Clarification on the relationships between soil and land surface conditions and threshold wind speeds for aeolian dust generation aimed at the evaluation of wide-area wind erosion

我们调查了2000年以来东亚地区频繁发生沙尘事件的原因。我们开发了一种利用气象台数据统计估计起尘阈值风速的方法，并将该阈值风速作为土壤和地表条件的指标。通过对沙尘发生频率、大风频率和阈值风速的分析，明确了内蒙古、内蒙古东部和中国东北地区沙尘事件增加的主要原因是沙漠化（即阈值速度降低）。

We investigated the cause of frequent dust events in East Asia since 2000. We developed a methodology to statistically estimate a threshold wind speed for dust generation using meteorological observatory data, and we employed this threshold speed as an index of soil and land surface conditions. We clarified that a major cause of increased dust events is a desertification (i.e., a decrease of threshold speed) in Mongolia, eastern Inner Mongolian and the northeastern China from an analysis of dust generation frequeny, strong wind frequency, and threshold speed.