sand gradation

• 砂粒级配

sand gradation的用法和样例：

例句

1. Western Kunlun area locates in the area of eolian sand accumulation in China, and the granularity of eolian sand is smaller than that of the other areas.
   摘要西昆仑地区地处中国风成沙的沉降区，与其它区相比较，风成沙粒级偏细。