An Investigation Into the Feasibility of Using Passive Microwave Remote Sensing to Monitor Freeze/Thaw Erosion in China

摘要

Freeze/thaw erosion is the third largest soil erosion type, after water erosion and wind erosion and is a serious threat to agricultural land and various structures, especially those used in water projects. In this paper, an investigation into the feasibility of using passive microwave remote sensing to monitor freeze/thaw erosion area and intensity in China is presented. At the core of the method are two important indices: average annual cumulative frozen days and average daily normalized phase change water. The relationships between the first index and erosion area and between the second index and erosion intensity were explored. The results show that the index of average annual cumulative frozen days can distinguish freeze/thaw erosion areas from nonfreeze/thaw erosion areas if an appropriate threshold is selected and that the index of average daily normalized phase change water is correlated with the freeze/thaw erosion intensity, which can be described using a logarithmic function. Finally, the freeze/thaw erosion area and intensity obtained from passive microwave remote sensing were compared with a grading thematic map of freeze/thaw erosion obtained in the First National Census for Water sponsored by the Ministry of Water Resources of China. The results agree with the grading thematic map of the freeze/thaw erosion intensity in China. The results also demonstrate that passive microwave remote sensing has the potential to monitor freeze/thaw erosion, and it is feasible to use the two indices to determine freeze/thaw erosion area and intensity.