Advanced Materials Research Vols. 518-523

Abstract: The evolution of growth rate and eigenfunction of kink instability in a cylindrical plasma column with different plasma pressure is studied by a semi-analytical method. The method can transform magnetohydrodynamics (MHD) equations into a second-order ordinary differential equation. Growth rate can be obtained by solving the second-order ordinary differential equation. 2-D radial eigenfunction can be calculated with a fixed growth rate. The significant change of growth rate and eigenfunction indicates inhomogeneous plasma pressure P0 is destructive for kink instability. The advantage of our method is that it can divide problem into two parts and then solve them separately.

Abstract: On the basis of ecological footprint, the energy analysis theory is used to establish the urban ecological footprint model , the model is used to calculate the ecological footprint of Yantai and measure the regional sustainable development status.The influense that the international trade to the regional ecological footprint is considered in the article.The improved model is applied to analyse the enviroment status of eco-economic system of Yantai in 2008.The results indicate the ecological footprint of Yantai is 12.9082hm², and the aquatic prdouct is 7.57 hm² occupying 58.6% of the total footprint, the ecological footprint is 0.477 hm², the ecological footprint is bigger than the ecological capacity.

Abstract: In this paper, the seismic profiles of the central area of Huanghua depression were balanced and restored by 2DMove software. We calculated the extension parameters of the balanced corss-section in the different period, analyzed the tectonic deformation of Huanghua depression. According to the total extension parameters of balanced cross-section, the Cenozoic evolution of the Huanghua depression may be divided into two phase of tectonic evolution which are rifting stage and post-rift stage. The rifting stage included three episodic rifting: The third members of Shehejie with the rapidest subsidence,Ⅰepisodic rifting; The first and second members of Shahejie with the fault-depression,Ⅱepisodic rifting; The Dongying with terminal fault-depressed ,Ⅲepisodic rifting . The Huanghua depression shows a double-layer vertical structure with faulting structures in the lower and depressing structure in the upper sector.

Abstract: With the deepening of the degree of oil exploitation, investigation of geological structure is particularly important, especially those faults that have an important impact on the exploration and development of oil. However, seismic data is affected by various kinds of factors in the progress of data acquisition, which reduces SNR and interfere with the accuracy of geological structure interpretation. This paper based on image processing provides fault enhancement medthod. It can reduce random factors impact and depicte fault more clearly. This method combine anisotropy and orientation information of image, then use generalized Kuwahara filter to enhance fault. This technique has a most important value in seismic fault interpretation.

Abstract: In this paper, taken Landsat5/TM and SPOT5 image which was imaging in the close time as data source, the land-use map were obtained, respectively. In order to do some researches about LUCC and ecological effect, soil loss and landscape pattern metrics were selected as ecological index by corresponding counting methods. By analysis and contrast, it showed that soil loss obtained by Landsat5/TM and SPOT5 image has little difference, and the average soil erosion modulus are 181.54 t/(km2•a) and 190.17 t/(km2•a), respectively. The erosion area in different erosion classification does not appear distinct difference. By the landscape pattern metrics value, it showed that the difference of MSI, PAFRAC, CONTAG and SHDI in Landsat5/TM and SPOT5 is only between 0.07 and 0.3, and the difference of LPI and AI was higher than above 3 types of index. But in a word, there were no big difference for all the index.

