낙동강 하구 기수생태 복원이 본격으로 논의가 진행 전인 2016년까지는 하류 수위의 예측을 위해 하구에서 수km 떨어진 기존 조위관측소(부산 및 가덕도)의 측정 자료를 활용하여 분석을 수행하였지만, 조위와 위상 차이로 인해 예측이 용이하지 않았다. 따라서, 낙 동강 하굿둑 인접 외해역에서 조석 영향을 받는 수위관측치를 이용하여 조석조화분해를 통한 정밀한 조위 예측 산정의 필요성이 대두되 어 본 연구를 수행하였다. 연구의 방법으로는 낙동강하굿둑 인근 외해역에서 10분 간격으로 기간별 관측자료의 저장상태 및 이상자료 유 무를 확인하고, 조석조화분해 프로그램인 TASK2000(Tidal Analysis Software Kit) Package를 이용하여 관측조위와 예측조위를 1대 1 비교하여 회귀상관분석을 수행하였다. 분석 결과, 관측조위와 예측조위간의 상관도는 0.9334로 높게 나타났으며, 당해 연도의 조위예측 분석시 직전 연도의 1년 조석관측 자료를 조화분해하여 산출된 조화상수를 이용하여 조위예측을 실시하면 보다 정확한 결과를 산출할 수 있음을 확인 하였다. 이를 바탕으로 2022년 예측조위를 생성하여 낙동강 하구 기수생태 복원의 해수유입량의 산정에 활용 중이다.

Horizontal scale and movement of tidal front zone, front in the western regions of Korea in summer are studied in conjunction with numerical model and NOAH-11 satellite data analysis(AVHRR multi -channel sea surface temperature). In numerical model result, tidal mixing is dominant in the southeast region of Hwanghae, near field of Taean, Kyunggi bay, near field of Jangsan cape, Seoan bay, mid-east Chinese coast. But the results of the NOAH infra-red image analysis show that low surface temperature by tidal mixing is clear in the southeast region of Hwanghae, near field of Taean, near field of Jangsan cape but not in the Kyunggi bay, Seoan bay and mid- east Chinese coast in August and September, temperature gradient of frontal zone in the southwest region of Hwanghae is 0.05°∼0.1℃/㎞ and tidal mixing is dominant in the near field of Maenggal kundo and Hajodo and low surface temperature extends southwesrward. Early in August, west-east front(0.2°∼0.6℃/㎞) on the south region of Jindo moves northward and persists at east half on the joining line of Jindo and Sohuksando late September. The axis of front on the west region of Jindo is northeast~sorthwest early in August and moves westward until late September The tidal mixing in the near field of Jangsan cape is dominant in the region between Jangsan cape and Baengyougdo early in August and between Baengyougdo and Daechungkundo in late September. The axis of front on the west region of Jangsan cape is south-north and its temperature gradient is 0.2°∼0.4℃/㎞.

The purpose of this study is to investigate basic parameters which are essential for tidal correction of gravity data. This study involves computation of the theoretical values and laboratory measurements of tidal force of gravity. The theoretical variation of tidal force was computed according to the relative position of moon and sun on the celestial sphere by using a computer program Gravity measurements were carried out in Seoul University for 120 operation-hours, and also in coastal area in Incheon for 48 operation-hours. The gravimetric factor (δ) and phase delay were determined by comparing theoretical values with measured gravity data. Summarized results of this study are as follows ; (1) The gravimetric factor in Seoul is in the range of 1.22∼1.36(avg.=1.28) and the phase delay is in the range of 0.1∼0.3 hours (avg.=0.16 hours). (2) The mean garvimetric factor in Incheon is 1.31 and mean phase delay is 0.025 hours (3) The difference of mean gravimetric factor between in Seoul and in Incheon is 0.03 and that of phase delay is 8 minutes.