The subduction–collision tectonic setting of the Tibetan Plateau (TP) favors the formation of boron (B) deposits in salt lakes. Da Qaidam Salt Lake (DQL) in the northern TP is well known for giant brine–solid B resources. However, massive boron accumulation in the DQL cannot be balanced by the modern surface recharge system, and large boron isotopic offset (∼28 ‰) between source waters and brines indicates complex boron source–sink processes, which remain poorly constrained. Here, we present hydrochemical parameters, B concentrations and isotopes of river waters, groundwaters, geothermal springs, lake brines and intercrystalline brines from the DQL. The recharge waters are characterized by high B concentrations (0.1–44.8 mg/L) and large B isotopic variations (−11.94 ‰ to +16.46 ‰). Similarly, brines in the DQL also present varying B concentrations (234.1–1847.5 mg/L) and isotopes (−6.05 ‰ to +10.10 ‰). By integrating these results with previous studies on regional tectonic evolution, watershed geomorphology, hydrological reorganization and salt-forming periods in the DQL, the source–sink process and enrichment mechanisms of B in the DQL are discussed. Key conclusions are as follows. Besides the supply of hot springs and rivers in the modern drainage area, neighboring Tataleng and Yuka rivers provide ample B to match the giant resources in the DQL through cross–basin groundwater flow regimes. The high B concentrations of rivers in the DQL are from weathering of boron-rich bedrock, recharge of hot springs and mud volcanoes, and leaching of early small intermontane B deposits and sediments. The subduction–collision tectonic setting in the northern Qaidam Basin facilitates the formation of various B-rich rocks and fluids surrounding the DQL. Various B sources and transportation–enrichment processes promote B isotopic discrepancy in recharge waters and lake brines. Furthermore, diversion of the Yuka and Tataleng rivers since ∼23 ka has sharply decreased water budget of the DQL, inducing rapid salt deposition and B enrichment under arid climate. Conclusively, the formation of large B deposits in the DQL is the collaboration of endogenic and supergene processes. The research findings in this study offer insights for understanding the formation of numerous B deposits in salt lakes on the TP.

Lake sediments constitute a significant yet vulnerable component of the global carbon cycle. Nevertheless, the mechanisms controlling the temperature response of source-specific organic carbon (OC) remain unclear, limiting predictive capability of climate-carbon feedbacks. To address this, we investigated the decomposition of plant- and microbial-derived OC in Qinghai-Tibetan Plateau lake sediments via a 180-day microcosm incubation at 8 degrees C and 18 degrees C, integrating biomarker analysis, optical spectroscopy, and mass spectrometry. The results show that plant-derived OC forms the foundational component of the sediment OC pool, dominating total OC accumulation and exhibiting low temperature sensitivity, which facilitates its preservation under warming. In contrast, microbial-derived OC shows higher temperature sensitivity and is preferentially decomposed at elevated temperatures; its stability depends strongly on mineral protection, correlating positively with clay content, reactive calcium, and cation exchange capacity. We propose a synergistic framework wherein the substrate source establishes the baseline stability of sediment OC, while mineral protection modulates the temperature-sensitive microbial fraction. The overall OC response to warming is determined by the trade-off between these two mechanisms, implying a potentially diminishing climate-carbon feedback from lake ecosystems over time. This study provides a mechanistic basis for predicting OC fate in inland waters under warming.

