Land Use Change And Simulation In The Pearl River Delta Urban Agglomeration Based On Multi-source Data

Land is an important resource for human survival and development.However,with the rapid development of industrialization and urbanization,problems such as extensive land use and ecological damage have arisen,leading to intense conflicts between humans and the land,and constraining the high-quality development of China’s territorial space.This contradiction is particularly prominent in China’s urban agglomerations,which are important spatial units that play a huge role in driving national economic development and improving comprehensive competitiveness.Therefore,how to optimize the spatial pattern of land use in urban agglomerations and achieve rational allocation of land resources has become a major practical issue for China’s economic and social development.Scientifically and accurately predicting the trend of land use changes in urban agglomerations is of great significance for promoting their sustainable and healthy development.The Pearl River Delta(PRD)urban agglomeration is the pioneer region of reform and opening up and the growth pole of economic development in China.In this study,we innovatively use billion-level mobile phone signaling data,combined with longterm land use data from 1990 to 2020 and multi-source data covering the entire PRD urban agglomeration,such as points of interest(POI).In addition,it employs various methods such as spatial statistics,land use transfer matrix,land use dynamic degree and landscape index to analyze the structural and quantitative changes in land use patterns,land use conversion,change rate,and landscape pattern changes in the PRD urban agglomeration over the past 30 years.Based on the Markov model and PLUS model,we simulate the land use pattern in the PRD urban agglomeration in 2020,explore the relationship between land use change and its driving factors,then predict the land use pattern in 2030 in four scenarios(natural development scenario,arable land conservation scenario,ecological protection scenario,and comprehensive optimization scenario).The main conclusions are as follows:(1)From 1990 to 2020,there has been a drastic change in land use in the PRD urban agglomeration.In terms of quantity and structure,forest land and farmland have always been the main types of land use in the Pearl River Delta urban agglomeration,while construction land has grown the fastest.Farmland,forest land,and water area have converted into construction land,and its proportion has almost tripled from 5.51%in 1990 to 14.91% in 2020.However,the fastest growth rate of construction land happened between 2000 and 2010,then the growth rate slows down after 2010.The expansion of construction land is centered around the Guangzhou-Shenzhen area,gradually connecting into a cohesive area.Other cities,such as Foshan and Dongguan,have also experienced rapid growth.The urban agglomeration is evolving towards a networked and multi-centered spatial structure.(2)From 1990 to 2020,the impact of human activities on the change of land use landscape pattern has gradually increased.In the past three decades,the expansion rate of construction land in the PRD urban agglomeration has accelerated,and the patches have gradually become contiguous and more regular in shape.Overall,the landscape heterogeneity of the PRD urban agglomeration has increased,while the landscape connectivity has been on a decreasing trend,and it is necessary to be alert to the destruction of landscape ecological functions by high-intensity construction and development activities.(3)Changes in the major land use types in the PRD urban agglomeration are influenced by a variety of factors.The change of farmland are influenced by the density of bus stops,GDP,and slope;elevation and slope have the greatest impact on forest land;watershed is most influenced by water system and elevation;and the expansion of construction land is mainly influenced by industry,population density and residential communities.(4)The model constructed in this study has high accuracy.Comparing and validating the simulated land use pattern of the PRD Urban Agglomeration in 2020 with the actual land use data in 2020,the overall accuracy of the model reached 0.90,and the kappa coefficient reached 0.84,indicating that the model has a good simulation effect which can be used for predicting and simulating future land use patterns in the PRD Urban Agglomeration.(5)The land use structure under the comprehensive optimization scenario is more balanced.Compared with other scenarios,the comprehensive optimization scenario integrates the advantages of arable protection and ecological protection scenarios,protecting both farmland and ecological land while leaving space for urban development.At the same time,the priority protection unit of Guangdong Province’s "Three Lines and One Permit" policy is used as an ecological protection area,making the prediction more in line with actual policies.In the future,the PRD Urban Agglomeration can make effective use of land resources,promote the upgrading of industrial structure and protect the ecological environment through the preparation of spatial planning,so as to achieve sustainable regional development.