ความสัมพันธ์ระหว่างอัตราการเติมน้ำใต้ดิน โดยแรงโน้มถ่วงของโลกกับการกระจายตัวของขนาดทราย / ธีระจิต จิตรากรณ์ = The relationship of gravity groundwater recharge rate and grainsize distribution / Teerachit Chitrakorn
Nowadays, Groundwater use rate increases and causes to the decrease of groundwater level. There are studies to find the way to increase groundwater level by recharging natural water via the spreading basin or well. In the study, gravity groundwater recharge experiments were conducted to find the relationship of recharge rate and grainsize distribution through porous media was studied. The results were compared with the field experiment done in Kamphaeng Phet Province. The physical model of 1x2.1x0.5 meter for gravity recharge experiment was built and the studies were done to determine hydraulic properties. i.e., horizontal hydraulic conductivity, infiltration rate, recharge coefficient, water level rise up, ground water profile compared with varied mean grainsize of both pond and well types. Field experiments were also conducted for comparison at Kilo song Village, Muang District, Kamphaeng Phet Province. The study found that recharge rate is affected by mean grainsize and groundwater level. The horizontal hydraulic conductivity increases with the increase of mean grainsize. The infiltration rate equals to about 12% of the horizontal hydraulic conductivity. The recharge rate is closed to infiltration rate and decreases with the increase of groundwater level. The groundwater level rise up at recharge point is higher with the decrease in mean grainsize. Groundwater profile depended on the groundwater level and the depth of recharge pond. The design of recharge pond or well sizing can be determined by using the experimental relationships to estimate the recharge rate from mean grainsize data.