Work

Construction and verification of distributed hydrothermal coupling model in the source area of the Yangtze River

Year: 2024

Type: article

Abstract: Climate change has caused significant changes in hydrological processes in the cryosphere, and the related study has become a hotspot. The source area of the Yangtze River (SAYR) is a key catchment for hydrological studies of the cryosphere, with widespread glaciers, snow and permafrost. However, the current hydrological modelling for the SAYR rarely depict the process of glacier/snow and permafrost runoff from the perspective of coupled water and energy transfer, resulting in the distortion of hydrological process simulations. Therefore, the study constructed a distributed hydrothermal coupling model WEP-SAYR based on the WEP-L (Water and Energy transfer Process in Large river basins) model by introducing modules on glacier and snow melt and permafrost freezing and thawing. The soil water-heat transfer equation was improved and the frozen soil freezing point equation was proposed. Furthermore, the WEP-SAYR and original WEP-L model were used to simulate daily/monthly runoff, and evapotranspiration processes, as well as the dynamic changes of soil temperature and soil water content, respectively. The applicability of the WEP-SAYR model was verified. The results show that WEP-SAYR can describe soil water content and soil temperature changes in soil layers of different depths from 0 to 140 cm. Meanwhile, the model has good accuracy in simulating daily/monthly runoff as well as evapotranspiration, with the Nash efficiency coefficient exceeding 0.75, and the relative error was controlled within ±10%.

Source: Journal of Hydrology Regional Studies

DOI: 10.1016/j.ejrh.2024.102057