基于COUPMODEL的松嫩平原黑土区土壤水热过程模拟

Simulation of soil water-heat process in black soil region of Songnen Plain based on COUPMODEL

为探究松嫩平原黑土区不同积雪覆盖条件下冻融土壤水热耦合过程。文章基于物理过程COUPMODEL模型,运用普适似然不确定方法(GLUE)估计积雪、土壤水热运移有关参数,模拟裸地、自然积雪、压实积雪、加厚积雪状态下各层土壤温度与土壤液态含水率变化情况。结果表明,模型对自然、压实、加厚积雪覆盖条件下雪深模拟较理想;模型可较好模拟裸地、自然积雪、加厚积雪覆盖条件下20~140cm土层土壤温度,其中裸地最佳,自然次之,自然略优于加厚,模型对压实积雪状态下20~100cm土层土壤温度模拟效果仍较好,但对140cm土层模拟效果略差;此外,模型可模拟各状态下20~60cm土层土壤液态含水率,模拟效果优劣排序依次为自然、裸地、加厚、压实。结合GLUE方法COUPMODEL模型可用于不同积雪覆盖条件下土壤水热变化规律研究。

In order to better understand the water-heat process of frozen-thawed soil under the conditions of four different snow covers in black soil region of Songnen Plain,this paper applied a physical-based COUPMODEL model,moreover combine with GLUE,the GLUE method was used to estimate the parameters related to snow cover and soil water-heat process.Based on this,soil temperatures and soil liquid water contents of the bare land,natural snow cover land,snow compacted land and snow thickened land were simulated.The results showed that the model was ideal for snow depth simulation under the natural,compacted and thickened snow cover conditions;as the same time,the model could successfully simulate the soil temperatures of 20-140 cm under the bare,natural snow and thickened snow cover conditions,the simulation effect of bare land was the best,the simulated effect of natural snow was the second,the simulation effect of natural snow was slightly better than thickened snow;the simulation effect of the model about soil temperature in the soil layer of 20-100cm under the condition of compacted snow cover was still good,but the simulation effect in the soil layer of 140cm was slightly worse;in addition,the model could also basically simulate the liquid water content of 20-60cm soil layers under different snow cover conditions,the simulation effect from good to bad were natural snow cover land,bare land,snow thickened land,snow compacted land.In general,the COUPMODEL model combine with the GLUE method could be used to study the soil water-heat process under different snow cover conditions.