Ecological risk of geohazards and its combination patterns: A case study of an ecologically fragile region, NW China

Abstract

Our comprehension of ecological risk in the Upper Yellow River region in China remains limited due to the prevailing focus of current studies on urbanized areas, with insufficient attention given to the mountainous regions. Luqu County is widely recognized as an important regional ecological barrier and ecologically fragile area, susceptible to geohazard effects. However, the relationship between ecological risk and geohazard remains unclear. To address this gap, we conducted an assessment of ecological risk and analyzed its combination patterns using the available geohazard inventory of Luqu. We established a framework for ecological risk assessment, employing the MaxEnt, Fragstats, and InVEST models to evaluate the degree of hazard, ecological vulnerability, and potential ecological loss. The evaluation results consider the significance of the geoenvironmental and climatic context in Luqu. Among the selected conditioning factors, elevation, distance to the river, average precipitation from May to September, gully density, and stratigraphic age exhibit the highest relative contribution values to the geohazards, with values of 0.861, 0.789, 0.764, 0.67, and 0.636, respectively. The Northern Taohe River Basin has been identified as a high ecological risk area characterized by highly fragmented landscapes. Furthermore, ecological risk exhibits a gradual decline trend from the northeast to the southwest. The combination pattern characterized by high ecological fragility-predominated, low hazard and low ecological loss-supplemented exhibits the highest ecological risk. This pattern covers over 60% of Luqu. The township-level ranking of medium-high and high ecological risk proportions is as follows: Ala (33.59%), Xicang (19.52%), Shuangcha (14.38%), Ma'ai (6.96%), Larenguan (4.49%), Langmusi (1.06%), and Gahai (0.13%). Compared with hazard and ecological loss, ecological fragility has generally maintained a relatively stable level during current period. Considering the positive correlation between ecological risk and geohazards found in this study, we recommend that local communities prioritize high-risk areas for effective risk management.