Abstract: The research of Three Dimensional City Model (3DCM) has become a hot topic in GIS field in recent years, and it also has played an important role in traffic, land, mining, surveying and mapping, and other fields, especially in urban planning. However, the difficulty to acquire 3D data is the key obstacle to the further development of 3DCM. Airborne LIDAR, integrating GPS, INS and scanning laser rangefinder, can rapidly acquire the 3D position of ground by airplane, which is very economical, efficient and convenient to acquire 3D data. Because traditional three-dimensional data acquisition method can’t meet the need of the city’s fast development, airborne LIDAR technology is regarded as a convenient, swift, high-efficient three-dimensional data acquisition method. Compared with traditional methods, the airborne LIDAR technology has the following characteristics: 1) High efficiency: in 12 hours, the airborne LIDAR can scan 1000 square kilometers, next, with the help of the related post-processing software, LIDAR cloud data can transform them into GIS format or other receivable format in certain automatic or semiautomatic mode. 2) High precision: because the pulse of laser light isn’t easily subject to shadow and solar angle, it greatly improves the data quality. The flight height limit has no influence on its elevation data precision, which is superior to the conventional photogrammetry. The plane precision may achieve 0.15 to 1 meter, the elevation precision may achieve 10 centimeters. 3) All-weather feature: airborne LIDAR is active remote sensing without considering the digital aerial photogrammetry. 4) Rich information: with the aid of airborne LIDAR ,we can obtains not only the three dimensional coordinate of ground point, but also the three dimensional coordinate of terrain details, such as trees, buildings, roads. If it is integrated with CCD, it could gains image information. We acquired the airborne LIDAR data of 20 square kilometers in the central area of Shanghai using ALTM3100 airborne LIDAR system of the Optech company in 2006.This paper introduces the data processing procedure of the airborne LIDAR data, LIDAR system uses random commercial software to process plane GPS tracking data、plane attitude data、 laser ranging data and the swinging angle data of laser scanning mirror, finally, obtaining the three-dimensional coordinates(X,Y,Z) data of various surveying points. Which three-dimensional discrete dot matrix data is without attribute suspending in the air namely LIDAR original data, named “point cloud”. LIDAR data performs pre-processing to obtain digital surface model (DSM), which is classified and extracted, we acquire topography and object related to modeling, preparing for three-dimensional city model. Data pre-processing includes abnormal point deletion, coordinate transformation and flight strip combination. At present, we used famous business software TerraSolid, developed by Company of Finland to realize the classification and extraction from the LIDAR data TerraSolid depends on MicroStation platform, on the basis of classification and extraction algorithms presented by Axelsson, et al. of Swedish, including a lot of module such as TerraScan, TerraModeler and TerraPhoto. TerraScan is used in the field of LIDAR data classification and extraction, TerraModeler is used for producing and dealing with various planes, TerraPhoto is used for dealing with the primitive image, topography model and building model are got by using this software, complicated artificial building (Oriental Pearl, Jin Mao mansion etc.) need artificial repair and disposal, data processing of 20 sq. km. takes more than one month, efficiency has been improved greatly on the premise of guaranteeing the precision. Topography model and building model can be obtained by using TerraSolid and combining a few manual intervention based on DSM, The topography model is expressed with the triangulated irregular network (TIN), the building model is expressed with 3ds format, three dimensional model of non - texture of Lujiazui region of Shanghai was gained by LIDAR data. In order to achieving better visualization effect, the topography model overlaps orthophoto, and stuck true texture to building model, true city landscape of Lujiazui region of Shanghai is established. This paper has introduce post-processing procedure of airborne LIDAR data systematically, has realized the fast reconstruction of three-dimension urban model based on LIDAR data, enable this technology to serve the information construction of the city better.

Abstract: the excessive exploration and utilization of land is the main cause of desertification. Utilizing and exploring sinking sandy land has been accelerating the process of desertification. The data sources for our research are mainly based on remote sensing data, and these data have been processed through a series of correcting and enhancing measures. By using these data and the results of some field investigations, the image features have been analyzed and then the interpretation keys of sinking sandy land are established. The distribution of sinking sandy land has been clarified by using the following two remote sensing methods: Man-Computer Interactive Interpretation classification and Supervised Classification. A comparison between the precision of these two methods has been done. The research is trying to find the most suitable method for the study of the spatial distribution of the sinking sandy land in West Ujimqin Banner and also trying to lay a scientific and theoretical foundation for determining the spatial distribution of the sinking sandy land in Inner Mongolia.

Abstract: Vegetation covering situation is very important for the quality of air quality, soil and water conservation ability and soil forming in an area. By using the remote sensing image of Taiyuan Valley Plain, the application of Normalized Difference Vegetation Index (NDVI) and unsupervised classification, the vegetation coverage map which includes non-cultivated land disposition and cultivated land disposition was obtained using ERDAS Imagine software. To evaluate the accuracy of the results, 200 points were sampled randomly, the high spatial resolution remote sensing image from Google Earth was used as the reference. The overall classification accuracy is 82%, with the Kappa statistic of 0.81. By counting the totally pixel acreage, it was gotten that the vegetation coverage was 46% and the cultivated land coverage ratio was 31% in the study area.

Abstract: The advance in monitoring forest fire in China based on multi-Satellite data were discussed in the paper. Since the 1980s in China, the satellite remotely-sensed data have been acquired, such as NOAA/AVHRR, FY-series, MODIS, CBERS, and ENVISAT, have been widely utilized for monitoring forest fire hot spots and burned areas in China. Some developed algorithms have been utilized for detecting the forest fire hot spots.

Abstract: In this paper,we use SPOT VEGETATION dataset of west mountain area of Henan provience in year 1998,2003 and 2008, calculated the vagetation coverage based on the normalized difference vegetation index and improved pixel binary model. And then, combine with the DEM, we quantitatively analysed the terrain effects to vegetation coverage,the result shows that: The vegetation coverage in high altitude areas was steady- going. But in the low altitude areas, the change of vegetation coverage is very sharp, and the ecosystem is fragile in the heavy gradient area. In the small slope areas, the probability of degradation and resoration both relative high; In a same phases,the vegetation coverage in south and north aspect is relatively high but lower in east and west aspect.The vegetation degradation in southwest aspect was more seriously than in southeast aspect.