Ecological vulnerability zoning research is an important basis for taking targeted regional ecological environment restoration and governance measures. This study analyzes the ecological vulnerability pattern and trend in the National Energy and Chemical Base (NECB) in the typical region of the Loess Plateau using GIS (Geographic Information System) data and the fuzzy analytic hierarchy process (FAHP) approach. Based on the human activity-natural environment factor index system, 13 factors representing human activities, socioeconomics, meteorology, soil and topography are selected to build an ecological vulnerability index (EVI) system in the NECB region, which aims at identifying the regional features of eco-environment and major environmental problems in the Loess Plateau. By calculating ecological vulnerability zoning, a model of ecological vulnerability trend change is constructed to quantitatively study the overall temporal and spatial variation of ecological vulnerability. The results indicate that the medium and heavy levels of ecological vulnerability index were mostly distributed in the areas with developed energy and chemical industries, and the slight and light levels were distributed in the southern area and developed agricultural regions. A comprehensive ecological vulnerability index had a score of 2.3207 in 2015 and 2.441 in 2000, indicating that the ecological security gradually improved. Nevertheless, highly intense human activities accelerated the degradation of regional eco-environment in recent years.
Keywords: NECB; ecological vulnerability index (CEVI); fuzzy analytic hierarchy process (FAHP); geographic information system (GIS).