Ranji Ranjithan

Professor, Director of Graduate Programs, Associate Head

Dr. S. Ranji Ranjithan is a Professor of Civil Engineering. He joined the Civil Engineering Department at North Carolina State University in 1995. He is also a faculty member in the Operations Research Program. His research interests are in the area of engineering systems analysis. Dr. Ranjithan is a member of the Environmental, Water Resources, and Coastal Engineering and Computing and Systems faculty groups within Civil Engineering. His primary areas of teaching and research focus on developing mathematical and computer-based procedures for modeling and analysis of engineering systems, and their implementations to aid decision makers explore and examine solutions to complex engineering problems.

Current and recent areas of application include infrastructure systems engineering, water and environmental sustainability, solid waste management, groundwater monitoring and remediation, watershed management, non-destructive testing of pavements and timber structures, and emergency evacuation management. Working in collaboration with fellow researchers, he focuses on approaching these problems from a multi-disciplinary perspective. Most of his applications research attempt to integrate systems analytic methods with different computational paradigms to develop working prototypes of engineering decision support tools.

His research sponsors and collaborating agencies include the US EPA, NSF, DHS, Center for Transportation and the Environment, North Carolina Supercomputing Center/MCNC, Oak Ridge National Laboratories, North Carolina Department of Environment and Natural Resources, Research Triangle Institute, North Carolina Department of Transportation, and Transportation Research Board.


Ph.D. 1992

Environmental Engineering

University of Illinois, Urbana-Champaign

M.Eng. 1985

Industrial Engineering and Management

Asian Institute of Technology

B.S. 1981

Mechanical Engineering

University of Peradeniya

Research Description

Dr Ranjithan is interested in mathematical modeling and optimization, evolutionary computation, systems analysis, computer-based decision support tools, decision making under uncertainty, artificial neural networks; areas of applications include air quality management, watershed management, animal waste management, solid waste management, and transportation engineering. He is involved with Computing and Systems, Energy, and Architectural research that is helping to innovate sustainable building design by coupling simulation and building information models with analytical and optimization methods to integrate architectural and engineering design processes such that the energy efficiency of buildings can be enhanced at every stage of building design. Mathematical modeling and computational procedures are being developed and used by his group of Computing and Systems researchers to quantify the resilience of a civil infrastructure system (CIS) in supporting lifeline services that are collectively enabled by the components of that CIS. Founded on these research results, the system-wide resilience metrics are combined with decision models and search algorithms to prioritize infrastructure investments to improve lifeline service resilience considering storm hazards and their impacts on the civil infrastructure systems. His Computing and Systems and Water Resources research collaborations are playing a key role in helping to detect leaks in water distribution networks by integrating hydraulic simulation models and infrastructure data with contemporary analytical methods that are enabled by high performance computing technologies. Computational and analytical procedures in sync with modern search algorithms developed by his research team have resulted in efficient and effective decision-support tools to identify sources of contamination in groundwater aquifer systems and water distribution networks. Through development and innovative interfacing of data, measurements, analytical and decision models, and search algorithms for optimization, he couples Computing and Systems and Environmental Engineering research to develop, test and apply one-of-a-kind life-cycle-based municipal solid waste management decision-support tool for generating integrated waste management plans that consider cost, energy and material consumption, environmental impacts and potential carbon prices. By his collaborative efforts in Computing and Systems and Water Resources research, flow alteration-driven ecological impacts in watersheds due to land-use and climate change effects are being modeled and studied through development of contemporary data and modeling tools and their integration with optimization methods that support water sustainability and adaptive watershed management.


