Journal of Hunan University Natural Sciences

Landslides on steep slopes composed of tropical volcanic soils constitute a major geotechnical hazard because intensive weathering and variations in water content can substantially affect soil shear strength and slope stability. This study evaluated the effectiveness of moisture-controlled compaction in improving the stability of a steep roadside slope in Aek Godang Arbaan Village, Onanganjang District, Humbang Hasundutan Regency, North Sumatra, Indonesia. The engineering properties of the soil were determined through laboratory Proctor compaction and direct shear tests to obtain the optimum moisture content (OMC), maximum dry density, cohesion, and internal friction angle. Slope stability was assessed using the Fellenius and Bishop limit equilibrium methods and a three-dimensional finite element model developed in PLAXIS 3D using the φ–c reduction approach. Three moisture conditions were considered: 14.70% on the dry side of the OMC, an OMC of 19.25%, and 23.80% on the wet side. The Proctor test yielded an OMC of 19.25% and a maximum dry density of 1.614 g/cm³. At the OMC, the factors of safety calculated using the Fellenius, Bishop, and PLAXIS 3D methods were 1.51, 1.66, and 1.997, respectively. The Bishop method produced a slightly higher factor of safety under the dry-side condition of 14.70% (1.69) than at the OMC (1.66), whereas the Fellenius and PLAXIS 3D analyses exhibited different trends. Nevertheless, when maximum dry density and the combined results of the three stability analyses were considered, the OMC of 19.25% was identified as the most favourable overall compaction condition. PLAXIS 3D provided additional insight into the stress distribution, deformation pattern, and progressive failure mechanism that could not be represented by the limit equilibrium methods. The large deformation values generated during the φ–c reduction analysis indicate numerical progression towards failure and should not be interpreted as predicted service-condition displacements. These findings demonstrate that controlling the water content during compaction at or near the OMC can enhance the stability of steep tropical volcanic soil slopes and provide a practical basis for slope stabilisation and landslide-risk mitigation.

Keywords: moisture-controlled compaction; slope stability; tropical volcanic soil; limit equilibrium method; finite element analysis.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.9

Climate change increasingly threatens farmers’ livelihoods and heightens the vulnerability of smallholder farming communities in flood-prone areas. Integrated agricultural and livelihood strategies are therefore needed to strengthen resilience and ensure long-term environmental and socioeconomic sustainability. This study aimed to develop and validate the Sustainable Livelihood Model for Flood Resilience Strategies (SLIMFRESS) for smallholder rice farmers in South Sumatra Province, Indonesia. An explanatory sequential mixed-methods design was employed, in which quantitative data were analysed first and subsequently complemented by qualitative evidence obtained from relevant stakeholders. A system dynamics model was developed using STELLA Architect 9 through causal-loop diagrams, stock-and-flow diagrams, and model validation procedures. Thematic analysis of stakeholder perspectives was conducted alongside the system dynamics modelling process to interpret the quantitative findings and refine the structure of the model. The resulting SLIMFRESS model integrates farmers’ sustainable livelihood assets with sustainable livelihood strategies to assess interventions aimed at reducing the economic and environmental risks associated with flooding in rice-farming areas. The simulation results indicate that livelihood resilience does not develop immediately but emerges gradually through sustained support, continuous knowledge development, and effective institutional collaboration. The model also highlights the importance of coordinated interventions addressing environmental conservation, household financial security, and market participation. Accordingly, policy measures should prioritise community-based conservation initiatives, financial mechanisms providing income support and agricultural insurance during flood events, and improved market access for products developed by smallholder enterprises. SLIMFRESS provides an integrated decision-support framework for designing and evaluating long-term flood-resilience strategies for smallholder rice-farming communities.

