About

Tammo Steenhuis is a faculty member associated with Cornell CALS, with research interests that include applied economics, biology, climate change, environment, and food. His work involves developing new thinking and solutions to some of today's biggest challenges in these fields. He collaborates with students and other researchers to advance understanding and practical applications in areas such as sustainable agriculture, environmental health, and food systems. His contributions are part of CALS's broader mission to bring innovative research from classroom to lab to field, impacting global development, health, and nutrition.

Research topics

• Environmental science
• Agronomy
• Geography
• Biology
• Engineering
• Ecology
• Environmental engineering
• Geology
• Environmental chemistry
• Agroforestry
• Chemistry
• Pulp and paper industry

Selected publications

• Citizen science as a catalyst for inclusive water and climate adaptation in data-scarce African landscapes

  2026-03-14

  articleOpen accessCorresponding

  Climate change, land degradation, and increasing water demand are intensifying pressure on water resources in data-scarce regions of Sub-Saharan Africa, where conventional monitoring systems are limited by cost, technical capacity, and sparse observational networks. This presentation provides evidence from multiple citizen science initiatives since 2010 demonstrating how participatory data collection and co-creation of local knowledge can enhance inclusive water resources management and climate adaptation.Drawing on case studies from Ethiopia and Ghana, we show how high school students, farmers, and local communities were trained to collect groundwater levels, soil moisture, rainfall, streamflow, and water quality data using low-cost instruments such as plastic gauges, manual staff meters and weirs, and manual sampling kits. These datasets complement validation of earth observation products (e.g., soil moisture products), groundwater recharge estimates in sloping aquifers, and hydrological models, enabling improved understanding of seasonal water availability, groundwater surface water interactions, and watershed management. In Ghana’s Ahafo Ano watershed, citizen-generated observations supported inclusive landscape management planning and prioritizing post-mined land for reclamation, while in Ethiopia, citizen monitoring informed understanding of runoff mechanisms, erosion control, watershed restoration, and adaptive land management practices.The results highlight that citizen science not only fills critical data gaps but also strengthens local capacity, trust in science, co-creation of local knowledge, and ownership of adaptation decisions. However, challenges remain related to data reliability, sustained engagement, and integration into formal decision-making processes. We argue that combining citizen science (CS) with existing community challenges, adapting new technologies for CS, implementing simple quality-control protocols, and integrating CS into government structures and budgets can unlock knowledge and enhance sustainability, scientific credibility, and policy relevance.

  PublisherDOI

• Climate change impacts on spatiotemporal variability of soybean water demands in North China Plain

  Agricultural Water Management · 2025-02-20 · 2 citations

  articleOpen access

  Climate change has been acknowledged as one of the greatest challenges for agricultural production and water management globally. This study investigates the trends and spatial distribution of the water demands of soybean ( Glycine max (L.) Merrill) from 1961 to 2020 in the Jing-jin-ji region of the North China Plain to reveal the effects of climate change. Climate data were collected from 179 weather stations to calculate soybean evapotranspiration ( ET c ) and irrigation demand using the SIMETAW (Simulation of EvapoTranspiration of Applied Water) model developed on Penman-Monteith equation with daily meteorology data. Results showed that soybean ET c during growth season decreased significantly over the last sixty years, from 435 mm yr −1 in 1961–1970–415 mm yr −1 in 2011–2020, around an average of 423 ± 20 mm yr −1 . Effective rainfall during the growth period increased by + 0.5 mm yr −1 rate, while irrigation demand declined by −0.9 mm yr −1 . Rainfall during growth seasons from May to September supplied about 92 % of the water demand for soybean, higher than winter crops. The spatial distribution of soybean ET c showed high values in the south and low values in the north during the past six decades. The initial maximum ET c area (> 480 mm) shrank after 1961–1970, disappearing after 2000. During the last sixty years, solar radiation, wind speed and sunshine hours decreased significantly, leading to a significant decline in soybean ET c at −0.4 mm yr −1 , but average daily precipitation had the most significant negative impact on ET c . The study provided spatial and temporal information needed to improve water use efficiency and increase the adaptability of soybean production to climate change. This is essential to ensure regional food security and promote sustainable agricultural development for water-stressed agricultural areas. • Soybean evapotranspiration ( ET c ) and irrigation need were simulated from 1961 to 2020. • Soybean ET c showed a significant decline in the last six decades in North China Plain. • Soybean ET c showed high values in the south and low values in the north. • Solar radiation decreased significantly, leading to a significant decline in soybean ET c .

