Spatial flow of food supply services based on supply and demand relations in Chongqing main city

Ecosystem food supply services are the foundation of sustainable development of society and nature. Taking the Chongqing main city as an example, based on multi-source data such as land use, food production and population, the supply and demand of food supply services (FS) were quantified by food calorie method. Then, the supply and demand relationships were clarified based on the supply-demand ratio and bivariate local spatial autocorrelation. Finally, the spatial flow characteristics of FS were explored based on transportation accessibility. The results show that: (1) From 2000 to 2020, the FS supply decreased from 5.2 × 10 12 to 1.7 × 10 12 kcal, and the high-supply areas disappeared in the west and only remained in the northeast and southeast. The FS demand increased from 4.7 × 10 10 to 6.5 × 10 10 kcal, and the high-demand areas expanded from the middle to the east and west sides. (2) The average supply-demand ratio of FS decreased from 0.348 to 0.222, indicating an increase in supply pressure. The area of the surplus regions shrank while that of the deficit regions expanded. In particular, the areas with high demand and low supply were significantly increased. (3) The spatial flow of FS was mainly concentrated in two directions: from Banan to the central and southern demand areas and from Yubei to the northern demand areas. The research results can provide strong data support for optimizing regional food resource allocation and promoting regional sustainable development.