Investigating the Impacts of Seasonal Temperature Variations on the Hysteresis Response of Groundwater in the Aquitard in a Plain Reservoir area

Seasonal climate variations (SCV) have a significant impact on the exchange of surface and groundwater in the reservoir area. As a crucial climatic element, temperature also has an important effect on the hydrological cycle. In the plain reservoir area, the hysteresis response of groundwater in the aquitard to reservoir level (RL) fluctuations is ever-present. To study the impacts of SCV on the hysteresis response of groundwater in the aquitard, the response of groundwater level (GL) of Jiangxiang Reservoir to the variation of the RL was examined. Considering the seasonal temperature variations (STV), the hydraulic diffusivity of the aquitard was calculated. Relying on the STV, the formula for calculating the variation of the GL with the RL was derived. The results showed that the hydraulic diffusivity is sensitive to temperature changes. The higher the temperature, the greater the hydraulic diffusivity, which results in a faster response of groundwater to changes in reservoir level. Additionally, the lag of groundwater level change in the aquitard became smaller. Considering STV, the calculated immersion scope with variable parameters was smaller than that with constant parameters.