Search Results (145)

In this case study, we used the Delta Simulation Model II (DSM2) to study the salt balance at the land–water interface in the river delta of California’s San Francisco Estuary. Drainage, a source of water and salt for adjacent channels in the study area, is affected by channel salinity. The DSM2 approach has been adopted by several hydrodynamic models of the estuary to enforce water volume balance between diversions, evapotranspiration and drainage at the land–water interface, but does not explicitly enforce salt balance. We found deviations from salt balance to be quite large, albeit variable in magnitude due to the heterogeneity of hydrodynamic and salinity conditions across the study area. We implemented a procedure that approximately enforces salt balance through iterative updates of the baseline drain salinity boundary conditions (termed loose coupling). We found a reasonable comparison with field measurements of drainage salinity. In particular, the adjusted boundary conditions appear to capture the range of observed interannual variability better than the baseline periodic estimates. The effect of the iterative adjustment procedure on channel salinity showed substantial spatial variability: locations dominated by large flows were minimally impacted, and in lower flow channels, deviations between baseline and adjusted channel salinity series were notable, particularly during the irrigation season. This approach, which has the potential to enhance the simulation of extreme salinity intrusion events (when high channel salinity significantly impacts drainage salinity), is essential for robustly modeling hydrodynamic conditions that pre-date contemporary water management infrastructure. We discuss limitations associated with this approach and recommend that—for this case study—further improvements could best be accomplished through code modification rather than coupling of transport and island water balance models. Full article

Coastal blue carbon ecosystems (traditional types such as mangroves, salt marshes, and seagrass meadows; emerging types such as tidal flats and mariculture) play pivotal roles in capturing and storing atmospheric carbon dioxide. Reliable assessment of the spatial and temporal variation and the carbon storage potential holds immense promise for mitigating climate change. Although previous field surveys and regional assessments have improved the understanding of individual habitats, most studies remain site-specific and short-term; comprehensive, multi-decadal assessments that integrate all major coastal blue carbon systems at the national scale are still scarce for China. In this study, we integrated 30 m Landsat imagery (1992–2022), processed on Google Earth Engine with a random forest classifier; province-specific, literature-derived carbon density data with quantified uncertainty (mean ± standard deviation); and the InVEST model to track coastal China’s mangroves, salt marshes, tidal flats, and mariculture to quantify their associated carbon stocks. Then the GeoDetector was applied to distinguish the natural and anthropogenic drivers of carbon stock change. Results showed rapid and divergent land use change over the past three decades, with mariculture expanded by 44%, becoming the dominant blue carbon land use; whereas tidal flats declined by 39%, mangroves and salt marshes exhibited fluctuating upward trends. National blue carbon stock rose markedly from 74 Mt C in 1992 to 194 Mt C in 2022, with Liaoning, Shandong, and Fujian holding the largest provincial stock; Jiangsu and Guangdong showed higher increasing trends. The Normalized Difference Vegetation Index (NDVI) was the primary driver of spatial variability in carbon stock change (q = 0.63), followed by precipitation and temperature. Synergistic interactions were also detected, e.g., NDVI and precipitation, enhancing the effects beyond those of single factors, which indicates that a wetter climate may boost NDVI’s carbon sequestration. These findings highlight the urgency of strengthening ecological red lines, scaling climate-smart restoration of mangroves and salt marshes, and promoting low-impact mariculture. Our workflow and driver diagnostics provide a transferable template for blue carbon monitoring and evidence-based coastal management frameworks. Full article

The accelerated industrialization in China has precipitated a dramatic surge in solid waste generation, causing severe land resource depletion and posing substantial environmental contamination risks. Simultaneously, the cement industry has become characterized by the intensive consumption of natural resources and high carbon emissions. This review aims to investigate the current technological advances in utilizing industrial solid waste for cement production, with a focus on promoting resource recycling, phase transformations during hydration, and environmental management. The feasibility of incorporating coal-based solid waste, metallurgical slags, tailings, industrial byproduct gypsum, and municipal solid waste incineration into active mixed material for cement is discussed. This waste is utilized by replacing conventional raw materials or serving as active mixed material due to their content of oxygenated salt minerals and oxide minerals. The results indicate that the formation of hydration products can be increased, the mechanical strength of cement can be improved, and a notable reduction in CO₂ emissions can be achieved through the appropriate selection and proportioning of mineral components in industrial solid waste. Further research is recommended to explore the synergistic effects of multi-waste combinations and to develop economically efficient pretreatment methods, with an emphasis on balancing the strength, durability, and environmental performance of cement. This study provides practical insights into the environmentally friendly and efficient recycling of industrial solid waste and supports the realization of carbon peak and carbon neutrality goals. Full article

