Map showing study areas for this research project
Study area of Eastern Washington with groundwater subareas (black outlines) as defined by Hall et al. (2021). Well locations for groundwater level data are classified by aquifer layer including the deepest Grande Ronde layer (circles), Wanapum (triangles), Saddle Mountains (diamond), and the shallowest Overburden (squares). The well locations are only shown for wells with a minimum of eight spring-high water level measurements between 2000-2020.

The proposed work will quantify the temporal evolution of drought occurrence from precipitation through the water budget to deep groundwater. The study area is the Washington State portion of the Columbia Plateau Regional Aquifer System. The work will produce a “drought cascade” figure, showing the temporal lag and drought signal attenuation as drought occurrence moves through the water cycle. Drought occurrence will be identified using z-scores and percentages of normal values for each variable of interest. The goal of the study is to identify the amount of time it takes for a surface-level drought signal to propagate to deep, confined groundwater layers or if the signal dissipates prior to reaching the deeper subsurface. The results can be used to inform how groundwater is used as a drought mitigation tool in Washington State.