Salt lakes on the Tibetan Plateau are generally enriched in rare alkali metals, including lithium (Li), rubidium (Rb) and cesium (Cs), which are mainly sourced from extensive geothermal fluids. However, geochemical behaviors of Rb and Cs during the source-sink process in salt lake basins are different from Li, resulting in their limited enrichment in brines and deviation from the geothermal source signatures. Using Damxung Co Salt Lake as a representative case, this study investigated the source-sink dynamics through hydrochemical analysis, H-O isotopes, and sediment sequential extraction. Results indicate that Rb and Cs are mainly derived from geothermal fluids, with deep high-temperature water-rock interactions and input of minor magmatic fluid. Sinters (Rb: 24.65 ppm; Cs: 13.65 ppm), lake brines (Rb: 13.64 mg/L; Cs: 0.54 mg/L), and sediments (Rb: 77.0 ppm; Cs: 32.0 ppm) act as the three major gathering carriers for Rb and Cs, in which lake sediments represent the dominant occurrence reservoir. Mass balance calculations indicate that approximately 69% of Rb and 97% of Cs have been removed from the water column and sequestered in the sediments. Rb and Cs are specifically associated with the acid-insoluble fraction of illite. This enrichment is controlled by salinity: in low-salinity environments (fresh-brackish water), the low hydration energies of Rb* and Cs* facilitate their preferential adsorption onto the illite. In contrast, during the high-salinity (salt lake) stage, part of Rb and Cs were desorbed from the sediments due to the competitive absorption of other high concentrations of cations (Na*, K*). This study elucidates Rb-Cs behavior in salt lakes, highlighting their preferential enrichment in sediments. It further suggests that ongoing lake desalination favors the preservation of Rb and Cs in the sedimentary sink. (c) 2026 China University of Geosciences (Beijing) and Peking University. Published by Elsevier B.V. on behalf of China University of Geosciences (Beijing). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

The global transition to low carbon energy has increased demand for strategic salt lake minerals such as lithium and potassium, while intensifying the tension between resource development and the protection of fragile ecosystems. Conventional ecological assessments rely largely on static background indicators and geometric buffers, which limit their ability to represent disturbance pathways across environmental media, such as salt dust dispersion and water and salt migration, and to account for climatic covariation in ecological change. Taking the Qinghai–Tibet Plateau as the study area, this study developed a regional ecological stress screening framework that integrates hydrological connectivity constraints, correction using seasonal wind fields, adjustment for climatic background conditions using multiscale geographically weighted regression, and regional extrapolation using a random forest model. The modeled disturbance fields exhibited pronounced differences among environmental media in spatial extent, transport direction, and seasonal variation. The hydrologically constrained soil and water disturbance field covered 66,745 km2, including 13,349 km2 classified as high stress areas. Analysis of seasonal wind fields identified spring as the dominant season for potential atmospheric transport of salt dust, accounting for 48.27% of the annual transport potential, with transport mainly associated with westerly and west northwesterly winds. After statistically accounting for the selected climatic covariates, development disturbance was generally associated with adverse changes in ecological health. This negative association, as estimated by the model, tended to be more pronounced in areas with a greater number of heavy precipitation days during the warm season. Within the influence zones of existing developed mining areas, higher modeled risk classes were generally accompanied by higher deterioration proportions for several ecological indicators, providing partial evidence of consistency between ecological responses and the local risk ranking. Extrapolation across the plateau using the random forest model indicated relatively higher modeled suitability in the southern Tibetan mountains, the Nagqu hilly uplands, and the broad valleys of the southern Qinghai Plateau. Relatively lower modeled suitability occurred in the lake basins of the Qiangtang Plateau and along both flanks of the Kunlun Mountains. The Qaidam Basin showed moderate modeled suitability and pronounced spatial heterogeneity. These results provide regional screening evidence for prioritizing subsequent field investigations, analyses using process models, and environmental assessments at individual sites.

