Using Temperature Measurements To Find the Flow Rate of Ground Water into a Stream

Abstract

This study explored how the groundwater inflow rate for a stream may be approximated by applying the heat transport equation to stream temperature measurements and weather data. The two primary parameters we worked with for the heat transport equation are the bulk surface heat exchange coefficient and the equilibrium temperature. Using both FORTRAN and EXCEL programs, we ran an iterative routine to calculate the groundwater inflow rate by means of a discretized version of the heat transport equation. Sample data was run through the programs to assure reliability. After we performed a regression on the ground water temperature in order for us to interpolate data we did not have, we tested the programs with actual data from the Vermillion River. The reach is from station VR809 to station HAMB. We finished by performing a verification test on the inflow rates of ground water. We determined that although the results are promising, they are not as accurate as we would like. The verification test shows that the ground water inflow rates that we approximated did not producing accurate volumetric flow rates for HAMB. A major source of error was likely the assumption of a steady state. In the future we would like to model this as an unsteady state, as well as perform sensitivity tests on the parameters of the heat transport equation.This study explored how the groundwater inflow rate for a stream may be approximated by applying the heat transport equation to stream temperature measurements and weather data. The two primary parameters we worked with for the heat transport equation are the bulk surface heat exchange coefficient and the equilibrium temperature. Using both FORTRAN and EXCEL programs, we ran an iterative routine to calculate the groundwater inflow rate by means of a discretized version of the heat transport equation. Sample data was run through the programs to assure reliability. After we performed a regression on the ground water temperature in order for us to interpolate data we did not have, we tested the programs with actual data from the Vermillion River. The reach is from station VR809 to station HAMB. We finished by performing a verification test on the inflow rates of ground water. We determined that although the results are promising, they are not as accurate as we would like. The verification test shows that the ground water inflow rates that we approximated did not producing accurate volumetric flow rates for HAMB. A major source of error was likely the assumption of a steady state. In the future we would like to model this as an unsteady state, as well as perform sensitivity tests on the parameters of the heat transport equation.This study explored how the groundwater inflow rate for a stream may be approximated by applying the heat transport equation to stream temperature measurements and weather data. The two primary parameters we worked with for the heat transport equation are the bulk surface heat exchange coefficient and the equilibrium temperature. Using both FORTRAN and EXCEL programs, we ran an iterative routine to calculate the groundwater inflow rate by means of a discretized version of the heat transport equation. Sample data was run through the programs to assure reliability. After we performed a regression on the ground water temperature in order for us to interpolate data we did not have, we tested the programs with actual data from the Vermillion River. The reach is from station VR809 to station HAMB. We finished by performing a verification test on the inflow rates of ground water. We determined that although the results are promising, they are not as accurate as we would like. The verification test shows that the ground water inflow rates that we approximated did not producing accurate volumetric flow rates for HAMB. A major source of error was likely the assumption of a steady state. In the future we would like to model this as an unsteady state, as well as perform sensitivity tests on the parameters of the heat transport equation.This study explored how the groundwater inflow rate for a stream may be approximated by applying the heat transport equation to stream temperature measurements and weather data. The two primary parameters we worked with for the heat transport equation are the bulk surface heat exchange coefficient and the equilibrium temperature. Using both FORTRAN and EXCEL programs, we ran an iterative routine to calculate the groundwater inflow rate by means of a discretized version of the heat transport equation. Sample data was run through the programs to assure reliability. After we performed a regression on the ground water temperature in order for us to interpolate data we did not have, we tested the programs with actual data from the Vermillion River. The reach is from station VR809 to station HAMB. We finished by performing a verification test on the inflow rates of ground water. We determined that although the results are promising, they are not as accurate as we would like. The verification test shows that the ground water inflow rates that we approximated did not producing accurate volumetric flow rates for HAMB. A major source of error was likely the assumption of a steady state. In the future we would like to model this as an unsteady state, as well as perform sensitivity tests on the parameters of the heat transport equation.This study explored how the groundwater inflow rate for a stream may be approximated by applying the heat transport equation to stream temperature measurements and weather data. The two primary parameters we worked with for the heat transport equation are the bulk surface heat exchange coefficient and the equilibrium temperature. Using both FORTRAN and EXCEL programs, we ran an iterative routine to calculate the groundwater inflow rate by means of a discretized version of the heat transport equation. Sample data was run through the programs to assure reliability. After we performed a regression on the ground water temperature in order for us to interpolate data we did not have, we tested the programs with actual data from the Vermillion River. The reach is from station VR809 to station HAMB. We finished by performing a verification test on the inflow rates of ground water. We determined that although the results are promising, they are not as accurate as we would like. The verification test shows that the ground water inflow rates that we approximated did not producing accurate volumetric flow rates for HAMB. A major source of error was likely the assumption of a steady state. In the future we would like to model this as an unsteady state, as well as perform sensitivity tests on the parameters of the heat transport equation.