Integrating development inhomogeneity into geological disasters risk assessment framework in mountainous areas: a case study in Lushan–Baoxing counties, Southwestern China

The impact of geological disasters on mountainous settlement have been focused on in recent years. Despite the booming development in the modeling of hazards and vulnerability, the risk assessment in mountainous area still have difficulty in absence of refined data. Moreover, development imbalances widely exist in mountainous areas, which were ignored in previous research. In this study, the refined distribution of socioeconomic data is obtained by using spatialization from the census, which eases the situation of the lack of data. Then, a frequency ratio-random forest model is conducted to evaluate the geological disasters hazards. Meanwhile, vulnerability was evaluated using triangular fuzzy number‑based analytic hierarchy process. In vulnerability assessment, the inhomogeneity index is integrated to evaluate the imbalance between indicators, the use of which can reward a more realistic vulnerability result. Finally, risk map was produced by multiplying hazard and vulnerability. The risk assessment framework is applied in Lushan and Baoxing counties of Southwestern China, which is a typical mountainous area with frequent earthquakes, uneven development, and a lack of high-precision data. The total area of high and extremely high hazards (868.82 km2), vulnerability (258.66 km2), and risk (113.49 km2) are estimated and mapped. The proposed risk assessment framework quantifies the impact of development inhomogeneity on risk and contributes to the scientific assessment of vulnerability for mountainous settlements.