To study the impacts of pipeline construction on eco-environment in the middle-low mountainous area

the quantitative prediction is made for the changes of landuse

agricultural production

the area and biomass of vegetation

soil erosion

and ecological system integrity in the Daba Mountains by the Sichuan-Shaanxi natural gas pipeline construction.An analysis of possible influences made to the eco-environment of the middle-low mountainous area by the pipeline construction is then presented.Results show that the construction can change the structure of regional landuse

which can in turn influence local agricultural production

reduce the area and biomass of vegetation

and increase soil erosion.Nevertheless

the influences are temporary and can be alleviated

as they mainly concentrated in the construction period.The environmental effects of the project will not essentially alter the original eco-integrity of the middle-low mountainous area.Therefore

the ecological system remains its complete structure and consistent operating process.