초록 ▼

개발결과요약
최종(연차)목표
◦ 수권경계면에서 물질순환 평가를 위한 수리생태학적 기법 개발 및 수리환경요소간 상호작용 규명
- 수리경계면에서의 상호작용을 규명하기 위한 수리생태학적 다중기법 개발
- 해저유출 지하수 특성 평가를 통한 지하수-해수 상호작용 규명
개발내용 및 결과
◦수권 경계면에서 물질순환 기작 규명을 위한 수리생태학적 기반 구축을 위해 물의 유출입량 평가 기법 분석 및 개발, 지하수내 미생물 분석 시스템, Ra/Rn 동위원소 기법 개발 및 시스템 구축
◦ 영양염류 및 미생물 거동

개발결과요약
최종(연차)목표
◦ 수권경계면에서 물질순환 평가를 위한 수리생태학적 기법 개발 및 수리환경요소간 상호작용 규명
- 수리경계면에서의 상호작용을 규명하기 위한 수리생태학적 다중기법 개발
- 해저유출 지하수 특성 평가를 통한 지하수-해수 상호작용 규명
개발내용 및 결과
◦수권 경계면에서 물질순환 기작 규명을 위한 수리생태학적 기반 구축을 위해 물의 유출입량 평가 기법 분석 및 개발, 지하수내 미생물 분석 시스템, Ra/Rn 동위원소 기법 개발 및 시스템 구축
◦ 영양염류 및 미생물 거동 평가를 위해 국제 공동 연구를 통해 지하수-지표수(호소수) 상호작용을 다학제적 기법을 활용하여 현장과 실내실험 연구 수행
◦ 지하수-해수 상호작용 평가를 위해 광역 해저유출지하수 탐지를 위한 항공원격탐사 기법 개발 및 적용, 해저유출지하수 분포 및 특성 분석, 지하수-해수 상호작용 모델링 및 담-염수 경계면 변동 특성화 기법 개발 수행
기대효과
◦지하수-지표수 상호작용을 고려한 유역규모에서 기후변화에 따른 수자원 변동성 평가 및 국가 수자원 정책 활용
◦부영양화 방지, 오염물 총량 관리 체계 보완 등 지표수계 수질 관리의 효율성 증대에 기여
◦지하수유입 특성을 고려한 연안 해수 수질 관리 체계 구축에 활용
적용분야
◦지하수-지표수 상호작용을 고려한 국가 수자원 정책 수립기반자료
◦영양염류 등에 대한 유역규모 오염물 총량관리 기초 자료 확보
◦하천수, 연안 해수 등 지표수계 수질관리기술 및 방안 기반 구축

Abstract ▼

An international collaborative research project between KIGAM (Korea Institute of Geoscience and Mineral Resources) and USGS (United States Geological Survey) was launched in the year 2013 as part of KIGAM’s World Class Department program awarded to the Groundwater Department. This multidisciplinary

