科尔沁沙地奈曼旗近5年来风况及合成输沙势

应用奈曼沙漠化研究站1998-2002年的气象资料, 统计分析了奈曼旗近5a来的风况特征和输沙势。结果表明: ①研究区3~5月起沙风发生频数最高, 占全年起沙风的38%~58%; 平均风速和最大风速值最大, 分别为6.0~7.5m·s^-1和9.5~16.9m·s^-1。该风况特征与地表冻融、裸露、干旱疏松相耦合, 形成了区内的风沙活动期。②在风沙活动期内, 风环境基本为锐双峰风况, 西北风居主导地位, 频数占54%; 南风和西南风次之, 频数占38%。③在风沙活动期内, 研究区属于高风能环境, 合成输沙势RDP为66.3VU(风速以m·s^-1为单位), 合成输沙方向RDD为ESE113°。

Wind Regime and Resultant Sand-transporting Potential of Naiman Banner in Horqin Sandy Land during Past Five Years

In this study a statistical analysis on the wind regime of Naiman banner in Horqin sandy land in past five years was made, meantime the resultant sand-transporting potential in the study area was explored. The results showed that:(1)The threshold wind of transporting sand in the study area between March to May were most frequent, with an accumulated frequency of 38%~58%. Mean and maximum wind velocities were 6.0~7.5 m·s^-1 and 9.5~16.9 m·s^-1 respectively. Such wind regime features, coupling with surface thawing, barren, drought and loose structure in the same period, initiated a phase of wind-sand activity.(2)During the phase of wind-sand activity the wind environment in the area roughly exhibited a bimodal wind regime, the northwest wind held a leading place, with a frequency of 54%; followed by south wind and southwest wind, with a frequency of 38%.(3)While throughout the phase of wind-sand activity resultant sand-transporting potential(RDP) was 66.7 VU(m·s^-1 is the unit of wind speed), resultant sand-transporting direction(RDD) was 113°ESE, this shows that the study area belongs to a high wind energy environment, sand activity is dominated by wind erosion and sand is transported southeastward.