Rubidium (Rb) and cesium (Cs) are important rare mineral resources with irreplaceable application value, particularly in high-technology fields. In the source-sink system of salt lakes in the southern Qaidam Basin, Rb and Cs are relatively enriched; however, pronounced differences exist between the source and sink ends, and the controlling factors for these differences are still unclear. Therefore, based on systematically collected samples of rocks, sediments and waters, this study investigates the distribution characteristics and genesis of Rb and Cs in the source-sink system through analyses of hydrochemical parameters and stable isotopes of hydrogen and oxygen. The results show that; (1) In source area, granites (Rb: 364.5 x 10(-6); Cs: 7 & times; 10( -6) ; n = 2 exhibit the highest average content of Rb and Cs, followed by rhyolites (Rb: 177 x 10(-6) Cs / 6.3 x 10(-6)) , intermediate-basic volcanic rocks (Rb: 106.4 x 10(-6) Cs / 4.2 x 10(-6); n = 8 ) , and altered granites (Rb: 56.2 x 10(-6) Cs: 12.9 x 10(-6); n = 4 . Among waters, deep geothermal waters (hot springs) show the highest average content of Rb and Cs (Rb: 13.40mg/L; Cs: 21.71mg/L; n = 5 ) , followed by intercrystalline brines (Rb: 6.08mg/L; Cs: 0.22mg/L; n = 21 of terminal salt lakes and surface brines (Rb: 0.66mg/L; Cs: 0.05mg/L; n = 14 . However, the maximum Rb and Cs concentrations occur in salt-pond brines (Rb: 34.54mg/L). In contrast, shallow geothermal waters (hot springs) (Rb: 0.02mg/L; Cs: 0.01mg/L; n = 16 ) and the Nalenggele River (Rb; 0.07mg/L; Cs: 0.04mg/L; n = 9 show the lowest average content of Rb and Cs, displaying a pattern of high contents at the source and sink ends but low contents during migration. (2) Deep geothermal waters (hot springs) are characterized by high Rb and Cs contents with Rb / Cs < 1 , whereas rocks, sediments, and terminal salt-lake brines exhibit high Rb and Cs contents with Rb / Cs > 1 Shallow geothermal waters (hot springs) and rivers are characterized by low Rb and Cs contents with Rb / Cs > 1 (3) The high Rb and Cs contents in deep geothermal waters are primarily controlled by magmatic fluids and deep-circulating water-rock interactions. The low Rb and Cs contents in shallow geothermal waters and river waters during migration are mainly controlled by surface weathering and leaching, adsorption-desorption processes, and seasonal variations in water balance. In terminal salt lakes, high Rb and Cs contents are mainly controlled by evaporative concentration, but are also jointly influenced by local recharge/mixing and water-sediment interactions. This study will help to deepen the understanding of the different constraints on the enrichment of Rb and Cs during source supply and migration processes, and enriches the theoretical framework for the genesis of Rb and Cs resources.

Although numerous studies have examined microplastic (MP) environmental exposure and contaminant characteristics, understanding of MP pollution in extreme saline environments remains limited. This study systematically investigated the distribution, migration, and potential ecological risks of MPs in the ultra-saline Qarhan Salt Lake, where intensive resource development occurs. MPs were widely detected, with higher abundances concentrated in the core industrial zones, including factories, salt ponds, and the eastern shore of Dabuson Lake. This spatial pattern closely matched the distribution of industrial facilities, identifying salt lake industry as the primary source. Accelerated aging and fragmentation driven by strong thaw and high salinity produced dominant MPs of 20–50 μm fragments across water, soil, and sediment. Polymers exhibited medium‑selective enrichment: dense polyamide accumulated in surface soil, while low‑density polypropylene migrated readily in water, governed by polymer properties and regional wind–water dynamics. A site-specific risk ranking framework, the Comprehensive Environmental Risk Index (CERI), was developed to integrate multi-media MP risk information at the same sampling locations, revealing surface soil as a key MP accumulation center. Localized high risks occurred in salt ponds and industrial areas due to toxic polymers, with core high‑risk zones in industrial clusters, salt ponds, and river estuaries. These findings reveal unique MP migration and risk patterns shaped by the synergy of resource development and extreme environments, providing a scientific basis for precise risk management and sustainable development in salt lake regions.

