Civil and Architectural Engineering
College of Engineering and Physical Sciences
Education:
- B.A. Civil Engineering, Chuo University, Japan, 1997
- M.A. Civil Engineering, Chuo University, Japan, 1999
- Ph.D. Civil Engineering, University of California, Davis, 2003
Research Interests:
- Hydrologic Modeling
- Snow Hydrology
- Hydrologic Field Observation
- Hydrometeorology
- Theoretical Treatment of Scale Gap
Professional Affiliations:
- American Society of Civil Engineers (ASCE)
- American Geophysical Union (AGU)
- Japan Society of Civil Engineers
Publications:
- Jones, B., C. D. Arp, G. Grosse, I. Nitze, M. J. Lara, M. S. Whitman, L. M. Farquharson,
M. Kanevskiy, A. D. Parsekian, A. L. Breen, N. Ohara, R. C. Rangel, and K. M. Hinkel,
“Identifying historic and future potential lake drainage events on the western Arctic
Coastal Plain of Alaska”, Permafrost and Periglacial Processes, accepted, 2020
- Ohara N.*, and K. Yamatani, "Theoretical Stable Hydraulic Section based on the Principle
of Least Action”, Scientific Reports, 9, Article number: 7957, 2019. https://www.nature.com/articles/s41598-019-44347-4
- Ishida, K., N. Ohara, A. Ercan, S. Jang, T. Trinh, M.L. Kavvas, K. Carr, M. L. Anderson,
“Impacts of Climate Change on Snow Accumulation and Melting Processes over Mountainous
Regions in Northern California during the 21st Century”, Science of The Total Environment,
accepted, 2019.
- He, S., N.Ohara*, “Modeling Sub-Grid Variability of Snow Depth using the Fokker-Planck
Equation Approach”, Water Resources Research, 2019.
- He, S, N.Ohara*, and S.N. Miller “Understanding sub-grid variability of snow depth
at 1 km scale using Lidar measurements”, Hydrologic Processes, 2019.
- Ishida, K., A. Ercan, T. Trinh, S. Jang, M. L. Kavvas, N. Ohara, Z. Q. Chen, S. Kure,
and Dib. "Trend analysis of watershed-scale annual and seasonal precipitation in Northern
California based on dynamically downscaled future climate projections", Journal of
Water and Climate Change, 2018.
- Ishida, K., Ercan, A., Trinh, T., Kavvas, M. L., Ohara, N., Carr, K., & Anderson,
M. L. “Analysis of future climate change impacts on snow distribution over mountainous
watersheds in Northern California by means of a physically-based snow distribution
model”, Science of The Total Environment, 645, 1065-1082, 2018.
- Thayer, D., A. D. Parsekian, K. Hyde, H. Speckman, D. Beverly, B. Ewers, M. Covalt,
N. Fantello, T. Kelleners, N. Ohara, and T. Rogers “Geophysical Measurements to Determine
the Hydrologic Partitioning of Snowmelt on a Snow‐Dominated Subalpine Hillslope”,
Water Resources Research, 54 (6), 3788-3808, 2018.
- Ohara, N.*, W.S. Holbrook, K. Yamatani, B.A. Flinchum, and J.T. St. Clair, “Spatial
Estimation of Riparian Groundwater Domain within Alluvium Deposit of Mountainous Areas”,
Hydrological Processes, 32 (1), 30-38, 2018.
- Ishida, K., N. Ohara, M. L. Kavvas, Z. Q. Chen, and M. L. Anderson. "Impact of air
temperature on physically-based maximum precipitation estimation through change in
moisture holding capacity of air." Journal of Hydrology, 556, 1050–1063, 2018.
- Pleasants, M.S.*, T. Kelleners, and N.Ohara, "Analysis of snowpack dynamics during
the spring melt season using point measurements and numerical modeling", Hydrological
Processes, 31(25), 4568-4585, 2017.
- He, S.*, and N.Ohara, “A new formula for estimating the threshold wind speed for snow
movement”, Journal of Advances in Modeling Earth Systems (JAMES), 9(7), 2514-2525,
2017.
