According to different regions and ecological conditions, the sandhazard along the railway was divided into four types and nine grades.
因不同地带生态条件不同，引起铁路沙害可划分为四类九级。
2
Ths differences of the type and extent of blown sandhazard between the east and west sides of the desert highway as well as different geomorphic sections are evident.
注意到防沙体系所受风沙危害类型和程度在公路东西两侧和不同地貌部位差异明显。
3
Man made reservoirs and sand excavation in some rivers reduce silt discharge into sea, these human activities are vital factors that cause coast erosion hazard in Qinhuangdao region recently.