This study investigated the impact of rainfall on the network performance and video transmission quality of smart CCTV systems deployed across 16 bridges over the Han River in Seoul. Using operational logs collected from September 22 to October 6, 2025 (n=254), a comparative analysis was performed between the wired (n=5) and wireless (n=11) network architectures. The results reveal that under rainfall conditions, wireless networks experienced critical performance degradation. Specifically, at a heavy rainfall intensity of 10 mm/h, the average latency (Ping) surged from 22.5 ms to 355.2 ms, while video frame rates (FPS) plummeted from 19.8 to 6.4. Notably, at a maximum rainfall intensity of 15 mm/h, the wireless network performance exhibited a 78.8% degradation compared with clear weather conditions, severely compromising real-time monitoring reliability. Conversely, the wired networks exhibited robustness, maintaining a Ping of approximately 20 ms and an FPS within the 19–20 range, regardless of weather conditions. A significant negative correlation (r = -0.81, p < 0.01) between Ping and FPS was identified, establishing increased network latency as the primary driver of video quality degradation. These findings provide a technical basis for implementing real-time operational thresholds at Ping 40 ms and FPS 15 as leading indicators to ensure surveillance reliability in a smart city infrastructure.

This study investigates the internal structure of the Habitat and Riparian Health Index (HRI) by identifying conditional dependencies among its components and the mechanisms that form grade boundaries, rather than treating HRI as a simple arithmetic sum. Using the 2024 national river assessment dataset, the analysis combined bootstrap-supported Bayesian Networks for stable dependency inference with classification decision trees for explicit grading rules and threshold identification. A multi-criterion priority scheme integrating network centrality, contribution to total-score variability, and classification contribution was also applied to derive management priorities within and across basins. Across all basins and analytical perspectives, Flow Velocity Diversity consistently emerged as the most influential component. It occupied the central position in the dependency structure and accounted for the largest share of variability in the composite score, indicating that it operates as a system-level outcome in which channel morphology, bed condition, and anthropogenic constraints converge. The grading mechanism was strongly asymmetric. Deficiencies in riverbank protection functioned as a dominant trigger for rapid grade deterioration, whereas attainment of the highest grade required a conjunctive and non-linear pathway in which sufficient flow heterogeneity was accompanied by the sequential resolution of structural constraints, particularly those associated with transverse structures and embankments. Basin-level comparisons further showed that network structures were not interchangeable, with the Nakdong River basin exhibiting the most distinct configuration and basinspecific priority patterns. These results imply that management should separate strategies aimed at preventing degradation through bottleneck control from strategies aimed at achieving top-tier conditions through coordinated, multi-component interventions.

This study investigated the meteorological characteristics and mechanisms of three distinct heavy snowfall events that occurred over the central Korean Peninsula on November 27, 2024, December 15, 2024, and March 18, 2025. Satellite imagery, total precipitable water, integrated vapor transport, and wind and pressure field data revealed that the November 27, 2024 event represented a compound case wherein strong moisture transport from the southwestern sea combined with a cut-off low, leading to the development of an atmospheric river (AR), synoptic-scale ascent, and countrywide heavy snowfall. In contrast, the December 15 2024 event exhibited a typical lake-effect snowfall pattern characterized by weak AR activity and a dominant localized moisture supply from the Yellow Sea, resulting in short-lived and spatially confined snowfall. The March 18, 2025 event was a mixed cycloniclake-effect case triggered by the interaction between mid-latitude moisture transported by southwesterly winds and an upper-level low, producing significant snowfall over the Seoul metropolitan and Yeongdong regions. These differences arise from variations in AR strength, lakeeffect processes, and cyclonic development, whereas all three events shared enhanced thermal instability, a moisture supply associated with a large SST850 hPa temperature difference (ΔT>10oC), and a prevailing northwesterly flow. These specific cases show that heavy snowfall intensity and duration are closely linked to sequential interactions between large-scale AR processes, regional lake effects, and cyclonic mechanisms. Overall, this study suggests that an increased AR frequency under climate change scenarios may increase the risk of extreme snowfall, thereby contributing to improved weather forecasting and disaster preparedness strategies.

