The 1927 Gulang M8.0 earthquake has triggered a huge number of landslides,resulting in massive loss of people’s life and property.However,integrated investigations and results regarding the landslides triggered by th...The 1927 Gulang M8.0 earthquake has triggered a huge number of landslides,resulting in massive loss of people’s life and property.However,integrated investigations and results regarding the landslides triggered by this earthquake are rare;such situation hinders the deep understanding of these landslides such as scale,extent,and distribution.With the support of Google Earth software,this study intends to finish the seismic landslides interpretation work in the areas of Gulang earthquake(VIII-XI degree)using the artificial visual interpretation method,and further analyze the spatial distribution and impact factors of these landslides.The results show that the earthquake has triggered at least 936 landslides in the VIII-XI degree zone,with a total landslide area of 58.6 km^2.The dense area of seismic landslides is located in the middle and southern parts of the X intensity circle.Statistical analysis shows that seismic landslides is mainly controlled by factors such as elevation,slope gradient,slope direction,strata,seismic intensity,faults and rivers.The elevation of 2000-2800 m is the high-incidence interval of the landslide.The landslide density is larger with a higher slope gradient.East and west directions are the dominant sliding directions.The areas with Cretaceous and Quaternary strata are the main areas of the Gulang seismic landslides.The X intensity zone triggered the most landslides.In addition,landslides often occur in regions near rivers and faults.This paper provides a scientific reference for exploring the development regularities of landslides triggered by the 1927 Gulang earthquake and effectively mitigating the landslide disasters of the earthquake.展开更多
Based on monthly evaporation of two meteorological stations in the Gulang River Basin of China,the inter-annual variation of evaporation during 1959−2013 were analyzed using Mann-Kendall and wavelet analysis.The resul...Based on monthly evaporation of two meteorological stations in the Gulang River Basin of China,the inter-annual variation of evaporation during 1959−2013 were analyzed using Mann-Kendall and wavelet analysis.The results demonstrated that the annual evaporation show a fluctuating increase over the past 50 years approximately,with an average increase rate of 4.26 mm per decade.The overall trend was decrease−increase−decrease.According to the cumulative anomaly curve,the turning point of the annual evaporation occurred in 1979,in which the evaporation increased in the early stage and decreased in the later stage.Meanwhile,the seasonal variation of the evaporation shows that it decreased in Spring and Autumn,and increased in Summer and Winter,especially obvious for the later.The evaporation abruptly changed in Spring and Summer in 2008 and in Winter in 1994.In addition,all evaporation increased after the changes.However,the evaporation in Autumn abruptly changed in 1986 and 1999,which show a trend of increase-decrease-increase.Wavelet analysis shows that evaporation in Summer and wet season would decrease in the next few years,and in the other seasons would increase.Based on the aforementioned analysis,it can be concluded that increased evaporation is mainly induced by increase of evaporation in dry season,especially in Winter,and this trend to be continued in the future for the Gulang River Basin.展开更多
The 1927 Gulang M_S8.0 earthquake is a severe earthquake that followed the Haiyuan M_S8.5 earthquake of 1920 in the Qilian Mt._Hexi Corridor earthquake zone. There are divergences of opinion in the previous studies ab...The 1927 Gulang M_S8.0 earthquake is a severe earthquake that followed the Haiyuan M_S8.5 earthquake of 1920 in the Qilian Mt._Hexi Corridor earthquake zone. There are divergences of opinion in the previous studies about the rupture properties of the earthquake. Based on trenching and field investigation, and analysis of historical data, we hold that the earthquake resulted from the joint process of the Tianqiaogou_Huangyangchuan fault, Dongqingding segment of the Huangcheng_Shuangta fault and the Wuwei_Tianzhu buried fault, which constitute the Gulang nappe. By finite_element numerical simulation on the deformation mechanism of Gulang nappe, it is found that the stress and strain mainly concentrate in the western segment of the Tianqiaogou_Huangyangchuan fault, the Dongqingding segment of the Huangcheng_Shuangta fault, and the Gulangxia segment of the Wuwei_Tianzhu buried fault and the Gulang_Shuangta fault. The stress concentration coincides with the distribution of the earthquake surface rupture. It also proves that the earthquake is an outcome of the Gulang nappe activity as a whole.展开更多
