A conceptual and statistical approach for the analysis of climate impact on ground water table fluctuation patterns in cold conditions

摘要

A robust conceptual and statistical approach is presented for the study of ground water table fluctuations with precipitation and temperature as input variables. A conceptual hydrological model was developed to generate daily rainfall, snowmelt and evapotranspiration values and these values were cross-correlated with observed ground water levels to find representative time lags and significant correlations to describe the ground water system. A statistical model linking rainfall, snowmelt, evapotranspiration and ground water level was then developed and validated for an unconfined esker aquifer in boreal environment in central Finland. The model predicted very well fluctuation of ground water level and timing of the minimum and maximum water levels. A future climate change scenario for the years 2010-2039 was subsequently simulated. The simulation indicates higher ground water levels in milder winter climate. This is due to increase in winter recharge. The model provides a new tool to assess the impacts and address the uncertainties related to climate variation and change in complex ground water systems in cold regions with snow cover.