Glaciers are excellent indicators of global climate change and vital freshwater reservoirs, significantly influencing social and economic development—especially in arid regions. This study analyzes the spatiotemporal changes of glacier area in the Tomur-Khan Tengri Range (Central Tienshan Mountains) from 2003 to 2023 using Landsat TM/ETM+/OLI data via the band ratio algorithm, examining correlations with glacier size, altitude, and location. Results show that the total glacier area decreased from 3089.62 km² to 2677.35 km² over the study period, with an annual shrinkage rate of 0.64%. Southern and northern regions experienced more pronounced retreat compared to eastern and western regions. All regions showed accelerated shrinkage during 2012–2017, coinciding with unfavorable climatic conditions. Meteorological data indicate significant warming and slight precipitation increase. Glacier loss is primarily driven by global warming, notably summer temperature rise. Regional differences are closely linked to local climate, glacial altitude distribution, and size-class proportion. These findings provide important insights for water resource management and climate change adaptation in arid Central Asia.

Determining the distribution characteristics of rubidium(Rb)and cesium(Cs)in salt lake brines and their associations with lithium(Li),boron(B)and potassium(K)can facilitate the gradient development and comprehensive,efficient utilization of diverse resource elements by salt lake enterprises.While research on the distribution features and source-sink processes of Li,B and K in the Qaidam Basin's salt lakes is well-established,their paragenetic coupling relationships with Rb and Cs have not been systematically analyzed,and the geochemical mechanisms controlling Rb-Cs enrichment and their coupling with associated elements remain unclear.To address this gap,the focus of this study was on Dabuxun Salt Lake in the central Qaidam Basin.Elemental content and H-O isotope analyses were conducted on 8 surface brine samples and 11 intercrystalline brine samples,to clarify Rb-Cs distribution characteristics and reveal their paragenetic coupling relationships and related geochemical mechanisms with Li,B and K.The results are as follows:(1)Rb and Cs are relatively enriched in the brines of Dabuxun Salt Lake,with higher average concentrations in intercrystalline brines(Rb 3312 μg/L,Cs 63.7 μg/L)than in surface brines(Rb 1352 μg/L,Cs 30.6 μg/L).(2)Both surface and intercrystalline brines show spatial distribution heterogeneity,and their paragenetic associations with Li,B and K also vary.Similar metallogenic material sources,evaporation and water-rock interaction are the key factors driving the strong paragenetic relationships(correlation coefficients>0.6)between Rb-Cs and Li-B-K in surface brines.(3)The negative correlation between Rb-Cs and Li in intercrystalline brines is controlled by evaporation and clay adsorption;the positive correlation with K is governed by evaporation and water-rock interaction;and the association with B is jointly constrained by evaporation,water-rock interaction and clay adsorption.The distribution characteristics of Rb-Cs and their paragenetic relationships with Li,B and K in the Dabuxun section of Qarhan Salt Lake were analyzed,providing a scientific basis for the exploration and development of salt lake resources in the Qaidam Basin.

Solution mining is an important technique for extracting strategic resources from heterogeneous salt lake reservoirs. However, its efficiency remains difficult to predict because dissolution of soluble salts does not necessarily lead to effective permeability enhancement, especially in clay rich salt lake materials. In this study, laboratory seepage experiments, X-ray micro-computed tomography (micro-CT), hydrochemical analysis, and inverse geochemical modeling were integrated to investigate permeability evolution in three representative lithologies under coupled thermal–hydraulic–chemical (THC) conditions. The results show that permeability evolution differed strongly among silty halite, silty clay, and clayey halite. In silty halite, permeability increased and remained relatively stable during part of the 20 °C stage, accompanied by pronounced Na⁺ and Cl⁻ release, modeled halite transfer into solution, and enlargement of CT-resolvable pores and throats after seepage testing. In contrast, silty clay showed a sharp permeability decrease after the 10 °C stage and did not recover during heating, although Mg2⁺ and K⁺ enrichment and modeled soluble salt transfer were observed. Clayey halite showed progressive permeability decline, continued solute release, and increased tortuosity in the CT-extracted pore network. These results indicate that permeability enhancement requires solute release and pore development to be converted into connected and hydraulically effective flow pathways. The findings clarify permeability evolution controlled by lithology in salt lake materials and provide a basis for evaluating solution mining responses across different lithologies.

