7 results
Filters
Settings
Now showing1 - 7 of 7
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Combined effects of salt and microplastics on evaporation and crystallization dynamics in porous media(American Chemical Society (ACS), 2026-03-18); ; ; ; This study investigates the combined effects of salinity and microplastic contamination on the evaporation process and salt crystallization in porous media through complementary column- and pore-scale experiments. Laboratory soil columns were packed with either pure sand or sand mixed with 5% (w/w) poly(vinyl chloride) (PVC) microplastics and subsequently saturated with freshwater or saline (NaCl) solution. Evaporation and crystallization dynamics were monitored by using mass loss measurements, surface optical and thermal imaging, and synchrotron X-ray tomography. Results show that salinity consistently suppressed evaporation by roughly 25–30%, whereas PVC microplastics enhanced it, generating substantial differences in cumulative water loss across treatments. Moreover, thermal imaging revealed distinct surface responses: NaCl samples developed salt crusts that progressively reduced local temperature contrasts and led to more spatially uniform surface conditions, whereas PVC-NaCl samples exhibited lower mean surface temperatures but substantially higher spatial variability, reflected in larger and more persistent temperature anomalies during drying. Pore-scale μCT imaging further confirmed that microplastics altered crystallization patterns by redistributing salt deposition over the upper part of the sand profile and modifying the nucleation behavior. Together, these findings underscore the complex interplay between microplastics and salinity, with implications for soil moisture regulation, surface energy flux, and environmental monitoring strategies.Publicationtype: Journal Article30 53 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Rethinking global soil degradation: drivers, impacts, and solutions(American Geophysical Union (AGU), 2025-12); ; ; ; The increasing threat of soil degradation presents significant challenges to soil health, especially within agroecosystems that are vital for food security, climate regulation, and economic stability. This growing concern arises from intricate interactions between land use practices and climatic conditions, which, if not addressed, could jeopardize sustainable development and environmental resilience. This review offers a comprehensive examination of soil degradation, including its definitions, global prevalence, underlying mechanisms, and methods of measurement. It underscores the connections between soil degradation and land use, with a focus on socio‐economic consequences. Current assessment methods frequently depend on insufficient data, concentrate on singular factors, and utilize arbitrary thresholds, potentially resulting in misclassification and misguided decisions. We analyze these shortcomings and investigate emerging methodologies that provide scalable and objective evaluations, offering a more accurate representation of soil vulnerability. Additionally, the review assesses both physical and biological indicators, as well as the potential of technologies such as remote sensing, artificial intelligence, and big data analytics for enhanced monitoring and forecasting. Key factors driving soil degradation, including unsustainable agricultural practices, deforestation, industrial activities, and extreme climate events, are thoroughly examined. The review emphasizes the importance of healthy soils in achieving the United Nations Sustainable Development Goals, particularly concerning food and water security, ecosystem health, poverty alleviation, and climate action. It suggests future research directions that prioritize standardized metrics, interdisciplinary collaboration, and predictive modeling to facilitate more integrated and effective management of soil degradation in the context of global environmental changes.Publicationtype: Review Article22 30 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , The Role of Wind Velocity in Saline Water Evaporation from Porous Media and Surface Salt Crystallization Dynamics(2025-07-06); ; ; ; This study systematically investigates the effect of wind flow on evaporation dynamics and salt crystallization patterns in porous media. Well-controlled experiments were conducted in a laboratory wind tunnel, where the surface of sand columns saturated with freshwater and NaCl solutions at concentrations of 10%, 15%, and 20% were subjected to wind flows of 0.5 and 5 m/s, corresponding to laminar and turbulent flow regimes, respectively. Mass loss measurements from the samples, combined with optical imaging of their surfaces, revealed distinct evaporation dynamics and crystallization patterns. We observed that the interaction between intermittent turbulent airflow and evolving salt crystals on the surface resulted in a relatively uniform crystallization pattern. In contrast, under laminar airflow conditions, salt crystal nucleation and formation primarily occurred at the leading edge of the sample, particularly at lower salt concentrations. We further investigated the impact of enhanced evaporative mass loss in the presence of wind on crystallization dynamics by quantifying the crystal coverage and its lateral extent on the surface. Under turbulent flow conditions, we observed that full coverage of the surface with salt crystals requires 2 to 3 times higher evaporative losses in 10% NaCl sample relative to the 15% and 20% samples, respectively. These findings highlight the complex interplay between evaporation and crystallization processes under varying airflow conditions, thus offering valuable insight for improving hydrological and climatological modeling.Publicationtype: Journal Article32 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , The role of wind velocity in saline water evaporation from porous media and surface salt crystallization dynamicsSaline water evaporation from porous media with the corresponding surface salt crystallization patterns play a vital role in many environmental and engineering applications. While the impact of factors such as type and concentration of salt, particle size and angularity, and ambient temperature and humidity are relatively well characterized [1]–[3], the influence of wind and aerodynamic conditions on saline water evaporation and salt crystallization is not fully understood. We conducted a series of laboratory experiments in a wind tunnel to systematically investigate the effect of wind flow on saline water evaporation and dynamics of salt crystallization. Cylindrical sand columns (D: 5 cm – H: 20 cm) were placed in the test section of the wind tunnel. Surface of the samples were exposed to uniform mean wind velocities of 0.5 and 5 m/s. To keep samples fully saturated during the evaporation experiments, sand columns were supplied from Mariotte bottles containing 10, 15, and 20% NaCl solutions. Evaporation rates were monitored by measuring mass losses from Mariotte bottles, while salt crystallization patterns were captured using an optical camera positioned above the surface of columns. Preliminary results indicate that variation in aerodynamic conditions and turbulence patterns, driven by changes in wind velocity and surface roughness (due to crystal growth), significantly alter evaporation rates and salt crystallization process. Distinct crystallization patterns were observed with variation of wind velocity with possible influences on the evaporative fluxes. Using the measured data, we will identify the key effects of air flow regimes coupled with the salt concentration on evaporative losses and the evolution of crystallized salts at the surface, which will be important for a wide range of environmental and hydrological applications.Publicationtype: Conference Paper11 15 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Sustainability Nexus AID: soil healthAbstract The Sustainability Nexus Analytics, Informatics, and Data (AID) Programme of the United Nations University (UNU), aims to provide information, data, computational, and analytical tools to support the sustainable management and long-term security of natural resources using a nexus approach. This paper introduces the Soil Health Module of the Sustainability Nexus AID Programme. Healthy soil is crucial for life on Earth, and it is essential for ecosystem services and functioning, access to clean water, socioeconomic structure, biodiversity, and food security for the growing population of the world. Healthy soils contribute to mitigating the effects of climate change and reduce the consequences of extreme events such as flooding and drought. Healthy soils influence the hydrologic cycle by regulating transpiration, water infiltration, and soil water evaporation affecting land–atmosphere interactions. The Soil Health Module of the UNU Sustainability Nexus AID Programme aims to evolve into the ultimate focal point, supporting a diverse array of stakeholders with state-of-the-art data and tools that are essential for soil health monitoring and projection. This paper discusses the importance of adopting a nexus approach for ensuring soil health, explores the AID tools currently at our disposal for quantifying and predicting soil health, and concludes with recommendations for future effort and direction within the Sustainability Nexus AID Programme concerning soil health.Publicationtype: Journal Article30 28 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Multi-scale soil salinization dynamics from global to pore scale : a reviewSoil salinization refers to the accumulation of water-soluble salts in the upper part of the soil profile. Excessive levels of soil salinity affects crop production, soil health, and ecosystem functioning. This phenomenon threatens agriculture, food security, soil stability, and fertility leading to land degradation and loss of essential soil ecosystem services that are fundamental to sustaining life. In this review, we synthesize recent advances in soil salinization at various spatial and temporal scales, ranging from global to core, pore, and molecular scales, offering new insights and presenting our perspective on potential future research directions to address key challenges and open questions related to soil salinization. Globally, we identify significant challenges in understanding soil salinity, which are (a) the considerable uncertainty in estimating the total area of salt-affected soils, (b) geographical bias in ground-based measurements of soil salinity, and (c) lack of information and data detailing secondary salinization processes, both in dry- and wetlands, particularly concerning responses to climate change. At the core scale, the impact of salt precipitation with evolving porous structure on the evaporative fluxes from porous media is not fully understood. This knowledge is crucial for accurately predicting soil water loss due to evaporation. Additionally, the effects of transport properties of porous media, such as mixed wettability conditions, on the saline water evaporation and the resulting salt precipitation patterns remain unclear. Furthermore, effective continuum equations must be developed to accurately represent experimental data and pore-scale numerical simulations.Publicationtype: Review Article35 132 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Quantifying salt crystallization impact on evaporation dynamics from porous surfaces(2024-11-14); ; ; ; We investigated the effects of salt crystallization on the dynamics of saline water evaporation in porous media. Water mass loss rates from sand columns supplied with NaCl solutions at three concentrations were monitored under controlled ambient conditions. The formation and evolution of salt crystals over sand surfaces were synchronously imaged optically and thermally. Despite identical experimental and ambient conditions, we observed distinct crystallization dynamics that affected evaporative mass loss rates for similar salt concentrations, highlighting high variability of crystallization and its impact on evaporation. We observed the enhancement of maximum evaporation rates by factors of 3 to 14 under our experimental conditions and attributed this enhancement to the formation and evolution of porous crystalized salts at the surface. Additionally, visible intermittent temperature fluctuations of the salt crust were quantified using thermal imagery attributed to the dynamic processes of crystallization, dissolution and evaporation occurring simultaneously at the surface.Publicationtype: Journal Article22 33