섬강 중·하류(본류)의 어류군집과 하천수생태계 건강성을 밝히기 위해 2024년 4월부터 8월까지 15개 지점을 선정하 여 2회 조사하였다. 조사기간 채집된 어류는 9과 45종 5,443개체였다. 우점종은 피라미(상대풍부도 41.4%), 아우점종은 참갈겨니(13.6%), 그 다음으로 쉬리(9.7%), 돌고기(6.6%), 꾸구리(6.3%), 돌상어(4.3%), 돌마자(2.3%), 밀어(2.0%), 줄납자루(1.7%), 납자루(1.6%) 등의 순으로 우세하게 출현하였다. 법정보호종은 환경부지정 멸종위기 야생생물 II급인 꾸구리와 돌상어, 한강납줄개, 묵납자루 4종이 확인되었는데, 꾸구리는 자갈의 비율이 높은 하류부의 빠른 여울에서, 돌상어는 큰돌과 돌의 비율이 높은 상류 및 하류의 빠른 여울에서 많이 서식하고 있어 주목되었고, 한강납줄개와 묵납자루는 각각 St. 12, 15에서 한 개체씩 채집되었다. 한국고유종은 20종이 채집되어 고유화율은 44.4%였고, 외래어 종은 생태계교란 생물로 지정된 배스와 블루길 2종이 확인되었다. 어류를 이용한 하천수생태 건강성(FAI)은 매우 좋음(A) 10개 지점, 좋음(B) 5개 지점으로 양호하게 평가되었고, 수질은 대부분 좋음(Ib)과, 약간 좋음(Ⅱ)으로 평가되 어 비교적 양호하였으나 수질이 나쁜 원주천(보통, III)이 합류되면서 수질이 저하되었다. 군집분석 결과, 지점들의 환경요인은 대부분 여울과 소가 크게 반복적으로 나타나는 중류형(Bb type)으로 비교적 유사한 환경 특징을 보였지만, 수심과 고도, 큰돌, 하폭, 자갈, 잔자갈에 유의한 차이를 보였는데, 상류에서 하류로 갈수록 고도와 큰돌의 비율이 낮아지고 자갈과 잔자갈의 비율이 높아지는 경향을 보였으며, 이러한 환경 요인과 수질 등은 종의 분포에 큰 영향을 미치고 있었다. 군집구조는 크게 상류(St. 1, 3)와 중류(St. 2, 4~8, 11), 하류(St. 9~10, 12~15)로 구분되었다. 교란요인으 로 하천정비공사(1개 지점)와 보의 설치(2개 지점), 생태계교란 생물인 배스와 블루길의 서식, 그리고 오프로드 차량에 의한 멸종위기종 꾸구리의 서식지인 빠른 여울의 교란(St. 15) 등이 있었다. 따라서 섬강 중·하류 본류 어류의 안정적인 서식을 위해서는 무분별한 하천공사는 지양하고 원주천의 수질개선이 필요하며 생태계교란 생물 배스의 확산을 방지할 수 있는 관리방안, 그리고 섬강 하류(St. 15)의 오프로드 차량의 출입을 막을 대책이 시급히 요구되었다.

This study utilized over 20 years of daily bivalve harvesting records from a local fisherman on Yubudo Island to examine potential structural changes in bivalve resources as perceived by the local community following a distant oil spill event. Temporal analyses revealed that while Mactra quadrangularis was historically the dominant commercial bivalve, the harvest of Meretrix petechialis significantly increased after 2007. Notably, during a period of severe regional decline in Meretrix production across Chungcheongnam Province (2008-2012), Yubudo maintained relatively stable yields. These findings suggest that, amid widespread depletion of major bivalve resources due to pollution, there was a shift in local bivalve resource utilization from Mactra to the higher-value Meretrix in the Yubudo area, which was not directly impacted by contamination. This indicates that Yubudo may have served as a substitute production area during the regional decline in bivalve resources. This study is significant as it quantitatively demonstrates how large-scale regional changes in bivalve resources can indirectly influence local resource utilization by integrating long-term harvesting records with community perceptions.

