this technology, we intend to secure sustainable groundwater-geothermal resources and maintain the groundwater dependent ecosys-tem with regard to climate change.
A survey and review of the literature related to hydrogeologic units domestically and overseas have been completed, and geologic maps (1:50,000) were collected and classified as the hydrogeologic units for the detailed specification. Groundwater databases from various basic groundwater sur-veys and investigations conducted by KIGAM and other organizations were constructed for the Geumgang area.
Detailed 3D geological modeling using geological core logging data of the National Groundwater Network of 109 stations in 34 cities and counties in the Geumgang area was completed, and a 3D visualization modeling for geological/hydrogeo-logical interpretation was finished.
A total of 2,900 rock thermo-physical data were collected to evaluate the feasibility of the shallow thermal energy development of the site. The monitoring systems in the KIGAM’s research buildings in Daejeon and Pohang were estab-lished, and a closed-type geothermal cooling and heating simulation technology was developed. In addition, a conceptual design of the composite closed/open heat exchanger was completed, and related designs and installation plans for the next year were established.
In order to analyze and evaluate the different types of groundwater dependent ecosystems, the collection of existing data and a field survey of the groundwater dependent ecosystem (ground-water, river, and wetlands) in the Geumgang area were completed. In addition, we conducted a monitoring survey of the groundwater dependent ecosystem related to a recent earthquake in the Gyeongju area for more than six months and accumulated basic data of groundwater dependent ecosystem changes caused by the earthquake.
The groundwater dependent ecosystem integrat-ed system was constructed for each database of the three factors (groundwater, geothermal, eco-system). Groundwater database contains the well yield, hydraulic conductivity, transmissivity, storage coefficient, groundwater level, groundwater temperature, and electrical conductivity, etc. The geothermal database was constructed for thermal conductivity, thermal diffusivity and the geothermal gradient. The ecosystem database includes the results of analyses of the concentrations of major dissolved substances, pollutants and mi-croorganisms in groundwater and surface water (rivers, wetlands, reservoirs).
Fig. 1. 3D geological modeling of the Geumgang area.
Fig. 2. Prediction of the ground-water temperature distribution in summer according to use of vertical closed type geothermal heat exchanger.
Fig. 3. Results of groundwater age analyses using 3H in the Geumgang area.