Water Resources Research is an open access journal that publishes original research articles and commentaries on hydrology, water resources, and the social sciences of water that provide a broad understanding of the role of water in Earth’s system.
In Memoriam: Harihar Rajaram
July 9, 2024
With deep sadness and an appreciation for his enormous contributions to the Earth and space sciences, AGU shares news of the loss of one of our esteemed, much-loved colleagues, Harihar Rajaram.
An AGU Fellow and longtime affiliate of the Hydrology Section, Dr. Rajaram was the Editor-in-Chief of Geophysical Research Letters (GRL) since 2019, a former editor on Water Resources Research (WRR), and served on the AGU Publications Committee.
Hari had a boundless energy. His thoughtfulness, diligence, dedication, sense of humor, and above all, his absolute kindness, will be missed. Even when dealing with the trickiest of situations on AGU journals, Hari never complained or quit. He found a way through bringing people together and finding solutions.
A professor in the Department of Environmental Health and Engineering at The Johns Hopkins University, Hari’s colleagues, Ed Schlesinger, the Benjamin T. Rome Dean and Department Chair Marsha Willis-Karp, shared the following remembrance.
The family obituary with many poignant remembrances is here with the suggestion of donations, in lieu of flowers, to the local Baltimore charity Beans and Bread.
Hari’s grounded perspective, exemplary scholarship, and warm friendship made a meaningful impact on all who knew him and worked beside him. May his memory leave a lasting impact on the Hydrology community and to his friends and colleagues around the world.
Water Resources Research is now a fully open access journal AGU remains committed to open science and open data. As part of our mission, we are focused on making science available to the widest possible audience. With the growing open access requirements placed by funders on researchers around the world, this transition to an open access model also makes compliance easier. All articles in the journal are open access as of 1 January 2024. For more information, including funding options for publishing fees, please visit the FAQ. |
Browse Articles
UAV‐Based Land Surface Temperatures and Vegetation Indices Explain and Predict Spatial Patterns of Soil Water Isotopes in a Tropical Dry Forest
-  14 February 2025
Graphical Abstract

Graphical abstract illustrating the concept of isotopic enrichment of soil water depending on canopy status and plant type. Because of less shading provided, evaporative enrichment in areas without canopy cover is higher compared to areas with intermixed evergreen and leaf-shedding trees and evergreen patches. E and T are Evaporation and Transpiration, respectively.
The Storage and Operation Changes of 256 Reservoirs Across the Contiguous United States
-  14 February 2025
Key Points
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Changes in reservoir storage and operation rules and practices are identified for 256 reservoirs in the Contiguous United States
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The increasing trend of storage is mainly due to operational changes, while the decreasing trend is due to sedimentation and inflow changes
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Both operation effectiveness and deficiencies responding to extreme events are found
Hydraulics of Channelized Flow in Ice‐Supersaturated Debris: 1. Rock Glacier Hydrology in Alpine Glacial‐Periglacial Systems
-  13 February 2025
Key Points
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Water flowing through active rock glaciers is concentrated along a network of channels on top and within their frozen core
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Flow along the channels is rapid, turbulent, and subject to substantial frictional resistance
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Effective heat transfer along the channels drives the expansion of channel networks and amplifies their hydrologic connectivity
A Novel Topography‐Based Approach for Real‐Time Flood Inundation Mapping
-  13 February 2025
Key Points
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Proposed a novel Topography-based approach for Real-Time Flood Inundation Mapping (TOPFIM)
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TOPFIM adapts to river segments and allocates flood volume based on topographical features by considering the water volume constraints
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TOPFIM has higher computational efficiency with accuracy approximating to hydrodynamic model
Reinforcement Learning of Multi‐Timescale Forecast Information for Designing Operating Policies of Multi‐Purpose Reservoirs
-  12 February 2025
Key Points
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Multi-timescale hydro-meteorological forecast information helps in multi-purpose reservoir operations
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A new methodology is proposed to learn the most valuable information from multiple forecasts and jointly design operating policies
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With the available operational products, more skillful short-range lead times are preferred to ideally more informative extended-range ones
Combining Local Head Differences and Topography‐Driven Groundwater Flow Reveals Gaining and Losing Patterns in Stream Networks
-  12 February 2025
Key Points