Construction and setup of a bench-scale algal photosynthetic bioreactor with temperature, light, and ph monitoring for kinetic growth tests
Karam, A. L., McMillan, C. C., Lai, Y. C., de los Reyes, F. L., Sederoff, H. W., Grunden, A. M., Ranjithan, R. S., Levis, J. W., & Ducoste, J. J. (2017), Jove-Journal of Visualized Experiments, (124).
Role of multimodel combination and data assimilation in improving streamflow prediction over multiple time scales
Li, W. H., Sankarasubramanian, A., Ranjithan, R. S., & Sinha, T. (2016), Stochastic Environmental Research and Risk Assessment, 30(8), 2255-2269.
An enhanced linear regression-based building energy model (LRBEM plus ) for early design
Al Gharably, M., DeCarolis, J. F., & Ranjithan, S. R. (2016), Journal of Building Performance Simulation, 9(2), 115-133.
Understanding the low-frequency variability in hydroclimatic attributes over the southeastern US
Wang, H., Sankarasubramanian, A., Ranjithan, R. S. (2015), Journal of Hydrology, 521, 170-181.
battle of the Water Networks II
Marchi, A., Salomons, E., Ostfeld, A., Kapelan, Z., Simpson, A. R., Zecchin, A. C., Maier, H. R., Wu, Z. Y., Elsayed, S. M., Song, Y., Walski, T., Stokes, C., Wu, W. Y., Dandy, G. C., Alvisi, S., Creaco, E., Franchini, M., Saldarriaga, J., & Paez, D. (2014), Journal of Water Resources Planning and Management, 140(7).
Improved regional water management utilizing climate forecasts: An interbasin transfer model with a risk management framework
Li, W. H., Sankarasubramanian, A., Ranjithan, R. S., & Brill, E. D. (2014), Water Resources Research, 50(8), 6810-6827.
A monitoring network design procedure for three-dimensional (3D) groundwater contaminant source identification
Jin, X., Ranjithan, R. S., & Mahinthakumar, G. (2014), Environmental Forensics, 15(1), 78-96.
Systematic exploration of efficient strategies to manage solid waste in US municipalities: Perspectives from the solid waste optimization life-cycle framework (SWOLF)
Levis, J. W., Barlaz, M. A., DeCarolis, J. F., & Ranjithan, S. R. (2014), Environmental Science & Technology, 48(7), 3625-3631.
Special issue on the role of systems analysis in watershed management
Cai, X. M., Vogel, R., & Ranjithan, R. (2013), Journal of Water Resources Planning and Management, 139(5), 461-463.
A generalized multistage optimization modeling framework for life cycle assessment-based integrated solid waste management
Levis, J. W., Barlaz, M. A., DeCarolis, J. F., & Ranjithan, S. R. (2013), Environmental Modelling Review & Software: With Environmental Data News, 50, 51-65.

View all publications via NC State Libraries


Maximizing Energy for Waste While Minimizing Life-Cycle Environmental Burdens and Cost
US Environmental Protection Agency (EPA)(12/09/14 - 3/31/18)
Water Distribution Modeling Experiments with the Cary Network
Sensus USA, Inc.(10/01/14 - 7/31/16)
Solid Waste Management Planning for Wake County in Consideration of Cost, Energy and Environmental Emissions
Wake County(7/01/14 - 12/31/17)
The NCSU Sustainable Cities Consortium: Addressing Grand Challenges in the Urban Environment
NCSU Office of Research, Innovation, and Economic Development(7/01/14 - 6/30/15)
SAVI: International Institute for Solid Waste Management Life-Cycle Modeling
National Science Foundation (NSF)(8/15/14 - 7/31/18)
EFRI-PSBR:Closing the Loop- Towards a PSBR Design Framework for Self-Sustained Marine Microalgal-Based Fuel Production
National Science Foundation (NSF)(9/01/13 - 8/31/18)
Graduate Industrial Traineeship for Shahrzad Azizzadeh
SAS Institute Inc.(1/10/11 - 12/23/11)
National Science Foundation (NSF)(8/15/11 - 7/31/16)
Building Design Process Innovation for Enhancing Energy and Environmental Sustainability
NCSU Strategic Research Initiative(7/01/10 - 6/30/11)
The Environmental Sustainability of Integrated Solid Waste Management in a Carbon Constrained World
National Science Foundation (NSF)(8/15/10 - 7/31/15)