Hydrologic Processes in a Cold, Snowy Region, and the Effects of Global Climate Change on Those Processes

这项研究探讨了气候变化和人类活动如何影响寒冷多雪地区的水文系统。一是降水、积雪条件；利用长期水文模型估算融雪量、径流、地下水和水质。其次，尝试分析水文系统对气候变化等环境变化的敏感性。最近，我们开始关注降雪短缺、融雪季节的强降雨和气温上升将如何影响水资源和洪水频率。建立了森林流域水文过程模型，分析了环境变化对流域水文过程的影响。还有人担心湿地的原生植被会因干旱而减少。利用地下水模拟模型分析了降水和河流水位对地下水位的影响，阐明了湿地地区的水量收支。我们关注的是水质问题，比如盆地中营养过剩导致的富营养化。为了了解封闭水域富营养化的原因并制定对策，明确了水热收支和水质组分的数量，并建立了模拟模型。我们开发了基于物理的模型，并将其应用于分析寒冷多雪地区水循环的长期趋势。这些环境变化包括自然气候变化和与人类有关的变化。这些模型对于分析不同地点的情况，澄清各种问题具有实际意义。

This research addressed how climate change and human activities affect hydrologic systems in a cold, snowy region. First, conditions of precipitation, snow cover; snowmelt, runoff, groundwater and water quality were estimated using a long-term hydrologic model. Second, an attempt was made to analyze the sensitivities of hydrologic systems to environmental changes like climate change. Recently, we have become concerned about how snowfall shortages, heavy rainfall in the snowmelt season and temperature rises will affect water resources and flood frequency. The hydrologic processes in forested watersheds, which are important regarding water resources, were modeled and the effect of environmental change on such processes was analyzed using the proposed model. There are also concerns about the loss of native vegetation in wetlands due to drying. The effects of precipitation and river water level on groundwater level were analyzed using a groundwater simulation model to clarify the water budget in the wetland area. We focused on water quality issues like eutrophication resulting from nutrient overload in the basin. To understand the cause of eutrophication in closed-water areas and to develop countermeasures, budgets of water and heat, and amounts of water quality components were clarified and a simulation model was developed. We developed physics-based models and applied them to analysis of long-term trends of water cycles in cold snowy regions. These environmental changes include natural climate changes and human-related changes. The models are of practical use to analyze the conditions at various sites toward clarifying various issues.