河西绿洲边缘积沙带与环境因子的关系

绿洲边缘积沙带的形成是一个新的科学问题。甘肃河西地区经过半个多世纪的防沙治沙,在绿洲边缘形成了一条积沙带。为了研究积沙带的形成及其与环境因子的关系,本文对河西走廊东端至走廊中西部绿洲边缘的积沙带进行了调查。结果表明:1)河西走廊东端至中西部绿洲边缘积沙带平均高12.77m,平均带宽308.48m。2)积沙带的宽度与高度呈显著正相关;积沙带的高度与当地的年降水量和年平均风速呈显著正相关;积沙带的增高速率与当地年降水量和年平均风速呈正相关。3)降水条件是决定积沙带高度的关键因子,其次是年平均风速。4)在高大沙丘顶部设置柴草沙障,能促使积沙带(沙丘)继续增高。

Relationships between sand-accumulation belt and environmental factors along oasis edge of Hexi, Gansu Province of Northwest China

The formation of sand-accumulation belt along oasis edge is a new scientific concern.In Hexi of Gansu,a sand-accumulation belt has been formed along oasis edge for almost 50 years as a result of desert control efforts.To understand the relationships between the formation of this belt and environmental factors,an investigation was conducted along the oasis edge from the east to the middle and west of Hexi corridor.The average height of the sand-accumulation belt is 12.77 m,and the average width is 308.48 m.There exists a significant positive correlation between the belt width and height,and the belt height and its increasing rate are significantly positively correlated with the mean annual precipitation and wind speed.Precipitation is the key factor deciding the belt height,while the mean annual wind speed is the secondary one.To set up a wheat straw sand barrier at the top of big sand dunes could continuously heighten the sand-accumulation belt.