This study was carried out to identify the problems of the underground watersheds on Jeju Island, and to establish the hydraulic groundwater basin to be used as basis for the analysis of the groundwater model. In order to evaluate the adequacy of the groundwater basin on Jeju Island, a correlation analysis between elevation and groundwater level was conducted using data from 125 observation wells. The analysis, conducted with an elevation step of 100 m, exhibited values of R2 in the range 0.1653-0.8011. No clear correlation was observed between elevation and groundwater level. In particular, the eastern and western areas showed an inverse proportionality between elevation and groundwater level. The Kriging technique was used to analyze the underground water level data and to define the equipotential lines for all areas of Jeju Island. Eight groundwater watersheds were delineated by considering the direction of groundwater flow, the positions of the observation wells, and the long and short axes of the watersheds.

Abstract
 1. 서 론
 2. 자료 및 방법
  2.1. 지하수위 관측정
  2.2. 상관관계 분석
  2.3. 공간보간기법
  2.4. 지하수 등수위선 검정
 3. 기존 지하수 유역의 적절성 평가
  3.1. 해안거리와 표고 상관분석
  3.2 지하수위와 해안거리 상관분석
  3.3. 표고와 지하수위 상관분석
 4. 지하수 등수위선 작성 및 유역경계 설정
  4.1. 지하수 등수위선 작성
  4.2. 지하수 등수위선의 검정
  4.3. 지하수 유역경계 설정
 5. 결 론
 REFERENCES

• 김민철(제주연구원) | Min-Chul Kim (Jeju Research Institute)
• 양성기(제주대학교 토목공학과) | Sung-Kee Yang (Department of Civil Engineering, Jeju National University) Corresponding author