Desalination is becoming crucial to meet the increasing global demand for potable water. Despite its benefits, desalination produces reject brine, a highly concentrated saline byproduct, which poses substantial environmental risks if not managed properly. It contains high levels of salts and other potentially harmful compounds, which, when discharged into oceans or land, can disrupt habitats, degrade soil quality, and harm biodiversity, creating serious environmental challenges. In response to these challenges, this study investigated various uses for reject brine, aiming to reduce its environmental footprint and explore its potential applications. This review paper synthesizes findings from previous studies on the disposal, management, and applications of reject brine in fields such as concrete production, road construction, and ground stabilization. In addition, this review highlights the potential cost savings and resource efficiency resulting from the utilization of reject brine, as well as the mitigation of environmental impacts associated with traditional disposal methods. This paper also provides a comprehensive overview of existing technologies and approaches used to utilize reject brine in various industries, including construction. This review contributes to the growing body of knowledge on environmentally friendly solutions for reject brine, emphasizing its potential role in supporting sustainable development goals through resource reutilization and waste minimization. The study also highlights current research gaps that are still unaddressed, hindering the complete realization of the full potential of reject brine as a sustainable resource. Full article

This paper systematically reviews the progress of remote-sensing technology in coastal-ecosystem health assessment. Coastal ecosystems, as transitional zones between land and ocean, play vital roles in maintaining biodiversity, carbon sequestration, and coastal protection, but currently face severe challenges from climate change and human activities. Remote-sensing technology, with its capability for large-scale, long time-series observations, has become a key tool for coastal-ecosystem health assessment. This paper analyzes the technical characteristics and advantages of optical remote sensing, radar remote sensing, and multi-source data fusion in coastal monitoring; constructs a health-assessment framework that includes water-quality indicators, vegetation and ecosystem function indicators, and human disturbance and landscape change indicators; discusses the application of advanced technologies from traditional methods to machine learning and deep learning in data processing; and demonstrates the role of multi-temporal analysis in revealing coastal-ecosystem change trends through typical case studies of mangroves, salt marshes, and coral reefs. Research indicates that, despite the enormous potential of remote-sensing technology in coastal monitoring, it still faces challenges such as sensor limitations, environmental interference, and data processing and validation. Future development should focus on advanced sensor technology, platform innovation, data-processing method innovation, and multi-source data fusion, while strengthening the effective integration of remote-sensing technology with management practices to provide scientific basis for the protection and sustainable management of coastal ecosystems. Full article

Saline–alkali land is a critical factor limiting agricultural production and ecological restoration. Utilizing salt-tolerant plants for bioremediation represents an environmentally friendly and sustainable approach to soil management. This study employed the highly salt-tolerant crop Portulaca oleracea L. cv. “Su Ma Chi Xian 3” as the test material. A plot experiment was established in coastal saline soils with planting P. a- oleracea (P) and no planting (CK) under three blocks with the different salt levels (S1: 2.16 g/kg; S2: 4.08 g/kg; S3: 5.43 g/kg) to systematically evaluate its salt accumulation capacity and effects on soil physicochemical properties. The results demonstrated that P. oleracea exhibited adaptability across all three salinity levels, with aboveground biomass following the trend PS2 > PS3 > PS1. The ash salt contents removed through harvesting were 1.29, 2.03, and 1.74 t/ha, respectively, in PS1, PS2, and PS3. Compared to no planting, a significant reduction in bulk density was observed in the 0–10 and 10–20 cm soil layers (p < 0.05). A significant increase in porosity by 9.72%, 16.29%, and 12.61% was found under PS1, PS2, and PS3, respectively, in the 0–10 cm soil layer. Soil salinity decreased by 34.20%, 50.23%, and 48.26%, in the 0–10 cm soil layer and by 14.43%, 32.30%, and 26.42% in the 10–20 cm soil layer under PS1, PS2, and PS3, respectively. The pH exhibited a significant reduction under the planting treatment in the 0–10 cm layer. A significant increase in organic matter content by 13.70%, 12.44%, and 13.55%, under PS1, PS2, and PS3, respectively, was observed in the 0–10 cm soil layer. The activities of invertase and urease were significantly enhanced in the 0–10 and 10–20 cm soil layers, and the activity of alkaline phosphatase also exhibited a significant increase in the 0–10 cm layer under the planting treatment. This study indicated that cultivating P. oleracea could effectively facilitate the improvement of coastal saline soils by optimizing soil structure, reducing salinity, increasing organic matter, and activating the soil enzyme system, thereby providing theoretical and technical foundations for ecological restoration and sustainable agricultural utilization of saline–alkali lands. Full article

