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

Abstract

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.