eNews November 2017

Meet the Researcher: Esther Xu, New Mexico Institute of Mining and Technology (continued)

Esther started her graduate student life working with her faculty advisors on estimating groundwater recharge for the entire state of New Mexico as part of the SWA. She followed the methodology developed by David Ketchum (a recent NMT hydrology MS graduate and NM WRRI-supported student) who initiated the development of the EvapoTranspiration and Recharge Model (ETRM). Esther has been expanding the ETRM beyond the estimates of diffuse groundwater recharge (i.e., rainwater percolating down through the soil where it fell) that it currently produces by incorporating focused groundwater recharge estimates (i.e., water that runs off the landscape and accumulates in washes or depressions where it then percolates down toward the aquifer).

This year, as part of the Transboundary Aquifer Assessment Program (TAAP), Esther is focusing on modifying and applying the ETRM model to the Mesilla Bolson. By mapping soil physical properties such as texture she has optimized estimates of saturated hydraulic conductivity, which is a key input to the model. As an intermediate step, she is now applying the model to a very densely instrumented watershed, Walnut Gulch Experimental Watershed in Arizona, to further calibrate and validate the model output. Once validated, Esther will then apply the model to the Mesilla Bolson. The model output can then be compared with a limited, but extremely valuable data set of discharge from ephemeral washes collected by Elephant Butte Irrigation District in order to estimate channel bed infiltration and the resultant focused aquifer recharge. These improvements to ETRM will greatly improve the applicability of its output for water planning in the face of future population and climate change.

Esther received a BS in geology from NMT in 2016, and a BEng in resources exploration from Yangtze University in Wuhan, Hubei Province, China, in 2017. Her interest in statistics led her to pursue and receive a minor in mathematics in her BS degree from NMT, and as part of her MS she is again including a mathematics minor.

Having adapted well to New Mexico, in spite of the cultural and environmental differences, Esther said, “I come from a big city, so the wild nature of NM brings me so many fresh views and enchants me. I particularly enjoy a walk on the streets of Santa Fe, the gloaming view of Bosque del Apache, the sky in NM, and seasons of M mountain.” Esther says that she also enjoys facing the unknown, and tries to live by the motto “Never be ordinary.” She is still mulling her options for the future. “I haven’t decided my future career path – I would either go for a PhD for satisfying my desire of exploring more in my favorite field or find a job to solve interesting problems.”