Microwave Remote Sensing disaster discrimination greatly improved the reliability of frozen (Figure)

 Recent years, the frequency of extreme weather, increasing social and economic development of China poses a serious threat. Following the South in 2008 after suffering a wide range of snow late last year until early this year, the South part of the provinces and one after another freezing weather, the temperature remains below freezing point, resulting in crop victims, traffic congestion, power and other facilities under threat, huge economic losses.


said frozen region shown in blue, yellow alternating freezing and thawing occurred in the area (usually for the night freezing, melting at noon), red means no freezing occurred. In addition, the need to explain that, in Inner Mongolia, Xinjiang, high-latitude regions of the red area is mainly desert, due to less water, even at low temperature, freezing does not occur; the data acquisition reasons, the figure the white areas and land and sea border the blue area should be considered invalid region identification.

the National Natural Science Foundation of
continued funding, Beijing Normal / Remote Sensing of the Chinese Academy of Sciences State Key Laboratory of Remote Sensing Science Zhang Lixin research group carried out a lot of basic research, on the frozen surface characteristics of microwave radiation have a more in-depth understanding of On this basis, the formation of a judge to freeze the surface of passive microwave remote sensing algorithms, and after a preliminary test showed high reliability of identification.

Zhang Lixin pointed out that the performance of freezing weather in the main ground surface soil freezing, freezing rain, freezing plants wilt or death; this phenomenon occurs in southern China of large-scale climate context of large rare the event is highly dynamic, complex spatial distribution, the ground can not reflect the whole picture of the observation site; and passive microwave remote sensing of soil moisture as a sensitive, high time resolution, less affected by the characteristics of atmospheric conditions, is very suitable for monitoring of the water phase to the core surface freezing process.

Therefore, after the ice storms in the south, Lixin AQUA satellite research group at once by the United States carry the Advanced Microwave Scanning Radiometer (AMSR / E) data, produced thematic maps of the distribution of freeze-thaw areas, on the frozen disasters area were monitored. However, limited by the data source (data lag 4 to 5 days), they only do the current monitoring results on Jan. 6 (January 6, 2011 as shown on the monitoring results.) Monitoring results indicate that: most of southern provinces of China suffered frozen disasters, long duration, the expected loss is huge. The results of the analysis and disaster relief decisions have important reference value. Zhang Lixin, said: I hope that the monitoring results of their provinces in the southern part of the frost damage assessment help, he wants to have the opportunity to get the first satellite data in order to achieve timely monitoring of disaster.