Abstract: The Wenchuan earthquake generated strong surface disturbances and triggered a large number of loose deposits, resulting in the disaster- prone environment with special watershed hydrological characteristics...Abstract: The Wenchuan earthquake generated strong surface disturbances and triggered a large number of loose deposits, resulting in the disaster- prone environment with special watershed hydrological characteristics. This paper was to propose a debris flow formation process and explore the permeability characteristics and critical hydrodynamic conditions of the loose deposits triggered by the earthquake. The Guo Juanyan gully (31005'27" N to 31005'46" N, 103036'58" E to 103037'09" E) in Du Jiangyan City, located in the meizoseismal areas of the Wenchuan earthquake, was chosen as the study area and the disaster-prone environment was analyzed. The formation process of the debris flow was first proposed using a stability analysis, and then, the permeability characteristics of loose deposits were determined via in situ permeability experiments. Finally, the critical 1 h rainfall was simulated through a distributed hydrological model and verified by field observations. The formation process of debris flow could be divided into three stages based on the relationship between the hydrodynamic force and loose deposit resistance. The critical 1 h rainfall amounts under three antecedent moisture conditions (I-dry, Ⅱ-normal and Ⅲ-wet) were 52 mm/h, 43 mm/h and 34 mm/h, respectively. This study proposed a debris flow formation process in the meizoseismal areas of the Wenchuan earthquake based on the stability analysis and defined the rainfall threshold for debris flow early warning at the local level, which is significant for debris flow mitigation and risk management.展开更多
This paper contributes to depict the current pattern of applications of digital 3D models for professional research and practice, and for broader dissemination of cultural heritage. Passing from a general review to th...This paper contributes to depict the current pattern of applications of digital 3D models for professional research and practice, and for broader dissemination of cultural heritage. Passing from a general review to the illustration of the background project, named MUSINT, the authors underline the objectives. The present case study primarily aims to share information about valuable archaeological collections which have little visibility. To enhance the project's contents, which include a whole set of different artifacts, the authors have reproduced high resolution, faithful and measurable digital models on one side, and on the other, lower resolution and geometrically simplified models are yet completed and very close to reality. The former are meant to implement a scholars' archive for further scientific activity. The latter to provide content for virtual exhibitions on the Web or on stand-alone interfaces situated in the actual physical museum spaces. The data acquisition and post-processing methods which have been tested and chosen are here briefly described. Hence, the authors then give an account of the most recurrent problematic issues of the established work-flow and how they should be solved. Touched instances are the delicate placing of the artifacts, which must be digitized, in relation to the triangulation-based laser scanner's functionality, the refining operations in order to build a coherent single polygon mesh, the most effective ways to deal with unavoidable missing parts or defected textures in the generated model and so on.展开更多
The spatial distribution of soil physical properties is essential for modeling and understanding hydrological processes. In this study, the different spatial information (the conventional soil types map-based spatial ...The spatial distribution of soil physical properties is essential for modeling and understanding hydrological processes. In this study, the different spatial information (the conventional soil types map-based spatial information (STMB) versus refined spatial information map (RSIM)) of soil physical properties, including field capacity, soil porosity and saturated hydraulic conductivity are used respectively as input data for Water Flow Model for Lake Catchment (WATLAC) to determine their effectiveness in simulating hydrological processes and to expound the effects on model performance in terms of estimating groundwater recharge, soil evaporation, runoff generation as well as partitioning of surface and subsurface water flow. The results show that: 1) the simulated stream flow hydrographs based on the STMB and RSIM soil data reproduce the observed hydrographs well. There is no significant increase in model accuracy as more precise soil physical properties information being used, but WATLAC model using the RSIM soil data could predict more runoff volume and reduce the relative runoff depth errors; 2) the groundwater recharges have a consistent trend for both cases, while the STMB soil data tend to produce higher groundwater recharges than the RSIM soil data. In addition, the spatial distribution of annual groundwater recharge is significantly affected by the spatial distribution of soil physical properties; 3) the soil evaporation simulated using the STMB and RSIM soil data are similar to each other, and the spatial distribution patterns are also insensitive to the spatial information of soil physical properties; and 4) although the different spatial information of soil physical properties does not cause apparent difference in overall stream flow, the partitioning of surface and subsurface water flow is distinct. The implications of this study are that the refined spatial information of soil physical properties does not necessarily contribute to a more accurate prediction of stream flow, and the selection of appropriate soil physical property data needs to consider the scale of watersheds and the level of accuracy required.展开更多
