Water Resources Research Act Program

Details for Project ID 2017NE308B

Spatial Variability of Streambed Hydraulic Conductivity across Multiple Stream Orders

Institute: Nebraska
Year Established: 2017 Start Date: 2017-03-01 End Date: 2018-02-28
Total Federal Funds: $19,992 Total Non-Federal Funds: $39,706

Principal Investigators: Aaron Mittelstet, Troy Gilmore

Abstract: To understand the impacts of water policy, land use change, climate change and irrigation management strategies, hydrologic models are often used. A recent merging of the Soil and Water Assessment Tool (SWAT) and MODFLOW will enhance the modeling of the surface water, groundwater and their interaction. The Frenchman River watershed, a sub-watershed in the Upper Republican River watershed with declining groundwater and streamflow levels, is an ideal location to apply this newly-coupled model. To understand the connectivity between surface water and groundwater, it is imperative to get a good estimate of streambed hydraulic conductivity (K). Though streambed K is one of the most important parameters controlling the movement of water from the stream to the aquifer and aquifer to the stream, none of the studies on the Frenchman River watershed report values of measured streambed K. The primary objectives of this study are to (1) measure the streambed K for multiple stream orders within the Frenchman River watershed and (2) quantify the difference in the streambed K within the same stream order and between stream orders as a function of bed slope and soil properties. With the support of three trained graduate and undergraduate students, our expected project outcomes include (1) streambed K values that can be directly input to our SWAT-MODFLOW hydrologic model and (2) the derivation of a relationship between streambed K, stream order, bed slope and the soil composition of the drainage area above the sampling site.