The western pipeline of PetroChina has

at present

the longest transportation distance among the petroleum pipelines in China. Because the pipeline was paved mechanically

original landform

top soil and vegetation were destroyed

which reduced soil anti-erodibility and caused soil and water loss.The natural sit-uation was firstly summarized and then

soil and water loss and its impacts on ecological environment were analyzed for the pipeline in Gansu Province.The "three synchronous steps" principle must be insisted on.In addition

the measures should be taken according to the following policies

such as the combination of com-prehensive control with comprehensive exploitation

scientific allocation of control measures

and prevention of soil erosion newly occurred