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A method was developed to estimate surface water levels along the stream network by correcting a digital elevation model with 25 m resolution
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Combining head gradients and topographic analysis reveals catchment-scale patterns and uncertainties in stream gains and losses
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About 42% of streams indicate locally losing conditions despite being in a topographical discharge zone
Evaluating the Performance of Sentinel‐1 SAR Derived Snow Depth Retrievals Over the Extratropical Andes Cordillera
-  12 February 2025
Key Points
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We derived 4 years of snow depth maps at 1 km2 over the Andes mountains with Sentinel-1 SAR and other globally and freely available data
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Snow depth retrievals perform best over sites with negligible evergreen forest cover and in deeper snow
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Snow depth is overestimated for Tundra and Prairie snow class sites, whilst Maritime is unbiased
Quantification of Carbopeaking and Fluxes in a Regulated Alpine River
-  12 February 2025
Key Points
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Flow regulation in an Alpine river affects the spatiotemporal variability and drivers of CO2 fluxes
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Diel metabolism and carbonate buffering sustained by lateral inflows dominate CO2 dynamics in the residual flow reaches
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Intense and localized peaks in CO2 concentration and evasion rate are observed downstream of the hydropower outlets during hydropeaking
Modeling of Low‐Velocity Non‐Darcian Flow With Nonlinear Consolidation in a Leaky Aquifer System Induced by a Fully Penetrating Confined Well
-  12 February 2025
Key Points
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We develop a model that describes low-velocity non-Darcian flow with nonlinear consolidation in a leaky aquifer system
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Characteristics of aquitard consolidation influenced by nonlinear consolidation and low-velocity non-Darcian flow are investigated
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The influences of various factors on the differences in results, with and without considering consolidation effects, are analyzed
Direct Observations of Solute Dispersion in Rocks With Distinct Degree of Sub‐Micron Porosity
-  12 February 2025
Key Points
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X-ray computed tomography and positron emission tomography applied in a multimodal imaging approach to study transport in rock cores
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Spreading and mixing are independently quantified from pulse tracer tests and correlated to distinct forms of subcore-scale heterogeneity
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When solely calibrated against the breakthrough curve, 1D transport models cannot accurately describe internal concentration profiles
A new model for predicting the hydraulic conductivity of unsaturated porous media
- Water Resources Research
-  513-522
-  June 1976
Evaluating the use of “goodness‐of‐fit” Measures in hydrologic and hydroclimatic model validation
- Water Resources Research
-  233-241
-  1 January 1999
Water management: Current and future challenges and research directions
- Water Resources Research
-  4823-4839
-  20 June 2015
Electromagnetic determination of soil water content: Measurements in coaxial transmission lines
- Water Resources Research
-  574-582
-  June 1980
A Transdisciplinary Review of Deep Learning Research and Its Relevance for Water Resources Scientists
- Water Resources Research
-  8558-8593
-  30 August 2018
Key Points
- Deep learning (DL) is transforming many scientific disciplines, but its adoption in hydrology is gradual
- DL can help tackle interdisciplinarity, data deluge, unrecognized linkages, and long-standing challenges such as scaling and equifinality
- The new field of AI neuroscience opens up many opportunities for scientists to use DL as an exploratory tool for scientific advancement
MERIT Hydro: A High‐Resolution Global Hydrography Map Based on Latest Topography Dataset
- Water Resources Research
-  5053-5073
-  28 May 2019
Key Points
- A global hydrography map was generated using the latest topography dataset
- Near-automatic algorithm applicable for global hydrography delineation was developed
- Adjusted elevation and river width layers consistent with flow direction map are provided
Validity of Cubic Law for fluid flow in a deformable rock fracture
- Water Resources Research
-  1016-1024
-  December 1980
Response of mean annual evapotranspiration to vegetation changes at catchment scale
- Water Resources Research
-  701-708
-  1 March 2001
Techniques of trend analysis for monthly water quality data
- Water Resources Research
-  107-121
-  February 1982
A Rainfall‐Runoff Model With LSTM‐Based Sequence‐to‐Sequence Learning
- Water Resources Research
-  3 January 2020
Key Points
- An hourly runoff model was developed using the LSTM sequence-to-sequence learning method for 24-hr predictions on USGS stations
- The proposed model shows better performance than traditional data-driven models and is applicable to different watersheds
- The advantages and limitations of seq2seq models and how this model structure could work on the rainfall-runoff modeling is presented
Investigating the Propagation From Meteorological to Hydrological Drought by Introducing the Nonlinear Dependence With Directed Information Transfer Index
