where, K(T) is the hydraulic conductivity at a temperatureT°C,\(K_{\text{ref}}\) is the hydraulic conductivity at a reference temperature ( \(T_{\text{ref}}\)) and f is the kinematic fluidity of water which is also a function of temperature.
The mean temperature of infiltration water is 15 °C. The upper quartile (3rd quartile) of pond water temperature provides the reference for the average hydraulic conductivities in summer and the lower quartile (1st quartile) provides reference for the winter conductivities. The upper quartile of pond water temperature is at 9.3 °C and the lower quartile is at 21 °C. After fitting these values to equation 8, it is observed that the hydraulic conductivity increases by 15 % in summer and decreases by 14.7 % in winter. In other words, there is a 30% increase in hydraulic conductivity of the pond bed in summer as compared to that in winter. The change in hydraulic conductivity is not constant through the entire soil profile since the temperature variation with depth is not uniform. According to (Vandenbohede & Houtte, 2012), the temperature of water changes as it moves down, which is influenced by the existing groundwater residing in the aquifer. Temperature becomes constant after a depth of 25 m below the ground surface. Hence, the influence of temperature is predominant only close to the ground surface.