Divergence or Convergence? A Comparison of InVEST and SWAT in Simulating Water Conservation Patterns and Drivers

Abstract The proper functioning of water conservation services is essential for regional ecological stability. To enhance assessment accuracy and support ecological management, this study evaluated the water conservation capacity of the Liupan Mountain area from 2003 to 2022 using the SWAT model, the InVEST model, and the regional water balance method. The results show that: (1) Both models indicated a significant increasing trend in water conservation over time, though SWAT exhibited more stable interannual variability. (2) Spatially, both models revealed a “ high in the south and low in the north, high in the east and low in the west ” pattern, with SWAT producing more continuous outputs and InVEST yielding finer spatial details. (3) Water conservation correlated positively with precipitation in both models. (4) SWAT demonstrated advantages in temporal stability and climatic mechanism interpretation, making it suitable for hydrological process studies, while InVEST, with fewer parameters and higher efficiency, is ideal for spatial pattern assessment and conservation effectiveness evaluation.