- Johnson, R. and N.Ohara*, “Dynamic Equilibrium Modeling of Snow and Inland Glaciers
under the Evolving Climate in Wyoming”, Journal of Hydrologic Engineering, ASCE, 23(1),
04017056, 2017..
- Jang, S.*, M.L. Kavvas, K. Ishida, T. Trinh, N.Ohara, S. Kure, Z.Q. Chen, M.L. Anderson,
G. Matanga, and K. J. Carr, “A Performance Evaluation of Dynamical Downscaling of
Precipitation over Northern California”, Sustainability, 2017. doi:10.3390/su9081457.
- Jang, S.*, S. Kure, N.Ohara, M.L. Kavvas, Z.Q. Chen, K. J. Carr and, M.L. Anderson,
“Application of WEHY-HCM for Modeling Interactive Atmospheric-Hydrologic Processes
at Watershed Scale to a Sparsely Gauged Watershed”, Sustainability, 2017. doi:10.3390/su9091554.
- Trinh, T.Q.*, M.L. Kavvas, K. Ishida, K. J. Carr, and N.Ohara, "Projected 21st Century
Climate Change on Snow Conditions over Shasta Dam Watershed by means of Dynamical
Downscaling", Hydrological Processes, 2017. 31:2887–2901. https://doi.org/10.1002/hyp.11231.
- Ohara, N.*, M.L. Kavvas, M.L. Anderson, Z.Q. Chen, and K. Ishida, "Characterization
of Extreme Storm Events using A Numerical Model Based Precipitation Maximization Procedure
in Feather, Yuba, and American River Watersheds in California", Journal of Hydrometeology,
18 (5), 1413-1423, 2017.
- Ohara, N.*, “An Eulerian Equation for Snow Accumulation Downstream of an Object”,
Water Resource Research, Volume 53, Issue 2, 1525–1538, 2017.
- Peel, T., M. Ahmed, and N.Ohara, “Investigating Safety-Effectiveness of Wyoming Snow
Fence Implementations along a Rural Mountainous Freeway”, Transportation Research
Record (TRR), 2017.
- Trinh, T.Q.*, S. Jang, K. Ishida, N. Ohara, Z.Q. Chen, M.L. Anderson, Y. Darama, M.L.
Kavvas, “Reconstruction of Historical Inflows into and Water Supply from Shasta Dam
by Coupling Physically Based Hydroclimate Model with Reservoir Operation Model." Journal
of Hydrologic Engineering, ASCE, 10.1061/(ASCE)HE.1943-5584.0001391, 04016029. 2016.
- Chen, J.F.*, M.L. Kavvas, K. Ishida, T.Q. Trinh, N.Ohara, M.L. Anderson, and Z.Q.
Chen, Role of Snowmelt in Determining whether the Maximum Precipitation Always Results
in the Maximum Flood." Journal of Hydrologic Engineering, ASCE, 10.1061/(ASCE)HE.1943-5584.0001366,
04016032, 2016.
- Amin M.Z.M., A. J. bin Shaaban, N.Ohara*, M.L.Kavvas, Z.Q.Chen, S. Kure, and S. Jang,
“Climate Change Assessment of Water Resources in Sabah and Sarawak, Malaysia, Based
on the Dynamically Downscaled GCM Projections Using a Regional Hydroclimate Model”,
Journal of Hydrologic Engineering, 10.1061/(ASCE)HE.1943-5584.0001242, 05015015.,
2015.
- Ishida*, K., M.L. Kavvas, S. Jang, Z.Q. Chen, N. Ohara, M.L. Anderson, “Physically
Based Estimation of Maximum Precipitation over Three Watersheds in Northern California:
Relative Humidity Maximization Method”, Journal of Hydrologic Engineering, ASCE, 20(10),
04015014, 2015.
- Ishida, K.*, M.L. Kavvas, S. Jang, Z.Q. Chen, N. Ohara, M.L. Anderson, ”Physically
Based Estimation of Maximum Precipitation over Three Watersheds in Northern California:
Atmospheric Boundary Condition Shifting”, Journal of Hydrologic Engineering, ASCE,
20(4), 04014052, 2015.
