Abstract: 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.

Key words: Dongxiang wild rice, low nitrogen tolerance, principal component analysis, comprehensive evaluation, index screening.