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91.
Qing Wang Yuanyuan Kong Wen Zhang Jianping Chen Peihua Xu Huizhong Li Yiguo Xue Xiaoqing Yuan Jiewei Zhan Yujie Zhu 《Arabian Journal of Geosciences》2016,9(18):718
A method was developed to analyze the susceptibilities of 541 regional basins affected by debris flows at the Wudongde Dam site in southwest China. Determining susceptibility requires information on source material quantity and occurrence frequency. However, the large number of debris flows can hinder the individual field investigation in a each small basin. Factors that may trigger debris flows can be identified using remotely sensed interpretation information. Susceptibility analysis can then be conducted based on these factors. In this study, SPOT5 satellite imagery, digital elevation models (DEM), a lithology distribution map, and rainfall monitoring data were used to identify 12 debris flow trigger factors: basin relief ratio, slope gradient in the initiation zone, drainage density, downslope curvature of the main channel, vegetation coverage, main channel aspect, topographic wetness index, Melton’s ruggedness number, lithology, annual rainfall, form factor, and cross-slope curvature of the transportation zone. Principal component analysis was used to obtain the eight principal components of these factors that contribute to susceptibility results. Then, a self-organizing map method was adopted to analyze the principal components, which resulted in a debris flow susceptibility classification. Field validation of 26 debris flow basins was used to evaluate the errors of the susceptibility classification, as well as assess the causes of such errors. The study found that principle component analysis and self-organizing map methodologies are good predictors of basin susceptibility to debris flows. 相似文献
92.
As an effective livelihood approach to alleviate poverty without rural population migration, ethnic tourism has become the primary choice of economic development in ethnic areas worldwide in addition to traditional livelihood approaches. This article applies the theories of livelihood to study the community evolution driven by tourism livelihood and examine three mountainous tourism communities in different stages of tourist area life cycle. Drawing on the methods of GIS spatial analysis, semi-structured interviews and questionnaires, this article proposes a sustainable livelihood framework for ethnic tourism to explore the evolution of ethnic tourism communities by identifying changes in livelihood assets (natural, financial, social, cultural and human capitals) in the process of tourism development. The results show that the development of ethnic tourism has led to changes in the increase of building land, and the diversification of land use functions with a trend of shifting from meeting local villagers' living needs to satisfying tourists, income composition and uneven distribution of tourism income spatially. Ethnic tourism also led to the deterioration of traditional social management structure, collapse of neighboring relationship, the over- commercialization and staged authenticity of ethnic culture, as well as the gradual vanish of agricultural knowledge with a trend of increasing modern business knowledge and higher education. In addition, these changes, involving livelihood assets from natural, economic, human, social and cultural aspects are interrelated and interactive, which form new evolution characters of ethnic community. This study reveals the conflicts over livelihood approaches which have formed new vulnerabilities to impact on sustainable evolution of ethnic communities. This research provides implications for achieving the sustainable development of ethnic communities with the driving force of tourism livelihood. 相似文献
93.
Wei-yue Li Chun Liu Yang Hong Xin-hua Zhang Zhan-ming Wan Manabendra Saharia Wei-wei Sun Dong-jing Yao Wen Chen Sheng Chen Xiu-qin Yang Yue Yue 《山地科学学报》2016,13(7):1275-1285
Landslide inventory plays an important role in recording landslide events and showing their temporal-spatial distribution. This paper describes the development, visualization, and analysis of a China's Landslide Inventory Database (CsLID) by utilizing Google’s public cloud computing platform. Firstly, CsLID (Landslide Inventory Database) compiles a total of 1221 historical landslide events spanning the years 1949-2011 from relevant data sources. Secondly, the CsLID is further broken down into six zones for characterizing landslide cause-effect, spatiotemporal distribution, fatalities, and socioeconomic impacts based on the geological environment and terrain. The results show that among all the six zones, zone V, located in Qinba and Southwest Mountainous Area is the most active landslide hotspot with the highest landslide hazard in China. Additionally, the Google public cloud computing platform enables the CsLID to be easily accessible, visually interactive, and with the capability of allowing new data input to dynamically augment the database. This work developed a cyber-landslide inventory and used it to analyze the landslide temporal-spatial distribution in China. 相似文献
94.
WU Yanyan CHEN Yufeng LI Laihao YANG Xianqing YANG Shaoling LIN Wanling ZHAO Yongqiang DENG Jianchao 《中国海洋大学学报(英文版)》2016,15(4):681-689
This study was carried out to investigate the biogenic amines(BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish were gathered from retail and wholesale markets and manufacturers, which had been produced in various regions in China. Cadaverine(CAD) and putrescine(PUT) were quantitatively the most common biogenic amines. About 14% of the samples exceeded the histamine content standards established by the FDA and/or EU. The highest histamine content was found in Silver pomfret(Pampus argenteus)(347.79 mg kg-1). Five of forty three samples exceeded the acceptable content of TYR(100 mg kg-1), and 23.26% of dried-salted fish contained high contents of biogenic amines(above 600 mg kg-1). In addition, species, regions, pickling processes and drying methods made the physicochemical property, microorganisms and biogenic amines in dry salted fish to be different to some extents. The total plate count(TPC) was much higher than that of total halophilic bacteria in all samples. The biogenic amines, physicochemical property and microbiological counts exhibited large variations among samples. Furthermore, no significant correlation between biogenic amines and physicochemical property and TPC was observed. This study indicated that dry salted fish may still present healthy risk for BAs, depending on the processing methods, storage conditions among others. 相似文献
95.