Salt accumulation in arable lands causes significant abiotic stress, resulting in a 10% loss in global arable land area and jeopardizing food production and agricultural sustainability. In order to attain high and sustainable food production, it is imperative to enhance traditional agricultural practices with modern technology to enable the restoration of arable lands afflicted by salinity. This review consolidates recent rice-specific advancements aimed at enhancing salt stress resilience through integrated strategies. We explore the functions of primary and secondary metabolic pathways, organic amendments, microbial symbiosis, and plant growth regulators in reducing the negative impacts of salt. Furthermore, we highlight the significance of emerging genetic and epigenetic technologies, including gene editing and transcriptional regulation, in developing salt-tolerant rice cultivars. Physiological studies reveal salt stress responses in rice plants, biochemical analyses identify stress-related metabolites, microbial investigations uncover beneficial plant–microbe interactions, and molecular approaches enable the identification of key genes—together providing essential insights for developing salt-tolerant rice varieties. We present a comprehensive overview of the multilayered strategies—ranging from agronomic management and physiological adaptations to molecular breeding and microbial applications—that have been developed and refined over recent decades. These approaches have significantly contributed to understanding and improving salinity tolerance mechanisms in rice. This review provides a foundational framework for future research and practical implementation in stress-resilient rice farming systems. Full article

Utah, USA, relies heavily on snowpack for water to sustain its growing population. Scientists and policy makers are exploring and proposing several potential sustainable solutions to improving flow to the Great Salk Lake as it recently has significantly declined in size, including removing tree canopy. This study examines the influence of tree canopy coverage, climate, and topography on snow water equivalent (SWE) within the Great Salt Lake Watershed. Using SNOTEL data, NLCD land use/land cover rasters, t-tests, and multiple linear regression (MLR), the study analyzed SWE variability in relation to canopy density, winter precipitation, elevation, temperature, and latitude. Initial t-tests showed significant differences in SWE between sites with canopy coverage below and above 70%, yet tree canopy was excluded as a significant predictor in the MLR model. Instead, SWE was primarily explained by mean winter precipitation, elevation, average winter high temperatures, and latitude. Additionally, canopy change analysis of the 2018 Pole Creek Fire in the Jordan River watershed showed no significant changes in SWE following canopy loss. This study highlights the dominant role of climatic factors in influencing snowpack dynamics on a watershed scale. It also provides important data for sustainable watershed and forestry management and a framework for understanding snowpack responses to climate and land cover changes in saline lake ecosystems. Full article

Agricultural water resource management is increasingly challenged by climate variability, land degradation, and socio-economic pressures, particularly in the Mediterranean region. This study, conducted in 2023–2024 within the REACT4MED project (PRIMA initiative), addresses sustainable water use through a comparative analysis of organic and conventional farms in the Stornara and Tara area (Puglia, Italy). The research aimed to identify critical indicators for sustainable water management and develop ecosystem restoration strategies that can be replicated across similar Mediterranean agro-ecosystems. An interdisciplinary, participatory approach was adopted, combining technical analyses and stakeholder engagement through three workshops involving 30 participants from diverse sectors. Fieldwork and laboratory assessments included soil sampling and analysis of parameters such as pH, electrical conductivity, soil organic carbon, nutrients, and salinity. Cartographic studies of vegetation, land use, and pedological characterization supplemented the dataset. The key challenges identified were water loss in distribution systems, seawater intrusion, water pumping from unauthorized wells, and inadequate public policies. Soil quality was significantly influenced by salt stress, hence affecting crop productivity, while socio-economic factors affected farm income. Restoration strategies emphasized the need for water-efficient irrigation, less water-intensive crops, and green vegetation in infrastructure channels while incorporating also the native flora. Enhancing plant biodiversity through weed management in drainage channels proved beneficial for pathogen control. Proposed socio-economic measures include increased inclusion of women and youth in agricultural management activities. Integrated technical and participatory approaches are essential for effective water resource governance in Mediterranean agriculture. This study offers scalable, context-specific indicators and solutions for sustainable land and water management in the face of ongoing desertification and climate stress. Full article