  PublisherDOI

• The Impact of Expanding Eucalyptus Plantations on the Hydrology of a Humid Highland Watershed in Ethiopia

  Hydrology · 2025-05-17 · 2 citations

  articleOpen access

  Changes in climate and land use significantly impact downstream water availability. Quantifying these effects in the Ethiopian Highlands is crucial, as 85% of the transboundary water in Egypt and Sudan originates from these highlands. While the impact of climate change on water availability has been widely studied, few experimental studies have examined how it is affected by eucalyptus reforestation. Therefore, the objective was to investigate how eucalyptus expansion impairs water availability in the Ethiopian Highlands. The study was conducted in the 39 km2 Amen watershed, located in the upper reaches of the Blue Nile. Rainfall data were collected from local agencies from 1990 to 2024, while streamflow data were available only for 2002–2009 and 2015–2018. Actual evapotranspiration was obtained using the WaPOR portal, and land use was derived from Landsat 5 TM and Landsat 8 OLI. The satellite images showed that the eucalyptus acreage increased from 238 ha in 2001 to 799 ha in 2024, or 24 ha y−1. The actual evapotranspiration of eucalyptus was up to 30% greater than that of other land uses during the dry monsoon phase (January to March), resulting in decreased water storage in the watershed over a 23-year period. Since runoff is generated by saturation excess runoff, it takes longer for the valley bottoms to become saturated. In the 2002–2009 period, it took an average of around 160 mm of cumulative effective rain for significant runoff to start, and from 2015 to 2018, 274 mm was needed. Additionally, base flow decreased significantly. The annual runoff trended upward when the annual rainfall was more than the additional amount of water evaporated by eucalyptus, but decreased otherwise.

  PublisherOA PDFDOI

• Measuring pore water velocities and dynamic contact angles at unstable wetting fronts

  Advances in Water Resources · 2024-02-22 · 4 citations

  articleSenior authorCorresponding
  PublisherDOI

• Satellite-based Near-Real-Time Global Daily Terrestrial Evapotranspiration Estimates

  2024-01-10 · 5 citations

  preprintOpen accessCorresponding

  Abstract. Accurate and timely information on global terrestrial actual evapotranspiration (ET) is crucial in agriculture, water resource management and drought forecasting in a changing climate. While numerous satellite-based ET products have been developed in recent decades, few provide near-real-time global terrestrial ET estimates. The MOD16 ET dataset, currently updating at the fastest rate, still experiences a delay of over two weeks. This is because most satellite-based ET algorithms rely on meteorological data from land surface models or in situ measurements, which cannot be obtained in near-real-time, resulting in delays of more than two weeks. To expedite global ET data access, we developed the Moderate Resolution Imaging Spectroradiometer (MODIS) based Variation of Standard Evapotranspiration Algorithm (VISEA) to provide global daily ET data within a week of the actual measurements at a spatial resolution of 0.05°. The VISEA model incorporates several key components: (1) A vegetation index (VI)-temperature (Ts) triangle method to simulate air temperature (Ta), serves as a basis for calculating other meteorological parameters (e.g., water vapor deficit and wind speed); (2) A daily evaporation fraction (EF) method based on the decoupling parameter, converts satellite-based instantaneous observations into daily ET estimates; (3) A net radiation calculation program takes into account cloud coverage in the atmosphere's downward longwave radiation. The VISEA model is driven by shortwave radiation from the European Centre for Medium-range Weather Forecasts (ERA5-Land) and MODIS land products, e.g., surface reflectance, land surface temperature/emissivity, land cover products), vegetation indices, and albedo as inputs. To assess its accuracy, we compared VISEA-with measurements from 149 flux towers, five other satellite-based global ET products, and precipitation data from the Global Precipitation Climatology Centre (GPCC). The evaluations show that the near-real-time ET using VISEA performs with similar accuracy to other existing data products and offers a significantly shorter time frame for daily data availability. Over 12 landcover types, the mean R is about 0.6 with an RMSE of 1.4 mm day-1 at a daily scale. Furthermore, the consistent spatial patterns of multi-year average VISEA align closely with GPCC precipitation data, reaffirming the dataset's ability to accurately represent global terrestrial ET distribution. To emphasize the capabilities of the VISEA for drought monitoring, we analyzed the spatial and temporal variations of ET during a drought event and subsequent recovery with precipitation in the Yangtze River basin from August 28th to September 1st, 2022. The VISEA distinctly illustrated low ET levels (<0.2 mm day-1) across most areas of the Yangtze River Basin on August 28th, indicating the severity of the drought. Conversely, a noticeable increase in ET (>0.9 mm day-1) is observed on August 29th, signifying the retreat of the drought due to precipitation. The near-real-time global daily terrestrial ET estimates could be valuable for meteorology and hydrology applications requiring real-time data, particularly in coordinating relief efforts during droughts. The VISEA code and dataset are available at https://doi.org/10.11888/Terre.tpdc.300782 (Huang et al., 2023a).