This study examined the vertical distribution of conservative elements (Al, Fe, Li, and Cs) and trace metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) in sediment cores collected from the tidal flats of Yubudo in the Geum River estuary. Two sediment cores were obtained from different depositional environments: an estuary-proximal mudflat (Core A) and an offshore-influenced sandflat (Core B). These cores were subsampled at 2 cm intervals for ICP-MS analysis. The conservative elements displayed consistently higher concentrations in the finer-grained Core A, reflecting natural enrichment associated with silt and clay-dominated sediments. All seven trace metals were found to be below the Threshold Effect Level (TEL), indicating a low potential for ecological risk in both cores. The higher concentrations of trace metals observed in Core A were interpreted as natural enrichment due to the greater proportion of fine-grained, estuary-derived sediments rather than anthropogenic accumulation. These findings provide a geochemical baseline for understanding natural variability in the Yubudo tidal-flat system and offer crucial information for the future conservation and management of the tidal flats in the Geum River Estuary.

The Yangtze River Delta region of China takes the lead in the protection of traditional crafts across the country. Studying the current situation of its policy system is of great significance for the protection of intangible cultural heritage not only in the Yangtze River Delta but also throughout China. Focusing on the traditional craft protection policies in the Yangtze River Delta, this study selected 64 relevant policy texts from 2000 to the present. Using NVivo 11 software, it conducted coding extraction and qualitative analysis on 188 free nodes and 29 tree nodes under 10 core categories covered in the policies, including the concept and directory system, legal subjects' rights and interests, the concept of hierarchical protection, talent team building, fund investment, resource utilization, multi-field collaboration, research deepening, digital technology support, and work coordination and supervision mechanisms.The research results show that the traditional craft protection policy system in the Yangtze River Delta region has presented diversified policy orientations, a relatively complete four-level structure, differentiated cross-border integration characteristics, and an initially formed regional collaboration mechanism. However, there are still certain limitations in aspects such as the precision of rights and interests protection, the explicit integration of digital technology, the construction of a sustainable path for "productive protection", the improvement of the closed-loop evaluation and supervision system, and the in-depth expansion of regional collaboration.

This study examines the current framework for diagnosing the causes of stream ecosystem impairment in South Korea and proposes strategies to improve the effectiveness of aquatic ecosystem restoration policies. While technical guidelines and manuals for impairment diagnosis have been developed, they remain limited in practice due to weak legal enforceability, lack of integration with restoration planning, and insufficient coordination between related laws such as the Water Environment Conservation Act and the River Act. To address these issues, this study highlights the need for institutional reforms, including the legal establishment of a national inventory of impaired streams, the development of a comprehensive management plan, and the incorporation of diagnosis results into river planning processes. It also proposes clarifying the roles of central and local agencies to enhance administrative efficiency and reduce project fragmentation. Furthermore, the study emphasizes the potential of Nature-based Solutions (NbS) as a paradigm shift in stream restoration. The application of NbS should be linked to the results of scientific diagnosis and tailored to the specific characteristics and impairment mechanisms of each stream. By strengthening the link between diagnosis, planning, and implementation, and adopting ecosystem-based approaches such as NbS, this study aims to inform integrated policy and institutional directions for sustainable stream restoration in South Korea.

