Sun Yonghua

Flood disaster response and decision-making support system based on remote sensing and GIS

With the development of remote sensing and geographical information system technologies, they are being applied to the every periods of flood disaster monitor and evaluation more and more. In the aspect of data acquisition, China is preparing for the launch of the small satellite constellation for environment and disaster. Currently, it is the principal problem that design and develop an integrative application platform for the flood disaster emergency response, the fast loss evaluation and the salvation decision-making support based on existing data, software and methodologies. At the same time, the trend of technology developing must be considered. Taking the requirement of China civil affairs department and the new satellite remote sensing data source guarantee into account, three key technologies about the development of flood disaster emergency response decisionmaking support system were designed. Based on the object- oriented, reuse, geodatabase, component object model and RS, GIS software technologies, the demonstrative application of key technologies in the integrative operational system was realized. Existing RS data were selected to simulate the future data. The demonstrative operational system has the characteristics of continuous monitoring, extensible, easy-to-use and so on. It can be utilized in many phases of operational work of flood disaster administration. Good effect was viewed in the usage of China National Natural Disaster Reduction Center.

A study on optical and SAR data fusion for extracting flooded area

This article proposes a method of fusing the optical data before the flood and SAR (synthetic aperture radar) data during the flood. The main goal of this study is to evaluate the capability of data fusion to combine the information from Landsat ETM image with Radarsat SAR image for water body and flooded area extraction. The Landsat ETM data will basically provide the information of landform and background information which includes the normal water extent. The Radarsat SAR data however was taken during flood will provide information mainly on water body extent and flooded area. In the result image, flooded area was significantly enhanced. We can distinguish the flooded area and normal water area easily.

The dynamic change of the urban thermal environment landscape patterns in Beijing from 2003 to 2011

Urban thermal environment have drawn a lot of attentions all around the world. The study focused on the dynamic changes of the urban thermal environment landscape patterns in Beijing. For this study, 40 MOD11A2 scenes recorded from 2003 to 2011 have been processed firstly. Then two new methods have been applied, Landscape centroid evolution and spatial autocorrelation. Using method of maximum difference normalization, the whole area of Beijing was divided into 5 parts: the Green Island, the Weak Heat Island, the Heat Island, the Strong Heat Island and the Serious Heat Island. On the one hand, this paper extracted the centroids of above 5 types of landscape and studied the evolution; on the other hand, using the spatial autocorrelation theory researched the relationships between the five kind thermal landscapes. In the end the paper drew several conclusions and inadequacies for the future study.

Analysis of Beijing's urban heat-island under the influence of extrme heat based on HJ-1B data

In recent years, urban heat island effect has become a hot international issue. In this study, referencing Jimenez-Munoz & Jose A. Sobrinos single-channel method, surface temperature inversion was conducted to HJ-1B satellite remote sensing image under extreme temperature events on July 6, 2010 in Beijing using thermal infrared band image provided by environmental mitigation satellite HJ-1B. We extracted and analyzed the area and distribution of urban heat island under the influence of extreme high temperature, and compared with those of temperature rating chart on July 9, 2009 in Beijing. These researches show that comparing with non-extreme high temperature, there is a reducing of the area of urban middle temperature zone under the extreme high temperature and increasing of that of hot zone. Thus, the total area of urban heat island increased. In addition, Landuse has a great influence of the urban heat island. When the temperature rises, the increasing margin of surface temperature in the plant developed is small and that in urban lands is large. We also get a conclusion that as temperature increasing, the distribution of urban heat island is a radiant extension from the city center to the outer suburbs.

Analysis and study of urban heat environment and respirable particulate matter in Beijing city

The phenomenon of temperature in urban cities is higher than that in suburbs is called Urban Heat Island (UHI), which is put forward by Lake Howard[1] in 1833. Three main algorithms of land surface temperature retrieval of existing thermal infrared remote sensed data has been developed: single channel algorithm, split window algorithm and multi-band algorithm. The thesis selected split window algorithm and improves the split window algorithm of AVHRR to suit MODIS image data. This split window algorithm is based on the thermal radiation data which is observed by NOAA-AVHRR. This paper retrieved land surface temperature and analysis the spatial characteristics of Beijing urban heat island as well as its influencing factors. The result indicates that analysis on urban heat island effect based on split window algorithm of Beijing is available. There is a clear urban heat island in summer, and it is quite close with vegetation index. Besides, the negative correlation relationship between land surface temperature and Respirable Particulate Matter is also emphasizely analyzed.

Research on Improving Spatial Resolution of RS Images Based on Quadtree Decomposition

Spatial resolution is an important index to evaluate the quality of remote sensing images. For the application of remote sensing satellite images, improving spatial resolution is significant. Super-resolution technology is one of the important ways to improve spatial resolution. According to the single visual light image, this paper discusses two super-resolution algorithms. One is mixed pixel quadtree decomposition algorithm based on weight analysis. The other one is mixed pixel quadtree decomposition algorithm based on edge detection. The experimental results indicate that: the algorithms can improve the spatial resolution of remote sensing images, and make the appearance of cultural feature clearer; important information beyond the limits of their spatial resolution from satellite images can be obtained.

Research on Current Situation Investigation by Remote Sensing and Division Protection Zone of Great Wall of Ming Dynasty in Beijing

By utilizing SPORT5 and aerial images, Great Wall of Ming Dynasty in Beijing has been investigated in detail and current distribution of Great Wall has been reported. In this paper, DEM is assisted to extract Great Wall information and the length of Great Wall has also been calculated. It studies the relationship between Great Wall and the surrounding land use, villages, roads, terrain by using GIS spatial analysis method. Finally, the influence weight of every relevant factor is calculated by AHP(Analytic Hierarchy Process) method and this thesis sets up buffer model and confirms the protection zone, all these has proposed scientific basis for the protection, management, and investigation of Great Wall in Beijing.