Search Results (132)

Numerical simulations quantify the transient impacts of implementing green infrastructure (GI) grass swales on unconfined aquifer storage and groundwater-surface water interactions around the Red Butte Creek (RBC) of Utah, USA. The Red Butte Creek Watershed (RBCW) transitions from undeveloped mountainous National Forest land to downstream urbanized areas within Salt Lake Valley (SLV). This reconnaissance-level study demonstrates that increasing stormwater infiltration in urbanized areas during the rainy months (April-June) can, until at least the subsequent March, (a) enhance aquifer recharge and support sustainable groundwater yields; and (b) improve surface water availability. Simulations predict hydrologic impacts of aquifer recharge resulting from hypothetical grass-swale implementation within a 704-acre area located around RBC. The employed model, HyperRBC, is an adaptation of a United States Geological Survey (USGS) transient numerical flow, MODFLOW, model implementation for SLV. Adaptations involved (a) uniformly refined horizontal discretization of seven aquifer layers within a sub-area encompassing parts of RBCW and an adjacent watershed; (b) updated input data; and (c) MODFLOW’s Streamflow-Routing (SFR) package to simulate RBC flow and aquifer-stream seepage. Model predictions indicated that by the end of next March: (a) about 3% of the GI-induced recharge would remain within the unconfined aquifer in the HyperRBC area; (b) 66.6% of the recharge would flow northward into the downgradient continuation of the unconfined aquifer; and (c) 30.3% would discharge to nearby stream and river. In summary, predicted hydrologic changes due to the short-term GI-induced recharge highlight increased groundwater availability within and outside the study area for at least the subsequent 12 months, including high-water-demand summer. These findings show the importance of GI in interim environmental management and in enhancing the effective use of water resources. Full article

Sentiment expressions related to child maltreatment (CM) in public discourse are influenced by demographic, economic, and cultural factors and individual characteristics. Using 188,429 geotagged CM-related tweets during 2018–2022, we explored public sentiment expression about CM across the contiguous U.S. We applied multiscale geographically weighted regression (MGWR) to examine how contextual factors relate to the percentage of CM-related tweets with negative sentiment at the county level, revealing the spatial heterogeneity and varying geographic scales of these associations. Counties with higher male-to-female ratios and lower education levels tended to express negative sentiment in CM-related tweets, with consistent patterns observed nationwide. Five factors exhibited spatially varying associations by U.S. region, with higher levels of negative sentiment in the following contexts: a lower percentage of residents living in group quarters or a higher percentage of same-sex couples (Eastern and Central); fewer households lacking broadband access (Central); a higher percentage of single-parent households (New England and Southern Mississippi River); and areas where professionals are mandated to report CM (Great Lakes and Southern Appalachian Mountains). This study provides critical insights for policymakers to adjust policies, educators to design focused interventions, and the public to raise CM awareness. The methodology also provides a valuable framework for investigating public discourse on other social issues. Full article

Grassland lake basins are mostly located in arid and semi-arid regions and represent typical ecologically fragile zones. As a representative inland lake in the cold and arid region of northern China, Hulun Lake serves as a crucial node for maintaining the ecological balance of the Hulunbuir grassland. Studying its ecological carrying capacity is particularly key to implementing the philosophy of a holistic approach to the management of mountains, rivers, forests, farmlands, lakes, grasslands, and deserts. Based on data from 2018 to 2024 across four cities (banners, districts) in the Hulun Lake basin, this study constructs an evaluation system to measure ecological carrying capacity across three dimensions—ecosystem support, human activity pressure, and socio-economic response—using the Pressure–State–Response (PSR) model. Spatial analysis and geodetector methods are employed to explore its spatiotemporal differentiation and influencing factors. The findings are as follows: (1) The ecological carrying capacity in the Hulun Lake basin exhibits a significant spatial differentiation pattern, characterized by a gradient of “high in the east, low in the west; high in pastoral areas, low in urban areas.” (2) The overall trend in ecological carrying capacity shows a slow increase amid fluctuations, but the carrying capacity level remains relatively low. (3) The core driving forces of ecological carrying capacity primarily stem from the dimensions of population quality and infrastructure, while the direct influence of agricultural production is relatively limited. (4) Transportation infrastructure plays a strongly influential role as a driving mechanism of ecological carrying capacity in the Hulun Lake basin. Its synergy with factors such as education, information, and industry significantly affects both the ecosystem support capacity and the socio-economic responses of the basin. This study provides a reference for ensuring the ecological security of the Hulun Lake basin. Full article

