Yanfang Dong

Coupling analysis of China’s urbanization and carbon emissions: example from Hubei Province

Urbanization is a process of human production and lifestyle reform as the social productive forces reach a certain level. There is a very tight coupling relationship between urbanization and energy consumption as well as carbon emissions, e.g., mutual promotion or mutual restraint. Taking Hubei Province as an example, comparative analyses between urbanization and energy consumption as well as carbon emissions are conducted based on the data from 1990 to 2012; they can be observed roughly that the overall trend is basically consistent; and in recent years, after 2000, they all show rapid growth, indicating the strong correlation. In addition, the Logarithmic Mean Divisia Index (LMDI) method is applied to decompose the change in carbon emissions into some influencing factors caused by urbanization. The decomposition results show that economic development has the greatest positive effect on carbon emissions, and energy intensity contributes largely to carbon emission reduction; the contribution of energy mix and gross population is not absolute and obvious due to the small change during the period of 1990–2012. To harmonize the development of urbanization with low carbon emissions, the energy development pattern and carbon dioxide (CO2) capture, utilization, and storage (CCUS) strategy are proposed for Hubei Province. In the short term, new energy and renewable energy should be explored and developed, such as nuclear power and biomass, whereas for long-term interests, the development of CCUS will be a significant choice in the process of urbanization and industrialization.

PS-InSAR monitoring and finite element simulation of geomechanical and hydrogeological responses in sedimentary formations

With the first use of the corner reflector based permanent scatterer interferometric synthetic aperture radar (CR-PS-InSAR) technology, the earths surface deformation, strongly associated with subsurface flow, of Horonobe underground research laboratory (URL) is successfully monitored during its construction. The temporal and spatial characteristics of interferometric signatures collected from CR point targets are exploited to accurately map surface deformation histories and terrain heights of the URL site, especially around the monitoring boreholes. By developing a hydromechanical poroelastic model, satellite monitoring is linked to characterization of deep groundwater flow. The geomechanical and hydrogeological responses of sedimentary formations to the drilling of the shaft was modeled using a two-dimensional finite element model. A good correlation between measured and modeled responses indicated that both the boundary conditions and rock properties are well understood by the proposed coupled inversion methodology.

Disaster mapping from medium spatial resolution alos palsar images

All-day and all-weather Synthetic Aperture Radar (SAR) can measure both intensity and phase of the reflected signal. The backscattering coefficients measured by SAR reflect the backscatter characteristics of surface targets. Changes happened to a targets surface roughness, geometric and structural characteristics will result in the change of its backscattering intensity recorded in SAR image. The 2008 Wenchuan earthquake, China have caused widely distributed geological disasters, such as landslides, mudfloods and barrier lakes, which resulted in the difference between pre- and post-earthquake SAR images. Comparison between the pre- and post-earthquake SAR intensity images will reveal the damage information. In this study, PALSAR Level 1.0 data acquired for the Wenchuan earthquake were used to analyze the geological disasters. Results show that medium spatial resolution SAR data, such as 10 m resolution ALOS PALSAR data, especially when both pre- and post-earthquake images are available, are useful in revealing the distribution of landslides and barrier lakes.

Cloud detection based on decision tree over Tibetan Plateau with MODIS data

Snow cover area is a very critical parameter for hydrologic cycle of the Earth. Furthermore, it will be a key factor for the effect of the climate change. An unbelievable situation in mapping snow cover is the existence of clouds. Clouds can easily be found in any image from satellite, because clouds are bright and white in the visible wavelengths. But it is not the case when there is snow or ice in the background. It is similar spectral appearance of snow and clouds. Many cloud decision methods are built on decision trees. The decision trees were designed based on empirical studies and simulations. In this paper a classification trees were used to build the decision tree. And then with a great deal repeating scenes coming from the same area the cloud pixel can be replaced by “its” real surface types, such as snow pixel or vegetation or water. The effect of the cloud can be distinguished in the short wave infrared. The results show that most cloud coverage being removed. A validation was carried out for all subsequent steps. It led to the removal of all remaining cloud cover. The results show that the decision tree method performed satisfied.

Damage assessment of Haiti earthquake emergency using high resolution remote sensing imagery

This paper introduces the procedure of emergency remote sensing assessment for Haiti earthquake happened on Jan 12 2010. The procedure is divided into 4 steps: data preparation, data processing, information extraction and damage assessment, and contains three key targets which are damage information extraction, quantitative assessment and estimation of casualties and economic losses. In the first stage, the damage information of the buildings is the basis, and the other information, including building type, damage grade, built-over area, would be extracted by visual interpretation and automatically statistic with human-computer interaction from the high resolution disaster imageries. Then the remote sensing damage index and equivalent ground damage index of building could be counted in the second stage. According to this result, the specialists sketch a more exact intensity distribution in different regions of the metropolis. At last, the number of casualties is estimated by an empirical model adapting to worldwide earthquake as the detailed construction damage has been known. To assess the economic losses, we use a macro economic-based model which only needs population, per capita GDP and statistical macro-economic fragility related to seismic intensity. In this case, it is the first time to implement the methods of remote sensing assessment in foreign serious earthquake emergency, which is proven of being applicable outside China.

