As climate change-induced weather variability increases, various green infrastructure plans, such as stream ecosystems, have been studied to overcome ecological and environmental problems arising from extreme weather events; however, our understanding of them and their resilience to extreme weather events is considerably limited. This study proposes a multicriteria inventory classification while planning green infrastructure for resilient stream ecosystems under extreme weather events. Literature reviews, expert surveys, and reliability/validity analyses were used to enlist indicators for this classification. The analytic hierarchy process (AHP) and fuzzy analytic hierarchy process (fuzzy AHP) were used to compute the weights and ranks of indicators for identifying critical indices while planning green infrastructure. The AHP and fuzzy AHP analysis suggested that meteorological phenomena and disasters, hydraulic characteristic of streams, land use/geographic characteristics, and experience/damage restoration were important factors. High weights were attributed to aquatic ecology, potentially vulnerable areas, population, topography, and heat waves. The weights and ranks attributed by AHP and fuzzy AHP varied slightly, but the indicator groups with high and low weights were the same; hence, primary indicators to be considered while planning green infrastructure for resilient stream ecosystems could be suggested. These results could be used as a preliminary analysis in establishing countermeasures against climate change or in distributing budgets for green infrastructure plans.

As the COVID-19 pandemic continues, the stress of city dwellers is increasing, and some adapt to the pandemic by pursuing physical and psychological well-being in neighborhood parks. To improve the resilience of the social-ecological system against COVID-19, it is important to understand the mechanism of adaptation by examining the perception and use of neighborhood parks. The purpose of this study is to investigate users’ perceptions and use of urban neighborhood parks since the outbreak of COVID-19 in South Korea using systems thinking. To verify the hypotheses about the relationship between variables involved in COVID-19 adaptive feedback, two research objectives were set. First, this study determined the causal structure leading to park visits using systems thinking. Second, the relationship between stress, motivation, and the frequency of visits to neighborhood parks was empirically verified. To conduct the research, the system of use and perceptions of parks were analyzed through a causal loop diagram to determine the feedback between psychological variables. Then, a survey was conducted to verify the relationship between stress, motivation for visits, and visit frequency, which are the major variables derived from the causal structure. A total of three feedback loops were derived in the first step, including a loop in which COVID-19 stress was relieved by visits to parks and a loop in which COVID-19 stress worsened due to crowding in parks. Finally, the relationship of stress leading to park visits was confirmed, and the empirical analysis showed that anger about contagion and social disconnection were linked as motives for park visits, and that park visits were mainly motivated by the desire to go out. The neighborhood park functions as an adaptive space for the stress of COVID-19 and will maintain its role as social distancing becomes more important to various socio-ecological changes. The strategies driven by the pandemic can be adapted in park planning to recover from stress and improve resilience.

Land use and land cover changes driven by urbanization and agricultural expansion have increasingly degraded the ecological health of stream ecosystems across watersheds. In Republic of Korea, the Ministry of Environment has designated riparian zones to protect water quality and preserve aquatic ecosystems and continues to implement policies for their management. Given the long-term nature of riparian zone management, providing robust scientific evidence to justify and refine these policies is imperative. In this study, we quantitatively evaluated the role of riparian vegetation on water quality and aquatic ecosystems by using Bayesian Networks. Scenarios were designed to compare the individual effects of riparian vegetation and combined effects of urban and agricultural land use changes. The results indicated that riparian vegetation positively influenced water quality and the benthic macroinvertebrate index at the sub-watershed scale. When riparian vegetation and land use factors were jointly adjusted, scenarios with high riparian vegetation coverage showed improved probabilities of good BMI scores—24.3% under highly agricultural conditions and 27.4% under highly urbanized conditions—highlighting a substantial vegetation effect, particularly in urban areas. This study provides a scientific basis for guiding future riparian restoration and management efforts.

In Republic of Korea, pronounced seasonal precipitation variability poses substantial challenges for stream water quality management and the effective utilization of water resources. Ecologically degraded streams are particularly vulnerable to these fluctuations, which can exacerbate their already fragile condition. We assessed the resilience of reference and impaired streams in response to rainfall through water quality system performance (WQSP). The WQSP is quantified as the concentration of BOD, T-N, and T-P, which represent streams’ eutrophication and anaerobic conditions and respond quickly to disturbances. Reference and impaired streams are classified according to the biological condition and habitat environment of the streams in the Han River watershed of Republic of Korea. The resilience of the stream ecosystem was estimated using WQSP, the linear multiple regression model, and the generalized additive model for rainfall and WQSP. The WQSP reference streams have a lower sensitivity to disturbance and recover more quickly from the influence of rainfall; therefore, they have higher resilience than impaired streams to rainfall events. This study facilitates understanding changes in stream ecosystems of varying conditions in response to rainfall for ensuring long-term stability and adaptability.

In Korea, rural regions increasingly function as peri-urban zones integrated into urban systems. To assess vulnerabilities in these transitional areas characterized by mixed land use and uneven access to infrastructure, this study developed a three-tiered peri-urban livability vulnerability framework by integrating the analytic hierarchy process and the entropy weight method. The results indicated that medical facilities, childcare and education centers, and village communities consistently emerged as key indicators, linking peri-urban livability directly to the stability of settlement environments and the quality of life of residents. Contrastingly, expert evaluations and data-driven outcomes related to road networks and agricultural infrastructure displayed substantial discrepancies, revealing gaps between perceived importance and actual provision levels. Such differences highlight the risk of underestimating infrastructure-related vulnerabilities when subjective assessments are employed exclusively. By synthesizing subjective and objective weights, this study advances urban and environmental analysis and supports evidence-based decision-making for policy prioritization. The findings demonstrate that peri-urban vulnerability is shaped less by productive capacity than by social infrastructure and community stability. This conclusion offers crucial insights for enhancing livability and guiding urban planning strategies.

Anthropogenic influence has altered watershed environments and hydrological processes, leading to increased occurrences of impaired streams and negative impacts on benthic invertebrates. While individual environmental factors affecting benthic macroinvertebrates have been studied, the cascading effects of land use change and hydrological alterations remain unclear. This study employed structural equation modeling (SEM) to analyze the interactions among land use proportion, hydrological characteristics, substrate composition, and water quality and their influence on benthic macroinvertebrate communities in impaired streams upstream of the Paldang Dam in the Han River Basin, South Korea. Analysis of data from 24 streams surveyed between 2018 and 2022—3 or 6 streams per year—under the Impaired Stream Diagnosis Program indicated that urban and agricultural land cover, low substrate diversity, high pollutant concentrations, and altered flow conditions (low velocity and discharge) were associated with decreased pollution-sensitive Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa and increased pollution-tolerant and collector–gatherer taxa. These findings highlight the role of land use-driven hydrological changes in stream ecosystem degradation and underscore the need for targeted restoration strategies, such as riparian buffer zones, substrate enhancement, and hydrological flow restoration, to mitigate these impacts and improve benthic macroinvertebrate habitats.