- Water Resources Research
-  26 July 2021
Key Points
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Directed information transfer index was introduced in drought propagation study to build a new drought response time evaluation system for the first time
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Trigger thresholds from meteorological to hydrological drought were determined by a drought propagation model
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Sub-regions with smaller meteorological drought trigger thresholds had longer durations of hydrological drought events
Water management: Current and future challenges and research directions
- Water Resources Research
-  4823-4839
-  20 June 2015
Water Use in Global Livestock Production—Opportunities and Constraints for Increasing Water Productivity
- Water Resources Research
-  20 November 2020
Key Points
- Annually, 4,387 km3 of water is required to produce the feed consumed by the global livestock sector, of which 94% is green water
- Opportunities for increasing livestock water productivity exist for all livestock types but are particularly large for ruminants
- Water productivity improvements for ruminants through supplementation with feed crops are constrained by high water cost to produce crops
The science and practice of river restoration
- Water Resources Research
-  5974-5997
-  24 July 2015
Key Points
- River restoration is a prominent area of applied water-resources science
- restoration includes connectivity, physical-biotic interactions, and history
- effective restoration requires collaboration among scientists and practitioners
Status of CO2 storage in deep saline aquifers with emphasis on modeling approaches and practical simulations
- Water Resources Research
-  6846-6892
-  30 July 2015
Key Points:
- Carbon storage in deep saline aquifers is a viable carbon mitigation option
- A wide range of modeling approaches can provide practical simulation results
- Field-scale observations and modeling enhance system understanding
A Method for Objectively Integrating Soil Moisture Satellite Observations and Model Simulations Toward a Blended Drought Index
- Water Resources Research
-  6772-6791
-  7 May 2018
Key Points
- Develop a viable approach to validate the satellite soil moisture products
- Translate model and satellite soil moisture into useful information for drought monitoring
- An objective blended drought index is recommended
Global Groundwater Modeling and Monitoring: Opportunities and Challenges
- Water Resources Research
-  3 December 2021
Key Points
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A global groundwater framework is needed to address critical gaps in our understanding and predictive capacity of the hydrologic cycle
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We envision a framework that will combine observations and models to provide spatially and temporally continuous groundwater information
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The proposed framework could improve predictability in existing models and provide valuable new information for water management
Plain Language Summary
Groundwater is an important part of the water cycle but we are still working on the best ways to include it in global models. This study provides an overview of the state of the science for groundwater modeling and outlines a road map for what is needed to improve global groundwater models.
Satellite Remote Sensing for Water Resources Management: Potential for Supporting Sustainable Development in Data‐Poor Regions
- Water Resources Research
-  9724-9758
-  29 October 2018
Key Points
- Satellite remote sensing is being incorporated into water resources management but is generally underutilized
- New and proposed missions have the potential to transform water resources management for sustainable development, especially in data-poor regions
- Ongoing challenges of accuracy, sampling, and continuity and capacity development need to be addressed, as well as new challenges of information volume and diversity
Remote Sensing of Groundwater: Current Capabilities and Future Directions
- Water Resources Research
-  29 September 2022
Key Points
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Accurately measuring and monitoring groundwater storage and fluxes is critical for water, food, and energy security
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Remote sensing approaches such as gravitational measurements, Interferometric Synthetic Aperture Radar, Global Navigational Satellite System, lidar altimetry, and Airborne Electromagnetic Systems can yield indirect yet valuable information about groundwater
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Fusing multiple remotely sensed data sets or employing other tools such as numerical models increase the applicability of individual approaches
ChatGPT in Hydrology and Earth Sciences: Opportunities, Prospects, and Concerns
- Water Resources Research
-  28 September 2023
Key Points
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Large language models (LLMs) such as ChatGPT, are new technological tools that might fundamentally change academia
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ChatGPT can assist in academic writing but should not be relied on as the only source of information in hydrology and Earth Science studies
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Authors should exhibit transparency in their utilization of LLMs and uphold ethical responsibility