An international collaborative research project between KIGAM (Korea Institute of Geoscience and Mineral Resources) and USGS (United States Geological Survey) was launched in the year 2013 as part of KIGAM’s World Class Department program awarded to the Groundwater Department. This multidisciplinary research team is composed of hydrologists, geochemists, microbiologists, and mineralogists from KIGAM, USGS, and VIMS (Virginia Institute of Marine Sciences). The overarching goals of the collaborative project are to identify the processes influencing the fate of nitrate and ammonium during discharge from groundwater to surface water, to understand the time scales of these processes, and to identify the controls on these processes and their time scales.
Dissolved inorganic nitrogen (DIN) takes a variety of chemical forms depending on the redox conditions. As DIN in groundwater is discharged to a surface water body, it may go through transformations across the groundwater-surface water interface zone with a redox gradient. In addition to the well-known microbial processes including denitrification and nitrification, new processes such as dissimilatory nitrate reduction to ammonium (DNRA), anaerobic ammonium oxidation (anammox), and denitrification coupled anaerobic methane oxidation (DAMO) have been recently reported to contribute to nitrogen transformations. However, their relative importance and prevailing conditions at the groundwater-surface water interface are largely unknown.
Several groundwater flow-through, kettle hole ponds on Western Cape Cod, Massachusetts, USA, were examined as potential field sites. Ashumet pond was selected as the study site based on field observation of anoxic groundwater discharge to the pond water with elevated concentrations of nitrate and ammonium. Groundwater and sediment samples were collected at the nitrate site, ammonium site, and two reference sites in the pond and used for further characterization and laboratory experiments. Vertical head difference, seepage measurement, and tracer test were performed to study the hydrologic characteristics of the study sites. The approach spans from a molecular scale (microbial community structure study) to a laboratory scale (incubation to determine time scales of N transformation processes) and a field scale (in situ measurement of N transformation and transport).
Details of the findings during the year 2013 are discussed in the attached annual report prepared by USGS.
Environmental tracer methods were evaluated to determine residence time at the groundwater-surface water interface which can provide basic information for ecohydrologic investigation. CFCs, SF6, 3H/3He, and 18O/D(water) were selected as applicable tracers and the first investigation were carried out for the alluvial aquifer near Nakdong river. CFCs results showed groundwater in the aquifer is old with ages greater than 50. However, effects of microbial degradation should be checked using dating results from other tracers because groundwater is largely anaerobic. An automatic water sampler was made to collect water samples from 3 points with adequate purging and store the samples at least for one month without evaporation. This machine was tested in the test wells in KIGAM and daily water samples were successfully collected during 10 days. The feasibility of temporal monitoring of hydrochemical and isotopic parameters were tested for the samples.
In an effort to establish ecohydrological analytical systems for the assessment of materials transfer between water bodies, microbiological and molecular biological laboratory was organized, so that microorganisms important to biogeochemical reactions in subsurface environments would be investigated. Lithoautotrophic nitrate-dependent Fe(III)-oxdizing (NDFO) bacteria were targeted to understand the potentials of microorganisms contributing on materials transfer at the interfaces of groundwater-surface water where organic materials are limited. The NDFO microorganisms were enriched from the basalt rock groundwater, which showed apparent difference between abiotic/chemical and biotic reactions of Fe(II) oxidation in terms of the reaction rate and extent. The anoxic Fe oxidation indicated the potential importance of biological activities at the surface water-groundwater interfaces, where are susceptible to transitional oxidation-reduction, though further investigation should be done for lithoautotrophic growth on the single isolate and physiological characterization. As an additional observation, a condition change in the same groundwater showed opposite reactions of Fe oxidation and Fe reduction from the parallel incubations with variational treatments, which suggested that microbial activities could affect transformation, transport, and cycle of diverse organic and inorganic materials in the groundwater-surface water interfaces where dynamic changes of the condition occur.
Interaction between groundwater and surface water is an important hydrologic process involving fluxes of water, nutrients, and other solutes at the water/sediment interface. Two common field methods for quantifying groundwater exchange with surface water are Darcian flux calculations and seepage meter measurements. In this study, a new device to quantify exchange between groundwater and surface water by measuring hydraulic conductivity and hydraulic gradient in sediment at water/sediment interface was developed. Field assessment of this device will be conducted in next year.
To evaluate a temperature tracer system, a developed numerical model is applied to the in situ experiments where heat is injected from the heater and temperature is observed at the divers. The objective of this study is to find the groundwater velocity and dispersivities by comparing numerical results with the in situ temperature data. From the numerical simulation result, the averaged x-axis and y-axis velocities of groundwater are 1.016 m/day and 0.00063 m/day, respectively. Therefore, horizontal flow is dominant flow in the field. In addition, the numerical results give best agreement with the observed data at 2 m and 0.2 m of longitudinal and transverse dispersivities, respectively.
A new method using a floating device to monitor the time series change of the freshwater-saltwater interface is developed for the first time and applied to Handong-1 Sea water intrusion monitoring station with a fixed-depth pressure sensor. The floating device, named sea water intrusion monitoring (SWIM) probe, can move up and down along with the freshwater-saltwater interface movement because it has intermediate density between freshwater, about 1.0 kg/L, and saltwater of about 1.025 kg/L. Based on the 21-days time series data in August, 2013, it is found out that maximum amplitude of the freshwater level and the interface are damped down to 1.1m and 0.14m, respectively, compared to tide of which maximum amplitude was 2.6 m. Lag times of the freshwater level and the interface compared to tide were calculated to be 80 minute and 195 minutes, respectively. The SWIM probe can be expanded to sea water intrusion warning system if it is combined with a wireless submersible distance measuring device and remote commnication technology.
We have developed time series models for forecasting groundwater and interface level fluctuations for an effective management of groundwater and its monitoring system at a costal area. Time series data of tide level, groundwater level, and interface level were used. For the model development, an artificial neural network structure trained by back-propagation algorithm was employed. In order to overcome the local minima problem of artificial neural network, we also employed a momentum term and an initial weight group searching strategy. The result showed that the correlation coefficient values between the observed and estimated data were as high as over 0.9 for groundwater level and 0.7 for interface level. Long term trend was not estimated properly, because the whole range of data was about 7 days. It is expected that the model performance will be improved when a lond term data was obtained and used for the model construction.
High resolution airborne thermal remote sensing technique was developed to reveal the location of coastal spring and submarine groundwater discharge (SGD). We have developed airborne thermal remote sensing system and applied it to East Sea and Jeju island in order to test the stability of the airborne remote sensing system. The airborne thermal image successfully captured temporal variation of sea surface temperature (SST) due to the ocean currents, surface water discharge, and groundwater discharge. In Jeju Island, airborne thermal imagery captured strong cold plumes along the coastline, which are associated with fresh submarine groundwater discharge. Chemical composition of sampled water is highly correlated with temperature and salinity, which implies dynamic changes of near-shore environment by a mixing of fresh water and seawater. In further study, we will measure the spatial and temporal variation of SST due to the SGD and detect the locations of SGD in Korea.
The radon isotopes (²²⁰Rn, ²²²Rn) and their progenitors (²²³Ra, ²²⁴Ra, ²²⁶Ra, ²²⁸Ra) occur ubiquitously throughout the geologic environment as intermediate decay products in the natural U-Th decay series.
They have been applied with great success to a wide range of submarine groundwater discharge tracing studies. In this year, several measurement systems such as RAD7, Alpha-GUARD and RaDeCC have been established to measure radon and radium isotopes.

