Thomas Parris

Thomas Parris, President, ISciences, LLC

Research Interests: Using remotely sensed Earth observation data to inform and enhance public policy; assessing the impact of water and climate stress on people, industry, and agriculture; helping companies understand and manage their exposure to environmental risk; and analyzing and assessing the risk of environmental and social threats to human security. Research Highlights: When seen from space, the blue sphere that we call home seems to have all the water we could ever need. Most of that blue, however, is saltwater. According to information from NASA, only 2.5% of Earth’s water is freshwater, and most of that is frozen in polar ice caps, glaciers, and other ice. The small amount of freshwater that remains is all that’s available for us to use—and as Earth’s human population grows, so does our demand for it.

The United Nations reports that global freshwater use has increased by a factor of six over the past 100 years, and it has continued to grow at a rate of roughly 1% per year since the 1980s. Much of this growth can be attributed to a combination of population growth, economic development, and shifting consumption patterns. Climate change is having an impact on freshwater supplies too, as rising temperatures and shifting precipitation patterns have already led to both prolonged drought and increased incidences of flooding in the United States and around the world.

Given these freshwater realities, scientists and business leaders are developing novel ways to monitor water quality, estimate water availability, track water use, and measure world-wide precipitation to help resource managers and decision-makers better manage water resources for critical industries and populations around the globe. One of them is Thomas Parris, President of the Michigan-based limited liability company ISciences. Parris’ company provides consulting services to clients in the public, private, and nonprofit sectors in the areas of water and climate, human security, corporate sustainability, remote sensing, and geospatial analysis.

In addition, Parris is also a member of NASA's Socioeconomic Data and Applications Center (SEDAC) User Working Group (UWG). SEDAC, one of 12 Distributed Active Archive Centers (or DAACs) in NASA’s Earth Observing System Data and Information System (EOSDIS), is operated by the Center for International Earth Science Information Network, a unit of the Earth Institute at Columbia University based at the Lamont-Doherty Earth Observatory in Palisades, New York. As part of its mission to synthesize Earth science and socioeconomic data and information for policymakers and applied science users, SEDAC archives, manages, and distributes the data and tools that pertain to both Earth science and the social sciences.

ISciences has been involved in projects ranging from assessments of COVID-19’s impact on electricity demand and forecasting food crises in Africa and political instability in India to evaluating nation-state resilience to political instability and assessing the effectiveness of corporate sustainability programs. However, a major focus of its work is assessing the impact of water stress on agriculture, industries, and people around the globe.

As a case in point, ISciences has developed a Water Security Indicator Model (WSIM) that monitors and forecasts water anomalies on a near global basis.

“The WSIM monitors and forecasts surface water anomalies—droughts and floods—worldwide with lead times of up to nine months,” said Parris. “[It] has been in continuous operation since 2011 and we provide monthly reports as a public service. Anyone interested can subscribe by pressing the “sign up” button on the ISciences website. These reports are routinely used to assess emerging water security, food security, energy security, public health, governance, and humanitarian response issues in the public, private, and non-governmental sectors worldwide.”

The WSIM identifies regions with significant water anomalies, either deficits or surpluses, relative to past events and conditions based on a historical period from 1950 to 2009. This allows users to assess current and forecast anomalies in an historical context.

To produce its assessments and forecasts of water anomalies, the WSIM uses a variety of terrestrial (i.e., temperature, precipitation, soil moisture, etc.) and human geography data as inputs. These data come from a several sources, including the Climate Forecast System of the NOAA National Centers for Environmental Protection (NCEP) and NASA DAACs. Included among the latter are the Gridded Population of the World data collection from SEDAC; the Moderate Resolution Imaging Spectroradiometer (MODIS) Land Cover Type and Land Cover Dynamics data products from the Land Process DAAC (LP DAAC); and the Global Land Data Assimilation System (GLDAS), North American Land Data Assimilation System (NLDAS), and Famine Early Warning Systems Network Land Data Assimilation System (FLDAS) data products from the Goddard Earth Sciences Data and Information Services Center (GES DISC).

“We use a variety of NASA Earth observation products to drive the WSIM model,” said Parris. “Among them are the Gridded Population Data from SEDAC to evaluate impacts of past, present, and forecast surface water anomalies on human populations in specific areas; MODIS land cover and land cover dynamics from the LP DAAC to map consumptive use of water and area actually irrigated; and the GLDAS, NLDAS, and FLDAS from the GES DISC to map past surface water anomalies.”