Qarhan Salt Lake (QSL) in the Qaidam Basin is China’s largest source of potassium fertilizer. However, several decades of intensive subsurface brine extraction have triggered severe groundwater depletion, large-scale cones of depression, and disruption of the regional water-salt equilibrium, threatening the sustainability of this resource. This study aimed to resolve the scientifically and practically significant issue of determining a sustainable subsurface brine extraction volume that reconciles potassium production targets with hydrological recovery and environmental constraints. By employing a refined MODFLOW-based numerical model that incorporates actual extraction and recharge dynamics, we simulated five subsurface brine extraction scenarios (4.0 to 6.0×108 m3/a) over a 20-year period. Results demonstrate that an annual brine extraction volume between 4.5 and 5.0×108 m3/a supports stable production of over 5 million tons of potassium fertilizer while providing key ecological-hydrogeological benefits: an average water level rise of 0.5–0.6 m, a reduction of the area of the cone of depression by 35–75 km2, a consistent positive water balance of 0.4–0.5×108 m3/a, and minimized evaporation losses. These findings offer a validated, multi-criteria framework for sustainable brine mining in QSL and present a transferable model for managing hypersaline resources in water-limited regions worldwide.

Salt lake lithium (Li) and boron (B) deposits on the Tibetan Plateau, a global salt lake hotspot hosting China's largest Li reserves and major B resources, are critical for new energy and industrial applications. This study diagnoses climate-driven decades scale source variations in Laguo Co through coupled hydrochemistry and delta 11B delta 7Li isotopes, which dictate its spatiotemporal Li-B distribution. Building on these decadal diagnostics, we integrate paleolake evolution with millennial source-transport-sink processes to reveal causal linkages between mineralization sources and paleolake residues, while comparative analysis further identifies key divergence mechanisms within the homologous salt lake system. Key findings include: (1) Under warming-wetting climateinduced hydrological changes, Laguo Co brines show declining Li-B grades, Li/TDS ratios but rising B/TDS ratios. The former reflects dilution dominance, while the latter arises from competition between dilution and enhanced B recharge fluxes within the catchment-salt lake systems; (2) Sustained warm-wet conditions trigger variations in weathering fluxes, resulting in an annual increase in dissolved riverine B flux (released from carbonate clays) alongside a decrease in Li flux (retained within clays); (3) Similar hydrochemical-delta 11B-delta 7Li signatures between Laguo Co and Jibu Chaka salt lakes support their common paleolake origin. Their differences can be explained by distinct recharge processes occurring at millennial scales, based on the impacts of decades scale hydrological changes on hydrochemistry of Laguo Co. Specifically, the hydrochemical and delta 11B-delta 7Li contrasts between Laguo Co and Jibu Chaka stem from their independent source-transport-sink systems altering paleolake water evolution; (4) A pioneering validation framework tests the paleolake fragmentation and inheritance hypothesis by resolving hydrochemical divergences through contemporary source-transport-sink controls: source solutes, catchment lithology, and sink mineral sequences. This study provides valuable insights into both the impacts of climate change on salt lake resources and genetic connection between mineralizing sources and paleolake residues in salt lake deposits.