The aim of this study is to determine the characteristics of the chemical and mineral composition of sediment layers in a technogenic settling pond. This pond is located on urban land in Berezniki (Perm Krai, Russia), outside the territory of operating industrial facilities, and contains alkaline saline industrial wastes. The origin of this waste was related to sludge from the Solvay soda production process, which had been deposited in this pond over a long period of time. However, along with the soda waste, the pond also received wastewater from other industries. As a result, the accumulated sediment is characterized by variation in morphological properties both in depth and laterally. Five undisturbed columns were taken to study the composition of the accumulated sediment. The obtained samples were analyzed by X-ray diffraction (XRD), synchronous thermal analysis (STA), and X-ray fluorescence (XRF) analysis. The results showed that the mineral composition of bottom sediments in each layer of all studied columns is characterized by the predominance of calcite precipitated from wastewater. Along with calcite, due to the presence of magnesium and sodium in the solution, other carbonates precipitated—dolomite and soda (natron), as well as complex transitional carbonate phases (northupite and trona). Together with carbonate minerals, the chloride salts halite and sylvin, sulfate minerals gypsum and bassanite, and pyrite and nugget sulfur were established. The group of terrigenous mineral components is represented by quartz, feldspars, and aluminosilicates. The chemical composition of sediments in the upper part of the section generally corresponds to the mineral composition. In the lower sediment layers, the role of amorphous phase and non-mineral compounds increased, which was determined by the results of thermal analysis. The content of heavy metals and metalloids also increases in the middle and lower sediment layers. When categorized according to the Igeo value, an excessive degree of contamination (class 6) was observed in all investigated columns for copper content (Igeo 5.2–6.1). Chromium content corresponds to class 5 (Igeo 4.1–4.6), antimony to class 4 (Igeo 3.0–4.0), and lead, arsenic, and vanadium to classes 2 and 3 (moderately polluted and highly polluted). The data obtained on variations in the mineral and chemical composition of sediments represent the initial information for the selection of methods of accumulated waste management. Full article

Groundwater is a critical freshwater resource, yet its quality is increasingly threatened by anthropogenic activities, particularly in urbanized regions. This study employs geospatial analysis to evaluate the spatiotemporal variability of groundwater quality across 11 Watershed Management Areas (WMAs) in northern New Jersey, from 1999 to 2016. Using specific conductance (SC) as a proxy for salinity, we applied Ordinary Kriging interpolation to estimate SC values in unmonitored locations, leveraging data from 295 shallow wells within the New Jersey Ambient Groundwater Quality Monitoring Network. The results reveal significant spatial heterogeneity in groundwater quality, strongly associated with land use and road density. The Northeast water region, characterized by high urbanization and extensive road networks, exhibited the poorest water quality, with salinity levels exceeding the 750 μS/cm threshold for freshwater in WMAs such as Lower Passaic (WMA-4) and Hackensack (WMA-5). In contrast, the Northwest region, dominated by agricultural and undeveloped land, maintained better water quality. Temporal analysis showed a worrying decline in freshwater coverage, from 80% in 1999–2004 to 74% in 2014–2016, with deicing salts and aging sewer infrastructure identified as major contamination sources. The study highlights the efficacy of Kriging and GIS tools in mapping groundwater quality trends and highlights the urgent need for targeted water management strategies in vulnerable regions. These findings provide policymakers and stakeholders with actionable insights to mitigate groundwater degradation and ensure long-term freshwater sustainability in northern New Jersey. Full article

Large-scale inter-basin water transfer is an important means to alleviate the pressure on water resources in water shortage regions. However, the long-term impacts of inter-basin transfers on the regional water–salt balance and associated land productivity remain poorly understood, especially in salt-affected arid environments. To fill this gap, the core objective of this study was to reveal the implications of inter-basin water transfer on soil salinity and sodicity and the crop yield response under different irrigation practices. We conducted a case study on the Karamay irrigation district (KID), an artificial oasis with a 30-year history of inter-basin water transfer in northwestern China, using trend and correlation analyses, water–salt balance analyses, and salt-controlled yield reduction functions as well as field comprehensive measurements over 1996–2023. The results indicate that soil salinity and sodicity profiles, overall, exhibited a clear vertical stratification under both the early and late crop growing stages, and the degree of the soil salinization was decreasing, and the area of non-saline land was increasing significantly from 1996 to 2023 in the KID. Owing to the lack of salt-washing water and the poor irrigation water quality, the water-saving irrigated farmland was in the slight salt-aggregating state in the topsoil layer, while the other soil layers were in the salt-expelling or salt-equilibrating state in the KID. The profile distribution and exchange fluxes of soil salinity and sodicity are mainly characterized by climate, irrigation, and groundwater dynamics, as well as the plant salt tolerance, soil properties, and agronomic management which also influence the soil salt accumulation. With the transformation of irrigation schemes from traditional flood irrigation to modern water-saving irrigation during 1996–2023, the impact of soil salinity on relative crop yields has been substantially reduced in the KID, especially for salt-sensitive crops. This revealed that optimizing the drainage facilities, precise field irrigation and fertilization measures, and rational crop selection and agronomic practices are vital for high-quality development in the KID. Capitalizing on these research findings, we would provide effective directives for maintaining the sustainability of agricultural development in other similar inter-basin water transfer zones in the world. Full article