낙동강 하굿둑 인근 해역은 하천수 방류, 갑문 및 수문 조작, 장기간에 걸친 하구역의 연안 사주 지형 변화 등 인위적 요인과 기상 성분에 의한 교란이 중첩되어 일반 연안과는 다른 불규칙한 조석 변동 특성을 보인다. 특히 하굿둑을 통한 해수 유입량은 내·외수위 차에 크게 좌우되며, 외측 조위의 예측 정확도는 수문 운영의 정밀도와 기수역 복원 사업에 직결된다. 본 연구에서는 낙동강 하굿둑 외측 에서 2007~2024년까지 확보된 장기 관측자료를 대상으로 Utide를 적용하여 조석조화분해를 수행하고, 2021~2023년 자료를 활용한 Task2000 결과와 비교하였다. 분석 결과, Utide는 장주기 성분(SA, SSA, MM, MF 등)을 포함한 대표 조화상수를 안정적으로 추출하였으며, TASK2000 은 연도별 분석 결과가 변동하여 장기적 대표성이 부족한 것으로 나타났다. 또한 2022년~2024년 조위 예측 성능을 평가한 결과, 평균오차 (ME), 평균절대오차(MAE), 평균제곱근오차(RMSE) 및 효율성계수(CE), 일치지수(IA)에서 Utide가 전반적으로 TASK2000보다 우수하였고, 결 정계수(R²)에서도 유사하거나 높은 값을 나타내었다. 이는 Utide가 평균 편향을 줄이고 예측오차를 감소시키며, 장기적인 안정성과 합치도 를 확보하는 데 효과적임을 보여준다. 따라서 낙동강 하굿둑과 같이 조석 변동이 복잡한 하구역에서는 단기 예측에는 TASK2000도 일정 수 준 활용 가능하나, 장기적이고 신뢰도 높은 조위 예측 및 수문 운영·기수역 복원 사업 지원에는 Utide의 적용이 더 적합하다고 판단된다.

한강지류 왕숙천의 어류군집과 하천수생태계 건강성 특징을 밝히기 위해 2021년 5월부터 9월까지 26개 지점을 선정하여 2회 조사하였다. 조사기간 채집된 어류는 10과 36종 6,618개체였다. 출현종 중 우점종은 피라미(상대풍도도, 36.7%), 아우점종은 버들치(20.3%)였고, 그 다음으로 참갈겨니(19.1%), 누치(4.4%), 밀어(3.1%), 돌고기(2.1%), 납자 루(1.9%), 붕어(1.6%), 참마자(1.5%) 등의 순으로 우세하게 출현하였다. 법정보호종은 환경부지정 멸종위기 야생생물 II급인 둑중개 1종이 확인되었으며, 한국고유종은 12종이 확인되어 고유화율은 33.3%였고, 회유성 어류(양측회유성 어류)는 은어 1종, 기후변화민감종은 둑중개 1종, 외래어종은 생태계교란 생물로 지정된 배스 1종이 확인되었다. 어류군집을 분석한 결과, 환경요인에 따른 종의 분포도는 일차적으로 상류에서 하류로 이어지는 유폭과 고도, 하천차 수, 하천경사도 등의 종적인 요인과 이차적으로 하상의 종류(큰돌, 돌, 자갈, 모래), 그리고 수질과 하천에 설치된 보(어도) 등의 요인에 영향을 받고 있었다. 군집분석은 상류에서 하류로 갈수록 우점도는 낮아지고 다양도와 풍부도는 높아지는 경향을 보였으며, 군집구조는 크게 최상류, 중·상류, 하류로 구분되었다. 하천수생태계 건강성(FAI)과 수질은 비교적 양호하였고 상류에서 하류로 갈수록 나빠지는 경향을 보였으며, 하천건강성은 매우 좋음(A) 9개 지점, 좋음(B) 8개 지점, 보통(C) 8개 지점, 나쁨(D) 1개 지점으로, 수질은 좋음(Ib) 3개 지점, 약간 좋음(II) 2개 지점, 보통(Ⅲ) 2개 지점으로 평가되었다. 그러나 하천공사와 낮은 어도 설치율, 수질오염, 생태계교란생물 배스 등의 교란 요인이 확인되었다. 따라서 왕숙천의 안정적인 어류의 서식을 위해서는 무분별한 하천공사를 지양해야 하고 보에 어류의 이동이 가능한 어도 설치가 필요하며 하류부의 수질 개선 및 생태계교란 생물 배스의 확산을 방지할 수 있는 관리방안 이 요구되었다.