At 5:39 am on June 24, 2017, a landslide occurred in the village of Xinmo in Maoxian County, Aba Tibet and Qiang Autonomous Prefecture(Sichuan Province, Southwest China). On June 25, aerial images were acquired from a...At 5:39 am on June 24, 2017, a landslide occurred in the village of Xinmo in Maoxian County, Aba Tibet and Qiang Autonomous Prefecture(Sichuan Province, Southwest China). On June 25, aerial images were acquired from an unmanned aerial vehicle(UAV), and a digital elevation model(DEM) was processed. Landslide geometrical features were then analyzed. These are the front and rear edge elevation, accumulation area and horizontal sliding distance. Then, the volume and the spatial distribution of the thickness of the deposit were calculated from the difference between the DEM available before the landslide, and the UAV-derived DEM collected after the landslide. Also, the disaster was assessed using high-resolution satellite images acquired before the landslide. These include Quick Bird, Pleiades-1 and GF-2 images with spatial resolutions of 0.65 m, 0.70 m, and 0.80 m, respectively, and the aerial images acquired from the UAV after the landslide with a spatial resolution of 0.1 m. According to the analysis, the area of the landslide was 1.62 km2, and the volume of the landslide was 7.70 ± 1.46 million m3. The average thickness of the landslide accumulation was approximately 8 m. The landslide destroyed a total of 103 buildings. The area of destroyed farmlands was 2.53 ha, and the orchard area was reduced by 28.67 ha. A 2-km section of Songpinggou River was blocked and a 2.1-km section of township road No. 104 was buried. Constrained by the terrain conditions, densely populated and more economically developed areas in the upper reaches of the Minjiang River basin are mainly located in the bottom of the valleys. This is a dangerous area regarding landslide, debris flow and flash flood events Therefore, in mountainous, high-risk disaster areas, it is important to carefully select residential sites to avoid a large number of casualties.展开更多
In this paper,an HPLC-DAD-ELSD method was developed to determine main 20 components of Ginkgo biloba L.leaves from different ages and sources,including six flavonol glycosides,five terpene lactones and nine organic ac...In this paper,an HPLC-DAD-ELSD method was developed to determine main 20 components of Ginkgo biloba L.leaves from different ages and sources,including six flavonol glycosides,five terpene lactones and nine organic acids.Using statistics method and establishing relevant mathematics models,the measured data has proceeded correlation analysis,principal component analysis,and regression statistics and the results showed generality and specific characteristics.We defined p-hydroxybenzoic acid,catechinic,KRcG and ginkgolide A as characteristic indexes representing commonness and speciality of Ginkgo biloba L.leaf.The four characteristic indexes can reflect the quality of Ginkgo biloba L.leaf,and the intermal relations between them are significant.The contents of other compounds could define the quantity relation with characteristic markers.It simplified the approach of quality control,and provided a basis for quality control of Ginkgo biloba L.展开更多
基金funded by the National Key Technologies R&D Program of China (Grants No. 2017YFC0505104)the Key Laboratory of Digital Mapping and Land Information Application of National Administration of Surveying, Mapping and Geoinformation of China (Grants No. DM2016SC09)
文摘At 5:39 am on June 24, 2017, a landslide occurred in the village of Xinmo in Maoxian County, Aba Tibet and Qiang Autonomous Prefecture(Sichuan Province, Southwest China). On June 25, aerial images were acquired from an unmanned aerial vehicle(UAV), and a digital elevation model(DEM) was processed. Landslide geometrical features were then analyzed. These are the front and rear edge elevation, accumulation area and horizontal sliding distance. Then, the volume and the spatial distribution of the thickness of the deposit were calculated from the difference between the DEM available before the landslide, and the UAV-derived DEM collected after the landslide. Also, the disaster was assessed using high-resolution satellite images acquired before the landslide. These include Quick Bird, Pleiades-1 and GF-2 images with spatial resolutions of 0.65 m, 0.70 m, and 0.80 m, respectively, and the aerial images acquired from the UAV after the landslide with a spatial resolution of 0.1 m. According to the analysis, the area of the landslide was 1.62 km2, and the volume of the landslide was 7.70 ± 1.46 million m3. The average thickness of the landslide accumulation was approximately 8 m. The landslide destroyed a total of 103 buildings. The area of destroyed farmlands was 2.53 ha, and the orchard area was reduced by 28.67 ha. A 2-km section of Songpinggou River was blocked and a 2.1-km section of township road No. 104 was buried. Constrained by the terrain conditions, densely populated and more economically developed areas in the upper reaches of the Minjiang River basin are mainly located in the bottom of the valleys. This is a dangerous area regarding landslide, debris flow and flash flood events Therefore, in mountainous, high-risk disaster areas, it is important to carefully select residential sites to avoid a large number of casualties.
基金National Administration of Traditional Chinese Medicine Standardization Project(Grant No.ZYBZH-C-HEB-16)
文摘In this paper,an HPLC-DAD-ELSD method was developed to determine main 20 components of Ginkgo biloba L.leaves from different ages and sources,including six flavonol glycosides,five terpene lactones and nine organic acids.Using statistics method and establishing relevant mathematics models,the measured data has proceeded correlation analysis,principal component analysis,and regression statistics and the results showed generality and specific characteristics.We defined p-hydroxybenzoic acid,catechinic,KRcG and ginkgolide A as characteristic indexes representing commonness and speciality of Ginkgo biloba L.leaf.The four characteristic indexes can reflect the quality of Ginkgo biloba L.leaf,and the intermal relations between them are significant.The contents of other compounds could define the quantity relation with characteristic markers.It simplified the approach of quality control,and provided a basis for quality control of Ginkgo biloba L.
