Advanced Materials Research Vols. 726-731

Abstract: Based on the geographic information systems and database technology, this study set up a contaminated sites information and remediation management decision-making system using Beijing sites data, which include a web portal interface and three major modules: site management, risk assessment and remediation decision. People can inter the system to browse and inquiry the information concerned, zoom in and zoom out the map, statistics and analysis the data. This system provided tools for risk assessment, remediation decision and expert review. This system will provide technical support for government departments and technical institutions.

Abstract: Changes in spatial patterns of hydrophyte of Wuliangsuhai wetland since 1986 are analyzed based on the remote sensing principle. The methods of computer automated classification combining with visual interpretation are used for the extraction of wetland information. Furthermore, overall accuracy and kappa coefficient are applied to the assessment of classification accuracy. The results show the macrophyte is the dominant type in the Wuliangsuhai wetland.

Abstract: Abstract:For studying the characters of dynamic changes of land Desertification in Songnen Plain, this paper makes use of remote sensing data and geography information system technology and introduces some characteristic parameters, such as the degree of desertification change, to get the numerical value of these characters. The research result shows that: in 1975-1988, the land area of desertification increases rapidly; the deterioration in the border region of land desertification is stronger than that in the center; and in 1988-2001, the area of desertification decreases slowly, the reversion in the border of desertification is stronger than that in the center, then the tendency of expansion of land desertification been initially contained.

Abstract: Wuliangsuhai wetland located in Inner Mongolia Autonomous Region (IMAR) is selected as the study area to analyze the wetland environment evolution. Wuliangsuhai wetland is the largest freshwater lake in the Yellow River basin, and also the largest natural wetland along the same latitude on the earth. Through the optimization comparison of multiple wave-band reflection combination, the regression equation of the water depth and wave band reflection combination of TM3, TM2 and TM1 is established based on the remote sensing principles.

Abstract: The hazard of Semiothisa cinerearia was explosive in multiple regions of China in recent years. The potential geographic distribution of S. cinerearia in China was predicted by the GARP ecological niche model combining with terrain and climate informations. The results indicated that 8 environmental variables could improve the accuracy of prediction. The test by using 50% of all the samples showed good performance and all the known distribution points in China were all correctly predicted. The potential distribution areas of S. cinerearia included whole China except Tibet, Qinghai, Xizhang, Hainan, Taiwan and south of Guangdong and Guangxi. And the central, North, East and Northeast of China had high suitability (>90%). Measures inhibiting Sophora japonica should be taken protect early and rapidly in its suitable areas.

Abstract: There are a great number of index methods used to extract impervious surface from satellite images. However, these indices are not robust enough to detect steel framed roof due to the diversity of impervious materials. The extraction of steel framed roof information by remote sensing technology is becoming increasingly important because of its environmental and socio-economic significance. A new index, Normalized Difference Steel framed roof Index (NDSI) is proposed to extract steel framed roof surface information from TM images. The NDSI was created based on its spectral characteristics of TM image and the steel framed roof information can be extracted fast by NDSI threshold method. Additionally, Shijiazhuang city, which has experienced rapid urbanization, was chosen as the study area. And the classification results show that the new index NDSI can effectively extract steel framed roof information with higher accuracy.

Abstract: The objective of this paper is to compare and analyze the forest height retrieval methods from Polarimetric SAR Interferometry(POLINSAR).Both of the methods based on DEM difference and that on interferometry coherence amplitude are generalized, analyzed, and compared.Also in this paper combined methods of DEM difference and interferometry coherence amplitude are proposed and validated.The ESA full
polarimetric interferometry L-band data are used for forest height analysis.The results show that the height is severely underestimated using DEM difference method,In constast,interferometry coherence amplitude method has a overest imation of height.The combined method of DEM difference and interferometry coherence amplitude has a much better estimate,closer to the true height than these two methods.

Abstract: Regional tourism is a part of China's economic income. It is of great significance for tourism economy development to study spatial-temporal evolvement. This study analyzed time-based characteristics and spatial cluster characteristics through methods including Spatial Weight Matrix, global spatial autocorrelation (Morans I) statistic, spatial Statistics (Getis-Ord Gi*) and local spatial autocorrelation calculations. Results show that the overall spatial autocorrelation model changed slowly from negative (-0.05) to positive (0.08) while eastern part of study area clustered as hotspot and western part clustered as coldspot. It can be concluded that the spatial distribution pattern of the tourism economy in study area from 2002 to 2007 was increasingly clustered and the tourism development of each units in study area will be much more spatially inter-dependent.

Abstract: The Shuttle Radar Topography Mission (SRTM) is an international research effort that obtains digital elevation models (DEM) over 80% of the Earths land surface. SRTM DEM plays a key role in geosciences and GIS. In order to investigate the vertical accuracy of SRTM DEM, we evaluated the root mean square error (RMSE) of height between SRTM DEM and 1:50,000 scale topographic map within north China, and extracted the related topographic factors including height, slope and aspect. Then, we analyzed the relationship between the topographic factors and SRTM DEM errors. The results show that the SRTM DEM errors not only have a tendency to get larger in areas of large slope and complex topography, but also have a strong correlation with aspect. Furthermore, this correlation appears increasingly strong with great slope.

Abstract: This paper researches on spatial analysis on soil heavy metal pollution based on GIS. Taking Anqiu city for study area, this paper acquired the soil heavy metal pollution data through investigation and sampling.After the analysis on spatial distribution feature and assessment of soil heavy mental pollution of Cd,Pd,Hg,Cr and As in research area, we found that the pollution situation of Pd,Hg,Cr and As were very slight and reached the national standards. But the pollution situation of Cd in some area is some severe. So it is urgent to find the pollution reasons of Cd and make effective measures for soil remediation.This paper is very important to the sustainable development of agriculture in study area.