The administrative boundaries of ecosystems do not necessarily align with natural watershed boundaries, which is a significant reason for the current inefficiency and pronounced conflicts in ecological governance. Using the watershed as the fundamental unit, this study assessed the forest ecosystem services (FES) of the Beihai Wetland watershed in Tengchong (As of 2025). Forest vegetation was classified to the formation level, and the functional value method was employed. The results showed the following order of service values: regulating services > provisioning services > supporting services > cultural services. Biodiversity was identified as the most valuable ecosystem function. The study further revealed that factors such as stand type, stand age, and altitude influence the total FES value within the watershed. Analysis of FES per unit stand (1 ha) indicated that Lithocarpus variolosus Franch. Chun (natural forest) exhibited the highest value. Through in-depth analysis of linear correlations and spatial associations of FES per unit stand, a synergy-trade-off visualization was constructed. This revealed that natural forests in the upper watershed may exert systemic effects on nutrient cycling in the lower watershed. The results obtained at the formation level provide support for the development of watershed-based forest tending plans. Moreover, studying FES using the watershed as a unit represents a practical exploration of the “life community of mountains, rivers, forests, farmlands, lakes, grasslands, and deserts” and offers a potential reference for maintaining the ecological security and supporting the ecological protection and restoration of the Beihai watershed. Full article

Groundwater quantification is essential for sustainable water resources management, yet it is often hampered by limited data availability and difficulties in measuring spring discharges. This study investigates three carbonate aquifers in Central Italy’s Abruzzo region: the Genzana–Greco, Morrone, and Marsicano mountains. The aim is to resolve uncertainties in spring attribution, and groundwater flow patterns using isotopic analyses combined with field surveys. The Genzana–Greco aquifer was examined to clarify the sources of the Acquachiara spring and the previously unreported Germina spring, assessing whether recharge occurs locally or from the carbonate massif. In this case, the results indicate that the Germina, together with a similar known spring of Capolaia, share a common recharge sector, while the Acquachiara spring is mainly fed by higher-elevation carbonate areas, excluding significant contributions from local alluvial deposits. In the Morrone mountain aquifer, discharge gains along the Pescara River through the Gole di Popoli were quantified, and spring isotopic compositions were compared to the main basal spring Giardino to better define groundwater contributions. In this case study, the stable isotopes and tritium data confirm recharge from the central–southern massif and support the identification of basal springs and Pescara River gains as primary discharge points, with minimal influence from surface water. For the Marsicano mountain aquifer, the role of Lake Scanno in feeding the Villalago springs was investigated through isotopic analysis of inflows, downstream springs, and basal aquifer discharge points to constrain the hydrogeological water budget. The results highlight Lake Scanno’s role in the recharge of Villalago springs and delineate the Cavuto group as a major discharge system receiving inputs from central and northern sectors of the massif. Overall, the integration of isotopic tracers with hydrological measurements allowed a more precise characterization of aquifer recharge areas, Mean Residence Times, and groundwater flow paths, improving the understanding of regional water resources in a complex carbonate setting. Full article

Water levels in the Great Salt Lake (GSL), UT, USA, have been declining overall since 1989, leading to a 70% decrease in surface area. To understand GSL’s future, we seek to image fresh groundwater input and lithologic variation along the lake’s boundary. Determining the amount of groundwater recharge into GSL is crucial for lake management but currently unknown. During the Fall of 2024 and Spring 2025, we conducted 16 electrical resistivity tomography (ERT) and six transient electromagnetic (TEM) surveys along the southern shore of GSL between Burmester Road (to the West), Saltair, and Lee’s Creek (to the East). These measurements indicate a low-resistivity layer consistent with brine pore-water, with variable thickness ranging from 7.1 ± 0.1 m at Burmester to 9.6 ± 0.2 m at Saltair. The Saltair region shows a high-resistivity layer, consistent with a 4.4 ± 0.05 m thick layer of mirabilite. This layer contains vertical conduits that allow saline pore-water to upwell onto the surface forming evaporite deposits. Near Lee’s Creek, we find evidence of high resistivities consistent with fresher groundwater as shallow as 2.8 ± 0.03 m, where increased permeability along the paleo-Jordan River corridor may provide a path for groundwater recharge from the Wasatch Mountains. Full article

