본 연구는 지형⋅생태적으로 중요한 기능과 역할을 담당하는 불갑천 하구역의 보전과 지속가능관리를 위한기초자료를 구축하고자 현장조사를 기반으로 지리공간정보 및 퇴적물 분석을 수행하였다. 불갑천은 1930년대 근대식수리시설이 도입되고 대규모 경지정리가 진행되어 유역환경이 크게 변화하였다. 하지만 불갑천 하구역은 중상류 지역보다 비교적 온전한 자연성을 유지하고 있으며, 다양한 해안지형과 하천지형이 어우러져 지형다양성도 높다. 불갑천은 하구로부터 상류로 약 15.8㎞ 구간이 감조하천이며, 이러한 특징은 퇴적물 입경의 공간분포패턴에서도 확인된다. 퇴적물 입경은 연구지역 내 최하류 구간인 BG1 지점에서 모래가 높은 비율(약 90%)을 보였지만, 중⋅상류 구간에 해당하는 BG2 및 BG3 지점에서는 실트의 비율(약 80%)이 현저히 높게 나타났다. 퇴적물의 전기전도도, 유기물, 유효인산, 양이온치환용량도 각 구간(BG1∼BG3)에서 큰 차이가 있었으며, 동일 구간 내에서도 퇴적물 고화도, 하도인접성, 식생 피복 정도에 따라 차이를 보였다. 또한, 대부분의 퇴적물 시료에서 납과 수은 같은 중금속이 검출되어정확한 중금속 오염실태 파악과 오염원 추적이 필요하다. 불갑천 하구역의 지속가능관리를 위해서는 보와 수문으로단절된 유역 내 하도 체계를 개방 조성해야 하며, 빠르게 변화하는 토지이용 양상에 조응하는 관리와 모니터링이 필요하다.
We performed geospatial and sediment analysis to document database for sustainable management and conservation of the Bulgap Estuary which has an important function from the point of view of geomorphology and ecology. The watershed environment of the study area has extremely changed due to modern irrigation facilities and large-scale land consolidation in the late 1930s. However, the estuary not only preserves its initial environment compared to the upper and middle streams but also has high geodiversity developing various coastal and fluvial landforms. Bulgap river is a partially tidal river with a length of~15.8 km from the estuary, this tidal characteristic is reflected by the spatial distribution of the grain size. As a result of sediment analysis, sand accounts for a high ratio (~90%) in the downstream (BG1), whereas s ilt has a remarkably higher ratio (~80%) than sand in the middle (BG2) and upper (BG3) streams in the study area. The results of electrical conductivity, organic matter, available phosphate, and cation exchange capacity also markedly differ between the BG1, BG2, and BG3 in the river section. Even in the same river section, the results were different depending on the sediment consolidation, channel adjacency, and vegetation cover. In addition, heavy metals such as lead (Pb) and mercury (Hg) were detected in most of the sediment samples and need to be identified and traced to the resource of the pollution. For the sustainable management of the Bulgap Estuary, it is necessary to make an open environment of the channel system disconnected by weir and watergate and to monitor corresponding to the rapid change of land-use.
We performed geospatial and sediment analysis to document database for sustainable management and conservation of the Bulgap Estuary which has an important function from the point of view of geomorphology and ecology. The watershed environment of the study area has extremely changed due to modern irrigation facilities and large-scale land consolidation in the late 1930s. However, the estuary not only preserves its initial environment compared to the upper and middle streams but also has high geodiversity developing various coastal and fluvial landforms. Bulgap river is a partially tidal river with a length of~15.8 km from the estuary, this tidal characteristic is reflected by the spatial distribution of the grain size. As a result of sediment analysis, sand accounts for a high ratio (~90%) in the downstream (BG1), whereas s ilt has a remarkably higher ratio (~80%) than sand in the middle (BG2) and upper (BG3) streams in the study area. The results of electrical conductivity, organic matter, available phosphate, and cation exchange capacity also markedly differ between the BG1, BG2, and BG3 in the river section. Even in the same river section, the results were different depending on the sediment consolidation, channel adjacency, and vegetation cover. In addition, heavy metals such as lead (Pb) and mercury (Hg) were detected in most of the sediment samples and need to be identified and traced to the resource of the pollution. For the sustainable management of the Bulgap Estuary, it is necessary to make an open environment of the channel system disconnected by weir and watergate and to monitor corresponding to the rapid change of land-use.