These inputs enable the WSIM to deliver assessments and forecasts of water anomalies on a monthly basis with lead-times of up to nine months. The model then produces risk maps wherein regions with deficits are shown in increasing intensity of red; surpluses are shown in blue. Purple regions exhibit aspects of both deficit and surplus (see graphic above).

To quantify the rarity of an event, WSIM transforms all of its water security indicators from units of measurement (e.g., millimeters or cubic meters) into return periods expressed in years. The inverse of the return period is the probability of observing an event greater than or equal to a given magnitude in a given year, so a five-year event would have a 20% probability of occurring in any given year. (Note: For a detailed explanation of the WSIM’s anomaly and return period calculations, see the WSIM User Guide.)

For example, as seen in the June 2022 ISciences Worldwide Water Watchlist, the map presents a selection of regions “likely to encounter significant water anomalies” during the year-long period from March 2022 to February 2023. The forecast uses three months of observed temperature and precipitation data and nine months of forecast data. In the case of the United States (shown in the image below), “The forecast through August indicates water deficits of varying intensity in the West, Southwest, Rockies, parts of the Pacific Northwest, Virginia, North Carolina, and Georgia. Areas with a forecast of surplus include the Dakotas and Minnesota, and western Washington and Oregon.”

The WSIM model has been validated against subsequent monitoring based on observed data, and according to remarks Parris delivered at the 2015 Population-Environment Research Network Cyberseminar, it has been proven to provide reliable forecasts of emerging water security concerns.

“We have been able to compare our composite water anomaly forecasts with subsequent estimates based on observed weather data in order to evaluate skill,” he said. “While these forecasts are not perfect, they do provide significant value added. In general, our skill is better for regionally significant persistent anomalies as opposed to localized singular events such as flash floods or tropical storms.”

In addition to monitoring and forecasting water anomalies, ISciences has also developed algorithms that allow it to use the WSIM to assess how droughts and floods will impact agricultural production and electricity generation.

Along with water anomaly data, the agricultural production algorithm uses data about cultivation areas, relative yields, crop calendars, and reservoir capacity to provide geographically explicit loss risk maps. This capability has been validated against USDA yield and insurance data for the conterminous United States. Similarly, the electricity assessment evaluates the degree to which water deficits restrict electricity production from hydropower and thermal plants (including nuclear facilities). It considers upstream reservoir capacity and consumption, fuel stock and cooling technology, and downstream water stress. (Note: For a detailed explanation of how the WSIM electric power assessment estimates the risk of electrical generation loss due to hydrologic and temperature anomalies, see the WSIM User Guide.)

Parris considers the IScience’s Global Water Monitor & Forecast capability to be an effective tool for anticipating large scale regional water anomalies, and he says its accuracy will improve as measurements from Earth-observing satellites and climate models become more precise. In the meantime, he is grateful that the free and open data from NASA’s EOSDIS are available to inform the WSIM’s water anomaly forecasts and support ongoing efforts by ISciences to help resource managers and decision-makers prepare for and address the potential environmental, humanitarian, and security risks associated with them.

Representative Data Products Used or Created:

Available through SEDAC:

• Gridded Population of the World, Version 4 (GPWv4) doi:10.7927/H45Q4T5F

Other data products used:

• Terra and Aqua combined MODIS Land Cover Type (MCD12Q1) Version 6 (LP DAAC) doi:10.5067/MODIS/MCD12Q1.006
• Terra and Aqua combined MODIS Land Cover Dynamics (MCD12Q2) Version 6.1 (LP DAAC) doi:10.5067/MODIS/MCD12Q2.061
• GLDAS - Global Land Data Assimilation System (GES DISC) doi:10.5067/E7TYRXPJKWOQ
• NLDAS - North American Land Data Assimilation System (GES DISC) doi:10.5067/6J5LHHOHZHN4
• FLDAS - Famine Early Warning Systems Network Land Data Assimilation System (GES DISC) doi:10.5067/5NHC22T9375G
• Climate Forecast System (version 2), NOAA NCEP

Read about the Research:

Parris, T.M. (2017). User Guide: WSIM – Water Security Indicator Model. ISciences.com.

Parris, T.M. (2015). "ISciences Global Water Monitor & Forecast: Anticipating Change in the Human-Earth System." Panel contribution to the Population-Environment Research Network Cyberseminar, Water and Population Dynamics.

Explore more Data User Profiles