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 1차년도 보고서 요약서 ... 3
• 요약문 ... 4
• SUMMARY ... 10
• Contents ... 14
• 목차 ... 16
• 제 1 장 연구개발과제의 개요 ... 19
• 제 1 절 연구 배경 및 필요성 ... 19
• 제 2 절 연구 목적 ... 23
• 제 3 절 연구 범위 ... 31
• 제 2 장 국내외 기술개발 현황 ... 44
• 제 1 절 선행기술 조사 ... 44
• 제 2 절 선행연구사업 수행 현황 ... 47
• 제 3 장 연구개발 수행내용 및 결과 ... 50
• 제 1 절 수리생태학적 다중기법 적용 기반 구축 ... 50
• 1. 지표수-지하수 상호작용 평가를 위한 다중추적자 평가 기반 구축 ... 50
• 2. Darcian flux meter 개발 및 평가 ... 62
• 3. 열추적자 기법 개발 및 현장 적용 ... 72
• 4. 수리생태학적 분석 시스템 기반 구축 ... 87
• 5. 지하수-지표수 경계대 질소 순환 기작 연구 ... 93
• 제 2 절 지하수-해수 상호작용 규명을 위한 기반 구축 ... 98
• 1. 해저지하수유출 (SGD)의 중요성 ... 98
• 2. 원격탐사를 활용한 해안 지하수 유출 탐사 적용 기술 개발 ... 111
• 3. Ra/Rn 동위원소기법 개발 및 시스템 구축 ... 149
• 4. 담-염수 경계면 모니터링 및 예측 ... 161
• 5. Submarine Groundwater Discharge(SGD)내 오염물질/영양염류 거동모사 ... 174
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 180
• 제 1 절 목표 달성도 ... 180
• 1. 최종 연구목표의 달성도 ... 180
• 2. 연차(1차년도) 목표 달성도 ... 181
• 제 2 절 관련분야에의 기여도 ... 182
• 제 5 장 연구개발결과의 활용계획 ... 184
• 가. 정책적 측면 ... 184
• 나. 과학기술적 측면 ... 184
• 다. 국민생활과 사회수준 향상에의 기여 측면 ... 185
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 187
• 제 1 절 UNEP-DHI 연구사업 협력 ... 187
• 제 2 절 USGS 국제공동연구 ... 192
• 제 3 절 미생물 유전학 및 생태학 분야 연구 동향 ... 197
• 제 4 절 환경 방사능 측정 분야 연구 동향 ... 201
• 제 7 장 참고문헌 ... 206
• 부록 ... 214
• 끝페이지 ... 254