空间治理视角下的城市建成区土地混合利用功能与结构

A study on the function and structure of mixed land use in urban built-up areas from the perspective of spatial governance

城市建成区土地混合利用对促进城市用地集约利用、提升国土空间治理水平具有重要意义。以福州市七个区县为研究区,利用多源数据提取福州建成区范围;在街区尺度下,基于POI数据与自然语言处理技术(BERT模型),构建一种顾及城市混合功能语义的混合模式提取方法(MixedFunc2Vec),并从土地利用混合功能与结构两大维度开展城市建成区土地混合利用研究。结果表明:(1)MixedFunc2Vec方法解决了传统城市功能语义提取中存在的“一词多义”问题,能够捕捉更加丰富的POI语义信息,并提取得到六大类混合功能模式;(2)福州市建成区内,模式6(居住+公管公服+绿地)内部的土地利用结构多样性最为丰富,而以各类产业为主导的模式5则处于最低的多样性水平,建成区内呈现多地多中心集聚式发展态势;(3)在结构兼容性方面,建成区内兼容性指数达到0.7以上的街区约有1803个,模式1(居住+商服)与模式6(居住+公管公服+绿地)的平均兼容性指数均为0.8525,除此之外,以产业功能为主导的区域及其周边区域,其混合兼容性水平仍有提升空间;(4)综合结构多样性与兼容性的测度结果,福州市建成区内各街区可划分得到“高—高”街区“、高—低”街区“、低—高”街区与“低—低”街区等四类街区,并提出了基于不同混合功能模式的空间差异化街区调整建议。本文可为丰富现有土地混合利用理论与方法体系、城市空间格局优化及国土空间规划政策制定提供一定科学依据。

Mixed land use in urban built-up areas is important for promoting intensive use of urban land and improving the level of land spatial governance.This paper takes seven districts and counties in Fuzhou as the study area and uses multi-source data to extract the built-up area of this city.Based on POI data and natural language processing technology(BERT model),a mixed pattern extraction method(MixedFunc2Vec) that takes into account the semantics of urban mixed functions is constructed at the block scale,and the study of mixed land use in urban built-up areas is carried out from two dimensions of mixed functions and structures of land use.The results show that:(1) MixedFunc2Vec method solves the problem of "multiple meanings of words" in traditional city function semantic extraction,captures richer semantic information of POI,and extracts six types of mixed function patterns.(2) In the built-up area of Fuzhou,mode 6(residential + public services + green space) has the richest land use structural diversity,while mode 5,which is dominated by various industries,is at the lowest diversity level and shows a cluster development trend of multi-location and multi-center.(3) In terms of structural compatibility,there are about 1803 blocks in the built-up area with a compatibility index of 0.7 or more.The average compatibility index of mode 1(residential + commercial services) and mode 6(residential + public services + green space) are both 0.8525,except for the industrial function-oriented areas and their surrounding areas,which still have room for improvement.(4) Based on the measurement results of structural diversity and compatibility,the blocks in the built-up area of Fuzhou can be divided into four types,including high-high,high-low,low-high,and low-low patterns,and suggestions are made to adjust the blocks based on different mixed functional patterns.This study can provide some scientific basis for enriching the existing theoretical and methodological system of mixed land use,urban spatial pattern optimization and territorial spatial planning policy formulation.