Introduction:
The islands of the Persian Gulf are highly vulnerable to human interventions and tourism development due to their limited area, ecological fragility, and low ecosystem resilience. In recent years, the concept of an “ecopark” has emerged as an integrated approach to simultaneously conserve nature and support sustainable recreational use. However, scientific evidence indicates that implementing such initiatives without prior ecological capacity-based assessments can lead to irreversible degradation of island ecosystems. Bumusi Island—a small, strategically positioned, and relatively understudied island in the Persian Gulf—exemplifies areas with significant natural values yet lacking scientifically grounded frameworks for development decision-making. This study aims to quantitatively assess the ecological quality of Bumusi Island and evaluate its spatial suitability for ecopark development by employing the Remote Sensing-based Ecological Index (RSEI) combined with a fuzzy logic-based multi-criteria decision-making model. By minimizing subjective bias and accounting for environmental uncertainties, this research seeks to establish an evidence-based foundation for sustainable tourism planning within a dry island ecosystem.

Materials and Methods:
Initially, the ecological quality of Bumusi Island was monitored over a 24-year period (2000, 2014, and 2024) using Landsat satellite imagery processed within the Google Earth Engine platform. The RSEI was calculated without subjective weighting by integrating four key components—vegetation greenness (NDVI), moisture (Wetness), surface temperature (LST), and built-up/soil dryness (NDBSI)—through Principal Component Analysis (PCA). Subsequently, to assess spatial suitability for ecopark development, the 2024 RSEI map—used as the base layer—was combined with Land Use/Land Cover (LULC), Digital Elevation Model (DEM), and carbon dioxide concentration/dispersion (CO₂) layers. After standardizing all layers using appropriate fuzzy membership functions, they were integrated within ArcGIS Pro using the Fuzzy Gamma operator (γ = 0.8). The model output was a continuous ecological suitability map ranging from 0 to 1, which was subsequently classified into qualitative suitability categories.

Results and Analysis:
Time-series RSEI results indicated that the overall ecological quality of Bumusi Island falls within the "moderate" to "relatively good" range, but exhibits a highly heterogeneous spatial pattern. The southern and southeastern coastal zones—particularly areas with salt-tolerant vegetation—displayed the highest RSEI values, reflecting high ecological integrity and extreme sensitivity to human disturbance. Conversely, the central parts of the island showed moderate RSEI values, higher thermal stress, and sparse vegetation cover, suggesting a relatively greater capacity to accommodate controlled human activities. The fuzzy ecological suitability modeling revealed that only a limited portion of the island’s central areas fall into the “suitable” and “moderately suitable” categories for ecopark development. Regions with high ecological quality were classified as “unsuitable” or “highly sensitive” due to their conservation value, while areas with poor ecological quality and elevated CO₂ concentrations were similarly deemed unsuitable. The concentration of low-suitability patches in specific zones highlights the decisive role of the CO₂ indicator as a limiting factor within the fuzzy model and underscores the importance of incorporating anthropogenic pressure metrics alongside classical ecological indicators.

Conclusion:
Overall, this study demonstrates that Bumusi Island possesses only very limited and localized ecological capacity for ecopark development, necessitating any intervention to be strictly constrained, phased, conservation-oriented, and guided by rigorous zoning. The combined application of RSEI and fuzzy logic effectively distinguished between suitable and unsuitable areas. The findings offer decision-makers an objective, replicable tool while also providing a transferable framework for assessing other islands in the Persian Gulf. This approach aligns with the objectives of the Convention on Biological Diversity and Iran’s National Strategy for Sustainable Tourism Development.