Spatio-temporal characteristics and influencing factors of trade-offs/synergies in land use functions in Hangzhou City, China

Abstract: The contradictions between land production, living, and ecological functions have gradually emerged, as industrialization and urbanization continue to advance. It is necessary to accurately allocate and coordinate the functions of land development and protection for the reasonable distribution of human activities in sustainable agriculture. This study aims to explore the spatiotemporal characteristics of trade-offs/synergies in the land use functions and the influencing factors. Taking Hangzhou City of China as an example, an attempt was made to evaluate the land production, living and ecological functions at the fine scale from 2000 to 2018 using the multi-source data and a series of geospatial models. Then, the correlation analysis was used to reveal the trade-offs/synergies of land use functions at the global and grid scales. The influencing factors of land use function trade-offs/synergies were also identified by the linear regression model. The results showed that: (1) The living function showed a trade-off relationship with the production and ecological function between 2000 and 2018, whereas the trade-off intensity of production and living functions was stronger than that of living and ecological functions. Production and ecological functions were established to determine a synergistic relationship during the study period. There was a trend of increasing first and then decreasing in the trade-off relationship between production and living functions, where the trade-offs of living and ecological functions gradually weakened. The interactive relationship between production and ecological functions was shifted from a synergistic relationship in 2000-2005 to a trade-off relationship in 2015-2018. (2) Spatially, the production-living function was dominated by strong trade-off and production-weakening trade-off, where the trade-off intensity tended to weaken from the east to the west and from the central to the periphery. The areas with a synergy state were located in the low-altitude mountain of central and western Hangzhou. The production-ecological function presented a mixed pattern of trade-off and synergy areas in space. The trade-off areas accounted for about 31%, with the weak trade-off and production-weakening trade-offs, mainly distributed in northern and eastern Hangzhou. The synergy areas occupied about 38%, with the weak synergy and simultaneous improving synergy, mainly distributed in the western and southern Hangzhou. The living-ecological function was dominated by the weak trade-off and ecology-weakening trade-off. The trade-off area accounts for 14%, where the trade-off intensity showed a trend of high in the east and low in the west, gradually decreasing from the center to the edge. The synergy relationship was dominated by weak synergy and simultaneous weakening synergy, the synergy areas accounted for 8%, mainly scattered in the outer suburbs. (3) Natural conditions and geographical location posed significant negative effects on the trade-offs/synergies in production-living and living-ecological functions, whereas there were significant positive effects on production-ecological function trade-offs/synergies. The urbanization-induced land conversion and the increase of land-use intensity further aggravated the trade-offs in land use functions. Therefore, there were different trade-offs/synergies in the land use functions at global and grid scales. The overall characteristics and local differences can be fully considered in the decision-making on land use function, according to the local conditions.