沙尘暴过程中气象要素响应及输沙分析

通过野外监测系统获取的试验数据，对拐子湖地区2011年4月份一次强沙尘暴过程中贴地层微气象要素和输沙进行分析，得出如下结论：大气高温干燥，地表高温低湿、气压下降，风速增大是沙尘暴来临的前兆；沙尘暴过程中风向和风速相对稳定，气压、水汽压和相对湿度都会明显下降；地温下降速度较慢，土壤湿度略有上升；输沙量主要集中于距地表50cm以内高度层，在0-20cm高度层里输沙量呈增大趋势，20cm以上随着高度升高含沙量逐渐下降；跃移沙粒输沙量的空间分布与风向频率既有相似性，又有差异性；蠕移输沙量的方向分布比较复杂，同风向分布有显著的差异。这些结果对沙尘暴预报和沙源区的防风治沙有指导意义。

Analysis of Meteorological Elements Response and Sand Transport in the Process of Sand-dust Storms

Based on the field monitor data, the meteorological elements response and sand transport in the process of sand-dust storms at the Guaizi Lake area in April 2011 were analyzed. The following conclusions showed that hot and dry atmosphere, high surface temperature and low humidity, pressure drop and wind speed increase were the precursor to the coming of sand-dust storm. During the period of sandstorm, the pressure, the vapor pressure and relative humidity decrease apparently, with slow decline rate of ground temperature and slight increase of soil moisture. Sand transport mainly concentrated within the height of 50cm from the ground, in the 0-20cm layer sand transport tended to increase, and decreased with increasing height above 20cm. Spatial distribution of sand transport frequency of saltating sand particles was similar to the wind direction. Direction distribution of creeping sand transport was more complex, significantly different from wind direction. The results were instructive to forecasts of sand-dust storms and resistance to wind-sands.