Spatial Fuzzy Assessment of Ecological Suitability for Urban Land Use Based on Local Penalty Variable Weights——A Case Study of Yan'an Baota District

The ecological suitability evaluation is of help to optimize the space layout of construction land.In view of the ambiguity of ecological suitability and the insufficiency of variable weights,the local penalty variable weight is adopted to improve the spatial fuzzy assessment.The reasonable punishment highlights the restrictive effect of bottleneck factors on the evaluation results, reflecting the ecological suitability status as well.The results show that the assessment results are in accord with the actual situation when the adjustment weight level is 0.25 and the punishment level is 0.8418. In Yan'an Baota District the height, medium and low suitable areas are 4.63%, 20.71%, 47.28% respectively, and the unsuitable area is 27.38%. 90.26% of the construction land is in the high, moderate suitable area. The grade of ecological suitability in different regions is affected by different leading restrictive indexes. The factors such as topography, distance from ecological protection area, distance from water bank are widespread. Disaster density affects the urban areas; the distance affects remote areas. Soil quality, beneficial elements in soil, and the land resistance have limited effect. In order to optimize the layout of land in Baota district, it is suggested in this paper to strengthen the prevention and monitoring of geological disasters in urban areas of this district,to standardize the examination and approval of urban construction land, and to promote the renovation of remote rural settlement.