Assessing the relative contributions, combined effects and multiscale uncertainty of future land use and climate change on water-related ecosystem services in Southwest China using a novel integrated modelling framework

Investigating the effects of prospective land use and land cover change (LUCC) and climate change (CC) on water-related ecosystem services (WRESs) is crucial for sustainable urban ecosystem planning. However, few studies have taken into account the relative contributions and comprehensive effects of different CC and LUCC on WRESs in the future. The multiscale uncertainty of future implications of LUCC and CC on WRESs remains unclear. This study proposed a novel framework integrating the BNU-ESM, FLUS, and InVEST models to explore the independent contributions and combined effects of CC and LUCC on water yield (WY) and soil conservation (SC) in Southwest China, and further innovatively quantify the multiscale uncertainty using mapping comparative statistics (MCS) approach. WY reduced in future scenarios, while SC initially decreased and then enhanced. CC contributed over 84.23 % and 91.76 % to WY and SC, respectively, while the impact of LUCC continued to grow over time. LUCC introduces the least uncertainty and CC exhibits significant uncertainty, but interannual changes causing the greatest uncertainty. Uncertainty has obvious scale dependence, but remains relatively stable at different scales. This critical knowledge can be applied in addressing future climate change risks, optimizing land use spatial patterns, and executing cross-scale sustainable ecosystem management.