The Longchi area with the city of Dujiangyan, in the Sichuan province of China, is composed of Permian stone and diorites and Triassic sandstones and mudstones intercalated with slates. An abundance of loose co-seismi...The Longchi area with the city of Dujiangyan, in the Sichuan province of China, is composed of Permian stone and diorites and Triassic sandstones and mudstones intercalated with slates. An abundance of loose co-seismic materials were present on the slopes after the May 12, 2008 Wenchuan earthquake, which in later years served as source material for rainfall-induced debris flows or shallow landslides. A total of 48 debris flows, all triggered by heavy rainfall on 13th August 20l0, are described in this paper. Field investigation, supported by remote sensing image interpretation, was conducted to interpret the co-seismic landslides in the debris flow gullies. Specific characteristics of the study area such as slope, aspect, elevation, channel gradient, lithology, and gully density were selected for the evaluation of debris flow susceptibility. A score was given to all the debris flow gullies based on the probability of debris flow occurrence for the selected factors. In order to get the contribution of the different factors, principal component analyses were applied. A comprehensive score was obtained for the 48 debris flow gullies which enabled us to make a susceptibility map for debris flows with three classes. Twenty-two gullies have a high susceptibility, twenty gullies show a moderate susceptibility and six gullies have a low susceptibility for debris flows.展开更多
This paper divides the genus Limnophora R.-D., into f ive species-group, s, namely L.triangula -gr., L.spoliata -gr., L.exi gua -gr., L.nigripes -gr. and L.scrupulosa -gr.. A key to each group i s provided and three n...This paper divides the genus Limnophora R.-D., into f ive species-group, s, namely L.triangula -gr., L.spoliata -gr., L.exi gua -gr., L.nigripes -gr. and L.scrupulosa -gr.. A key to each group i s provided and three new species from Yunnan Province, L.longispatula sp.nov. , L.yulongxueshanna sp.nov.and L.yunnanensis sp.nov.,described.Type speci mens are deposited in the Institute of Entomology,Shenyang Normal University.展开更多
基金supported by the Key Projects in the National Science & Technology Pillar Program (Grant No. 2011BAK12B01)Basic Scientific Project of Ministry of Sciences and Technology of China (Grant No. 2011FY110100-3)
文摘The Longchi area with the city of Dujiangyan, in the Sichuan province of China, is composed of Permian stone and diorites and Triassic sandstones and mudstones intercalated with slates. An abundance of loose co-seismic materials were present on the slopes after the May 12, 2008 Wenchuan earthquake, which in later years served as source material for rainfall-induced debris flows or shallow landslides. A total of 48 debris flows, all triggered by heavy rainfall on 13th August 20l0, are described in this paper. Field investigation, supported by remote sensing image interpretation, was conducted to interpret the co-seismic landslides in the debris flow gullies. Specific characteristics of the study area such as slope, aspect, elevation, channel gradient, lithology, and gully density were selected for the evaluation of debris flow susceptibility. A score was given to all the debris flow gullies based on the probability of debris flow occurrence for the selected factors. In order to get the contribution of the different factors, principal component analyses were applied. A comprehensive score was obtained for the 48 debris flow gullies which enabled us to make a susceptibility map for debris flows with three classes. Twenty-two gullies have a high susceptibility, twenty gullies show a moderate susceptibility and six gullies have a low susceptibility for debris flows.
文摘This paper divides the genus Limnophora R.-D., into f ive species-group, s, namely L.triangula -gr., L.spoliata -gr., L.exi gua -gr., L.nigripes -gr. and L.scrupulosa -gr.. A key to each group i s provided and three new species from Yunnan Province, L.longispatula sp.nov. , L.yulongxueshanna sp.nov.and L.yunnanensis sp.nov.,described.Type speci mens are deposited in the Institute of Entomology,Shenyang Normal University.
