重庆主城区建设用地爬坡特征及其圈层性

Slope distribution change and multi-ring pattern of construction land in Chongqing,China

坡地建设现象在中国的山地丘陵城市正日益增多,并且逐渐突破了一些早期形成的关于建设用地与坡度关系的认知。以重庆市主城区为研究区域,以2000~2020年为研究时段,以30m分辨率建设用地解译产品和数字高程模型为数据源,借助坡谱分析方法整体认知建设用地在坡度梯度上的分布与演变特征,运用圈层分析方法细化解析建设用地爬坡现象的水平圈层时空格局。研究发现:研究区建设用地整体呈现持续爬坡态势,建设用地上限坡度“违规”现象日益增多,现有相关规范的用地坡度上限规定正在丧失约束力;研究区建设用地一直保持着“内陡外缓”水平圈层格局,坡地建设的充填效应促进了城市建设用地的节约集约利用。建议修改国家行业标准《城乡建设用地竖向规划规范》,将城镇建设用地坡度上限从14°上调至20°附近,将城镇中心区用地选择的特殊坡度规定去除,同时各地也可根据自身实际出台更为严格的地方性规定。

The phenomenon of slope construction is increasing in mountainous and hilly cities in China,and it gradually breaks through some early understanding of the relationship between construction land and surface slope,but detailed studies on this phenomenon are rare.This paper studied the slope gradient characteristics and the horizontal multi-ring spatial-temporal pattern of construction land in the main urban area of Chongqing using multi-temporal construction land data from 2000 to 2020 and Digital Elevation Model(DEM)data integrated with methods of slope spectrum analysis and ring sector statistical analysis.The results show that:the overall situation of construction land in the study area is continuous climbing,the phenomenon of"violation"of the upper slope of construction land is increasing day by day,and the existing regulations on the upper slope of construction land are losing its binding force;the horizontal circle pattern of"steep inside and slow outside"has been maintained in the study area,and the filling effect of slope construction promotes the economical and intensive use of urban construction land.We propose to revise the Code for Vertical Planning of Urban and Rural Construction Land,raise the upper limit of slope of urban construction land from 14°to 20°,and remove the special slope of land selection in the central area of cities and towns,At the same time,local governments should also issue more stringent local regulations according to their own reality.