Tracer Techniques Used to Analyze Spatial and Temporal Processes Controlling Groundwater and Near Surface Water Contribution to the Ruby River in the Upper Ruby River Valley, MT.
Date of Award
Master of Science (MS)
Stable water isotopes, δD and δ18O as well as specific conductance (SC) are often used as chemical tracers, or water fluxes, to understand basin hydrological processes including precipitation, groundwater recharge, groundwater-surface water interactions. In understanding the behavior of isotopes in a natural system, quantitative models can be produced to identify volumes and sources of groundwater recharge or losses as well as how groundwater pumping and surface water irrigation affects groundwater storage and discharge. The overarching questions are: i) what are the current spatial and temporal processes controlling groundwater and surface water, ii) what are the major sources of water and iii) what is the interaction between restoration and the hydrology of the upper Ruby Valley. This study found that the upper Ruby Valley is a seasonally dynamic hydrologic system dominated by snowmelt runoff and groundwater depending on the time of year. The source-sink dynamics show significant spatial variations with many gaining and losing reaches and has a complex surface water dynamic because of numerous ditches and tributaries contributing and withdrawing from the river. While some tributaries are groundwater dominated, others are near surface water dominated. This study also suggests that there are two sources of groundwater and a near surface water contributing to the upper Ruby Valley from the three-component mixing analysis. This study suggests source of the F1-1st groundwater is most likely groundwater from irrigation return flow from ditches. The source of F2 is likely near surface water while F3-2nd groundwater is generally the upper Ruby valley groundwater. As F1-1st groundwater component is most likely from irrigation return, it can be suggested that the plug and pond restoration system will store the F2-near surface water in surface water delineations of side channels and oxbow lakes for late season signatures of the F1- 1st groundwater
Nelson, Max-Henry, "Tracer Techniques Used to Analyze Spatial and Temporal Processes Controlling Groundwater and Near Surface Water Contribution to the Ruby River in the Upper Ruby River Valley, MT." (2022). Graduate Theses & Non-Theses. 291.
A thesis submitted in partial fulfillment of the requirements for the degree of