Water Resources Research

Featured Articles

Distinguishing drought and water scarcity
(18 March 2013)

Water resources can become strained by both natural factors such as drought and by human factors such as unsustainable use. Water resource managers can develop practices to reduce overuse of water resources, but they cannot prevent droughts, so distinguishing the causes of water stress can be useful. However, since the two factors often occur at the same time, separating them can be difficult...[more]

Projected U.S. water use likely to increase as climate warms
(4 March 2013)

Despite increases in efficiency, water demand in the United States is likely to increase substantially in the future if climate continues to warm, new projections indicate...[more]

Improving estimates of extreme snowfalls in a spatial context
(28 February 2013)

Mapping extreme snowfalls in mountainous areas is important for directing resources to keep roads clear and manage avalanche risk. But data in mountainous areas are sparse,...[more]

Freshwater storage declining in Middle East
(21 February 2013)

It is an important approach to estimate water loss and over exploitation in data-poor environments and it is one of the few, albeit indirect, that in these areas massive groundwater depletion occurs,...[more]

Improving flood frequency analysis with more information
(4 February 2013)

Flood frequency estimates can be improved by combining local flood data with three additional types of information,...[more]

Does parameterization technique affect simulations of water fluxes?
(25 January 2013)

Predictions of water fluxes and properties including runoff, evapotranspiration, and groundwater recharge are useful for regional water management. These properties are usually estimated using distributed hydrologic models,...[more]

A geostatistical approach to downscaling climate forecasts
(24 January 2013)

Though global general circulation models are the tool of choice for forecasting the effects of climate change, their spatial resolutions are too broad for the needs of regional planners. To provide locally relevant information,...[more]

Statistical framework for assessing uncertainty in hydrological models
(20 November 2012)

For regional managers trying to make long-term investments in hydrological infrastructure, having a reliable forecast of how their watershed may evolve in a changing climate is a significant boon. To make a projection of the regional effects of climate change,... [more]

Dynamic Pressures in Porous Media
(16 November 2012)

Understanding the relationship between fluid pressures and water content (saturation) in soils or other porous media can be important in a wide range of practical areas, including oil recovery, infiltration and flooding during extreme weather events, and envir... [more]

Debating how to assess hydrological model uncertainty and weaknesses
(6 November 2012)

The projections of hydrological models, as numerical abstractions of the complex systems they seek to represent, suffer from epistemic uncertainty due to approximation errors in the model, incomplete knowledge of the system, and, in more extreme cases, flawed ... [more]

Regional Shifts in Snowfall, Melt, in the Intermountain West
(1 November 2012)

The freshwater supplies of the American West rely, for the most part, on snow. The Colorado River, the Rio Grande, and other rivers in the intermountain west—the area bounded by the Sierra Nevada and Cascade mountains to the west and the Rockies to the e... [more]

Studying dynamics of soil moisture patterns
(27 October 2012)

Soil moisture variations in space and time are important to the hydrological cycle. To better understand the dynamics of the various factors affecting soil moisture patterns, Rosenbaum et al. (2012) conducted a comprehensive study in the small Wüs... [more]

Hydrological resilience and how catchments can switch steady states
(16 October 2012)

If a system has a positive feedback, then it may have multiple stable states, or attractors, and finite resilience. Traditional techniques to calculate system resilience to outside pressures revolve around identifying the system state at a transition point and... [more]

Water crises—a new approach
(5 October 2012)

Water crises are one the biggest challenges facing humanity in the 21^st century. But what exactly is the nature of the crises? Scientists investigate the underlying causes driving water scarcity in 22 of the best studied cases across India, China, S... [more]

A statistical basis for multiobjective calibration
(25 September 2012)

Mathematical models are very powerful tools for improving the understanding of environmental systems. However, the output of such models usually deviates systematically from observations, and this bias is typically larger than the measurement error. These prob... [more]

Linking typhoon tracks with rainfall patterns and flood timing
(22 September 2012)

Being able to predict the timing and amount of flooding during and following a hurricane or typhoon would improve early warning and mitigation efforts. However, variable typhoon tracks and interaction between typhoons and varied landscapes make flood predictio... [more]

The pros and cons of trading water: A case study in Australia
(21 September 2012)

Water is a commodity, and water rights can be freely traded in an open market. Proponents of the free market approach argue that it leads to the most efficient allocation of water resources, as it would for any other commodity. However, unlike some commodities... [more]