The primary soil types in the Qinghai Lake Basin are meadow soil and gray calcareous soil. This study aims to delineate the characteristics, spatial distribution, and origins of surface soil heavy metals in this region. We collected 227 surface soil samples across various sedimentary landscapes within the basin. Analyses were conducted on twelve heavy metals: As, Ba, Co, Cr, Cu, Mn, Nb, Ni, Pb, V, Zn, and Zr. We employed methods such as the Enrichment Factor (EF), Geo-Accumulation Index (Igeo), Nemero Index (PN), and Absolute Principal Component Scores-Multiple Linear Regression (APCS-MLR) model to quantitatively assess contamination levels and pinpoint potential sources of these metals. Our findings reveal:1. The heavy metal contents in the Qinghai Lake Basin are generally similar to those of the Earth’s crust (UCC). However, compared to the Hoh Xil Nature Reserve, concentrations of Ba, Cr, Mn, Zn, and Zr are significantly higher, suggesting possible point-source pollution. 2. EF, Igeo, and PN analyses indicate a moderate enrichment of Cr, potentially pointing to localized pollution sources. All Igeo values were below zero, suggesting an absence of widespread heavy metal pollution in the basin. The PN values emphasize the influence of extreme values in environmental assessment. 3. APCS-MLR analysis identified natural factors and transportation as the primary sources of surface soil heavy metal pollution, detailing the specific metals influenced by each source. 4. It is recommended to establish long-term monitoring in key areas and strengthen ecological management to prevent potential contamination. Future research should address heavy metal–microplastic co-pollution in alpine ecosystems. Overall, current soil contamination is low, but continued monitoring is necessary.

The Aptian Loeme Fm. in the Lower Congo Basin (LCB) is a large potash deposit formed under the intracontinental rift setting during the Cretaceous. Its genesis holds significant implications for understanding the evolution of Atlantic rifting, yet its provenance remains highly debated. The provenance differences and their formation processes in different depositional cycles, as well as the tectonic-depositional interaction mechanisms, remains unclear. Based on drill core samples from the potash deposits in the LCB, the study investigates the "tectonic ore-control mechanisms" by utilizing mineralogical analyses, major and trace element geochemistry, isotope geochemistry, and Monte Carlo simulation methods, in conjunction with existing research findings. The following insights are thereby obtained: (1) The high 87Sr/86Sr ratio (0.7113-0.7517) of carnallite is attributed to the combined effects of continental water and deep hydrothermal water, both of which have high strontium isotope compositions closely related to the high 87Sr/86Sr ratio of the basement rocks of the Congo Craton. (2) The first documented delta 11B values (20.77%o-26.99%o) of whole-rock samples and their comparison with theoretical seawater evaporation fractionation values, both demonstrating significant contributions from non-marine fluids; (3) Distinct variations in Br-Li-Fe-Ba-Cu-Co-Ni contents among salts across different sedimentary cycles, indicating heterogeneous evaporative processes during various mineralization phases; (4) Tectonic activity can not only alter the chemical composition of provenance, but also influence the replenishment process and pattern of provenance. The study offers significant insights into the genesis of evaporite deposits within global rift tectonic settings, with a particular emphasis on the controlling influence of extensional tectonics on mineral sources.

To address soil salinization's significant impact on human production and livelihood in arid regions,especially in high-salinity areas like salt lake regions,this study used mul-ti-source remote sensing data to extract 52 surface factors.Combined with measured soil salinity data,correlation analysis,multicollinearity testing,and projection importance analysis identified eight dominant factors.Subsequently,four machine learning algorithms were ap-plied for modeling,and the optimal models were selected to study the spatiotemporal varia-tion of soil salinization.The results indicate that the average soil salt content in the study area was 20.74％in 2020.LST(land surface temperature)can effectively identify areas with high salinity,such as saline-alkali land and salt flats.Among inversion models,the GBDT(gradient boosting decision trees)model demonstrated the highest predictive ability and minimal errors.The optimal inversion results revealed that soil salinization distribution was influenced by topographic elevation,distance from Qarhan Salt Lake,and river network density.Over the past 21 years,there was significant fluctuation in soil salinity observed in the concentrated area of grassland within the groundwater overflow zone,indicating strong variation in salini-zation.This fluctuation correlates with changes in groundwater levels in the groundwater overflow zone,which are influenced by temperature variations that determine the amount of snow and ice meltwater,and the precipitation in the upstream area.This study enhances understanding of soil salinization and its drivers in extremely arid salt lake regions.