- Ohara, N.*, “A Practical Formulation of Snow Surface Diffusion by Wind for Watershed
Scale Applications”, Water Resources Research, Vol. 50, Issue 6, 5074-5089, 2014.
- Ohara, N.*, S. Kure, S. Jang, Z.Q. Chen and M.L. Kavvas, “Modeling of Interannual
Snow and Ice Storage in High Altitude Region by Dynamic Equilibrium Concept”, Journal
of Hydrologic Engineering, ASCE, 19(12), 04014034, 2014.
- Ohara, N.*, M.L. Kavvas, Z.Q.Chen, L. Liang, M. Anderson, J. Wilcox and L.Mink, “Modelling
atmospheric and hydrologic processes for assessment of meadow restoration impact on flow
and sediment in a sparsely gauged California watershed”, Hydrological Processes, 28,
3053–3066, 2014.
- Oh, N.H.*, B. Pellerin, P. Bachand, P. Hernes, S. Bachand, N. Ohara, M. L. Kavvas,
B. Bergamaschi, and W. Horwath. “The Role of Irrigation Runoff and Winter Rainfall
on Dissolved Organic Carbon Loads in an Agricultural Watershed”, Agriculture, Ecosystems
and Environment, Volume 179, 1 October, 1–10, 2013.
- Kavvas, M.L.*, S. Kure, Z.Q. Chen, N.Ohara, and S. Jang, “WEHY-HCM for Modeling Interactive
Atmospheric-Hydrologic Processes at Watershed Scale. I: Model Description”, Journal
of Hydrologic Engineering, ASCE, Vol. 18, No. 10, pp. 1262-1271, 2013.
- Kure, S., S. Jang*, N. Ohara, M. L. Kavvas, and Z. Q. Chen, “WEHY-HCM for Modeling
Interactive Atmospheric-Hydrologic Processes at Watershed Scale. II: Model Application
to Ungauged and Sparsely Gauged Watersheds”, Journal of Hydrologic Engineering, ASCE,
Vol. 18, No. 10, pp. 1272-1281, 2013.
- Kure, S., S. Jang*, N.Ohara, M.L. Kavvas, and Z.Q. Chen, “Hydrological Impact of Regional
Climate Change for the Snowfed and Glacierfed River Basins in the Republic of Tajikistan:
Statistical Downscaling of Global Climate Model Projections”, Hydrological Processes,
2012.
- Kure, S., S. Jang*, N.Ohara, M.L. Kavvas, and Z.Q. Chen, “Hydrologic Impact of Regional
Climate Change for the Snowfed and Glacierfed River Basins in the Republic of Tajikistan:
Hydrological Response of flow to Climate Change”, Hydrological Processes, 2012.
- Chen, Z.Q., Kavvas, M.L, Ohara N.*, Anderson, M. L., and Yoon, J. “A Coupled Regional
Hydro-Climate Model and its Application to the Tigris-Euphrates basin”, Journal of
Hydrologic Engineering, ASCE, Vol. 16, No. 12, 1059–1070, 2011.
- Ohara, N.*, Kavvas, M.L., Anderson, M.L., Chen, Z.Q., and Yoon J. “A Water Balance
Study for the Tigris-Euphrates River Basin”, Journal of Hydrologic Engineering, ASCE,
Vol. 16, No. 12, 1071–1082, 2011.
- Chen, Z.Q., Kavvas, M.L, Ohara N.*, and Anderson, M.L. “Impact of Water Resources
Utilization on the Hydrology of Mesopotamian Marshlands”, Journal of Hydrologic Engineering,
ASCE, Vol. 16, No. 12, 1083–1092, 2011.
- Ohara, N.*, Chen, Z.Q., Kavvas, M.L., Fukami, K., and Inomata, H. “Reconstruction
of Historical Atmospheric data by A Hydroclimate Model for Mekong River Basin”, Journal
of Hydrologic Engineering, ASCE, Vol. 16, No. 12, 1030–1039, 2011.
