典型山原过渡区建设用地扩张过程研究——以龙门山地区为例

Evolution process of constructed land in the typical mountain-plain transition zones:A case study of Longmen mountain.

龙门山地区属青藏高原东缘典型的山原过渡区,人地耦合作用的地貌梯度分异显著,研究建设用地扩张过程及驱动力可为生态地质环境保护提供参考。基于五期建设用地数据,获取建设用地扩张信息,应用灰色关联度分析法分析其扩张驱动力。研究表明:建设用地面积近20 a呈持续增长态势,增速具有“提速→减速→快速”波动变化的特征,扩张面积地域差异显著,东部区扩张面积是西部区的近6倍;地质构造制约建设用地的空间扩张,距中央断裂带8 km范围内,新增建设用地核密度呈减少态势;建设用地空间扩张模式以边缘式扩张为主,跳跃式和填充式扩张为辅;地形地貌和人类活动是影响东部区建设用地扩张的主要因素,地质构造和河流水文是影响西部区建设用地扩张的主要因素。未来建设用地扩张应关注地质环境影响,规避地震和地质灾害等风险。

The Longmen mountain is located in the typical mountain-plain transition zones on the eastern margin of the Qinghai-Tibet Plateau,where the human-environment interaction has significant geomorphological gradient differentiation.To address this issue,the purpose of this study focuses on the expansion process and driving forces of constructed land expansion so as to support ecological and geological protection.The information of constructed land expansion was obtained by analyzing the spatial distribution data of constructed land in five periods,while the driving forces were revealed by using the grey correlation analysis.The results show that the constructed land had continued to grow in the past 20 years,despite that the growth rate fluctuated from“speed up”to“slow down”and then“fast”.The expansion of the eastern region was nearly six times that of the western region,yet geological structure restricted its expansion.The core density of new constructed land decreased continuously within 8 km from the central fault zone and the spatial expansion mode was mainly marginal expansion,supplemented by jumping and filling modes.The main driving factors for the expansion in the eastern region are topography and human activities,while geological structure and river hydrology are driving forces in the western region.To avoid the risk of earthquake and geological disaster,it is suggested to further understand the influence of geological environment on the expansion of constructed land.