  PublisherDOI

• A Distributed Catchment—Scale Evaluation of the Potential of Soil and Water Conservation Interventions to Reduce Storm Flow and Soil Loss

  Water · 2024-04-25 · 1 citations

  articleOpen accessSenior author

  Finding effective ecosystem services (ESS) management practices to counteract land degradation and poverty is becoming increasingly urgent in the Ethiopian highlands, where livelihood security is strongly dependent on local ESS, particularly those provided by water and soil. In this paper, we test the effects of widely implemented soil and water conservation (SWC) interventions on storm flow and sediment concentration in the Debre Mawi watershed (representative of watersheds in the upper Blue Nile basin and Ethiopian highlands). The SWC interventions were tested with a Parameter Efficient Distributed (PED) model. The PED model simulates saturation excess runoff from degraded and saturated valley bottoms, and base and interflow from hillsides. The model was calibrated with observed runoff and sediment data in a 95-ha subcatchment. We found that the PED model simulated the discharge and soil loss well by decreasing the proportion of degraded lands due to installing SWC practices. The results show that four years after the implementation of SWC practices, the infiltration of rainwater was improved in 53% of the degraded lands. Thus, installing SWC practices on hillsides where infiltration is limited is most beneficial and will result in greater water availability during the dry phase, especially in locations where volcanic dikes block the lateral flow.

  PublisherDOI

• Satellite-based near-real-time global daily terrestrial evapotranspiration estimates

  Earth system science data · 2024-09-12 · 7 citations

  articleOpen access

  Abstract. Accurate and timely global evapotranspiration (ET) data are crucial for agriculture, water resource management, and drought forecasting. Although numerous satellite-based ET products are available, few offer near-real-time data. For instance, products like NASA's ECOsystem Spaceborne Thermal Radiometer Experiment mounted on the International Space Station (ECOSTRESS) and MOD16 face challenges such as uneven coverage and delays exceeding 1 week in data availability. In this study, we refined the Variation of the Standard Evapotranspiration Algorithm (VISEA) by fully integrating satellite-based data, e.g., European Centre for Medium-Range Weather Forecasts ERA5-Land shortwave radiation (which includes satellite remote sensing data within its assimilation system) and MODIS land surface data (which include surface reflectance, temperature and/or emissivity, land cover, vegetation indices, and albedo as inputs). This enables VISEA to provide near-real-time global daily ET estimates with a maximum delay of 1 week at a resolution of 0.05°. Its accuracy was assessed globally using observation data from 149 flux towers across 12 land cover types and comparing them with five other satellite-based ET products and Global Precipitation Climatology Centre (GPCC) data. The results indicate that VISEA provides accurate ET estimates that are comparable to existing products, achieving a mean correlation coefficient (R) of about 0.6 and an RMSE of 1.4 mm d−1. Furthermore, we demonstrated VISEA's utility in drought monitoring during a drought event in the Yangtze River basin in 2022 in which ET changes correlated with precipitation. The near-real-time capability of VISEA is, thus, especially valuable in meteorological and hydrological applications for coordinating drought relief efforts. The VISEA ET dataset is available at https://doi.org/10.11888/Terre.tpdc.300782 (Huang, 2023a).

