In the Southeast Margin of the Tibetan Plateau, low-velocity sedimentary layers that would significantly affect the accuracy of the H-κ stacking of receiver functions are widely distributed.In this study, we use tele...In the Southeast Margin of the Tibetan Plateau, low-velocity sedimentary layers that would significantly affect the accuracy of the H-κ stacking of receiver functions are widely distributed.In this study, we use teleseismic waveform data of 475 events from 97 temporary broadband seismometers deployed by ChinArray Phase I to obtain crustal thicknesses and Poisson's ratios within the Chuxiong-Simao Basin and adjacent area, employing an improved method in which the receiver functions are processed through a resonance-removal filter, and the H-κ stacking is time-corrected.Results show that the crustal thickness ranges from 30 to 55 km in the study area, reaching its thickest value in the northwest and thinning toward southwest, southeast and northeast.The apparent variation of crustal thickness around the Red River Fault supports the view of southeastern escape of the Tibetan Plateau.Relatively thin crustal thickness in the zone between Chuxiong City and the Red River Fault indicates possible uplift of mantle in this area.The positive correlation between crustal thickness and Poisson's ratio is likely to be related to lower crust thickening.Comparison of results obtained from different methods shows that the improved method used in our study can effectively remove the reverberation effect of sedimentary layers.展开更多
利用降水资料、地形资料与社会经济数据,建立楚雄彝族自治州(以下简称楚雄州)洪涝风险评估体系及评估模型.运用层次分析法计算出各个洪涝指标的权重值,再用加权综合评价法建立各影响因子模型,并用GIS(Geographic Information System)软...利用降水资料、地形资料与社会经济数据,建立楚雄彝族自治州(以下简称楚雄州)洪涝风险评估体系及评估模型.运用层次分析法计算出各个洪涝指标的权重值,再用加权综合评价法建立各影响因子模型,并用GIS(Geographic Information System)软件对数据结果制图,对致涝因子危险性、孕涝因子敏感性和承涝因子脆弱性3个指标进行分析,得到楚雄州洪涝风险的危险性、敏感性、脆弱性和综合风险评估指数.结果表明:楚雄州致涝因子危险性最高的是双柏县,危险性值是0.575,危险性最低的区域是元谋县,危险性值是0.067;楚雄州孕涝因子敏感性较高的是元谋县,敏感性值是0.392,敏感性最低的是双柏县,敏感性值是0.074;楚雄州承涝因子脆弱性最高的区域是双柏县,脆弱性值是0.194,脆弱性最低的区域是楚雄市,脆弱性值是0.011.洪涝风险综合评估的最高风险区域主要是双柏县,风险指数是0.437,最低风险的区域主要是元谋县,风险指数是0.137.展开更多
基金supported by the National Natural Science Foundation of China (Project 41730212)the Basic Research Project of the Institute of Earthquake Forecasting, China Earthquake Administration (2017IES0102)
文摘In the Southeast Margin of the Tibetan Plateau, low-velocity sedimentary layers that would significantly affect the accuracy of the H-κ stacking of receiver functions are widely distributed.In this study, we use teleseismic waveform data of 475 events from 97 temporary broadband seismometers deployed by ChinArray Phase I to obtain crustal thicknesses and Poisson's ratios within the Chuxiong-Simao Basin and adjacent area, employing an improved method in which the receiver functions are processed through a resonance-removal filter, and the H-κ stacking is time-corrected.Results show that the crustal thickness ranges from 30 to 55 km in the study area, reaching its thickest value in the northwest and thinning toward southwest, southeast and northeast.The apparent variation of crustal thickness around the Red River Fault supports the view of southeastern escape of the Tibetan Plateau.Relatively thin crustal thickness in the zone between Chuxiong City and the Red River Fault indicates possible uplift of mantle in this area.The positive correlation between crustal thickness and Poisson's ratio is likely to be related to lower crust thickening.Comparison of results obtained from different methods shows that the improved method used in our study can effectively remove the reverberation effect of sedimentary layers.
文摘利用降水资料、地形资料与社会经济数据,建立楚雄彝族自治州(以下简称楚雄州)洪涝风险评估体系及评估模型.运用层次分析法计算出各个洪涝指标的权重值,再用加权综合评价法建立各影响因子模型,并用GIS(Geographic Information System)软件对数据结果制图,对致涝因子危险性、孕涝因子敏感性和承涝因子脆弱性3个指标进行分析,得到楚雄州洪涝风险的危险性、敏感性、脆弱性和综合风险评估指数.结果表明:楚雄州致涝因子危险性最高的是双柏县,危险性值是0.575,危险性最低的区域是元谋县,危险性值是0.067;楚雄州孕涝因子敏感性较高的是元谋县,敏感性值是0.392,敏感性最低的是双柏县,敏感性值是0.074;楚雄州承涝因子脆弱性最高的区域是双柏县,脆弱性值是0.194,脆弱性最低的区域是楚雄市,脆弱性值是0.011.洪涝风险综合评估的最高风险区域主要是双柏县,风险指数是0.437,最低风险的区域主要是元谋县,风险指数是0.137.
