| The agro-pastoral ecotone is the most sensitive eco-environmental area in North China.It is also a typical region in which the eco-environment issues, such as soil erosion, desertification, and the grassland degeneration is prominent, which is attributed to the natural conditions and human activities.Using the method of principal component analysis, the main affecting factors are analyzed.The results indicate that the natural ecological pressure and water use efficiency factor, resources and human activities pressure, agricultural production and water resources pressure factor play important roles in eco-environmental evolution in this area.The linear regression analysis simulation indicates that the score of eco-environment quality takes on the degradation trends in Yuyang, Shenmu, Hengshan and Fugu from 1994 to 2005.On the contrary, the score of ecoenvironment has increased in 0.09/a and 0.08/a in Jingbian and Dingbian.The results of spatial changing of eco-environment indicate that Yuyang gets 1.32, which belongs to potential.Meanwhile, Jingbian and Hengshan get 0.61 and 0.43, belonging to light vulnerability area;Shenmu gets 0.26, belonging to medial vulnerability area;Fugu and Dingbian get-1.41 and-1.01, belonging to extreme vulnerability area. |