Salt lakes, with their relatively closed hydrological systems, respond rapidly to climate changes in their catchments. This high sensitivity makes them effective archives for recording both climate responses and variations in hydrological budgets. In recent decades, the persistent warming–wetting trend across the Tibetan Plateau has led to continuous lake expansion, prompting a key scientific question: how is this change affecting the boron (B) resources of salt lake brines? To uncover the response patterns and underlying mechanisms, this study combined modern brine observations (from the 1970s onward) with paleo-brine records derived from halite fluid inclusions, and performed a multi-scale geochemical analysis. A systematic review and reanalysis of the compiled data indicate that: (1) B in the Tibetan Plateau's salt lakes stems mainly from geothermal sources and surface weathering, and its spatial distribution is closely tied to climate and hydrological conditions; (2) Under the ongoing warming–wetting trend, brine-type B deposits exhibit declining B concentrations and B/Cl ratio as lakes expand, whereas borate-brine coexisting-type systems respond to competition between lake water dilution and mineral redissolution, driving a steady increase in the B/Cl ratio and complexity of B concentrations. By regulating riverine input, climate alters the riverine–geothermal balance, reshaping brine chemistry and B isotope composition. This reorganization is illustrated in the B–Li–K diagram by a shift toward the potassium end-member under warm–wet conditions and toward the B end-member under dry–cold conditions; (3) This geochemical pattern is also consistently recorded in paleo-brines and aligns with paleoclimate signals from sedimentary proxies; (4) Based on the multi-scale evidence presented, this study develops a unified conceptual framework that systematically clarifies the mechanisms by which salt-lake B resources respond to climate forcing. By integrating modern processes with geological records, this study demonstrates the efficacy of brine geochemistry in reflecting and recording climate change. It provides a framework for predicting and reconstructing the elemental evolution of brines under climate forcing, while enhancing the reliability of paleoclimate reconstructions derived from sedimentary sequences.

Water is a vital strategic resource in hyper-arid endorheic watersheds, yet its availability is severely constrained by excessive salinity under extreme conditions, posing socioeconomic and ecological challenges. This study examines a hyper-arid watershed in the Qaidam Basin, using multifaceted hydrochemical analysis to investigate how anomalously enriched salts affect water availability. The findings indicate that both surface and subsurface water in the watershed are brackish, with mean TDS values of 2.6 g/L and 2.1 g/L, respectively, and both exhibiting similar Cl center dot SO4-Na or Cl center dot SO4-Ca center dot Mg facies. Significant enrichment of trace elements (Li, B, Sr) is also observed, with 93.1%, 100%, and 62.1% of groundwater samples exceeding drinking standards. EWQI results (72-339) confirm that high salinity and elevated trace elements collectively degrade groundwater quality, with only 6.9% of groundwaters in the alluvial fan remaining drinkable. Meanwhile, groundwater in the alluvial plain poses non-carcinogenic health risks from Li and B exposure, with children exhibiting higher vulnerability. Surface and subsurface water show complementary irrigation advantages, yet both are constrained by high salinity. The hydrochemical quality is primarily governed by intense evaporation and natural water-rock interactions including evaporite and silicate dissolution and cation exchange. These processes drive significant salt accumulation, particularly in the alluvial plain where weak hydrodynamic conditions enhance solute enrichment, substantially limiting its development potential. Although hyper-arid watersheds have limited potential for water development, sustainable regional development can still be achieved by clarifying the ecological functions of water resources, implementing appropriate ecological water level regulations, and adopting tiered management strategies.