Keywords: sustainable livelihoods; flood resilience; system dynamics modelling; smallholder rice farmers; climate change adaptation.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.8

This systematic literature review synthesizes evidence on the challenges affecting teacher recruitment, professional development, and retention across educational institutions. Findings from 20 eligible studies were analyzed to identify recurring barriers and proposed responses across different institutional and regional contexts. The synthesis revealed persistent teacher shortages, particularly in high-need fields such as science, technology, engineering, and mathematics (STEM) and special education. Low compensation, limited access to meaningful professional development, and the low perceived status of the teaching profession were frequently identified as barriers to attracting and retaining qualified teachers. Teacher preparation programs were also commonly described as insufficiently aligned with the practical demands of classroom teaching. Moreover, professional development often consisted of isolated, short-term activities that lacked sustained support and relevance to teachers’ day-to-day professional needs. Retention was particularly challenging in underserved regions, where high turnover was associated with burnout, unfavorable working conditions, and inadequate institutional support. The findings highlight the need for flexible and inclusive recruitment practices, continuous and job-embedded professional development, and supportive school environments that prioritize teacher well-being and career advancement. Addressing these interconnected challenges requires a coordinated and context-sensitive strategy that accounts for regional and institutional differences and supports the long-term sustainability and quality of the teaching workforce.

Keywords: teacher recruitment; teacher professional development; teacher retention; teacher shortages; teaching workforce; systematic literature review.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.7

Agricultural systems in developing countries depend on complex interactions among farmers, agricultural extension agents, market actors, and institutions, making communication networks important for innovation diffusion, coordination, food security, and economic resilience. Conventional surveys, however, often fail to capture the relational structures underlying these processes. This study developed and applied a sociometric survey framework integrated with Social Network Analysis (SNA) to examine collaborative communication networks within agricultural systems. Using an exploratory research design, data were collected from 241 maize farmers belonging to two farmer groups located in the northern and southern areas of Lamongan Regency, East Java, Indonesia. Communication networks across nine sustainable agricultural technology (SAT) domains were examined using network density, degree centrality, closeness centrality, and betweenness centrality. The results revealed distinct communication patterns between the two groups. The southern group had denser communication networks for innovation generation and development, whereas the northern group had denser networks for innovation use and harvest-related activities. This mismatch suggests that intensive communication during innovation development does not necessarily correspond to equally developed networks for subsequent adoption and application. Centralized network configurations may facilitate rapid information exchange but can also increase dependence on a limited number of key actors. More distributed configurations may promote broader participation and reduce vulnerability to the loss of individual network actors. These findings demonstrate how the integration of sociometric surveys and SNA can identify structural strengths and communication bottlenecks within farmer groups. The resulting evidence may inform agricultural governance and the design of network-based interventions intended to support innovation diffusion, food security, and economic resilience.

Keywords: social network analysis; sociometric survey; innovation diffusion; agricultural governance; farmer groups; sustainable agricultural technology.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.6

The rapid growth of social media has made Instagram one of the most prominent platforms in adolescents’ everyday lives. Although Instagram provides opportunities for self-expression and social interaction, it may also expose users to adult content, with potential implications for adolescents’ psychological, social, and moral development. This study explored the lived experiences of adolescents in Makassar City who encountered adult content on Instagram. A qualitative phenomenological design was employed. Twelve adolescents aged 13–18 years were recruited using purposive sampling and participated in in-depth interviews. The data were analyzed using Interpretative Phenomenological Analysis (IPA). The analysis generated four main themes: (1) curiosity and initial exposure, (2) emotional and psychological responses, (3) coping strategies, and (4) the influence of cultural and religious values. Participants’ accounts indicated that curiosity frequently contributed to initial exposure, which elicited varied emotional and psychological responses. Adolescents employed different coping strategies, while cultural and religious values shaped how they interpreted and managed their encounters with such content. The findings demonstrate that Indonesian adolescents are not merely passive recipients of digital content but actively negotiate their experiences within prevailing cultural and religious norms. This study extends understanding of adolescent digital experiences in Southeast Asia and may inform the development of culturally responsive digital literacy education and parental guidance strategies.

Keywords: Instagram; adolescents; adult content; digital literacy; coping strategies.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.5