Global climate warming has increased the risk of glacial lake outburst debris flows (GLODFs) in high mountain regions. It is characterized by frequent and clustered occurrences, particularly in the Himalayan region, and represents an inescapable challenge for high mountain areas in the future. GLODF susceptibility assessment is critical to risk mitigation but remains a challenge owing to its complex triggering mechanisms and watershed structure. GLODF is a complex system failure process, including the failure probabilities of multiple glacial lakes in a watershed, the complex flow path of flood, the transition probability from flood to debris flow, and the overlapping of debris flows formed in different branches in the watershed. Therefore, multiple trigger factors, hazard sources and flow paths should be considered in the assessment of susceptibility to GLODFs. In this study, a systematic approach and mapping for GLODF susceptibility assessment are proposed based on the theory of system failure analysis. The main steps include: (1) identification and classification of the potential hazard sources in the target watershed; (2) arrangement of the flow path and abstraction of the key-node diagram; (3) establishment of the system failure structure of a GLODF; and (4) predisposing factor analysis and susceptibility assessment. Moreover, the predisposing indexes of GLODF susceptibility assessment are proposed, combining the main factors affecting both glacial lake outbursts and subsequent debris flows. The proposed model was applied in the Congduipu River basin, Nyalam, Tibet, China, which has more than 6 glacial lakes and 11 gullies, with an area of 366 km², and encountered more than four GLODFs in recent years. The results show that there are one very high-susceptibility glacial lake, two high-susceptibility glacial lakes, and gullies that are in series with high-susceptibility glacial lakes that are mostly medium–highly susceptible to glacial outbursts. The results were verified by historical records and field investigations in the Congduipu River basin. This method is applicable to quickly evaluate the susceptibility to GLODFs at the watershed and regional scales with multiple glacial lakes and gullies. Full article

This study explores the hydrochemical and thermal characteristics of a fault-controlled geothermal field within the Northern Qinghai Lake Coalfield Area on the northeastern Qinghai–Tibetan Plateau (QTP). This research integrates hydrochemical analyses, isotopic tracers, and the regional geological framework to define hydrochemical signatures, identify recharge sources and flow paths, assess cold–hot water mixing, estimate reservoir temperatures, determine circulation depths and residence times, and explain the geothermal system’s formation. Systematic sampling included geothermal waters, cold springs, and surface waters, followed by laboratory analysis of major ions, stable isotopes (δ²H, δ¹⁸O), radiocarbon (¹⁴C), and tritium (³H). The geothermal water is categorized as a low-temperature, weakly acidic to near-neutral HCO₃-Ca•Mg type, exhibiting temperatures from 35.6 to 46.2 °C. Isotopic analyses indicate that cold spring and river waters align with the local meteoric water line, while geothermal waters display distinct isotopic signatures, suggesting deeper circulation. A silica–enthalpy mixing model reveals substantial cold-water mixing during upwelling, with mixing ratios between 74.5% and 85.6%. The corrected recharge elevation is estimated to be 4378–4456 amsl, implying a primary recharge zone in the branch of the Qilian mountains—the middle section of Datong Mountain to the northeast. Geothermometry, employing quartz and chalcedony temperature scales and accounting for mixing, estimates reservoir temperatures of 150–202 °C. The calculated circulation depth spans 3211–4291 amsl. Low tritium levels and carbon dating suggest a deep-cycling system predating 1952, characterized by deeply circulating “ancient water”. The geothermal system’s development is associated with regional tectonics, fault systems, and the Kesuer Formation (J_xk) acting as the reservoir. This study provides a scientific foundation for the development and sustainable use of geothermal resources in the northern Qinghai Lake region and offers insights applicable to comparable fault-controlled geothermal systems across the QTP. Full article

