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Jiang G.,Changan University | Wen X.,Xian Changqing Technology and Engineering Co. | Lai B.,Aerial Photogrammetry and Remote Sensing Bureau | Yang Z.,Changan University
Journal of Convergence Information Technology

With the increasing human activities, how to protect increasingly fragile ecological environment have become an urgent problem to be solved. In recent years, our country has invested over 18 billion Yuan in Xinjiang Tarim river comprehensive treatment. Under the frame of "digital river basin", relying on the main line of ecological environment remote sensing monitoring, with the application of integrated "3S"technology, build ecological environment data collection, data transmission, data storage as well as management, dynamic monitoring, analysis and early warning management information systems to better protect ecological environment. The following paper, through the description of the 3S integration technology in the construction of Xinjiang Tarim River basin digital ecological environment and land use, discusses and analyzes the main factors influencing the ecological environment. It, through using monitoring and analysis on its land utilization of Aksu river reaches, objectively analyses the changes of the farmland and the construction land, which provides basis for the planning of land development and the comprehensive assessment for the ecological environment, and provides significant reference to ecological environment monitoring system research, and gives consultation to "digital river basin" construction. Source

Zhao J.,Aerial Photogrammetry and Remote Sensing Bureau
Journal of Geomatics

Based on embedded-GIS, WAP, wireless network, image pyramid and related technologies, we designed a land use visitatorial system with hand mobile equipment. This system implemented rapid acquisition and field verifying of land use change information. Source

Li W.,Tongji University | Pan C.,Aerial Photogrammetry and Remote Sensing Bureau | Men Y.,Changan University
Advanced Materials Research

Based on surveys of buildings passing through ground fissures, failure and deformation characteristics of buildings are analyzed. Failure models of buildings under the influence of Xi'an ground fissures are proposed. By means of the simulations on PLASIX, taking for the f6 of ground fissures in Xi'an city, the variations of stress field and displacement field of the overlying soil layer which the normal fault qualitative ground fissures lead to are studied. It separately calculated out of the variation of the features of deformation, when brick masonry, block masonry and stone masonry act as solely material of the building. The total, vertical and horizontal deformation of buildings built of stone masonry are the largest and brick masonry's deformations are the smallest. It is suggested that materials with small gravity density should be used for building materials. Source

Zhu H.-C.,Nanjing Normal University | Zhu H.-C.,Shandong University of Science and Technology | Tang G.-A.,Nanjing Normal University | Wu L.-C.,Aerial Photogrammetry and Remote Sensing Bureau | Qian K.-J.,Nanjing Normal University
Shuikexue Jinzhan/Advances in Water Science

A gully node is the intersection of gully or river networks, which reflects the geomorphological structure and hydrological characteristic of the gully area. Effective extraction and analysis of gully nodes are essential to understand the spatial structure, morphology, and hydrological characteristic of a catchment. An algorithm based on high resolution digital elevation model (DEM) data is proposed for extracting gully nodes together with the classification method. The algorithm and method are tested in an experimental area on the Loess Plateau of North Shaanxi Province. The numbers of gully nodes of different order gullies and the flow accumulation value associated with each gully node are obtained. The relationship between the numbers of gully nodes in any given order class and the sum of corresponding flow accumulation values is obtained using a mathematical model. The variations in the spatial distribution of flow accumulation values in different geomorphological regions are studied using the arithmetic progression classification method. Finally, the spatial regularity of geomorphological features is preliminary discussed. Source

Ma D.-M.,Xian University of Science and Technology | Ma D.-M.,State Energy Key Laboratory of Joint Exploitation of Coal and Coal bed Methane | Li L.-X.,Shaanxi Coalbed Methane Development Corporation Ltd. | Li X.-P.,Team 131 of Shaanxi Coalfield Geology Bureau | And 4 more authors.
Meitan Xuebao/Journal of the China Coal Society

The study investigated the technology of the replacement of CH4 by CO2 in order to rapidly reduce the coalbed methane content in coal seam 4 at Dafosi Coal Mine and improve the recovery factor of the ground coalbed methane wells. Contrastive experiments on adsorption and desorption of CH4 and CO2 of cylinder raw coal and 60-80 mesh equilibrium water samples at different temperatures are conducted using the samples collected from the working face 40114 at Dafosi Coal Mine. The results indicate: the adsorption and desorption of CO2 on coal pore surface is consistent with that of CH4, the pressure-rising process abiding by Langmuir equation and the pressure-dropping process being described by desorption expression. Based on thermodynamic calculation, in cylinder raw coal during pressure-rising process, the adsorption heat of CO2 is 56.827 kJ/mol while that of CH4 is 12.662 kJ/mol. During pressure-dropping process, the adsorption heat of CO2 is 115.030 kJ/mol while that of CH4 is 23.602 kJ/mol. In both processes, the adsorption heat of CO2 is far greater than that of CH4, which proves that CO2 is more competitive over CH4 in their adsorption on coal pore surfaces, leading to replacement desorption. The conclusion is verified by the calculations of adsorption potential and adsorption space. The technology of replacing CH4 by CO2 is feasible with strong theoretical ground, and useful for improving the recovery factor of coalbed methane. Source

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