Development of a Coupled Framework for Simulating Interactive Effects of Frozen Soil Hydrological Dynamics in Permafrost Regions.

摘要

Projections of long-term effects of climate warming on high latitude ecosystems require a coupled representation of soil thermal state and hydrological dynamics. We developed such a framework to explicitly simulate the soil moisture effects of soil thermal conductivity and heat capacity and its effects on hydrological response. Our model is the result of coupling the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model with the Geophysical Institute Permafrost Laboratory (GIPL) model. The GIPL model simulates soil temperature dynamics, the depth of seasonal freezing and thawing, and the permafrost location by numerically solving a onedimensional nonlinear heat equation with phase change. The GSSHA model is a spatially explicit hydrological model that simulates two dimensional groundwater flow and one- dimensional vadose zone flow. We combined these two models by incorporating the GIPL model into the GSSHA model. Our test case results indicate that freezing temperatures reduces soil storage capacity thereby producing higher peak discharges and lower base flow.