Huang Shifeng

Monitoring seasonal changes in the water surface areas of Poyang Lake using Cosmo-Skymed time series data in PR China

Poyang Lake, the largest freshwater lake in China, is well known for its ecological importance as a wetland system.. Understanding dynamics change in wetlands may benefit from a joint variation analysis in changes of size, shape, position and extent of water bodies. In this study, we used Cosmo-Skymed ScanSAR mode (HH) data for one-year monitoring of seasonal changes in the water surface areas of Poyang Lake from January 2014 to December 2014. To delinate water surface area, a histogram analysis with a global threshold classification was performed, and the results were validated using Landsat8 OLI data. The results showed: Poyang Lake water body area showed a significant seasonal variation, minimum value was about 690 km2 and maximum value reached 3500 km2. A unique spatial pattern occurred during those months that a dramatic flooding or recession happened. The Cosmo-Skymed time series could capture temporal changes in the water body spatial distribution. Comparison of the resultant classification of Cosmo-Skymed and Landsat8 OLI yielded 95% of mapping accuracy and 87% of puduct accuracy. This demonstrates the X-band Synthetic Aperture Radar is applicable to detect the wetland inundation area and there is a great potential of Cosmo-Skymed constellation for water bodies monitoring, regarding relative great revisit frequency and high resolution.

A Model of Flood and Waterlogging Disaster Loss Assessment Based on The Remote Sensing and GIS Spatial Information Grid

Flood and waterlogging disaster is very serious in china. an applicable, reliable and useful model of flood disaster loss assessment is imperative in the task of flood prevention, wrecking and disaster relief. Flood disaster loss assessment is processed by establishing GIS spatial information grid model. Social-economic and flood character parameters obtained from GIS spatial information grid are introduced, and a calculation formula of flood disaster loss rate is given in this paper. Flood disaster loss assessment and analysis of storing flood water effect is processed in Menwa Storing Floodwater Area on basis of flood remote sensing monitoring in 2003’s Huaihe river flood. The result indicate that the model of flood disaster loss assessment based on spatial information grid is feasible and applicable, and Menwa Storing Floodwater Area has brought into an important play in the task of 2003’s Huaihe river flood prevention.