To promote the development of the intangible cultural heritage of the world, shadow play, many studies have focused on shadow puppet modeling and interaction. Most of the shadow puppet figures are still imaginary,spre...To promote the development of the intangible cultural heritage of the world, shadow play, many studies have focused on shadow puppet modeling and interaction. Most of the shadow puppet figures are still imaginary,spread by ancients, or carved and painted by shadow puppet artists, without consideration of real dimensions or the appearance of human bodies. This study proposes an algorithm to transform 3D human models to 2D puppet figures for shadow puppets, including automatic location of feature points, automatic segmentation of 3D models, automatic extraction of 2D contours, automatic clothes matching, and animation. Experiment proves that more realistic and attractive figures and animations of the shadow puppet can be generated in real time with this algorithm.展开更多
The planning Yalong-River water transfer project will transfer 5.65 billion cubic meters water from the Yalong River into the Yellow River per year.The Yalong River will be dramatically impacted hydrologically and eco...The planning Yalong-River water transfer project will transfer 5.65 billion cubic meters water from the Yalong River into the Yellow River per year.The Yalong River will be dramatically impacted hydrologically and ecologically because more than 60% of the runoff will be diverted.An ecohydrological model was used to evaluate the impacts of the project on river corridor and wetland in this study.Schizothorax is a typical plateau river species and was used as the indicator species for assessment of the impact of water transfer project.The model simulated the habitat area of Schizothorax in the reach between the Reba Dam and the Ganzi Hydrology Station on the Yalong River.The Reba Dam,A'an Dam and Renda Dam will be constructed in the Yalong River for enhancing the water level for water diversion into the Yellow River.The velocity,channel width,runoff,and water depth will be reduced due to the water transfer,especially during flood season.The reduction in the velocity,channel width,runoff and water depth will occur mainly in the reach near the three dams and the reduction will be reduced to a minimum level in a distance about 100 km downstream of the dams.The maximum net water loss of Kasha Lake is only 1197200 m3,only 0.3% of runoff flowing into the lake.The project cannot bring adverse effect on the lake.The habitat area of Schizothorax in the Yalong River might be reduced if the water was transferred from the Reba Dam.The habitat area of this species will be reduced more than 40%.展开更多
基金Financial support was provided by the international cooperation project of the Ministry of Science and Technology (Grant No.2013DFA21720)the Key Laboratory of Mountain Hazards and Earth Surface Processes independent project fundingthe National Natural Science Foundation (Grant No. 41372331)
文摘Abstract: The Wenchuan earthquake generated strong surface disturbances and triggered a large number of loose deposits, resulting in the disaster- prone environment with special watershed hydrological characteristics. This paper was to propose a debris flow formation process and explore the permeability characteristics and critical hydrodynamic conditions of the loose deposits triggered by the earthquake. The Guo Juanyan gully (31005'27" N to 31005'46" N, 103036'58" E to 103037'09" E) in Du Jiangyan City, located in the meizoseismal areas of the Wenchuan earthquake, was chosen as the study area and the disaster-prone environment was analyzed. The formation process of the debris flow was first proposed using a stability analysis, and then, the permeability characteristics of loose deposits were determined via in situ permeability experiments. Finally, the critical 1 h rainfall was simulated through a distributed hydrological model and verified by field observations. The formation process of debris flow could be divided into three stages based on the relationship between the hydrodynamic force and loose deposit resistance. The critical 1 h rainfall amounts under three antecedent moisture conditions (I-dry, Ⅱ-normal and Ⅲ-wet) were 52 mm/h, 43 mm/h and 34 mm/h, respectively. This study proposed a debris flow formation process in the meizoseismal areas of the Wenchuan earthquake based on the stability analysis and defined the rainfall threshold for debris flow early warning at the local level, which is significant for debris flow mitigation and risk management.
文摘This paper contributes to depict the current pattern of applications of digital 3D models for professional research and practice, and for broader dissemination of cultural heritage. Passing from a general review to the illustration of the background project, named MUSINT, the authors underline the objectives. The present case study primarily aims to share information about valuable archaeological collections which have little visibility. To enhance the project's contents, which include a whole set of different artifacts, the authors have reproduced high resolution, faithful and measurable digital models on one side, and on the other, lower resolution and geometrically simplified models are yet completed and very close to reality. The former are meant to implement a scholars' archive for further scientific activity. The latter to provide content for virtual exhibitions on the Web or on stand-alone interfaces situated in the actual physical museum spaces. The data acquisition and post-processing methods which have been tested and chosen are here briefly described. Hence, the authors then give an account of the most recurrent problematic issues of the established work-flow and how they should be solved. Touched instances are the delicate placing of the artifacts, which must be digitized, in relation to the triangulation-based laser scanner's functionality, the refining operations in order to build a coherent single polygon mesh, the most effective ways to deal with unavoidable missing parts or defected textures in the generated model and so on.
