Diking and channelizing in the Toppenish Creek basin, associated with irrigated agricultural development, has altered its natural ecosystem function and hydraulic processes. We seek to answer two research questions: if surface waters are diverted for aquifer recharge in the winter, will this water be available for ecosystem function in the...
Sand dams – low-head dams built in ephemeral streambeds that store water within saturated sediments – are a proven means to increase water supplies for rural communities in arid and semiarid regions. Water percolates into the reservoir-impounded sediments during wet season rains and can subsequently be extracted during the dry...
Survival of ecological systems pivot on critical moments. In the arid John Day Basin of Eastern Oregon, extensive restoration of the stream and floodplain focused on supporting salmon has been ongoing for the past 20 years, but recurring short periods of extreme temperature increase and low flows result in mortality...
Finding trees and crops that are resistant to pathogens is key in preparing for current and future disease threats. In this dissertation, we analyzed the potential of using hyperspectral imaging (HSI) to find infection while identifying issues and strategies addressing differences over time, in spatial resolution, the application of machine...
In the face of climate change droughts are predicted to become more persistent, further intensifying the need for accurately predicting the timing and magnitude of summer streamflow in rivers. In order to determine the sensitivity of a watershed to drought, there is a need to describe what these drought conditions...
Urban development causes changes in the hydrology, increasing stormwater runoff volumes, which often leads to flooding and ecosystem degradation. This is a common phenomenon in most urban Africa, due to lack of stormwater drainage infrastructures. Green Infrastructure (GI) has been shown to be an effective approach to lessen the effects...
Surface water and groundwater are intimately connected by a two-way flux between the stream and the underlying aquifers; a complicated yet crucial relationship to represent in models. However, the National Water Model currently only considers a one-way flux, where groundwater can enter a stream but cannot return to the aquifer....
As the number of weather stations declines globally, ensuring that meteorological monitoring networks efficiently and effectively monitor weather variables becomes increasingly important. Multi-variable weather sensors are becoming more widely available and make monitoring weather phenomena more economical. However, when seeking an optimal spatial distribution of these stations, choosing an objective...
The Middle Fork John Day Basin in Northeastern Oregon is prime habitat for spring Chinook salmon and Steelhead trout. In 2008, a major tributary supporting rearing habitat, Big Boulder Creek, was restored to its historic mid-valley channel along a 1 km stretch of stream 800 m upstream of the mouth....
Surface water and groundwater interactions are a key component in the functioning of stream ecosystems. Exchange of water between the stream and the hyporheic zone creates habitat for aquatic organisms and serves as a control for stream biogeochemical, thermal, and flow processes. This study takes a multi-method field-based approach to...