Global Rivers Group
@Texas A&M

We use satellites, models, and fieldwork to study Earth's freshwater


We're a growing academic research group in the Department of Geography at Texas A&M University. Founded in 2018 by Dr. George H. Allen, we are recruiting students who are interested in using emerging technology to tackle global-scale questions involving rivers, freshwater resources, and a changing planet.

What we do

We study rivers, streams, and other surface water bodies using remote sensing, fieldwork, and models. We seek to understand how climate change and land use are altering the global water cycle, in particular river hydrology. With rapid advancements in remote sensing technology, computing power, and model sophistication, it is truly an exciting time to be studying the global water cycle.


Why we do it

Water is widely considered to be the world’s most vital natural resource, yet freshwater systems are directly endangered by human activities. Our work is motivated by a desire to promote the conservation, management, and understanding of Earth's surface water resources.



Updated Feb 14th, 2021

Feb 8, 2021 - GRG M.S. student Ennis Rios awarded the Mills Scholarship for conducting water-related research on remote sensing of river water temperature. Congratulations, Ennis! 

Feb 7, 2021 - Paper led by Alessandra Marzadri (University of Trento, Italy) and Giuseppe Amatulli (Yale) published in Science of The Total Environment on estimating global nitrous oxide emissions from rivers and streams.


Jan 26, 2021 - Paper led by Peirong Lin at Princeton University published in Scientific Data. This paper presents a state-of-the-art global vector hydrography dataset of rivers with spatially variable drainage density and flow intermittence. An innovative example of using machine learning to extend information from the national scale to the global scale. Great job, Peirong!


Jan 13, 2021 - Paper led by Yao Li at Texas A&M Department of Civil Engineering published in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing on tracking reservoir storage variations using TanDEM-X satellite mission inSAR data:


Dec 17, 2020 - Paper led by John Hammond at the USGS published in Geophysical Research Letters on the spatial patterns and drivers of no-flow regimes in the contiguous United States. Dr. James Famiglietti Tweeted that this paper "looks like a modern classic": 

Dec 9, 2020 - Two coauthored papers, Lin et al. (2019) and Yamazaki et al. (2019), received the Editor's Choice Award from Water Resources Research. Editors’ Choice Award are given to about 1% of published articles in any calendar year to provide professional recognition to scientists for their outstanding work. The selection is made by the Editors of WRR based on technical significance, novelty, originality, presentation, and broader implications of the publication. 

Nov 23, 2020 - Paper led by Yuta  Ishitsuka at the University of Massachusetts Amherst published in Water Resources Research. This study combines millions of river remote sensing measurements and hydrologic modeling to produce daily discharge estimates over the Missouri River basin. This study forms the basis of a global effort underway at Fluvial@UMass:

Oct 6, 2020 - Ryan, Ennis, and George have their abstracts accepted to the AGU Fall Meeting 2020. George will also convene a session entitled, Remote Sensing and Modeling of Global Rivers from the Headwaters to the Ocean


Aug 17, 2020 - John Morgan (BS Geology, Western Carolina University, Summa Cum Laude) joins the Global Rivers Group. He will be working on constraining global estimates of river and stream surface area using remote sensing and fieldwork. Welcome John! 

Aug 3, 2020 - We are seeking a graduate student (PhD or MS) starting Spring 2021 to work on remote sensing of water quality in Earth's inland waters. The project is funded by a Texas A&M X-Grants award.: Graduate student opportunity announcement

July 17, 2020 - Editorial led by Carl Legleiter at the USGS published in Remote Sensing describing the contents of the special issue entitled "Remote Sensing of Flow Velocity, Channel Bathymetry, and River Discharge": 


July 13, 2020 - Paper led by Michelle Busch at the University of Oklahoma published in Water. This study reviews the historic usage of non-perennial river and stream epithets and suggests a path forward for unifying the terminology of the discipline: 

June 23, 2020 - AGU Fall Meeting accepts session proposal entitled, Remote sensing and modeling of global rivers from the headwaters to the ocean to be convened by George Allen and his colleagues, Peirong Lin (Princeton), Xiao Yang (UNC) and Rodrigo Paiva (UFRGS Federal University of Rio Grande do Sul). 


June 12, 2020 - TAMU X-Grant proposal selected for funding. Proposal title: "Developing a SmallSat Mission to Track the Global Movement of Water, Carbon, and Sediment across Landscapes." Investigators: George H. Allen in TAMU Geography (Lead), Daniel Selva Valero in TAMU Aerospace Engineering (Co-lead), Huilin Gao in Civil Engineering (Co-lead), and Helen Reed in TAMU Aerospace Engineering (project member). 


May 9, 2020 - Paper led by George Allen published in Remote Sensing. Study shows that the Landsat archive accurately captures the long-term flow frequency distribution of rivers, except for extreme conditions like maximum and minimum flow. TAMU undergraduate research assistant, Joel Holliman coauthored the study:

April 30, 2020 - Lin et al. (2019), Frasson et al. (2019), and Yamazaki et al. (2019) all recognized by AGU as the Most Downloaded Papers of 2018-2019. 

Apr 20, 2020 - Ennis Rios, a current MS student in the TAMU Water Management and Hydrological Science Program, joins the Global Rivers Group. Welcome aboard, Ennis!  

Apr 13, 2020 - Paper by lead author Margaret Zimmmer (at UC Santa Cruz) published in WIREs Water. This paper explores several causes and consequences of zero‐flow gage readings including frozen surface water, flow reversals, instrument error, bypass flow and upstream source loss:

Apr 11, 2020 - NASA SWOT Science Team proposal selected for funding. Proposal title: Integrating reservoirs into SWOT's global surface water storage and discharge monitoring. Investigators: Jida Wang at KSU (PI), Yongwei Shen at UCLA (Co-I), George H. Allen at TAMU (Co-I). 

Apr 2, 2020 - Paper by lead author Peirong Lin (at Princeton) published in Geophysical Research Letters. This paper uses machine learning and Big Geospatial Data to predict global bankfull river width at 723,822 river reaches globally, totaling 7.3M km in length:

Jan 22, 2020 - Paper by lead author Stephen Coss (at Ohio State) published in Earth System Science Data. This paper presents GRRATS, a new global river elevation dataset produced from satellite altimetry data:

Jan 1, 2020 - Paper led by Dr. Xiao Yang (at UNC) published in Nature. Our study quantifies the decline of Earth's river ice using big data remote sensing and then forecasts future declines using climate simulations:


We are actively recruiting graduate students to join the GRG@TAMU. If you are interested, please email George for more information. Funding is available!


©2020 by Global Rivers Group