Alpine Regosols are vital for sustaining alpine desert steppe ecosystems in cold, arid, high-altitude regions. However, the parent material provenance, formation processes and vertical physicochemical gradients of these soils remain poorly understood along the Tibetan Plateau's cryospheric boundaries. This study focuses on Regosols and their potential parent materials (e.g., glacial debris, alluvial deposits) in an eastern Pamir alpine valley, aiming to elucidate provenance relationships and sediment cycling pathways between these soils and their source materials. We further characterize the formation of sand dunes along Baisha Lake via comprehensive physicochemical analyses. The results demonstrate: 1) A felsic-dominated provenance (Th/Sc > 3, Cr/Th < 2.5), showing minimal particle-size sorting effects, with sediment type being the primary factor controlling elemental concentration signatures across various sedimentary deposits. 2) Regosols are dominated by <125 mu m particles, maintaining consistent fine-fraction characteristics across elevation gradients. Geochemical indicators confirm their alluvial sediment origins, aligning with the physicochemical properties of alluvial deposits. Valley Fluvisols, however, contain localized coarse particles (>250 mu m), likely introduced via slope processes or episodic flooding and disrupting their otherwise homogeneous fine-grained composition. 3) Dune and river sand exhibit negligible <20 mu m fractions but significant Zr-Hf enrichment in the <63 mu m fraction; their corresponding physicochemical characteristics (e.g., grain-size distributions, Zr-Hf concentrations) indicate a proximal source relationship, demonstrating that Baisha Lake's aeolian dunes are principally derived from river sands. 4) We propose a developmental model for alpine Regosols, emphasizing the combined effects of cryo-aeolian processes and limited chemical weathering in the Tibetan Plateau's cold, arid, high-mountain valley environments.

In this study, we employ a straightforward one-pot heating method to synthesize coral-like palladium-gold- copper trimetallic alloy nanoparticles (Pd-Au-Cu NPs). These nanoparticles are characterized by a coral-like structure with multiple spines radiating outward. Their unique morphology, substantial specific surface area, and trimetallic composition confer exceptional Fenton catalytic activity and photothermal conversion capabilities. We characterized the materials using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), transmission electron microscopy (TEM), and UV-visible spectroscopy of organic dyes. The material demonstrates strong photothermal properties and significant Fenton catalytic activity in the near-infrared region, achieving up to 98 % degradation of organic dyes, such as methylene blue (MB). Even after multiple cycles, Pd-Au-Cu NPs retain distinct nanoprotrusions, exhibit good photothermal stability, and maintain sustained Fenton catalytic activity, achieving up to 90 % degradation of MB after five cycles. Compared to previous and existing nanomaterials, our trimetallic nano- particles with unique structure exhibit superior photothermal conversion efficiency and contribute to environmental protection. This study presents a novel approach for environmentally sustainable treatments.

Study region Qarhan Salt Lake, the largest salt lake in China, located in the Qaidam Basin. Study focus Sustainable management of brine resources in Qarhan Salt Lake is crucial due to the impacts of sustained brine pumping, which has altered brine level and salinity distributions. This study developed an automated machine learning (AutoML) approach to model brine levels and salinity, providing a tool for informed resource management decisions. The Geodetector was employed to quantify the influence of various factors on these parameters. New hydrological insights for the region An integrated approach using AutoML and GIS significantly improved prediction accuracy for both brine levels and salinity. For brine level prediction, the LightGBM (LGBM) model performed best, achieving an R2 of 0.880 (training) and 0.869 (testing). For salinity, Random Forest (RF) was optimal, with an R2 of 0.895 (training) and 0.881 (testing). Geodetector analysis revealed that distance to pumps (q = 0.544), canal density (q = 0.346), lithology (q = 0.324), and distance to lakes (q = 0.260) are key factors influencing brine levels. For salinity, precipitation (q = 0.350) and distance to lakes (q = 0.097) were found to be the most influential. This study demonstrates AutoML's effectiveness in modeling brine dynamics and offers insights into factors influencing changes, aiding brine extraction optimization and sustainable resource management in fragile salt lake ecosystems.