Spatial distribution characteristics of geological hazards and their response to extreme temperatures in the Shaanxi section of the Yellow River Basin
[Objective]It is of great practical significance to study the impact of extreme temperature on geological disasters in the Shaanxi section of the Yellow River Basin and put forward effective strategies for disaster prevention and mitigation strategies.[Methods]Based on the daily temperature data of 17 meteorological stations in the Shaanxi section of the Yellow River Basin from 1975 to 2020,the ETCCDMI index system is used to filtrate extreme climate event and calculate 20 extreme climate indices.Then,overlaying the data of 5 521 geological disaster points in the Shaanxi section of the Yellow River Basin,the geological dis-aster hotspots and kernel density in the study area can be identified.Then,the clustering characteristics of the geological disaster points under different MinPts parameter values are observed to analyze the spatial variation of extreme temperature in the study ar-ea,establish a spatial database of geological hazard density and extreme temperature in the Shaanxi section of the Yellow River Basin,and explore the correlation between extreme climate and geological disasters based on the single-factor correlation coeffi-cient and multi-factor grey correlation degree.[Results]The result are shown as following:(1)The hotspot area whose signifi-cance level achieves 90％in the study area is about 7,100 km2,and the kernel density range is between 322.68-2 050.72,showing uneven spatial distribution of aggregation characteristics,mainly distributed in Tongchuan City and the central part of Xi'an-Weinan.(2)The aggregation patterns under small,medium and large MinPts values reflect the effects of microenviron-ment,regionality and larger spatial scales,respectively.(3)The warm correlation index in the study area is ascending notably,while the cold-correlation index declining,with the overall temperature in the study area increasing significantly.(4)There is a significant difference between the northern and southern extreme temperature indicators change,with more frost days in the north than in the south,and growing season longer in the south.The tendency of climate change in the study area is consistent with the overall trend of global warming,with the number of cold days decreasing and the number of warm days and extreme high tempera-ture days increasing significantly.(5)The kernel density of geological hazards is positively correlated with multiple extreme tem-perature indicators,among which TR10(R2=0.314)is the strongest,while indicators such as TX90P(R2=0.310)show a negative correlation.(6)The grey correlation coefficients between kernel density and extreme temperature indicator all exceed 0.74,especially the correlation coefficients of TN90P,TX90P,TNn and TNx reach a significant level.[Conclusion]Different temperature indexes of climate change in the Shaanxi section of the Yellow River Basin have significant promoting or inhibiting effects on geological disasters,which should be considered comprehensively to deal with the risk of geological disasters.
extreme climategeological HazardsMulti-FactorGrey Relational AnalysisYellow River Basinclimate changerainfalllandslide
万方数据
维普
