John Nimmo, Ph. D.
National Research Program
345 Middlefield Road
Menlo Park, CA 94025
- habitat alteration
- contamination and pollution
- ecosystem functions
- forest ecosystems
- desert ecosystems
- human impacts
- land use and land cover
- waste treatment and disposal
- groundwater flow
- groundwater level
- soil resources
- water resources
- flowering plants
- plants (organisms)
- field methods
- laboratory methods
- mathematical modeling
- groundwater quality
- water cycle
- water properties
- water quality
John Nimmo is a Research Physicist working toward establishment of a sound twenty-first century framework of water flow processes in soils and rocks. His specialty is the unsaturated zone, between the land surface and the water table. Applications of his work include aquifer recharge estimation, contaminant transport, ecohydrology, land-use evaluation, andclimate-change. As Lead Scientist for Unsaturated Flow Processes, he supervises a research group at the USGS that pursues these objectives through field and lab experiments, mathematical modeling, and development of unsaturated-flow theory.
Problems of water quality, water availability, land-use evaluation, ecosystem preservation and restoration, andclimate-change impacts require knowledge of the unsaturated-zone dynamics of water and substances it carries. Measurement, prediction, and understanding of the flow of water through soil and rock is crucial to this effort. In the National Research Program of the Water Mission Area of the USGS, great progress is possible through in-depth investigations and field experiments applying to diverse locations. Beyond individual-site applications, this diversity affords a vital opportunity to synthesize and develop specific findings into broad-scale and fundamental advances in unsaturated-zone hydrology.
Current and recent emphases include:
(1) preferential flow, including the influence of soil structure and rock fractures on water flow and contaminant transport
(2) aquifer recharge estimation
(3) flow at low water contents
(4) transport of water and contaminants in thick and geologically complex unsaturated zones
(5) effects of climate change on water resources
(6) interactions of soil moisture, plants, and ecological habitat
(7) theory and mathematical representation of flow behavior and properties
(8) advancement of techniques for measuring and evaluating flow in the unsaturated zone, especially (a) simple, low-technology methods for rapid characterization of areally-diverse field sites, and (b) advanced-technology methods for maximal subsurface information-acquisition with minimal intrusion from the land surface.
I earned a Ph.D. in porous media physics in 1983 and began full-time work in the USGS. My early career focused mainly on lab experiments and measurement techniques related to soil hydraulic properties, with the main application being aquifer-recharge estimation. Since the 1990s I have broadened my research efforts: (1) topically, to permit a more complete treatment of the inherently multidisciplinary concerns of earth science, (2) methodologically, to select from a large toolbox of lab, field, theoretical, and modeling techniques to best approach a given problem, and (3) geographically, to broaden the applicability of my work to a wide range of climate, geology, soils, hydrology, vegetation, and land use. Besides research, I contribute much effort to review of research papers and programs, consultation, teaching, and leadership of scientific groups within and outside the USGS.
Publications (See complete list in CV)
Perkins, Kimberlie S.; Nimmo, John R.; Medeiros, Arthur C., 2012. Effects of native forest restoration on soil hydraulic properties, Auwahi, Maui, Hawaiian Islands. American Geophysical Union , 4 p. [Link]
Nimmo, John R., 2012. Preferential flow occurs in unsaturated conditions. Wiley , 4 p. [Link]
Nimmo, John R., 2012. Response to Masciopinto's Comment on "Theory for source-responsive and free-surface film modeling of unsaturated flow". Soil Science Society of America , Soil Science Society of America [Link]
Mirus, Benjamin B.; Perkins, Kim S.; Nimmo, John R., 2011. Assessing controls on perched saturated zones beneath the Idaho Nuclear Technology and Engineering Center, Idaho. U.S. Geological Survey Scientific Investigations Report 2011-5222, vi, 20 p. [Link]
Perkins, K. S.; Nimmo, J. R.; Rose, C. E.; Coupe, R. H. , 2011. Field tracer investigation of unsaturated zone flow paths and mechanisms in agricultural soils of northwestern Mississippi, USA. ,
Ebel, Brian A.; Nimmo, John R., 2010. Hydraulic Property and Soil Textural Classification Measurements for Rainier Mesa, Nevada Test Site, Nevada. U.S. Geological Survey Open-File Report 2009-1264, iv, 17 p. [Link]
Ebel, Brian A.; Nimmo, John R., 2009. Estimation of Unsaturated Zone Traveltimes for Rainier Mesa and Shoshone Mountain, Nevada Test Site, Nevada, Using a Source-Responsive Preferential-Flow Model. U.S. Geological Survey Open-File Report 2009-1175, vi, 74 p. [Link]
Nimmo, J. R.; Perkins, K. S. , 2008. Effect of soil disturbance on recharging fluxes: Case study on the Snake River Plain, Idaho National Laboratory, USA. ,
Rousseau, Joseph P.; Landa, Edward R.; Nimmo, John R.; Cecil, L. DeWayne; Knobel, LeRoy L.; Glynn, Pierre D.; Kwicklis, Edward M.; Curtis, Gary P.; Stollenwerk, Kenneth G.; Anderson, Steven R.; Bartholomay, Roy C.; Bossong, Clifford R.; Orr, Brennon R., 2005. Review of the transport of selected radionuclides in the interim risk assessment for the Radioactive Waste Management Complex, Waste Area Group 7 Operable Unit 7-13/14, Idaho National Engineering and Environmental Laboratory, Idaho. Scientific Investigations Report 2005-5026, 283 p. in two volumes (211 p. in volume 1 and 72 p. in volume 2) [Link]
Heppner, Christopher S.; Nimmo, John R., 2005. A computer program for predicting recharge with a master recession curve. Scientific Investigations Report 2005-5172, 10 p. [Link]
Perkins, K. S.; Nimmo, J. R., 2000. Measurement of hydraulic properties of the B-C interbed and their influence on contaminant transport in the unsaturated zone at the Idaho National Engineering and Environmental Laboratory, Idaho. Water-Resources Investigations Report 2000-4073, 30 p.
Nimmo, J. R.; Shakofsky, S. M.; Kaminsky, J. F.; Lords, G. S., 1999. Laboratory and field hydrologic characterization of the shallow subsurface at Idaho National Engineering and Environmental Laboratory waste-disposal site. Water-Resources Investigations Report 99-4263, 31 p.
Perkins, K. S.; Nimmo, J. R.; Pittman, J. R. , 1998. Hydrologic and meteorological data for an unsaturated-zone study area near the Radioactive Waste Management Complex, Idaho National Engineering and Environmental Laboratory, Idaho, 1990-96. U.S. Dept. of the Interior, U.S. Geological Survey ; Information Services [distributor], Open-File Report 98-9, iv, 13 p. :ill., maps ;28 cm. +1 computer laser optical disc.