The management and use of saline–alkaline land is a global concern and research focus. Although there is extensive long-term global research on soil salinization and improvement, systematic summaries of research progress in this field are insufficient. This study, based on the Web of Science (WOS) and incoPat database, analyzes the literature and patents on saline–alkaline land over the past 30 years, sums up research progress and current status, and proposes future directions to lay a foundation for further study. Research hotspots are mainly salt-tolerant plant growth mechanisms and gene expression under salt stress, interactions between salt-tolerant plants and microbes, soil conditioner use, remote sensing monitoring of saline–alkaline land changes, irrigation and drainage techniques, and soil nutrient status and improvement. Saline–alkaline land management research is moving toward integrated application of multiple improvement measures. Priority should be given to developing land remediation technologies and salt-tolerant plant varieties suited to different regions; studying the compatibility among technologies, plant varieties, and cultivation techniques; establishing region- and type-specific integrated management and ecological use methods; and creating comprehensive development plans to boost soil productivity and protect the ecology. Full article

Background/Objective: Salinity is a growing problem affecting a large portion of global agricultural land, particularly in areas where water resources are scarce. The objective of this study was to provide physiological and molecular information on salt-tolerant citrus rootstocks to mitigate the detrimental effects of salinity on citriculture. Methods: Ten accessions belonging to eight Citrus species and four to Poncirus trifoliata Raf. were tested for salinity tolerance (0 and 15 mM NaCl for 1 year) in terms of vegetative and Cl⁻ tissue distribution traits. In addition, most accessions were evaluated for leaf Na⁺ and other cations. Results: All salt tolerant accessions tended to restrict the leaf Cl⁻ content, although in a lower degree than the Cleopatra mandarin. However, differences in their ability to restrict leaf [Na⁺] were evident, contributing to a classification of trifoliate and sour orange accessions that matched their genotypic grouping based on allele sharing at a marker targeting candidate gene coding for the NPF5.9 transporter within LCL-6 quantitative trait locus. Conclusions: Our markers targeting LCl-6 candidate genes coding for NPF5.9, PIP2.1, and CHX20 (citrus GmSALT3 ortholog) could be efficient tools for managing the detected salt tolerance diversity in terms of both Cl⁻ and Na⁺ homeostasis in rootstock breeding programs derived from these species, in addition to Citrus reshni. Full article

Soil microbes play a vital role in tidal flat ecosystems but are highly susceptible to disturbances from land reclamation. This study investigated the dynamics of bacterial communities and their environmental drivers across a 50-year reclamation chronosequence under three vegetation types (bare flats, reed beds, and rice fields). The results showed that, after 50 years of reclamation, total dissolved salts decreased significantly in vegetated zones, particularly in rice fields, where Cl⁻ dropped by 54.71% and nutrients (SOC, TN, TP) increased substantially. Key ions, including HCO₃⁻, Cl⁻, and K⁺, were the primary drivers of microbial community structure, exerting more influence than total salinity (TDS) or pH. Bacterial abundance and diversity increased over time, with rice fields showing the highest values after 50 years. Actinobacteriota and Proteobacteria were positively correlated with HCO₃⁻ and K⁺, while Cl⁻ negatively affected Acidobacteriota. Genus-level analyses revealed that specific taxa, such as Sphingomonas and Gaiella, exhibited ion responses diverging from broader phylum-level patterns, exemplifying niche-specific adaptations to salinity regimes. These findings underscore the pivotal role of vegetation type and individual salinity ions in driving microbial succession during tidal flat reclamation. A phased vegetation strategy, starting with reed colonization and followed by rice cultivation, can enhance soil quality and microbial diversity. This research provides important insights for optimizing vegetation management and ion monitoring in sustainable tidal flat reclamation. Full article