基金Under the auspices of Open Research Fund of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin (No. IWHR-SKL-201111)National Natural Science Foundation of China (No. 41101024)
文摘The spatial distribution of soil physical properties is essential for modeling and understanding hydrological processes. In this study, the different spatial information (the conventional soil types map-based spatial information (STMB) versus refined spatial information map (RSIM)) of soil physical properties, including field capacity, soil porosity and saturated hydraulic conductivity are used respectively as input data for Water Flow Model for Lake Catchment (WATLAC) to determine their effectiveness in simulating hydrological processes and to expound the effects on model performance in terms of estimating groundwater recharge, soil evaporation, runoff generation as well as partitioning of surface and subsurface water flow. The results show that: 1) the simulated stream flow hydrographs based on the STMB and RSIM soil data reproduce the observed hydrographs well. There is no significant increase in model accuracy as more precise soil physical properties information being used, but WATLAC model using the RSIM soil data could predict more runoff volume and reduce the relative runoff depth errors; 2) the groundwater recharges have a consistent trend for both cases, while the STMB soil data tend to produce higher groundwater recharges than the RSIM soil data. In addition, the spatial distribution of annual groundwater recharge is significantly affected by the spatial distribution of soil physical properties; 3) the soil evaporation simulated using the STMB and RSIM soil data are similar to each other, and the spatial distribution patterns are also insensitive to the spatial information of soil physical properties; and 4) although the different spatial information of soil physical properties does not cause apparent difference in overall stream flow, the partitioning of surface and subsurface water flow is distinct. The implications of this study are that the refined spatial information of soil physical properties does not necessarily contribute to a more accurate prediction of stream flow, and the selection of appropriate soil physical property data needs to consider the scale of watersheds and the level of accuracy required.
基金supported by the National Natural Science Foundation of China(Nos.61103100,61303137,and 51205059)the Natural Science Foundation of Zhejiang Province,China(Nos.Y13F020143 and LY13F030002)the Fundamental Research Funds for the Central Universities,China(No.2014QNA5009)
文摘To promote the development of the intangible cultural heritage of the world, shadow play, many studies have focused on shadow puppet modeling and interaction. Most of the shadow puppet figures are still imaginary,spread by ancients, or carved and painted by shadow puppet artists, without consideration of real dimensions or the appearance of human bodies. This study proposes an algorithm to transform 3D human models to 2D puppet figures for shadow puppets, including automatic location of feature points, automatic segmentation of 3D models, automatic extraction of 2D contours, automatic clothes matching, and animation. Experiment proves that more realistic and attractive figures and animations of the shadow puppet can be generated in real time with this algorithm.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51027006,51109224)the National Key Basic Research Program of China ("973" Program) (Grant No. 2010CB951102)the National Key Project of Scientific and Technical Supporting Program (Grant No. 2006BAB04A08)
文摘The planning Yalong-River water transfer project will transfer 5.65 billion cubic meters water from the Yalong River into the Yellow River per year.The Yalong River will be dramatically impacted hydrologically and ecologically because more than 60% of the runoff will be diverted.An ecohydrological model was used to evaluate the impacts of the project on river corridor and wetland in this study.Schizothorax is a typical plateau river species and was used as the indicator species for assessment of the impact of water transfer project.The model simulated the habitat area of Schizothorax in the reach between the Reba Dam and the Ganzi Hydrology Station on the Yalong River.The Reba Dam,A'an Dam and Renda Dam will be constructed in the Yalong River for enhancing the water level for water diversion into the Yellow River.The velocity,channel width,runoff,and water depth will be reduced due to the water transfer,especially during flood season.The reduction in the velocity,channel width,runoff and water depth will occur mainly in the reach near the three dams and the reduction will be reduced to a minimum level in a distance about 100 km downstream of the dams.The maximum net water loss of Kasha Lake is only 1197200 m3,only 0.3% of runoff flowing into the lake.The project cannot bring adverse effect on the lake.The habitat area of Schizothorax in the Yalong River might be reduced if the water was transferred from the Reba Dam.The habitat area of this species will be reduced more than 40%.