New insights into faster computation of uncertainties
(14 September 2012)

Heavy computation power, lengthy simulations, and an exhaustive number of model runs—often these seem like the only statistical tools that scientists have at their disposal when computing uncertainties associated with predictions, particularly in cases o... [more]

The Everglades still threatened by excess nutrients
(14 September 2012)

Since 1985, a state agency has constructed and continues to maintain hundreds of square kilometers of wetlands built to regulate the amount of nutrients reaching the Everglades in southern Florida. But this is proving to be ineffective in controlling concentra... [more]

A new remote sensing technique to measure global reservoir storage
(5 September 2012)

Nearly 60% of the world's large rivers are affected by dams, with more than 33,000 large dams holding back upward of 8300 cubic kilometers of water across the planet. Though reservoirs are employed worldwide, helping to ensure regular access to fresh water, mi... [more]

Summarizing the field of surrogate modeling research
(31 July 2012)

As computer simulations of complex physical interactions grow, so do the time and expense required to operate them. Mirroring the development of such full-scale models has been the related field of surrogate modeling or metamodeling. Surrogate models take a va... [more]

Desert dust deposition reduces snow cover in Colorado Mountains
(26 July 2012)

Dust deposition on the mountains of southwest Colorado may have reduced springtime snow cover by 1–2 months per year, a new study finds. When dust is deposited on snow surface, it increases absorption of solar radiation, accelerating snowmelt. Increasing... [more]

The random walk of tracers through river catchments
(30 June 2012)

River catchments play critical roles in regional economies and in the global economy. In addition, rivers carry large volumes of nutrients, pollutants, and several other forms of tracers into the ocean. An intricate system of pathways and channels, both on the... [more]

Local factors important for water availability
(19 June 2012)

One important issue that has grabbed the attention of scientists and policy makers alike is the amount of freshwater that will be available to populations across different climate settings, especially as rain belts reorganize in response to warming temperature... [more]

Vegetation affects hillslope hydrodynamics
(19 May 2012)

Hillslopes are an important part of the hydrological cycle because water from rainfall or snowmelt runs downhill to networks of streams. Understanding hillslope hydrological dynamics is important for flood and debris flow prediction. However, because hillslope... [more]

A new and efficient approach to imaging underground hydraulic environments
(16 May 2012)

To better locate natural resources, treat pollution, and monitor underground networks associated with geothermal plants, nuclear waste repositories, and carbon dioxide sequestration sites, scientists need to be able to accurately characterize and image fluid s... [more]

Imaging hyporheic exchange
(13 April 2012)

The dynamics of flow through the subterranean area at the base and along the sides of streambeds, known as the hyporheic zone, affect stream ecosystem dynamics, but researchers don't have a solid understanding of what controls the amount of hyporheic exchange.... [more]

A general approach to spontaneous imbibition
(7 March 2012)

Spontaneous imbibition occurs in a porous medium when, driven by capillary forces, a wetting fluid such as water displaces a nonwetting fluid like oil or air. This is a common phenomenon, relevant to many processes such as groundwater contamination, steam migr... [more]

Model estimates soil permeability using induced polarization
(16 February 2012)

The speed at which water flows through the ground depends on a number of physical parameters, including the density of the soil and the number and sizes of open pores, with the cumulative effect of these parameters dictating the soil's permeability. When expos... [more]

Small dams need better management
(31 January 2012)

Many small dams around the world are poorly maintained and represent a safety hazard, according to Pisaniello et al. (2012). Better oversight of small dams is needed, the authors argue. The researchers reviewed literature, conducted case studies in four... [more]

Model investigation overthrows assumptions of watershed research
(28 January 2012)

A 2009 study revealed serious flaws in a standard technique used by hydrological researchers to understand how changes in watershed land use affect stream flow behaviors, such as peak flows. The study caused academics and government agencies alike to rethink d... [more]

Estimating hyperconcentrated flow discharge
(28 December 2011)

Estimating flow discharge in torrential mountain floods can help in managing flood risk. However, standard methods of estimating discharge have significant uncertainties. To reduce these uncertainties, Bodoque et al. (2011) developed an iterative method... [more]

Pairing simple and complex models could improve predictions
(28 December 2011)

Environmental management often relies on complex numerical models. Such models can represent complex natural processes in detail but generally take a lot of computational time to run and even greater computational effort to calibrate. Associating uncertainties... [more]

Climate has minor influence on mountain river runoff ratios
(20 December 2011)

Attempts to predict future water availability are muddled by the tendency of the hydrologic system's key drivers, weather and watershed topography, to change across space and time. Interannual climate variability, land use change, and watershed shape alter how... [more]

Groundwater nitrate pollution in intensively farmed regions
(12 November 2011)

Intensified agricultural practices that have developed during the past century have helped improve food security for many people but have also added to nitrate pollution in water supply. Balancing the needs for agriculture and clean groundwater for drinking re... [more]

Freshwater floods drive salt into arid region aquifers
(15 October 2011)

For people living in arid ecosystems, groundwater replenished during seasonal flooding is typically their most important source of freshwater. Yet these same floods may also be responsible for temporarily increasing the salinity of the vital freshwater stores,... [more]

New method improves estimation of subdaily rainfall statistics
(24 September 2011)

Daily rainfall data are readily available, but in many locations there are few rain gauges that provide subdaily rainfall data. Hydrologic models often deal with this problem by generating synthetic hourly rainfall series by assuming a temporal scaling behavio... [more]

Channel cross-section geometry affects basin response
(20 September 2011)

In river networks the shape of a cross section affects streamflow characteristics. Mejia and Reed (2011) developed an analytical framework to study the role of channel and floodplain cross-section geometry in basin-scale hydrologic response. They applie... [more]

Predicting interannual variability in evapotranspiration rates
(10 September 2011)

The amount of evapotranspiration (ET), the sum of all the water that evaporates from the surface or is drawn up through plants and vented as vapor, is a strong controlling factor for the amount of water left over for other purposes, such as groundwater recharg... [more]

All channel networks share some properties
(18 August 2011)

Channel networks transport water through a catchment and play a key role in hydrology. Understanding the network properties can be useful, so Moussa et al. (2011) developed a model to calculate the morphometric properties of catchments. They found some ... [more]

Estimating adsorbed water film thickness in unsaturated soil
(17 August 2011)

In saturated soil, water fills every crack and crevice between the individual grains of dirt. As the water evaporates or drains away, some water can become trapped between soil particles by capillary pressure or be adsorbed onto the surface of the grains in ex... [more]

New watershed classification based on distance to the drainage divide
(11 July 2011)

Models of watershed behavior are beginning to incorporate lidar (light detection and ranging) topography measurements with resolutions of the order of 1 m², but this increase in the availability of high-quality data is outpacing the ability to make ... [more]

Shrinking Alpine glaciers spell trouble for Europe's rivers
(8 July 2011)

Within the frosted peaks of the Swiss Alps, the cycle of winter precipitation accumulation and springtime melt provides a seasonal flow of water to much of western Europe. Research into the freshwater contributions of Alpine glaciers has predominantly looked t... [more]

Estimating contaminant spreading by subsurface water
(16 June 2011)

Spills of fuels, solvents, and solid waste continually emit pollutants into groundwater, the major source of drinking water for most of the world. These contaminants can react with dissolved oxygen or other chemicals present in groundwater, leading to natural ... [more]

Estimating the distribution of extreme events
(28 May 2011)

Modeling the distribution of extreme events such as major floods, severe rainfall, and high wind speeds can be challenging. Researchers in many fields commonly use the generalized extreme value (GEV) distribution to characterize how these events are distribute... [more]

Calculating specific catchment area
(25 May 2011)

Specific catchment area, defined as the area of land upslope of a width of contour, divided by the contour width, is a commonly used quantity in hydrology to describe complex terrain for analyzing water flow on hill slopes; it can be a surrogate for water disc... [more]

The global virtual water trade network
(17 May 2011)

While some countries have substantial supplies of freshwater, others need to import water to sustain their populations. Because food products contain significant amounts of water, global trade in food effectively moves water from one country to another in a "v... [more]

Agricultural chemical export dynamics in a watershed
(11 May 2011)

Understanding how agricultural chemicals filter through a catchment is important for managing water quality. Using a concept of the catchment as a physicochemical filter, Guan et al. (2011) examined nitrate, phosphate, and atrazine loads in the Little V... [more]

Hydroclimatic mechanisms of cholera transmission in the Bengal Delta
(10 May 2011)

Cholera, a deadly waterborne disease, remains a major threat in many areas of the world, including the Bengal Delta region. In this region, cholera outbreaks have two annual peaks; the first occurs during the dry season in the spring, and the second occurs in ... [more]

Fundamental issues of modeling in a climate of change
(22 April 2011)

Numerical models, one of the dominant modes of performing scientific research, fit into two broad classes: operational models, which aim to produce tightly constrained estimates of future behavior using historical observations, and exploratory, or novelty-seek... [more]

Modeling flow pathways through pores and cracks in aerated soils
(19 April 2011)

Knowledge of how chemical contaminants spread through soil is of vital importance to those who manage groundwater and agricultural resources, superfund sites, landfills, and mines. Of particular interest to contaminant transport studies is crop management&mdas... [more]

Can the cultivation of microalgae meet U.S. energy demands?
(13 April 2011)

As biofuels such as ethanol and esters become increasingly attractive alternatives to nonrenewable resources such as oil and coal, scientists have become interested in determining the feasibility of biofuels to help meet U.S. energy demands in light of governm... [more]

Using regional wind-inducing circulation patterns to estimate future rainfall
(12 April 2011)

The complex connections that drive Earth's changing climate are most easily understood on a broad scale, where rising temperatures, changing precipitation patterns, and shifting greenhouse gas concentrations can be examined through changes in the statistical a... [more]

Identifying misbehaving models using baseline climate variance
(1 April 2011)

The majority of projections made using general circulation models (GCMs) are conducted to help tease out the effects on a region, or on the climate system as a whole, of changing climate dynamics. Sun et al., (2011) however, used model runs from 20 diff... [more]

Floodplain dynamics included in river model
(1 April 2011)

Surface water flow is important to the climate system and to water resources management. Floodplain inundation dynamics are a key part of surface water flow, but most current river routing models do not include realistic representation of floodplain dynamics. ... [more]

Modeling saturation overshoot in porous media
(29 March 2011)

Infiltration of water into soils or porous rocks often proceeds in unpredictable, preferential flow paths, also known as fingers. These fingers are caused by a condition called saturation overshoot, where the water content in the finger tip is greater than the... [more]

Reservoirs affect irrigation and river discharge to oceans
(5 March 2011)

Humans have long altered the water cycle by damming rivers to create reservoirs to store water. To examine the effects of large reservoirs on the global water cycle and the availability of water for irrigation, Biemans et al. (2011) analyzed reservoir o... [more]

Using rainfall estimates to predict malaria transmission
(23 February 2011)

Malaria kills nearly a million people each year, mostly in rural Africa. The disease is spread by mosquitoes, which thrive in wet areas, so malaria transmission is closely linked to rainfall. Rainfall estimates could therefore be used to help predict potential... [more]

Trees may enhance landslide hazards
(23 February 2011)

The amount of water saturated in soil layers depends on many factors, such as weather, climate, local geology, slope steepness, vegetation cover, and vegetation type. In forests, vegetation plays a key role in regulating soil saturation; tree canopies intercep... [more]

New analysis can better anticipate the likelihood of flood occurrence
(23 February 2011)

To manage freshwater resources, communities need information on how likely the volume of flow for a river or stream will equal or exceed a certain value of interest. Such information, for example, helps engineers know how much water to release into dams' spill... [more]

Assessing phosphorus reduction efforts in the Everglades
(27 January 2011)

There is too much phosphorus in northern regions of the Florida Everglades, a result of years of agricultural and urban runoff. To deal with this problem, very large constructed wetlands, known as Stormwater Treatment Areas (STAs), have been built to strip pho... [more]

Dual-dynamic approach improves soil water transport model
(31 December 2010)

To perfectly simulate the flow of water through the ground, one would need to know the details of every pore, passage, and air pocket in the soil. To circumvent these daunting requirements, researchers simulate soil moisture transport as if the water were flow... [more]

Determining the underlying pattern of Arctic snowfall
(24 December 2010)

Across the Arctic terrain, more than a hundred bright orange markers dot the landscape, sticking up from the fallen snow. The fiberglass poles, standing 1.5 m high and spaced 100 m apart, allow Sturm and Wagner (2010) to track snow depth over their 1-km... [more]

Determining a relevant measure of hydrologic connectivity
(17 December 2010)

One of the biggest challenges in hydrology is to determine how rainwater moves through a landscape and feeds river flows. Water can circulate in underground channels, flow across the surface, or slowly permeate soil; it can either end up stored in the soil or ... [more]