Theoretical Study for Bare Soil Freeze/Thaw Process Detection Using GNSS-R/MR

GNSS-R remote sensing has emerged as a new promising remote sensing technique in the past two decades. It has gained wide attention at home and abroad. In essential, GNSS-R is a bistatic radar, the signals got by the GNSS-R receiver is delay Doppler map. Different from the specially designed receivers, the geodetic quality GPS receiver can be used to remotely sense the near surface soil moisture, vegetation growth and snow depth, i.e. GNSS-Multipath reflectometry (GNSS-MR). Three metrics, i.e. effective reflector height, phase and amplitude, are employed for retrieval. As for the applications of space-borne/air-borne GNSS-R or ground based GNSS-IR techniques, they include soil moisture, vegetation growth and snow depth retrieval. This paper has extended the bare soil freeze/thaw process detection, the theoretical fundamentals is that when the soil frozen/thawn process occurs, there is a big difference for the soil permittivity, which will result in the difference of reflectivities. The dielectric mixing models are employed for the calculations of the frozen/thawn soil permittivities, which are the inputs for the reflectivity models, the coherent scattering model and the random surface scattering models are employed for the calculation of specular scattering reflectivities and the diffuse scattering reflectivities, respectively. When the soil freeze/thaw process has occurred, the corresponding GPS multipath changes and the variations of delay Doppler map are simulated. The theoretical simulations indicate that the big difference of permittivity will result in the apparent changes of GPS multipath observables and delay Doppler map. It has been demonstrated in theory that the bare soil freeze/thaw process can be detected by the GNSS-R or GNSS-MR techniques.

Initial results for near surface soil freeze-thaw process detection using GPS-Interferometric Reflectometry

The geodetic-quality GPS receivers can be used for geophysical parameters retrieval, i.e. soil moisture, vegetation growth and snow depth, and it is called GPS-Interferometric Reflectometry (GPS-IR) remote sensing. In this paper, to detect the near surface soil freeze-thaw process using GPS-IR is evaluated for the first time. When the soil changes from frozen state to thawn state, the corresponding permittivities and reflectivities at RR, LR, VR and HR pol are changed. Triple-frequency effects are evaluated, for different frequencies, the modulations for SNR data are not the same, but within L-band, the observed surface has almost the same reflected properties (e.g. GPS L1 band, L2band and L5band). A GPS site in the EarthScope Plate Boundary Observatory (PBO) and a corresponding soil climate site in SCAN (Soil Climate Analysis Network) is used to examine the potential for near surface soil freeze-thaw process detection. Two representative days and a time series of SNR data show strong correlation with near surface soil temperature. Our initial results demonstrate that GPS-IR has the potential for bare soil freeze-thaw detection. Therefore, the new low-cost bare soil freeze-thaw monitoring networks are expected from geodetic GNSS network.

Thermal infrared variation associated with strong earthquakes in Xinjiang using satellite data

NOAA outgoing longwave radiation (OLR) data associated with five earthquakes (M > 6.0) in the Xinjiang area of China between 2008 and 2014 were analyzed in this research. The results of spatio-temporal analysis demonstrated that three events showed significant thermal anomalies. The focal mechanisms of three cases were of the thrust type (Wuqia M6.7 earthquake on 5 October, 2008) and of the strike-slip type (Yutian M7.3 earthquake on 12 February, 2014 and the Xinyuan-hejing M6.6 earthquake on 29 June, 2012). The focal mechanisms of the other two cases were the normal fault type. In particular, OLR anomalies associated with the Wuqia earthquake, a thrust type event, were more obvious, and it was consistent with the inverse fault mainly affected by extrusion pressure, which was beneficial to the formation of a thermal precursor. This result was consistent with the experimental results of rock mechanics. In addition, OLR anomalies related to the three cases were all found on the boundary of the Tarim active block, which indicated that stress was more easily accumulated on solid block boundaries.

Detecting seismic IR anomalies in bi-angular advanced along-track scanning radiometer data

The paper has developed and proposed a synthesis analysis method based on the Robust Satellite data analysis Technique (RST) to detect seismic anomalies within the bi-angular Advanced Along-Track Scanning Radiometer (AATSR) gridded brightness temperature (BT) data based on spatial/temporal continuity analysis. The proposed methods has been applied to analyze Yushu(Qinghai, China) earthquake which occurred on 14th April 2010 and the Wenchuan earthquake occurred on 12th May 2008, and a full AATSR data-set has been analyzed. Combining with the tectonic explanation of spatial and temporal continuity of the abnormal phenomena, the analyzed results indicate that: the infrared radiation anomalies detected by the AATSR BT data with nadir view appear and enhance gradually along with the development and occurring of the earthquake, especially along the Ganzi - Yushu fault, Nu River fault and Jiali - Chayu fault; more infrared anomalies along the earthquake fault zone (Lancangjiang fault and Ning Karma Monastery-Deqin fault) are detected using the proposed synthesis analysis method, and the main structure activity (the Yingxiu-Beichuan fault) characteristics of the Wenchuan earthquake can be identified and extracted using the bi-angular AATSR nadir and forward brightness temperature data.

Research on fault information extraction with Landsat TM images in Three Georges area

Landsat TM data of six multispectral bands were used to extract the fault information in the southwest region of Zigui basin which is near the Three Gorges bam, located at the eastern section of Daba Mountain tectonic belt. The techniques consist of spectral enhancement and spatial enhancement. Band ratioing methods, Principal component analysis(PCA), decorrelation stretching were applied in this paper. In the end, these methods would be compared and evaluated. The results showed that the fault information extraction method with Landsat TM data performed satisfied.