Current data from a moored Acoustic Doppler Current Profiler(ADCP) deployed at 69?30.155′N,169?00.654′W in the central Chukchi Sea during 2012 summertime is analyzed in the present paper.Characteristics of tidal and residual currents are ob-tained with Cosine-Lanczos filter and cross-spectral analyses.The main achievements are as follows:1) Along with the local inertial frequency of 12.8 h,two other peaks at ~12-h and ~10-d dominate the time series of raw velocity;2) The M_2 dominates the 6 resolved tide constituents with significant amplitude variations over depth and the ratios of current speed of this constituent to that of the total tidal current are 54% and 47% for u and v components,respectively.All the resolved tidal constituents rotate clockwise at depth with the exception of MM and O1.The constituents of M_2 and S_2 with the largest major semi-axes are similar in eccentricity and orientation at deeper levels;3) The maximum of residual currents varies in a range of 20–30 cms~(-1) over depth and the current with lower velocities flow more true north with smaller magnitudes compared to the current in surface layer.The ~10 d fluctuation of residual current is found throughout the water column and attributed to the response of current to the local wind forcing,with an approximate 1.4 d lag-time at the surface level and occurring several hours later in the lower layer;4) Mean residual currents flow toward the north with the magnitudes smaller than 7 cms~(-1) in a general agreement with previous studies,which suggests a relatively weaker but stable northward flow indeed exists in the central Chukchi Sea. 相似文献
96.
Human-machine interactive visiting and fixed-route visiting are currently the main roaming modes in digital three-dimensional (3D) scenes. However, in general, when a person visits an attraction area, s/he does not follow a fixed path, but instead wander about according to his/her interests. Here, we propose a new roaming mode, called autonomic visiting. That is, in a digital 3D scene, a user selects several interest spots, then a route connecting these spots can be automatically determined and 3D scene can be seen along this route. This study presents a technical approach that enables the realization of autonomic visiting in 3D scenes. Firstly, Delaunay triangular meshes for the terrain in 3D scene are established. Secondly, a plane-growth algorithm and a line-connection algorithm are introduced to automatically mend the broken parts of these triangular meshes. Thirdly, the triangular meshes are then merged and differently weighted according to different layers. Finally, a progress-zone transmission algorithm is presented to optimal the shortest route, which is derived from A-Star (A*) algorithm. Digital 3D campus of Nanjing University, China, is taken as the experimental materials. The experimental results prove the effect of the proposed approach. 相似文献
97.
98.
C.-S. Chiou H.-W. Chen Z.-T. Chen 《International Journal of Environmental Science and Technology》2018,15(9):1879-1886
The extensive use of Rhodamine B (RhB) for textile, paper, pigment, food, cosmetic, and drug manufacturing and its indiscriminate disposal leads to serious human, biological, and environmental hazards. A magnetic adsorbent with silicate and phenyl polymers (Ph/SiO2/Fe3O4) has been prepared to absorb RhB. The morphology and structure of the adsorbents have been characterized by TGA, XRD, FTIR, and adsorption–desorption measurement. The results revealed that Ph/SiO2/Fe3O4 exhibited a paramagnetic behavior and could easily and quickly be separated from a suspension. The RhB adsorption behavior was almost pH independent due to the adsorption between the phenyl ring of Ph/SiO2/Fe3O4 and RhB by π–π electron-donor–acceptor interactions. The adsorption behavior of RhB adsorption was in good agreement with the Langmuir adsorption isotherm, and the maximum adsorption capacity was 142.186 mg g?1. Good desorption performance of Ph/SiO2/Fe3O4 showed that this novel magnetic adsorbent cannot only be activated by ethanol extraction process but also reuse by the recovery of magnetic force. 相似文献
99.
Macroalgae plays an important role in coastal ecosystems. The accurate delineation of macroalgae areas is important for environmental management. This study compared the pixel- and object-based methods using Gaofen satellite no. 2 image to explore an efficient classification approach. Expert system rules and nearest neighbour classifier were adopted for object-based classification, whereas maximum likelihood classifier was implemented in the pixel-based approach. Normalized difference vegetation index, normalized difference water index, mean value of the blue band and geometric characteristics were selected as features to distinguish macroalgae farms by considering the spectral and spatial characteristics. Results show that the object-based method achieved a higher overall accuracy and kappa coefficient than the pixel-based method. Moreover, the object-based approach displayed superiority in identifying Porphyra class. These findings suggest that the object-based method can delineate macroalgae farming areas efficiently and be applied in the future to monitor the macroalgae farms with high spatial resolution imagery. 相似文献
100.
Zhu Yalin Ma Chi Tan Kun Chen Juxiang Wang Yixian 《Geotechnical and Geological Engineering》2021,39(8):5479-5492
Geotechnical and Geological Engineering - Due to the complexity of the interaction between the geogrid and the soil interface in high earth-rock dams, the method of replacing the grid with steel... 相似文献