In Sarobetsu Mire, the groundwater level has been dropping for the past few decades. There is great concern regarding the increase in sasa bamboo distribution and the displacement of the original vegetation. In the region of the mire, snow plays an important role in stabilizing the ground water level, especially in the bog area, because it recharges abundant amount of water to the groundwater.
Observation data showed that the ground water level in the bog area is kept high in winter by meltwater recharge from the bottom of the accumulated snow. An attempt was made to analyze the effect of snowmelt on groundwater level variation using a two-dimensional unsteady model. The simulation results indicated that lowering of groundwater level in the bog area could strongly relate to a decrease in snowmelt water. This means that mire conservation must take into account not only artificial influences like reclamation but also climate influences.