Expertise
I am currently working on a number of topics broadly falling under the umbrella of “impacts to water resources in a changing climate”. This entails a range of different projects.
One project involves the quantification of residential wells that my go dry during drought. Unlike public water supplies, residential wells are not regulated (besides some basic reporting when initially installed) so there is little information on the vulnerability of groundwater reliant homes to possible reductions in future recharge. This project relates measures of drought in a given region (i.e. the US Drought Monitor and USGS monitoring wells) to the number of new wells drilled each year in that same region, evaluating whether the number of new wells being drilled increases during period of drought.
Another project focuses on developing low-power sensors to measure sap flow in trees. Sap flow is a measure of how much water a tree is using. While sap flow sensors have been around for decades, nearly all to date require bulky car batteries or solar panels to power them. This limits where the sensors can be placed, whether in wild forests or urban areas. Led by PhD student Justin Beslity, this project has developed low-power sensors that are powered by rechargeable AA batteries, allowing for sensor placement in remote locations or in highly populated areas where the sensors can be kept out of sight. This project has also entailed improving the general methodology of sap flow measurements via the heat pulse technique by developing custom probes that better quantify radial variability in sap flow across the tree trunk and by using a custom drill guide that ensures probes are perfectly aligned when installed in the tree.
A third project considers new ways to evaluate the effectiveness of agricultural best management practices (BMPs), especially when considered at the watershed scale. A changing climate may modify rainfall patterns, changing nutrient loading to waterbodies. BMPs are a potential way to mitigate this nutrient loading. While BMP effects are often directly measured at the scale of individual BMPs, at the watershed scale most assessment is done by modeling. However, meta-analyses have revealed that standard modeling almost always identifies better results than attempts at more direct analysis using measured data. This project considers ways to integrate simple models with water quality data to more transparently explore watershed scale BMP function.