Coupling of a simultaneous heat and water model with a distributed hydrological model and evaluation of the combined model in a cold region watershed

Abstract

Snow and frozen soil prevail in cold regions worldwide, and the integration of these processes is crucial in hydrological models. In this study, a combined model was developed by fully coupling a simultaneous heat and water model with a geomorphologically based distributed hydrological model. The combined model simulates vertical and lateral water transfer as well as vertical heat fluxes and is capable of representing the effects of frozen soil and snowmelt on hydrological processes in cold regions. This model was evaluated by using in situ observations in the Binggou watershed, an experimental watershed for cold region hydrology of the Watershed Allied Telemetry Experimental Research Project. Results showed that the model was able to predict soil freezing and thawing, unfrozen soil water content, and snow depth reasonably well. The simulated hydrograph was in good agreement with the in situ observation. The Nash-Sutcliffe coefficient of daily discharge was 0.744 for the entire simulation period, 0.472 from April to June, and 0.711 from June to November. This model can improve our understanding of hydrological processes in cold regions and assess the impacts of global warming on hydrological cycles and water resources.

Hydrologic Impacts of Thawing Permafrost—A Review

“…Other hydrological models have incorporated numerical solution schemes (e.g., finite difference, finite element, or finite volume) to model ground freezing and thawing, particularly when simulating one‐dimensional infiltration intro frozen soils (e.g., Zhao et al, 1997). Recent examples of distributed hydrological models employing numerical soil freeze–thaw schemes include Gouttevin et al (2012), Rawlins et al (2013), Zhang et al (2013), and Clark et al (2015). These powerful numerical approaches can accommodate complex processes or conditions, including soil heterogeneities, coupled heat and water transfer, complex temperature boundary conditions, intermittent freeze–thaw, and temporally variable thermal properties.…”

Climatic and associated cryospheric, biospheric, and hydrological changes on the Tibetan Plateau: a review

“…Permafrost is a chief component of the cryosphere and susceptible to climate change on different spatial and temporal scales (Cheng and Wu, ). In cold regions, thawing depth of frozen soil influences the runoff generation on hillslopes which substantially differs in temperate regions (Zhang et al ., ). During the 1970–1990s, an increase in surface temperature over TP from 0.2 to 0.5 °C has caused permafrost reduction and permafrost loss is expected to continue in the future (Zhao et al ., ; Lemke et al ., ).…”

Influences of Topographic Shadows on the Thermal and Hydrological Processes in a Cold Region Mountainous Watershed in Northwest China

“…The land use map published by Ran et al (2012) and daily leaf area index produced by Yuan et al (2011) were used in the model. Soil parameters including bulk density, organic content, pore size distribution index, air entry potential, saturated hydraulic conductivity, porosity, field capacity, and fractions of sand, silt, and clay were taken from the data set published by Dai et al (2013).…”