Ecological Vulnerability Assessment Integrating the Spatial Analysis Technology with Algorithms: A Case of the Wood-Grass Ecotone of Northeast China

and Applied Analysis 3 TM images MODIS Meteorogical data Other dataset Landuse NDVI Precipitation Temperature Wind DEM Soil Dataset of study area Soil erosion sensitivity Soil desertification sensitivity Landscape unit plaques density Landscape evenness index Land utilization degree composite index Ecological suitability index Land resources utilization degree index Ecological vulnerability in 1990 Ecological vulnerability in 2005 Ecological vulnerability assessment Standard deviational ellipse The spatio-temporal variation of ecological vulnerability Analytical hierarchy process Landscape pattern index Figure 2: The workflow of ecological vulnerability assessment. factors that directly relate with contemporary status and potential problems in the study area. 3.3. Index Calculation and Standardization 3.3.1. Ecological Suitability Index. Ecological suitability is determined by ecological sensitive degree of ecosystem. Sensitivity analysis is to distinguish the area which it is easily deteriorated by exotic environment. Sensitivity analysis is comprised of soil erosion sensitivity and soil desertification sensitivity on the basis of contemporary status and potential problems in the study area. Soil erosion sensitivity is determined by precipitation, DEM, soil, and LUCC. Soil desertification sensitivity is evaluated by average precipitation, annual accumulated temperature (≥0C), windy days in winter and spring (>6m/s), and NDVI. (a) Soil Erosion Sensitivity. In the paper, we use the Wischmeier empirical formula to calculate the rainfall erosivity (R) [17]: