💧 WASH Investment Research Portal

The International Water Resources Association (IWRA) is pleased to announce the 2026 Call for Applications for the IWRA Membership Grants, offering individuals from around the world the opportunity to engage […]

Water is under increasing pressure around the world. As demand grows across agriculture, energy, industry, ecosystems, and domestic use, competition for water is intensifying – and with it,  so is […]

Turning regional water action into global impact The International Water Resources Association (IWRA) is pleased to announce the launch of the Regional Water Congress, a new initiative designed to strengthen […]

Discover key information on one of the world’s leading events this year dedicated to freshwater management in island contexts. We are pleased to share that the first announcement of the […]

Where Water Flows, Equality GrowsWomen Shaping the Present and Future of Water 14:00–15:30 CET | Tuesday, 10 March 2026 | Online (Zoom) Watch the recordings Background To jointly celebrate International […]

arXiv:2604.01940v1 Announce Type: cross Abstract: We introduce a residence-time approach (RTA) for determining position-dependent diffusivities from biased molecular dynamics simulations. The method is formulated for trajectory segments in which the effective drift along the transport coordinate is negligible, as realized here using adaptive biasing force simulations. In this regime, local diffusivities are obtained directly from mean first-exit times out of finite spatial intervals. Unlike conventional fluctuation-based approaches, the RTA does not require dedicated harmonically restrained simulations or numerical integration of noisy time-correlation functions. We assess the method for oxygen diffusion across a hexadecane slab, water permeation across a lipid bilayer, and permeation of water and selected volatile organic compounds through a model skin-barrier membrane. In the slab system, the RTA reproduces independently determined bulk diffusivities within statistical uncertainty. In the membrane systems, the inferred diffusivity profiles are supported by propagator-level validation. These results establish the RTA as a practical approach for extracting position-dependent diffusivities from biased molecular simulations.

dc.title: Scope and Feasibility of Enhancing the Irrigation Potential of the Kukadi Canal Command of Maharashtra, India dc.contributor.author: Panda, R. K.; Amarasinghe, Upali A.; Sarangi, A.; Sikka, Alok; Gorantiwar, S. D.; Mandave, Vidya; Mahapatra, Smaranika dcterms.abstract: Improving water use efficiency (WUE) in canal irrigation systems is vital for increasing agricultural output and maintaining ecological sustainability. Studies carried out in the Sina and Kukadi Left Bank Canal (KLBC) networks of Maharashtra, India, revealed marked disparities in the efficiency of the economic use of irrigation water. Investigations undertaken using geospatial tools highlighted a larger water influence zone (WIZ) in these systems, a factor often overlooked in conventional irrigation management. This finding led to the possibility of increasing the WUE by 113%, land productivity by 90% and EWP by 26% in KLBC, demonstrating the potential for optimising water resources and improving crop productivity. Additionally, the adoption of climate-resilient and water-efficient crop varieties resulted in a potential net value of output (NVOUP) increase of 80% in the KLBC irrigation system. These results emphasised the need for a comprehensive approach to irrigation water management that incorporates a detailed assessment of WIZ, conjunctive water use and sustainable cropping patterns. Such measures will not only improve water use efficiency but also contribute to a more sustainable and economically viable agricultural landscape in canal ecosystems.

dc.title: A Framework for Integrated Watershed and Climate Risk Hotspot Mapping to Support Adaptation Strategies in Refugee Camp Landscapes in Jordan dc.contributor.author: Leh, Mansoor; Akpoti, Komlavi; Jayathissa, Isuru; Khalifa, Muhammad; Umer, Yakob; Al-Zu’bi, Maha; Velpuri, Naga Manohar; Ruckstuhl, Sandra dcterms.abstract: This methodological brief presents an integrated framework for mapping watershed and climate risk hotspots in refugee-hosting landscapes in Jordan, using Jerash Refugee Camp as a pilot site. The approach combines hydrological analysis, climate projections, remote sensing data, and socio-economic indicators to assess water availability, accessibility, and community vulnerability. By integrating flood and drought hazard assessments with indicators of exposure, sensitivity, and adaptive capacity, the framework identifies spatial climate risk hotspots where vulnerable communities face the greatest climate-related pressures. The framework can be adopted in similar conflict afflicted landscapes to support evidence-based decision-making and help prioritize targeted adaptation strategies to improve water security and climate resilience in refugee and host communities. cg.contributor.programAccelerator: Food Frontiers and Security

dc.title: Water Data for Sudan’s Water, Food, and Environmental Systems dc.contributor.author: Khalifa, Muhammad; Berama, Siddig Mohammed Ali; Gebrezgabher, Solomie A.; Somorin, Tosin; Mekuria, Wolde; Ruckstuhl, Sandra; Velpuri, Naga Manohar dcterms.abstract: In fragile and conflict-affected regions, limited data and restricted access hinder effective water resource assessment and planning. To address this gap, IWMI developed a comprehensive data inventory for some parts of Sudan, integrating water, agriculture, and environmental indicators using publicly available datasets. The inventory enables spatial analysis of water availability, productivity, and climate stress to identify priority areas for intervention. cg.contributor.programAccelerator: Food Frontiers and Security

Hospital wastewater poses significant environmental and public health risks due to pathogenic microorganisms, pharmaceutical residues, and heavy metals. A 1-year temporal analysis of the hospital wastewater treatment system was conducted, involving a systematic evaluation of seasonal and monthly variations of above pollutants. The chemical oxygen demand (COD) concentration at the hospital wastewater treatment plant (HWTP) outlet peaked at 85 mg/L in summer. The suspended solids (SS) concentration exhibited an increasing trend over time, reaching a maximum of 38.3 mg/L at the end of the year. The highest concentration of fecal coliforms (FCs) (3.2 × 103MPN/L) appeared in May 2024. The moving bed biofilm reactor (MBBR) process demonstrates good performance in removing pollutants, such as ammonia nitrogen (NH3-N), COD, SS, FCs for hospital wastewater. The average removal rates of above pollutants reached 99.9%, 79.0%, 82.6%, and 71.5% respectively. Moreover, this study further investigates the emission patterns of fugitive gases (H2S, NH3, Cl2) from different azimuths around the HWTP. The concentrations of the six heavy metals in the effluent of the HWTP were all lower than the discharge standards. Both the single-factor pollution index (Pi) and the Nemerow pollution index (PN) were less than 0.1, indicating a low risk of heavy metal pollution. It provides a theoretical basis and practical guidance for the regulation of hospital wastewater and the optimization of operational parameters for treatment processes.

Raingardens offer a sustainable and nature-based approach to stormwater management and runoff control that provide multiple additional benefits to biodiversity, ecosystem services, and amenity, to name only a few. Raingardens vary in design and can be incorporated into a wide variety of urban landscapes, offering flexibility appropriate for the setting. The aim of this paper is to examine the hydrological performance and functionality of a raingarden installed in Edinburgh, Scotland over a prolonged period. Key characteristics of the raingarden are assessed and compared against the design. The raingarden was designed with two engineered soils: Engineered Soil 1 (retaining 30% existing soil–as recommended by the United Kingdom SuDs Manual) and Engineered Soil 2 (retaining 45% existing soil). We found that despite matching the recommended soil composition, the particle size distribution of Engineered Soil 1 showed variation from that recommended by the Manual. The key soil characteristics of bulk density, porosity, and saturated hydraulic conductivity correlated with the literature for both engineered soils and the existing soil. Whilst Engineered Soil 1 performed best in terms of its ability to intercept and drain runoff (having the highest saturated hydraulic conductivity, with fewer surface ponding events, and lowest retained soil moisture) it had lower soil storage capacity and plant available water than Engineered Soil 2. We also found distinct seasonal differences in infiltration performance in both engineered soils, with summer infiltration of Engineered Soil 1 being 2.5 times that of winter infiltration, and for Engineered Soil 2, summer infiltration was more than 1.4 times that of winter infiltration. Surface ponding in the raingarden was also found to be influenced by the season, with half of all ponding events occurring in winter when water uptake is reduced due to plants being dormant, and evapotranspiration is negligible. All ponding events de-watered within the recommended 48 h. Overall, the raingarden has been shown to retain 100% of runoff. The findings of this study provide helpful insight into key raingarden characteristics and functionality compared to design intent and should prove useful in informing future raingarden planning and implementation.

Flood hazards in monsoon-dominated river basins are influenced not only by total rainfall but also by the temporal sequencing, duration, and structural characteristics of typhoon events, particularly when these interact with the southwest monsoon (Habagat), a dominant driver of seasonal precipitation in the Philippines. However, many local flood studies in the Philippines rely on single representative storms, limiting their ability to capture how varying rainfall patterns influence runoff generation and floodplain dynamics. This study addresses this gap by analyzing six typhoon events—two pure typhoons and four enhanced by the southwest monsoon—and assessing their effects on the hydrologic and hydraulic response of the Talisay River basin in Balanga City, an urban catchment frequently affected by riverine flooding. Specifically, Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) was used to simulate rainfall–runoff processes under varying storm structures, whereas two-dimensional floodplain dynamics were modeled in Hydrologic Engineering Center-River Analysis System (HEC-RAS) using high-resolution terrain, land cover, and soil datasets. The modeling framework enabled a consistent comparison of peak discharge behavior, water surface elevations, flood depths, and inundation extents across events. The results showed a clear divergence between pure typhoon events and monsoon-enhanced storms, with the latter consistently producing higher runoff volumes, prolonged hydrograph responses, and far more extensive flooding. Monsoon-enhanced storms generated markedly different hydrologic signatures, including multi-peak hydrographs, sustained runoff, and peak discharges 1.5 to 1.7 times higher than those of pure typhoon events. Hydraulic simulations revealed even stronger contrasts where river stages increased by 0.5 to 1.2 m, inundation areas expanded up to 2.8 times, and flood depths exceeded 3 m in several low-lying barangays. Among all events, Typhoon Butchoy–Carina, which was intensified by the southwest monsoon in 2024, produced the most severe impacts and amplified inundation across all 10 of the most affected communities. These findings demonstrate that rainfall pattern variability plays a critical role in shaping flood severity, surpassing the influence of rainfall intensity alone. Incorporating compound storm characteristics into local flood assessments is therefore essential for effective planning, infrastructure design, and community-level risk reduction in monsoon-exposed river basins.

High-Andean lakes used as drinking-water sources are increasingly exposed to water-quality deterioration (particularly optical conditions) under strong seasonal hydrological forcing. This study evaluates trophic patterns in Pampaccocha Lagoon (Peruvian Andes) by distinguishing trophic classification (categorical outcomes from Carlson's Trophic State Index, TSI) from trophic expression (biological response, assessed primarily through chlorophyll-a), and by identifying the main statistical correlates structuring spatiotemporal variability across stations, depths, and hydrological periods. Water quality monitoring was conducted through eight sampling campaigns spanning wet and dry hydrological periods (48 observations). Physicochemical variables, nutrients, chlorophyll-a, biochemical oxygen demand (BOD5), dissolved oxygen, and Secchi depth were analyzed. Seasonal differences were tested using Mann–Whitney U-tests, trophic status was evaluated using component-wise Carlson's TSI as an indicator-based trophic assessment, and principal component analysis (PCA) was applied to explore multivariate structure. Median TSI_mean values indicated a persistent low trophic classification (oligotrophic to low-mesotrophic range) in both wet and dry periods (wet: 35.7, IQR 4.67; dry: 34.9, IQR 3.49). TSI components diverged markedly: Secchi-depth–derived values indicated eutrophic conditions (TSI_SD ≈ 56–57), chlorophyll-a-derived values indicated oligotrophic conditions (TSI_Chl ≈ 26–27), and TP-derived values remained within the oligotrophic range (TSI_TP ≈ 18–23), demonstrating strong decoupling among trophic indicators. Nutrient concentrations and chlorophyll-a did not differ significantly between hydrological periods (p > 0.05), whereas water transparency showed a pronounced seasonal contrast (p < 0.001; wet median 1.85 m vs. dry median 1.55 m). PCA explained 60.79% of total variance (PC1 40.33%, PC2 20.46%), indicating environmental organization along gradients integrating nitrogen forms, mineralization/ionic conditions, and optical–biological responses. Overall, Pampaccocha Lagoon exhibits a persistently low trophic classification with variable trophic expression governed primarily by optical and physical controls. The eutrophic signal detected by TSI is therefore best interpreted as a Secchi-depth-dominated index response associated with transparency variability rather than evidence of nutrient-driven biological eutrophication in the mechanistic sense. These findings highlight the importance of integrating optical indicators and multivariate diagnostics when assessing and managing high-Andean drinking-water sources under seasonal hydrological forcing.

Household drinking-water storage is widespread in Koya, Iraq, due to intermittent supply, yet its short-term implications for water safety and quality are not well characterized. This study combined a household survey (n = 83) with laboratory testing of stored water from 10 representative homes to evaluate how storage practices and container choice relate to water quality. Stainless-steel, plastic and clay containers were assessed, and samples were analyzed for organic load, suspended solids, and key physicochemical indicators, including nutrient forms. The analytical focus of the study was limited to physicochemical parameters, which were used to evaluate short-term water-quality stability rather than microbiological safety. Most households stored treated water for less than 24 h, and measured parameters remained largely stable during this period; container material did not produce meaningful differences in nutrient indicators (TN p = 0.082; NH4+–N p = 0.727). However, 22.9% of participants reported recent gastrointestinal symptoms, while poor hygiene routines were common (e.g., infrequent cleaning of rooftop tanks). Although no microbiological analyses were performed, these self-reported symptoms highlight the potential relevance of household handling and maintenance practices beyond physicochemical stability alone. Overall, no detectable physicochemical differences were observed across container materials under short-term storage conditions, suggesting that water quality at the point of use is more closely linked to storage duration, handling, and hygiene practices than to container material itself. Improving household maintenance and hygiene practices should therefore be prioritized as a precautionary measure to reduce potential health risks.

Groundwater recharge estimation in arid regions is challenged by data scarcity and high uncertainty. This study presents a Physics-Informed Bayesian Neural Network (PI-BNN) to quantify groundwater recharge and its uncertainty in the South Al Batinah (SAB) Basin, northern Oman. The PI-BNN was applied within a soil-moisture mass balance framework using 34 years (1990–2023) of monthly FLDAS remote sensing data, embedding the water balance equation directly into the training loss function through nine physics-informed penalty terms. Results were compared against Latin Hypercube Sampling (LHS) using the same inputs. Recharge is highly seasonal and episodic, peaking in December (~5–6 mm/month) with moderate values in February–March and July, and negligible recharge during dry months. Annual recharge is estimated at approximately 16 mm/yr (PI-BNN) and 7–11 mm/yr (LHS). Precipitation variability accounts for more than 70% of recharge uncertainty during wet months. The PI-BNN reduces uncertainty bounds by approximately 50% compared to independent LHS while maintaining physically consistent estimates. An ablation experiment confirms that the physics-informed constraints, rather than the Bayesian architecture alone, drive physically plausible recharge recovery. The proposed methodology offers a robust and transferable framework for recharge estimation in data-scarce arid environments.

Microplastic (MP) beaching is the buildup of microplastics (MPs) in sand and along the coastline. It is a growing environmental issue in which beaches act as traps for MPs, impacting marine life and potentially human health. This paper supports the hypothesis that microplastics (MPs) accumulation on sandy beaches is directly influenced by both sediment granulometry and proximity to anthropogenic sources. Two sampling campaigns were carried out at Pletera Beach, a nationally protected site in northeastern Spain on the western Mediterranean coast. This study focuses primarily on fibre and fragment abundances, as these were the dominant MP particles, accounting 95.88 and 84.40% of total MPs in the two sampling campaigns, respectively. The study further discusses how the surface distribution of MPs on beaches results from the capacity of microfibers and microfragments to infiltrate beach sediments. MP retention was higher in fine-grained sand sizes, suggesting that fine-sand beaches may be more prone to elevated surface MP concentrations due to a lower infiltration, whereas beaches characterized by coarser bed grains tend to present lower MP abundances at the surface due to the higher infiltration capacity. For the medium-grained sands, microfiber abundances were 7.6 fold higher than microfragments. Other grain-size fractions could not be considered in this study. Greater microfiber abundances are most likely caused by their entanglement within the interstitial spaces between sediment grains, indicating that differences in MP shape will result in differential depositional patterns. Higher MP abundances were found at the north of the Pletera Beach, and these were linked to both anthropogenic tourism and by the nearby port activities. Likewise, the stations closest to the Ter River had the lowest Pollution Load Indexes (PLI), which might be associated to the flushing and transport by the river while the stations closest to the northern urban area had the highest values. This study also reveals the high level of pollution at Pletera Beach, with localized MP abundances exceeding 6,000 MPs/kg, corresponding to Level 1 on the Higher Pollution Load Index.

IntroductionMicroplastic pollution consists of plastic particles smaller than 5 mm, originating from the fragmentation of larger plastic debris due to processes such as ultraviolet radiation, as well as from primary sources including industrial plastic pellets. These particles are widely transported across atmospheric, aquatic, and terrestrial systems and pose significant environmental and health risks to flora, fauna, and humans. Rivers play a critical role in conveying microplastics to aquatic environments. This study investigates microplastic pollution in the Hungarian section (Budapest reach) of the Danube River, Europe's second-largest river and a vital water resource for the region.MethodsWater samples were collected across different depths of the water column using a Multilevel Manta net. Laboratory analyses were performed using Fourier-transform infrared (FTIR) spectroscopy and digital microscopy for polymer identification and particle characterization. Concurrent flow measurements were conducted to estimate microplastic mass flux rates.ResultsThe average microplastic concentration was 0.311 mg/m3 (142 particles/m3). The most abundant polymers were polystyrene, polyethylene, and polypropylene. Detected particles occurred in various forms, including fragments, foam, and flakes, and exhibited colors such as yellow, black, gray, and green. These findings indicate substantial microplastic contamination in the studied reach of the Danube River.DiscussionThe results highlight the Danube River's role as a significant transport pathway for microplastics and underscore the need for targeted monitoring and mitigation strategies. This study contributes to understanding microplastic dynamics in large European rivers and provides valuable insights for developing effective pollution control and management approaches.

Scientists have discovered that the ocean’s “missing” plastic hasn’t vanished—it has broken down into trillions of invisible nanoplastics now spread through water, air, and living organisms. These tiny particles may be everywhere, including inside our bodies, raising serious concerns about their impact.

A sweeping global report finds that migratory freshwater fish are in steep decline, with populations down roughly 81% since 1970. These species depend on long, connected rivers, but dams and human pressures are cutting off their routes. Hundreds of species now need coordinated international protection. Experts say restoring river connectivity is critical to preventing further collapse.

Antibiotics are accumulating in a major Brazilian river, especially during the dry season when pollution becomes more concentrated. Scientists even detected a banned drug inside fish sold for food, raising concerns about human exposure. A common aquatic plant showed promise in removing these chemicals from water—but it also altered how fish absorb them, creating unexpected risks.

A popular climate theory suggested that melting Antarctic glaciers would release iron into the ocean, sparking algae blooms that pull carbon dioxide from the air. New field data from West Antarctica reveal that meltwater provides far less iron than scientists once believed. Instead, most of the iron comes from deep ocean water and sediments, not from the melting ice itself. The discovery raises new questions about how Antarctica influences climate change.

Antarctica’s Hektoria Glacier stunned scientists by retreating eight kilometers in just two months, with nearly half of it collapsing in record time. The rapid breakup was driven by a flat, underwater bedrock surface that allowed the glacier to suddenly float and fracture from below. Satellite and seismic data captured the dramatic chain reaction in near real time. The findings raise concerns that much larger glaciers could one day collapse just as quickly.

Far beneath the Atlantic Ocean, about 1,000 kilometers off Portugal’s coast, lies a colossal underwater canyon system that dwarfs even the Grand Canyon. Known as the King’s Trough Complex, this 500-kilometer stretch of trenches and deep basins formed not from rushing water, but from dramatic tectonic forces that once tore the seafloor apart.

A new study reveals that chemicals used to replace ozone-damaging CFCs are now driving a surge in a persistent “forever chemical” worldwide. The pollutant, called trifluoroacetic acid, is falling out of the atmosphere into water, land, and ice, including in remote regions like the Arctic. Even as older chemicals are phased out, their long lifetimes mean pollution is still rising.

SAR11 bacteria dominate the world’s oceans by being incredibly efficient, shedding genes to survive in nutrient-poor waters. But that extreme streamlining appears to backfire when conditions change. Under stress, many cells keep copying their DNA without dividing, creating abnormal cells that grow large and die. This vulnerability may explain why SAR11 populations drop during phytoplankton blooms and could become more important as oceans grow less stable.

Mountain regions around the world are heating up faster than the lands below them, triggering dramatic shifts in snow, rain, and water supply that could affect over a billion people. A major global review finds that rising temperatures are turning snowfall into rain, shrinking glaciers, and making mountain weather more extreme and unpredictable. These changes threaten water sources for huge populations, including those in China and India, while also increasing risks of floods, ecosystem collapse, and deadly weather events.

Scientists tracking Earth’s water from space discovered that El Niño and La Niña are synchronizing floods and droughts across continents. When these climate cycles intensify, far-apart regions can become unusually wet or dangerously dry at the same time. The study also found a global shift about a decade ago, with dry extremes becoming more common than wet ones. Together, the results show that water crises are part of a global pattern, not isolated events.

A meltwater lake that formed in the mid-1990s on Greenland’s 79°N Glacier has been draining in sudden, dramatic bursts through cracks and vertical ice shafts. These events have accelerated in recent years, creating strange triangular fracture patterns and flooding the glacier’s base with water in just hours. Some drainages even pushed the ice upward from below, like a blister forming under the glacier. Scientists now wonder whether the glacier can ever return to its previous seasonal rhythm.

Around 1,000 years ago, a major climate shift reshaped rainfall across the South Pacific, making western islands like Samoa and Tonga drier while eastern islands such as Tahiti became increasingly wet. New evidence from plant waxes preserved in island sediments shows this change coincided with the final major wave of Polynesian expansion eastward. As freshwater became scarcer in the west and more abundant in the east, people may have been pushed to migrate, effectively “chasing the rain” across vast stretches of ocean.