Gold mining in rural Philippines provides livelihood opportunities but has been associated with environmental degradation and health risks due to the use of mercury and cyanide in extraction processes. To address these concerns, the Green Mining Processing Facility Program for Small-Scale Mining was implemented through a university-led initiative to provide safer and more efficient gold recovery alternatives while reducing environmental impacts and operational costs. This study assessed the governance and adoption outcomes of the established pilot facilities and support systems. An ex-post and process evaluation approach was used, and data were collected through surveys, key informant interviews, and focus group discussions involving miners, local government units, project implementers, and other stakeholders. Results indicated that the facilities were technically viable and had potential economic benefits for small-scale miners. However, utilization remained limited due to institutional and regulatory constraints, including unclear governance arrangements, operational management gaps, restrictions in facility use, and weak stakeholder engagement, rather than technological limitations. Strengthening governance systems, improving regulatory coordination, and establishing clear operational management structures are necessary to enhance adoption and ensure sustainable and safe gold extraction practices.
Uncontrolled bauxite exploitation in the Rural Commune of Malapouyah (Guinea) exacerbates land degradation and disrupts local ecological balances. This study assesses the spatio-temporal variations in land use, vegetation, and land surface temperature (LST) between 2011 and 2024 using Landsat imagery and GIS-based spatial analyses. The Normalized Difference Vegetation Index (NDVI) highlights a worsening of vegetation stress, with minimum values dropping from 0.039 in 2011 to 0.000 in 2024. Land-use analysis reveals notable fluctuations: vegetation cover decreased from 50.82% in 2011 to 30.29% in 2014 before rising again to 59.04% in 2024, while bare soils increased from 7.28% to 29.28% during the first period and then declined to 8.90% in 2024. Water bodies peaked at 19.10% in 2014 and stabilized around 9.78% in 2024. Urban areas decreased from 41.34% in 2011 to 21.33% in 2014 before stabilizing near 22%. The average land surface temperature progressively declined from 45.96 °C in 2011 to 37.73 °C in 2024, with a maximum of 46.98 °C recorded in 2014. These findings reveal severe but evolving environmental impacts driven by mining and other anthropogenic pressures, while also highlighting partial ecosystem resilience. The study confirms the relevance of remote sensing and geographic information systems (GIS) as reliable, integrated, and cost-effective tools for monitoring land degradation and supporting sustainable land-use planning and natural resource management.
Soil erosion is a critical environmental problem threatening agricultural productivity and watershed sustainability in tropical developing countries. Despite growing interest in conservation adoption, empirical studies explicitly linking erosion hazard zonation with farmers' social conservation behavior at the micro sub-watershed scale remain scarce. This study examined soil conservation knowledge, attitudes, and practices among 110 farmers across five Erosion Hazard Level (EHL) zones in the Juwet Sub-Watershed, Special Region of Yogyakarta, Indonesia, using an integrated biophysical–social approach grounded in the Knowledge–Attitude–Practice (KAP) framework complemented by the Theory of Planned Behavior. The EHL map was derived by crossing erosion potential data with soil depth measurements and served as the spatial framework for stratified sampling. The results revealed a consistent knowledge–practice gap across all EHL zones: farmers demonstrated relatively high erosion awareness and positive perceptions of conservation effectiveness, yet actual practice remained uniformly moderate regardless of hazard level. The very high EHL zone, covering 69.7% of the sub-watershed, had the weakest institutional support, with only 24.6% of farmers actively discussing conservation issues. Financial constraints and extreme weather were the primary barriers, while limited knowledge ranked least significant. These findings confirm that the principal bottleneck is structural and economic rather than cognitive, underscoring the need for zone-differentiated conservation interventions grounded in participatory watershed development principles.
Nitrate is difficult to manage in shallow urban aquifers where polluted rivers and mixed land uses stress the same groundwater. This study examined the extent to which Kali Belik contributes to the long-term rise in nitrate at Umbul Pace, a spring-fed well supplying the SPAM TOYAGAMA system in the Yogyakarta-Sleman volcanic aquifer, Indonesia. The analysis combined water-quality sampling, spatial analysis, and a calibrated flow-and-transport model (RMSE = 1.39 m) over a 2.375 km² domain. The model showed Kali Belik losing water to the aquifer, yet the evidence does not support the river as the main nitrate source. Nitrate at Umbul Pace rose from 1.93 mg/L as NO?-N in 2001 to 16.5 mg/L in August 2025, while the river never exceeded 4.61 mg/L. Even with the river load doubled in the model, the concentration at the well reached only 5.01 mg/L. Backward particle tracking (77-123 days) delineates a local capture zone dominated by settlements, agriculture, and livestock facilities, pointing to persistent anthropogenic loading and land degradation along the recharge corridor as the more plausible explanation. Aquifer protection therefore cannot rely solely on the river: travel-time zoning, land-use controls, and nitrate treatment at the wellhead are needed.
Oil palm replanting often increases the risk of soil degradation due to soil disturbance, nutrient depletion, and erosion, particularly in highly weathered Ultisols. This study aimed to evaluate soil fertility status and erosion risk across different slope classes in post-replanting oil palm plantations and to assess the implications of conservation practices for sustainable land management. Soil samples were collected from three slope classes (3-8%, 8-15%, and 15-30%) at two soil depths (0-20 and 20-40 cm) for soil physico-chemical analysis. Erosion estimation was predicted using the Universal Soil Loss Equation (USLE). In addition, a conservation scenario analysis was conducted to evaluate the potential effectiveness of improved conservation practices in reducing erosion risk. The results showed that soil fertility status ranged from low to moderate across all slope classes, mainly due to low cation exchange capacity and base saturation. Soil organic carbon, total nitrogen, and available phosphorus generally decreased with increasing slope and soil depth. Predicted erosion rates varied among slope classes, with the highest erosion occurring in the 3-8% slope class (141.48 t/ha/year), primarily due to inadequate conservation practices. Conservation scenario analysis demonstrated that conservation practice improvement, factor (P) from 0.35 to 0.04, reduced predicted erosion up to 88.6% (16.17 t/ha/year), which is below the tolerable threshold. These findings indicated that integrating soil fertility improvement through organic matter management with effective conservation measures can substantially reduce land degradation risks and support the sustainable management of post-replanting oil palm plantations on Ultisols.
