Big Data Supports Urban Land Sustainability Analysis Of "One Belt One Road"

In 2015,the United Nations formulated 17 sustainable development goals(Sustainable Development Goals,SDGs)facing the world,SDG11 is the sustainable development goals for cities and human settlements,of which the specific goal of SDG11.3 is "by 2030,Increase capacity for inclusive and sustainable urbanization and participatory,integrated and sustainable settlement planning and management in all countries”,and indicator SDG11.3.1 is the Land Consumption Rate to Population Growth Ratio(LCRPGR).This indicator is mainly used to measure the information of urban land use efficiency,reveal the relationship between urban land consumption and urban population growth,and then provide data support for the sustainability evaluation of urban land.However,there are a large number of outliers in the index results of the LCRPGR calculation model given by the United Nations.This paper designs a ratio model of land consumption rate and population growth rate,which can effectively reduce the adverse effects of LCRPGR outliers on regional statistical results.Aiming at the problem that the results of SDG11.3.1 in the UN SDG report are all derived from statistical data,this paper makes full use of the advantages of big earth data,combines the LCRPGR calculation model given by the United Nations with the algorithm designed in this paper,and calculates 338 cities along the Belt and Road.The results of the LCRPGR reflect the overall land use efficiency of cities along the Belt and Road.On this basis,three indicators of compactness,urban expansion speed and urban expansion intensity are added to comprehensively reflect the changing trend of urban overall land use efficiency.In addition,in view of the fact that most of the current research focuses on the analysis of the entire urban built-up area,but not enough attention is paid to the urban land use efficiency in the urban expansion area,this paper divides the entire built-up area into new and There are two parts of the built-up area,the introduction of the per capita land use efficiency(LCPC)index,combined with the LCRPGR,the two transformation periods of the three phases of 2005,2010,and 2015 in the areas along the Belt and Road,the development and changes of urban built-up areas have an impact on urban land use efficiency.A comprehensive analysis was carried out on the impact of land use,and the relationship between land consumption and population growth was discussed from three aspects: the whole urban built-up area,the newly-built built-up area,and the built-up area.the result shows:(1)From 2005 to 2010,the average LCRPGR of cities along the Belt and Road was 0.82,while from 2010 to 2015,the value increased to 0.99,which is close to the ideal value of LCRPGR recommended by the United Nations Human Settlements Programme,which is 1.0.It shows that the land use efficiency of cities along the Belt and Road is on the rise in general,and the analysis results of related indicators of spatial morphology are consistent with this conclusion.This changing trend of urban land use efficiency will have a positive impact on the sustainability of urban land use along the Belt and Road.In addition,compared with large cities,the urban expansion rate of small cities tends to be slower,while the urban development is in a loose state,and the urban land use efficiency is low.The relationship between growth and its impact on urban sustainability deserves more attention.(2)Statistical analysis of LCPC shows that the average value of LCPC in built-up areas is generally similar to the trend of LCPC in the entire built-up area.The average LCPC of new built-up areas is higher than that of existing built-up areas,indicating that with the expansion of the city,the land consumption per capita of new built-up areas is lower than that of existing built-up areas.Although the land consumption per capita of new built-up areas in cities along the Belt and Road is generally on the rise,the land consumption per capita of new built-up areas in cities in some regions,such as Central Asia and Africa,is on the decline,which will affect the sustainability of cities.to negative effects.It shows that under the overall trend of improving the sustainability of urban land along the Belt and Road,more efficient planning of urban land in newly built areas is required.In addition,as the size of the urban population shrinks,the LCPC values of both the entire built-up area and expanded and existing built-up areas increase,indicating that the land use efficiency of small cities needs to be further improved.The above research results show that whether it is LCPRGR or LCPC,small cities along the Belt and Road have serious problems of low urban land use efficiency,and the sustainability of urban land development faces greater challenges.Provide data support for the improvement of land use efficiency and the formulation of urban planning schemes.