Design and construction of minipiezometers to determine surface water-groundwater interactions

Understanding the interactions of ground water and surface water is one of the most important challenges among hydrogeologists. Hydraulic gradient between ground water and surface water, as well as hydraulic conductivity of streambed sediments are required to determine ground water and surface water exchanges. Minipiezometers are simple instruments that measure flow direction and hydraulic gradients between ground water and surface water. Often temporarily installed, minipiezometers are essentially small-scaled versions of piezometers, which are commonly used to make groundwater level measurements. By combining water table data with surface water level measurements, flow direction can be determined. Minipiezometers are typically used in the areas where many measurements are required. Commercial minipiezometers are available, but they are very expensive. The purpose of this paper is to design and construc a low-cost minipiezometer for measuring ground water and surface water exchanges. In this study, a minipiezometer was made by simple and available materials such as steel pipe, steel 3NPSoft rob, clear plastic hose, gas valves, hand vacuum pump, hammer, U-shape clear tubing, graduated manometer board, and graduated transparent plastic cylinder and was successfully tested in the Soleghan River in the west of Tehran.