Threat Analysis and Mapping of Ecological sensitivity Index in King Salman Bin Abdulaziz Royal Reserve. Saudia Arabia.

Abstract: King Salman Bin Abdulaziz Royal Reserve (KSRNR) is the largest terrestrial reserve in Saudi Arabia and the Middle east. The reserve is managed by a science-based approach seeking solid knowledge backing the management decision especially regarding landuse permits and authorization to maintain sound sustainability and spatial conservation planning compliance. A MARXAN with zones based zoning plan was recently developed for KSRNR. The zoning plan needs to be augmented with ecological sensitivity to account for sound management and landuse authorization within the targets of KSRNR. King Salman Bin Abdulaziz Royal Reserve, identified and mapped nine distinct threats to the reserve’s ecological integrity. These threats, including overgrazing, agricultural expansion, urban development and other human-induced pressures, were evaluated independently, generating spatial layers that depicted the severity of each threat across the landscape. While this approach provided valuable insight into the distribution and magnitude of individual threats, it also act as an integral part in resources management in KSRNR. Unified ecological sensitivity index was archived through Multivariate Analysis (MVA) or MultiCriteria Decision Analysis (MCDA), designed to integrate multiple factors into a unified assessment framework. Specifically, we synthesized the nine previously analysed threats into a single model, accounting for their spatial overlap and potential interactions. Each threat is assigned a weight based on its relative impact, using a combination of expert judgment, literature review, and KSRNRspecific considerations. The final output is a combined threat impact map, which offers a holistic view of the cumulative pressures on the reserve's biodiversity and ecosystems The Multi-criteria Analysis was adopted, as it allows for the inclusion of multiple geolocated variables (in this case, threats) while accounting for the variability in their significance. In our context, we used a Weighted Linear Combination (WLC) technique to merge the individual threat layers. WLC enabled assigning specific weights to each threat, reflecting their relative importance to biodiversity loss and ecosystem degradation within KSRNR. The result of this analysis is a Combined Threat Map that reveals not only the areas subject to the highest overall threat intensity but also regions where multiple threats converge, posing a greater risk to ecological stability. This spatially explicit model will provide a robust foundation for decision-making and strategic conservation planning. The analysis highlights that the northern region, particularly around El Jouf, faces the most severe pressures, driven by a combination of urban expansion, agriculture, overgrazing, and industrial activities. This area is followed closely by Tabuk and Hail regions, which also exhibit notable ecological stress. Agriculture and overgrazing are identified as the two most pervasive threats across the reserve, with extensive cultivation and grazing practices severely disrupting natural habitats. Overgrazing, particularly by large herds of camels, is contributing to habitat degradation, soil erosion, and loss of vegetation cover, further exacerbating the region’s vulnerability. The proximity of agricultural lands to water sources and urban areas magnifies the intensity of these impacts, creating a mosaic of high-risk zones across KSRNR