Contribution degrees of precipitation and groundwater exploitation to the groundwater flow field in Shijiazhuang

In order to accurately identify the contribution degrees of precipitation and groundwater exploitation to the groundwater flow field in shijiazhuang, interactive features between the average water level, central level and area of groundwater depression cone and the precipitation and groundwater exploitation are studied through the methods of Wavelet Transform (WT) and correlation analysis. The results indicate that: ① During the period of 1961—1973, the average water level shows a power-function declining trend with increasing precipitation; during the period of 1974—2010, every decline in precipitation by 100 mm results in a rise in drawdown of central level of groundwater depression cone by 7.35 m and a rise in drawdown of average groundwater level by 2.15 m. ② During the period of 1961—1973, every rise in groundwater exploitation by 0.1 billion cubic meters results in a decline in average groundwater level by 0.28 m, a rise of 11.74 km² in area and a decline of 0.52 m in central level of groundwater depression cone; since 1974, every rise in cumulative amount of overexploitation by 0.1 billion cubic meters results in a rise of 1.52 km² in area and a decline of 0.18 m in central level of groundwater depression cone. ③ Every rise in precipitation by 100 mm results in a decline in contribution degree of precipitation by 3.0% and a rise in contribution degree of human exploitation by 2.76%.