  PublisherDOI

• Assessment of pollution and trophic state of a water hyacinth infested tropical highland lake: Lake Tana in Ethiopia

  Sustainable Water Resources Management · 2024-09-13 · 5 citations

  articleSenior author
  PublisherDOI

• Diversifying crop rotation increases food production, reduces net greenhouse gas emissions and improves soil health

  Nature Communications · 2024 · 391 citations

  • Environmental science
  • Agronomy
  • Agroforestry

  O emissions by 39%, and improve the system's greenhouse gas balance by 88%. Furthermore, including legumes in crop rotations stimulates soil microbial activities, increases soil organic carbon stocks by 8%, and enhances soil health (indexed with the selected soil physiochemical and biological properties) by 45%. The large-scale adoption of diversified cropping systems in the North China Plain could increase cereal production by 32% when wheat-maize follows alternative crops in rotation and farmer income by 20% while benefiting the environment. This study provides an example of sustainable food production practices, emphasizing the significance of crop diversification for long-term agricultural resilience and soil health.

  PublisherOA PDFDOI

• A theoretical underpinning of the pesticide Groundwater Ubiquity Score (GUS)

  Journal of Hydrology and Hydromechanics · 2024-08-15 · 1 citations

  articleOpen access1st authorCorresponding

  Abstract The Groundwater Ubiquity Score (GUS) is widely used to indicate the relative leachability of pesticides based on the soil half-life and the adsorption partition coefficient. In this manuscript, we derive mathematically the Theoretical Groundwater Ubiquity Score (TGUS) that, based on considerations of the preferential movement of pesticides to groundwater and a first-order pesticide degradation model, leads to a similar function as the GUS model. In the preferential flow model, movement to groundwater is fast, and the adsorption partition coefficient is thus not used for calculating the travel time to the groundwater (as it is in the advective-dispersive equation) but rather only determines the distribution of the pesticide between the water and soil phases. Both the GUS and TGUS models well predict the groundwater contamination of the originally studied pesticides for rainfall event(s) that caused pesticide leaching from 30 days after application. The theoretically derived Groundwater Ubiquity Score (TGUS) shows, in accordance with experimental evidence, that for leaching events shortly after spraying, the mass lost to (and resulting concentration in) groundwater is inversely related to the adsorption partition coefficient and not necessarily to the GUS index.

  PublisherOA PDFDOI

Recent grants

• Building on the Legacy of Wilfried Brutsaert and J.-Yves Parlange for Advances in the Ecological Hydrosphere

  NSF · $22k · 2012–2014

• Colloid Retention in Unsaturated Porous Media due to Capillary Forces

  NSF · $190k · 2007–2010

Frequent coauthors

• Seifu A. Tilahun

  Water Resources Commission of Ghana

  254 shared

• Amy S. Collick

  102 shared

• J.‐Y. Parlange

  Cornell University

  101 shared

• Zachary M. Easton

  100 shared

• Assefa D. Zegeye

  Amhara Regional Agricultural Research Institute

  90 shared

• Christian D. Guzmán

  Max Planck Institute of Colloids and Interfaces

  79 shared

• Brian K. Richards

  Cornell University

  77 shared

• M. Todd Walter

  Cornell University

  70 shared

Education

• Ph.D.

  University of Wisconsin, Madison

  1978

Awards & honors

• Fellow (2009) American Geophysical Union
• International Award (2011) American Geophysical Union
• Partnership Award for integrating science, education and ext…