基金sponsored by the the National key Research and Development Program of China(2018FYC1504703)Basic Scientific Fund of the Institute of Geology,China Earthquake Administration(IGCEA1604)the National Natural Science Foundation of China(41661144037)。
文摘The 1927 Gulang M8.0 earthquake has triggered a huge number of landslides,resulting in massive loss of people’s life and property.However,integrated investigations and results regarding the landslides triggered by this earthquake are rare;such situation hinders the deep understanding of these landslides such as scale,extent,and distribution.With the support of Google Earth software,this study intends to finish the seismic landslides interpretation work in the areas of Gulang earthquake(VIII-XI degree)using the artificial visual interpretation method,and further analyze the spatial distribution and impact factors of these landslides.The results show that the earthquake has triggered at least 936 landslides in the VIII-XI degree zone,with a total landslide area of 58.6 km^2.The dense area of seismic landslides is located in the middle and southern parts of the X intensity circle.Statistical analysis shows that seismic landslides is mainly controlled by factors such as elevation,slope gradient,slope direction,strata,seismic intensity,faults and rivers.The elevation of 2000-2800 m is the high-incidence interval of the landslide.The landslide density is larger with a higher slope gradient.East and west directions are the dominant sliding directions.The areas with Cretaceous and Quaternary strata are the main areas of the Gulang seismic landslides.The X intensity zone triggered the most landslides.In addition,landslides often occur in regions near rivers and faults.This paper provides a scientific reference for exploring the development regularities of landslides triggered by the 1927 Gulang earthquake and effectively mitigating the landslide disasters of the earthquake.
基金The research was funded by the Youth Science Foundationof Lanzhou Jiaotong University (2018026)the Key Research Program of Frontier Sciences, CAS(QYZDJ-SSW-DQC031).
文摘Based on monthly evaporation of two meteorological stations in the Gulang River Basin of China,the inter-annual variation of evaporation during 1959−2013 were analyzed using Mann-Kendall and wavelet analysis.The results demonstrated that the annual evaporation show a fluctuating increase over the past 50 years approximately,with an average increase rate of 4.26 mm per decade.The overall trend was decrease−increase−decrease.According to the cumulative anomaly curve,the turning point of the annual evaporation occurred in 1979,in which the evaporation increased in the early stage and decreased in the later stage.Meanwhile,the seasonal variation of the evaporation shows that it decreased in Spring and Autumn,and increased in Summer and Winter,especially obvious for the later.The evaporation abruptly changed in Spring and Summer in 2008 and in Winter in 1994.In addition,all evaporation increased after the changes.However,the evaporation in Autumn abruptly changed in 1986 and 1999,which show a trend of increase-decrease-increase.Wavelet analysis shows that evaporation in Summer and wet season would decrease in the next few years,and in the other seasons would increase.Based on the aforementioned analysis,it can be concluded that increased evaporation is mainly induced by increase of evaporation in dry season,especially in Winter,and this trend to be continued in the future for the Gulang River Basin.
文摘The 1927 Gulang M_S8.0 earthquake is a severe earthquake that followed the Haiyuan M_S8.5 earthquake of 1920 in the Qilian Mt._Hexi Corridor earthquake zone. There are divergences of opinion in the previous studies about the rupture properties of the earthquake. Based on trenching and field investigation, and analysis of historical data, we hold that the earthquake resulted from the joint process of the Tianqiaogou_Huangyangchuan fault, Dongqingding segment of the Huangcheng_Shuangta fault and the Wuwei_Tianzhu buried fault, which constitute the Gulang nappe. By finite_element numerical simulation on the deformation mechanism of Gulang nappe, it is found that the stress and strain mainly concentrate in the western segment of the Tianqiaogou_Huangyangchuan fault, the Dongqingding segment of the Huangcheng_Shuangta fault, and the Gulangxia segment of the Wuwei_Tianzhu buried fault and the Gulang_Shuangta fault. The stress concentration coincides with the distribution of the earthquake surface rupture. It also proves that the earthquake is an outcome of the Gulang nappe activity as a whole.
