ALY EL-KADIGroundwater Hydrologist and Professor Emeritus, WRRC; Professor Emeritus, Department of Earth Sciences


ALY EL-KADIGroundwater Hydrologist and Professor Emeritus, WRRC; Professor Emeritus, Department of Earth Sciences



  • PhD, Groundwater Hydrology, School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, 1983
  • MS, Surface Water Hydrology, Ain Shams University, Cairo, Egypt, 1976
  • BS, Fluid Mechanics and Hydraulics, Ain Shams University, Cairo, Egypt, 1971


  • Watershed modeling and analysis
  • Application and assessment of various types of groundwater models
  • Modeling multiphase flow and transport of hydrocarbons
  • Numerical modeling
  • Flow and transport in field soils
  • Databases and geographic information systems
  • Bioremediation in tidal aquifers
  • Contamination by agricultural and cesspool sources

Aly I. El-Kadi is a Professor Emeritus of hydrology in the department of Earth Sciences. His teaching and academic interests focused on hydrogeology and groundwater modeling. Professor El-Kadi is also an Affiliate Faculty researcher and Professor Emeritus at the Water Resources Research Center where his research interests covered a wide range of topics including climate change effects on water resources sustainability, numerical modeling, and modeling multiphase flow and transport of hydrocarbons.

Professor El-Kadi was the Associate Director (2000–2018) of the Water Resources Research Center, which serves the state of Hawaiʻi and other Pacific islands by researching water-related issues distinctive to the region. Between 2016–2022, he was also a member of the ʻIke Wai leadership and research teams. ‘Ike Wai was an EPSCoR project that was supported by the National Science Foundation. EPSCoR stands for Experimental Program to Stimulate Competitive Research, and ‘Iki Wai was aimed at increasing the understanding of Hawaiian island hydrology. The main objective of the project was to provide improved data for decision-making tools that address the challenges to water sustainability from climate variability, increasing population demands, and water contamination. His research for the project covered groundwater modeling and studied the increasing stress placed on Hawaiʻi’s aquifers due to factors associated with population growth, economic development, and climate change. Professor El-Kadi’s work expanded beyond Hawaiʻi to include projects in American Samoa and Jeju Island, Korea.

Professor El-Kadi earned his Ph.D. in Groundwater Hydrology from the School of Civil and Environmental Engineering at Cornell University in Ithaca, New York, an M.S. in Surface Water Hydrology from Ain Shams University, and a B.S. in Fluid Mechanics and Hydraulics from Ain Shams University located in Cairo, Egypt.



UH-ASPA Hydrologic Monitoring Network

ASPA-UHWRRC weather station, stream gauge, and monitoring well network instruments.
Hydrologic datasets are essential for the design of sustainable water supply systems and the prediction or detection of acute threats to drinking water quality or availability. We developed a hydrologic monitoring network consisting of 21 instruments including weather stations, stream gauges, and monitoring well dataloggers on the Island of Tutuila, American Samoa.

Assessment of Groundwater Ages Using Radiocarbon and Chlorofluorocarbons in West Hawai‘i Aquifer Systems

Figure 1. Apparent groundwater ages in West Hawai‘i, Hawai‘i Island.  
A multi-tracer approach was used to determine the apparent groundwater ages in West Hawai‘i. Radiocarbon chlorofluorocarbons were used to date water over a range of ages. The results can be used to assess aquifer storage and travel times, which are important is understanding the hydrologic system and assessing groundwater sustainability.

Development and Multi-Process Calibration for the Keauhou Aquifer in West Hawai‘i

Figure 1. Conceptual model for the Keauhou basal aquifer (KBA) illustrates various inflows and outflows, Hawai‘i Island.
The study included developing and implementing a conceptual model for the Keauhou Aquifer site in West Hawai‘i, calibrating the model using available data to their fullest extent to constrain parameters, and applying the model for management through simulating various scenarios aimed at assessing the risk to aquatic resources.

A Participatory and Model Based Approach to Assessing Groundwater Recharge Under Contemporary and Future Climate Scenarios: Tutuila, American Samoa

Illustration of present day model calculated average-annual groundwater recharge at 20 m cell-size resolution. Inset map shows detail of 1) flow routing effects, seen as higher recharge squares at the bottom of drainage channels, 2) direct infiltration from leaking water lines, seen as linear zones of higher infiltration, and 3) MFR zones seen as larger patches of high- infiltration.
A water budget approach using the Soil Water-Balance-2 model was applied to Tutuila Island in American Samoa. We also assessed potential future change in recharge by substituting rainfall and temperature projections from dynamically downscaled climate global climate model predictions and possible future land-cover scenarios developed with local stakeholders.

ASPA-UHWRRC Integrated Groundwater Modeling Framework

UH WRRC Director Tom Giambelluca visits one of the weather stations within the Tutuila Hydrologic Monitoring Network.
This work presents a collaborative modeling framework developed by participants at the American Samoa Power Authority and at the University of Hawai‘i Water Resources Research Center. The framework includes modular components including collection and analysis of climatic and streamflow data and development of a water budget model and groundwater model.

Ridge to Reef Management Implications for the Development of an Open-Source Dissolved Inorganic Nitrogen Loading Model in American Samoa

Staff member from the American Samoa Coral Reef Advisory Group measuring streamflow to provide flow information used to calculate surface water nitrogen loading to the coastal zone.
We developed a dissolved inorganic nitrogen (DIN) loading model by integrating commonly available datasets within a geospatial modeling framework for Tutuila, American Samoa. The model integrated an open-source water budget model, water sampling results, and publicly available streamflow data to predict watershed-scale DIN loading to the island’s entire coastline.

Incorporating Historical Spring Discharge Protection Into Sustainable Groundwater Management: A Case Study From Pearl Harbor Aquifer, Hawai‘i

Figure 1. Location of four (sub-) aquifer units (Ewa-Kunia, Waipahu-Waiawa, Waimalu, and Moanalua), Sumida Farm (within Kalauao spring complex) and other coastal springs situated in the Pearl Harbor aquifer of O‘ahu (from Burnett et al. 2020).
Using a simulation optimization framework, this study incorporates a spring discharge for a watercress farm into the analysis of sustainable yield for operationalizing groundwater policy in the state of Hawai‘i. The research provides decision-makers with information regarding the trade-off between groundwater pumping and spring discharge, which is connected to multiple benefits.

Groundwater Sustainability: A Review of the Interactions Between Science and Policy

Figure 1. Multi-process modeling, uncertainty analysis and participation are the main components of an effective scientific evaluation of aquifer-yield policy with sphere number reflecting the increasing degree of integration (from Elshall et al., 2020).
This study reviews the concept of groundwater sustainability from both a policy and scientific perspective, tracing the evolution of this concept from safe yield to sustainable groundwater management. The focus is on the diversity of societal values related to groundwater sustainability, and the typology of the aquifer performance and governance factors.

Hawaii Source Water Assessment and Protection Program Update and Maintenance

SPONSOR:Hawaii Department of Health, Safe Drinking Water Branch PROJECT PERIOD:04/23/04 – 06/28/05 ABSTRACT:A WRRC team headed by Dr. Aly El-Kadi has recently completed the task of conducting an assessment of the State’s 450-odd drinking water sources for the State Department…

Estimating Hydraulic Properties for Volcanic Aquifers Using Aquifer Tests and Tidal Responses

SPONSOR: USGS Pacific Islands Water Science Center PROJECT PERIOD: 7/2004 – 12/2005 ABSTRACT: Most published solutions for aquifer responses to ocean tides focus on the one-sided attenuation of the signal as it propagates inland. However, island aquifers experience periodic forcing…