Zachary D. Weller, PhD
I am an assistant professor of statistics at Colorado State University where I do statistical consulting through the Graybill Statistics and Data Science Laboratory and teach statistics courses. I also hold a joint appointment in the Colorado School of Public Health. I often work with the Department of Environmental and Radiological Health Sciences, but I also do general consulting for all departments across campus. Information for scheduling a consulting appointment with me or another consultant in the Graybill Lab can be found here.
My primary research interests lie in spatial, Bayesian, and non-parametric statistical methods with applications in ecological, environmental, and biological problems. I am also interested in applications in energy and wildlife management. One of my current areas of research is on a project to locate natural gas leaks and quantify their methane emissions. This work is one of several on-going research projects with the Dr. Joe von Fischer lab in the Department of Biology at Colorado State University. A second project involves assessing dust exposures and inflammatory markers for dairy workers. This is joint work with Emily Williams, Dr. Ander Wilson, Dr. Sheryl Magzamen, and Dr. Joshua Schaeffer. In addition to my research, I am also interested in scientific communication, the intersection of science and policy, and statistics education.
Selected Publications and Manuscripts
Characterizing detection probabilities of advanced mobile leak surveys: implications for sampling effort and leak size estimation in natural gas distribution systems. Luetschwager, E., von Fischer, J.C., Weller, Z.D. (2021). Elementa. doi: 10.1525/elementa.2020.00143
A National Estimate of Methane Leakage from Pipeline Mains in Natural Gas Local Distribution Systems. Weller, Z.D., Hamburg, S.P., von Fischer, J.C. (2020). Environmental Science and Technology, 54: 89548-8967. doi: 10.1021/acs.est.0c00437.
A Nonparametric Spectral Domain Test of Spatial Isotropy. Weller, Z.D & Hoeting, J.A. (2020). Journal of Statistical Planning and Inference, 204: 177-186. doi: 10.1016/j.jspi.2019.05.005.
An algorithm to process data from mobile methane surveys. Weller, Z.D., Yang, D.K., von Fischer, J.C. (2019). PloS One, 14(2). doi: 10.1371/journal.pone.0212287.
A Calibration-Capture-Recapture Model for Inferring Natural Gas Leak Population Characteristics Using Data From Google Street View Cars. Weller, Z.D., Hoeting, J.A., von Fischer, J.C. (2018). Environmetrics, 29(7): e2519. doi: 10.1002/env.2519
Vehicle-based Methane Surveys Help Find Natural Gas Leaks and Prioritize Leak Repairs. Weller, Z.D., Roscioli, J.R., Daube, W.C., Lamb, B.K., Ferrara, T.W., Brewer, P.E., von Fischer, J.C. (2018). To appear, Environmental Science and Technology, 52(20): 11922-11930. doi: 10.1021/acs.est.8b03135
spTest: an R package implementing nonparametric tests of isotropy. Weller, Z.D. (2018). Journal of Statistical Software, 83(4), 1-24. doi: 10.18637/jss.v083.i04.
A Review of Nonparametric Hypothesis Tests of Isotropy Properties in Spatial Data. Weller, Z.D. & Hoeting, J.A. (2016). Statistical Science, 31(3), 305-324. doi: 10.1214/16-STS547
R scripts for simulations available upon request
Reticulo-rumen Temperature as a Predictor of Calving Time in Primiparous and Parous Holstein Females. Costa, J. B. G., Ahola, J. K., Weller, Z. D., Peel, R. K., Whittier, J. C., & Barcellos, J. O. J. (2016). Journal of Dairy Science, 99(6), 4839-4850. doi: 10.3168/jds.2014-9289.
Selected Forthcoming Works
Environmental Justice Analysis of Urban Natural Gas Leaks. Im, S., Palacios, V., Stuchiner, E., von Fischer, J.C., Weller, Z.D. (2021+). In preparation.
Association of inflammatory biomarkers with bioaerosol exposure in livestock workers. Schaeffer, J.W., Williams, E., Weller, Z.D., Wilson, A., Bradford, M., Reynolds, S.J., Magzamen, S. (2021+) In preparation.
You can find more information about my publications on my Google Scholar page.
Below is a video from a seminar I gave in the fall of 2020 to discuss our recent national assessment paper.
Here is a news clip about our methane mapping project from China Global News.
Here is a link to a story about our collaboration with Consolidated Edison, a NY utility company that used advanced leak detection technology to help prioritize leak repairs.
My colleague Joe von Fischer and I were featured on a CSU Research podcast to discuss the methane mapping project:
Below is a write-up of the Methane Emissions Symposium hosted by the Stanford Natural Gas Initiative that I participated in during Spring 2021.
Last update: 08/20/2021