Search Results (3)

Landslides are a significant geological hazard with substantial socio-economic and environmental consequences, particularly in northwestern Sichuan, SW China, where complex geological and climatic conditions contribute to their occurrence. This study examines 1629 recorded landslide events, including 240 active landslides that have undergone substantial changes over the past two decades. By analyzing multi-temporal satellite imagery, this research investigates the relationship between landslide occurrence and key environmental factors such as annual rainfall and the Normalized Difference Vegetation Index (NDVI). The results reveal that landslides are most frequent on southwest-, south-, east-, and southeast-facing slopes, where the Föhn effect interacts with rainfall and vegetation patterns, thereby increasing landslide susceptibility. Rainfall intensity is identified as a critical factor, with landslide areas expanding significantly when annual rainfall exceeds 650 mm, while minimal changes are observed when rainfall is below 550 mm. The relationship between the NDVI and landslide occurrence is non-linear; higher vegetation cover does not necessarily correlate with reduced landslide frequency. Notably, landslide expansion is more pronounced when NDVI values are below 0.82, with a suppression effect occurring beyond this threshold. A threshold model based on the interaction between the NDVI and rainfall provides valuable insights into landslide dynamics, offering a framework for improved risk management. Slope characteristics are crucial in landslide evolution, with steeper slopes leading to greater vertical drops and more frequent events, making slope zone identification key for predicting future expansion. Full article

Urban medical facilities are an irreplaceable foundation for ensuring higher levels of public health and medical equity. Hospital accessibility has an extremely important impact on the allocation efficiency and fairness of medical facilities. Although critical, previous studies on accessibility have often overlooked the layout of medical facilities at different levels and the accurate measures of travel time to hospitals, which are both the most critical and fundamental indicators when assessing hospital accessibility. To avoid these pitfalls, this study considers the Shijingshan District, Beijing, China, as an empirical case and proposes an improved potential model based on Web Mapping API (Application Programming Interface) to assess the hospital accessibility of hospitals at different levels during different time periods. Results show that there are significant spatial and temporal differences in hospital accessibility in Shijingshan District, and traffic congestion and the layout of medical facilities are the two most important factors affecting hospital accessibility. This study further improves the hospital accessibility assessment method, with the findings provide a spatial decision support system for urban planners and policymakers regarding optimizing the spatial structure and layout of transportation systems and medical facilities. Full article

Hainan Island is endowed with unique climatic and geographical conditions in China. Green orange is a characteristic fruit and plays an important role in local agricultural production of the island. However, few studies have been available regarding the climatic suitability index of green orange planting suitable regions in the island. Based on 30 years (1980 to 2019) of climatic data from 19 meteorological stations in the island, this study established spatial analysis models with topographical data, land use and GIS spatial analysis. Based on climate suitability function, this study established the climate suitability models of temperature, sunshine, precipitation, accumulated temperature and comprehensive suitability model for green orange planting. The Climate suitability index model for green orange planting suitable zoning areas was developed using a natural point segmentation method, and future climate change scenarios were adopted for evaluating the trends of climate suitable areas. The results revealed that the most suitable areas for planting green orange are mainly located at the eastern central region in the island. The climate suitability index ranged from 0.9 to 1.0 in the most suitable regions. The suitable area is mainly distributed in the eastern part, most of the central and western parts of the island, with the climate suitability index ranging from 0.7–0.9. However, the population density in the area is large, and the planting land is limited. The sub-suitable area is mainly located in the coastal areas of the western island, and the high-altitude areas in the central and western regions of the island, with the climate suitability index varying from 0.4 to 0.7. The unsuitable area is mainly distributed in the central mountainous area, with the climate suitability index being 0.0–0.4. The suitability of temperature showed decreasing trend, and the suitability of precipitation gradually moved from the east to the central region under future climate change scenarios. This study is helpful in promoting the development and utilization of agricultural resources and the fine zoning of green orange planting climate suitability in the island. Full article