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

Open access

Estimating Soil‐Water Characteristic Curve From the Particle Size Distribution With a Novel Granular Packing Model

  •  6 February 2025

Key Points

  • A physical soil-water characteristic curve (SWCC) model based on the particle size distribution (PSD) considering granular packings is established

  • The model exhibits advantages in predicting the SWCC of most soil types

  • The model can illustrate the effects of granular packings, pore ratios and the contribution of capillary and adsorption on SWCC

Open access

Impacts of Bioenergy Crop Cultivation on Regional Climate, Hydrology, and Water Quality in the U.S. Northern High Plains

  •  6 February 2025

Key Points

  • Considering climate-crop feedback increases precipitation and decreases temperature in regional climate projection

  • Regional climate change outweighs marginal land use change in influencing watershed hydrology and water quality

  • The regional climate and water quality impacts of growing bioenergy crops on marginal lands should be carefully assessed in future sustainable bioenergy production

Open access

Optimizing Investments in Alternative Water Infrastructure for Urban Food Production in Water Stressed Cities

  •  6 February 2025

Key Points

  • A hybrid urban water system involving decentralized system of rainwater harvesting and centralized system of reclaimed water is optimized

  • A new spatial optimization model is developed for optimally deploying two alternative water infrastructures to expand urban food production

  • Expanding reclaimed water network is more cost efficient than applying rainwater harvesting for food production in a semi-arid city, Tucson

Open access

A Hybrid Model Coupling Data and Hydraulic Transient Laws for Water Distribution Systems

  •  4 February 2025

Key Points

  • A systematic water hammer model based on extended physics-informed neural network for pipeline network is proposed

  • Nodal information is incorporated in training process, enabling one jointly neural network to simulate pressure and flowrate synchronously

  • Uncertainty analysis is conducted, considering initial and boundary conditions, data augmentation, and variations in pipe characteristics

Open access

Potential for Augmenting Water Yield by Restoring Longleaf Pine (Pinus palustris) Forests in the Southeastern United States

  •  4 February 2025

Key Points

  • Longleaf pine forests (LLP) exhibit lower total evapotranspiration than loblolly pine (LOP) forests based on eddy flux and remote sensing data

  • Significantly lower leaf area, and higher albedo and land surface temperature found in LLP than LOP forests

  • Restoring LLP forests in the southeastern United States could potentially augment water yield compared to LOP forests

Open access

Probabilistic Trade‐Offs Analysis for Sustainable and Equitable Management of Climate‐Induced Water Risks

  •  4 February 2025

Key Points

  • The spatio-temporal change in the trade-offs between competing water uses is assessed using a stochastic dynamic hydro-economic model

  • Sector-priority water allocation policies could not ensure an equitable benefit sharing among all sectors under future climate uncertainty

  • Outcomes of sector-priority water allocation policies define the upper and lower bounds of the negotiation space among water use sectors

Open access

Confluence Effects of Dongting Lake in the Middle Yangtze River: Discontinuous Fluvial Processes and Their Driving Mechanisms

  •  4 February 2025

Key Points

  • The input of Dongting Lake introduced spatial discontinuities in the water-sediment regimes along the main stream

  • The hydrological characteristics of the confluence, rather than sediment transport, predominated the fluvial processes of the lowland river

  • The influx of tributary is not expected to change the channel shrinkage trend induced by the upstream reservoir

Open access

Bankfull and Mean‐Flow Channel Geometry Estimation Through Machine Learning Algorithms Across the CONtiguous United States (CONUS)

  •  3 February 2025

Key Points

  • Channel geometry estimation is essential for hydrological, geomorphological, and ecological modeling and analysis

  • A suite of data-driven models is developed to estimate channel width and depth under bankfull and mean-flow conditions

  • The best models are applied for reach-scale estimation of channel geometry for the contiguous United States

Open access

A Novel Surface‐Based Approach to Represent Aquifer Heterogeneity in Sedimentary Formations

  •  1 February 2025

Key Points

  • A new surface-based stochastic facies modeling algorithm is presented

  • It is flexible and relies on few parameters to produce a variety of geological settings

  • The proposed method can efficiently reproduce observed fluvio-glacial structures

More articles
Open access

A Transdisciplinary Review of Deep Learning Research and Its Relevance for Water Resources Scientists

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

Open access

MERIT Hydro: A High‐Resolution Global Hydrography Map Based on Latest Topography Dataset

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

free access

A Rainfall‐Runoff Model With LSTM‐Based Sequence‐to‐Sequence Learning

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

More articles
free access

Investigating the Propagation From Meteorological to Hydrological Drought by Introducing the Nonlinear Dependence With Directed Information Transfer Index

Key Points

  • Directed information transfer index was introduced in drought propagation study to build a new drought response time evaluation system for the first time

  • Trigger thresholds from meteorological to hydrological drought were determined by a drought propagation model

  • Sub-regions with smaller meteorological drought trigger thresholds had longer durations of hydrological drought events

Open access

Water Use in Global Livestock Production—Opportunities and Constraints for Increasing Water Productivity

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

free access

The science and practice of river restoration

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

free access

Status of CO2 storage in deep saline aquifers with emphasis on modeling approaches and practical simulations

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

free access

A Method for Objectively Integrating Soil Moisture Satellite Observations and Model Simulations Toward a Blended Drought Index

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

Open access

Global Groundwater Modeling and Monitoring: Opportunities and Challenges

Key Points

  • A global groundwater framework is needed to address critical gaps in our understanding and predictive capacity of the hydrologic cycle

  • We envision a framework that will combine observations and models to provide spatially and temporally continuous groundwater information

  • 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.

Open access

Satellite Remote Sensing for Water Resources Management: Potential for Supporting Sustainable Development in Data‐Poor Regions

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

Open access

Remote Sensing of Groundwater: Current Capabilities and Future Directions

Key Points

  • Accurately measuring and monitoring groundwater storage and fluxes is critical for water, food, and energy security

  • 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

  • Fusing multiple remotely sensed data sets or employing other tools such as numerical models increase the applicability of individual approaches

free access

ChatGPT in Hydrology and Earth Sciences: Opportunities, Prospects, and Concerns

Key Points

  • Large language models (LLMs) such as ChatGPT, are new technological tools that might fundamentally change academia

  • ChatGPT can assist in academic writing but should not be relied on as the only source of information in hydrology and Earth Science studies

  • Authors should exhibit transparency in their utilization of LLMs and uphold ethical responsibility

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