- Shaaban, A.J., Amin M.Z.M., Chen, Z.Q., and Ohara, N.* “Regional Modeling Of Climate
Change Impact On Peninsular Malaysia Water Resources”, Journal of Hydrologic Engineering,
ASCE, Vol. 16, No. 12, 1040–1049, 2011.
- Kure, S.*, Kavvas, M.L., Ohara, N., and Jang, S., “Upscaling of Coupled Land Surface
Process Modeling for Heterogeneous Landscapes: Stochastic Approach”, Journal of Hydrologic
Engineering, ASCE, Vol. 16, No. 12, 1017–1029, 2011.
- Florsheim, J.L.*, B.A. Pellerin, N.H. Oh, N. Ohara, P.A.M. Bachand, S.M. Bachand,
B.A. Bergamaschi, P.J. Hernes, M.L. Kavvas, “From deposition to erosion: Spatial and
temporal variability of sediment sources, storage, and transport in a small agricultural
watershed”, Geomorphology, Volume 132, Issues 3–4, 272–286, 2011.
- Ohara, N., Kavvas, M. L.*, Kure, S., Chen, Z. Q., Jang, S., and Tan, E. “A Physically-Based
Estimation of Maximum Precipitation over American River Watershed, California”, Journal
of Hydrologic Engineering, ASCE, Vol. 16, issue 4, 351-361, 2011.
- Kavvas, M.L.*, Z.Q. Chen, M.L. Anderson, N. Ohara, J.Y. Yoon, and Fu Xiang. “A Study
of Water Balances over the Tigris-Euphrates Watershed”, Physics and Chemistry of the
Earth, Elsevier, Vol. 36, 197-203, 2011.
- Ohara, N.*, Kavvas, M.L., Easton, D., Dogrul, C. E., Yoon, J., and Chen, Z.Q. “The
Role of Snow in Runoff Processes in a Sub-alpine Hillslope : Field Study in the Ward
Creek Watershed, Lake Tahoe, California during 2000 and 2001 Water Years”, Journal
of Hydrologic Engineering, ASCE, Vol. 16, No. 6, pp. 521-533, 2010.
- Fu Xiang, Kavvas, M.L.*, Chen, Z.Q., Bandeh, H., Ohara, N., Kim, S., Jand S.H., Churchwell,
R. “Experimental Study of Debris Capture Efficiency of Trash Racks”, Journal of Hydro-environmental
Research, No.3, 138-147, 2009.
- Ohara, N.*, Kavvas, M. L., and Chen, Z. Q., “Stochastic Upscaling for Snow Accumulation
and Melt Processes with PDF Approach”, Journal of Hydrologic Engineering, ASCE, Vol
13, issue 12, 1103-1118, 2008.
- Kavvas, M. L., Yoon, J*, Chen, Z. Q., Liang, L., Dogrul, E. C., Ohara, N., Aksoy,
H., Anderson, M. L., Reuter, J., and Hackley, S. “Watershed Environmental Hydrology
Model: Environmental Module and Its Application to a California Watershed”, Journal
of Hydrologic Engineering, ASCE, Vol. 11, issue 3, 261-272, 2006.
- Ohara, N.*, and Kavvas, M. L. “Field Observations and Numerical Model Experiments
for The Snowmelt Process At A Field Site”, Advances in Water Resources, Elsevier,
29, 194-211, 2006.
- Kavvas, M. L.*, Chen, Z. Q., Dogrul, J., Yoon, J., Ohara, N., Liang, L., Aksoy, H.,
Anderson, M. L, Yoshitani, J., Fukami, K. and Matsuura, T. “Watershed Environmental
Hydrology (WEHY) Model Based On Upscaled Conservation Equations: Hydrologic Module”,
Journal of Hydrologic Engineering, ASCE, Vol. 9, issue 6, 2004.
- Shimura, K., Ohara, N.*, Matsuki, H., and Yamada, T. “Study on Flood Wave Using Unsteady
Flow Analysis”, Journal of Japan Society of Hydrology and Water Resources, Vol. 14,
No. 3, May, 2001. (in Japanese)
Send page comments to ohara1@uwyo.edu