Abstract: Background, aim, and scope In this paper, the fluctuation law of groundwater table of Baotu Spring in Jinan spring area from May 2012 to November 2017 is analyzed. By analyzing and evaluating the situation of protecting spring water, exploring effective measures for protecting spring water area and supplying water for downtown Jinan. Materials and methods Based on the Holt-Winters exponential smoothing model, the Holt-Winters addition model is used to analyze and forecast the trend of the groundwater table in the Baotu spring from a new evaluation index and perspective. And the goodness of fit index and the fitted statistics of the model were calculated. Results The coefficient of determination R2 is 0.897, the stationary R2 is 0.627. The calculated values are larger and the other indexes of the goodness of fit are all good, indicating that the model fitting effect is better overall accuracy. Discussion By using the model, the water table of Baotu Spring in 2018 is predicted and the confidence interval of 95% of the predicted value is given. The predicted average annual water table is 27.814 meters, the spring water table fluctuates at a peak of 28.291 meters, the trough is 27.329 meters and the trough will appear in June 2018, the lowest water table for the last 6 years. This value is lower than the 27.6 meters spring red cordon and close to the 27.01 meters spring water spray line. Conclusions The forecast results show that there will be a potential crisis in Baotu Spring in 2018, and the task of spring preservation in Jinan will remain harsh. Recommendations and perspectives In order to strive for the continued spewing of spring water, the proposal of scientific spring preservation and the measures of saving water and keeping spring have been put forward. It will provide a scientific basis for Jinan City to judge, predict and adjust the layout of the water system and groundwater.
Keywords: Jinan; Baotu spring; Groundwater table; Holt-Winters exponential smoothing model; Spring protection