古尔班通古特沙漠路域风沙灾害风险评估与时空格局分析

Risk assessment and spatio-temporal pattern of road aeolian sand disaster in Gurbantunggut Desert

风沙灾害对我国西北交通要道的安全运行造成了严重的威胁,文中从致灾因子危险性、孕灾环境脆弱性和承灾体易损性三个方面构建路域风沙灾害风险评估模型,为了实现客观评价,指标除选取风速、降水、植被覆盖度、土壤湿度等风沙危害评估因子外,在承灾体易损性方面,引入区域的路网密度、路域沙尘含量等指标因子;同时采用AHP-CRITIC组合赋权法计算各评估指标权重;最后,对我国西北重要的古尔班通古特沙漠区域沿线交通要道建立2km×2km格网单元,评估了2019年逐月的路域风沙危害并分析其时空格局分布及影响因素。结果表明:1)在致灾因子、孕灾环境与承灾体的综合机制下,较高风险月份主要分布在4-7月份;较低风险月份主要分布在1-3月份、10-12月份。2)空间分布格局上,高风险路域主要分布在沙源丰富的中部腹地,而南部绿洲荒漠带,水土较好,路域遭受风沙灾害威胁程度低。3)通过影响因素探究结果显示,土壤沙物质供给量、风速、地表温度与地表潜在蒸散发量是造成古尔班通古特沙漠路域风沙灾害时空格局分异的主要影响因素。

Wind-sand disaster poses a severe threat to the safe operation of major transportation routes in northwest China.In the paper,we propose a risk assessment model for wind-sand disasters suffered by the road from three aspects:the hazardous factor risk,the vulnerability of the hazard forming environment,and the vulnerability of the hazard-bearing body.To achieve the goal of objective evaluation,the indicators,in addition to wind speed,precipitation,vegetation cover,soil moisture,and other wind and sand hazard assessment factors,the regional road network density,road area sand content,and other indicators in terms of vulnerability of disaster-bearing bodies are introduced.The AHP-CRITIC combination weighting method is used to calculate the weights of the evaluation indicators simultaneously.Finally,2 km×2 km grid cells are established for the major traffic routes along the Gurbantunggut Desert in northwest China,and the month-by-month road wind and sand hazards in 2019 are assessed,and their spatial and temporal pattern distribution and influencing factors are analyzed.The results show that:1)Under the comprehensive mechanism of disaster-causing factors,disaster-bearing environment,and disaster-bearing body,the higher risk months are mainly distributed in April-July,and the lower risk months are mainly distributed in January-March and October-December.2)In the spatial distribution pattern,the high-risk road regions are mainly located in the central hinterland with abundant sand,while the southern oasis desert zone with better water and soil is less threatened by wind-sand disasters.3)The results of the influencing factor analysis show that the supply of soil sand material,wind speed,land surface temperature,and potential surface evapotranspiration are the core influencing factors that cause the spatial and temporal pattern of wind-sand disasters in the Gurbantunggut Desert road areas.