Assessing ecosystem health in rapidly urbanizing watersheds requires policy-relevant and empirically grounded indicator systems. Focusing on the Luxi River Basin in Chengdu’s Tianfu New Area, this study develops an ecosystem health evaluation and restoration zoning scheme based on the Pressure–State–Response framework (PSR). Utilizing remote sensing land use maps for 2004, 2014, and 2024 with overall accuracy and Kappa above 85% and 0.80, respectively, a 13-indicator PSR health index with entropy-based weighting was constructed at the township and subdistrict scales. Aiming to support objective indicator selection and interpretation, multiscale landscape dynamics were further quantified using FRAGSTATS and moving window analysis, including mean patch area, patch density, landscape shape index, largest patch index, Shannon diversity index, Shannon evenness index, contagion index, and splitting index, and sensitive landscape descriptors and major driving factors were identified. Results show a shift in landscape patterns, from relatively aggregated configurations toward highly complex and fragmented ones. Largest patch dominance, measured by the largest patch index, declined from 66.71 to 22.79, while connectivity, measured by the contagion index, decreased from 59.74 to 45.10. Subdivision, measured by the splitting index, increased from 2.24 to 12.88, and compositional heterogeneity, measured by the Shannon diversity index, increased from 0.86 to 1.26. The PSR assessment indicates that demographic pressure intensified over time, whereas improvements in water resource supply, technological progress, and industrial upgrading partially alleviated overall pressure in some subregions. Ecosystem state exhibited strong spatial heterogeneity, with sustained high health in the eastern Longquan Mountain area and substantial improvement around Xinglong Lake, while northern urbanized and southern agricultural subregions lagged behind. Environmental governance responses strengthened, with the response index increasing from 0.2297 to 0.9885. Overall ecosystem health demonstrated a modest but stable improvement from 2004 to 2024, with 65.48% of the area revealing slight improvement, 1.14% experiencing substantial improvement, 29.62% remaining stable, and 3.76% experiencing slight degradation. Finally, restoration priority zones were delineated, and targeted strategies were introduced to inform basin-scale ecological management in the Luxi River Basin. Full article

Amid accelerating global urbanization, the Qinghai–Tibet Plateau, as a repository of multi-ethnic architectural heritage, plays a crucial role in preserving plateau cultural diversity and sustaining harmonious human–environment relationships. A critical research gap persists, however, in the systematic, comparable, and quantitative assessment of urban architectural character across plateau towns, particularly in high-altitude, ecologically sensitive, and multi-ethnic regions such as Haixi Mongol and Tibetan Autonomous Prefecture. This study takes the Haixi Mongol and Tibetan Autonomous Prefecture as a case to address the specific paradox between the homogenization of urban architectural styles and the erosion of cultural authenticity in plateau towns. We develop and apply an innovative three-dimensional evaluation model—encompassing natural substrate, built environment, and cultural context—to 22 towns. For the first time in research on this region, a chained methodological approach integrating descriptive statistics, principal component analysis (PCA), and cluster analysis is employed to systematically examine the spatial differentiation of architectural character. The analysis reveals three key findings. First, it delineates a regional composite landscape characterized by mountain-basin enclosures, seasonal arid rivers and lakes, small-scale towns with expansive layouts, and multi-ethnic cultural fusion. Second, it identifies a clear ternary differentiation in urban style dominance: nine towns are nature-dominated, nine are human-made (built environment) dominated, and only four are culture-dominated, quantitatively highlighting a significant weakness in the cultural dimension. Third, cluster analysis objectively classifies the towns into eight distinct character groups—for instance, Category I towns exhibit strong architectural regionalism and traditional continuity, whereas Category V towns integrate modern relics with adjacent mountain-water features. Methodologically, this study contributes by providing a replicable, chained quantitative framework that addresses a critical gap in comparative urban studies of high-altitude, underdeveloped regions. Empirically, it reveals the specific “nature > human-made > culture” dominance pattern in Haixi and offers a scientific foundation for formulating differentiated conservation and development strategies tailored to distinct town types in the ecologically fragile areas of western China. Full article

The Mahai Basin (MHB), situated in the northern Qaidam Basin on the Qinghai–Tibetan Plateau, hosts significant Quaternary potash resources. Nevertheless, the sources and evolutionary pathways of potash-forming fluids remain controversial. In this study, a comprehensive multi-isotope dataset and online-first publications spanning the period from 2015 to 2025 were compiled to constrain the end-member characteristics and evolution of brines in the MHB. δD-δ¹⁸O indicates that the initial fluids were derived mainly from Qilian Mountains precipitation and snowmelt, delivered via surface runoff and concentrated through prolonged evaporation under arid, semi-closed conditions, forming a river-lake-brine evolution sequence. δ⁷Li (+7‰ to +40‰) systematically increases with salinity and K content, reflecting long-term low-temperature water–rock interactions and selective ⁶Li adsorption by secondary clays, while deep Ca-Cl brines represent highly evolved endmembers. Elevated ⁸⁷Sr/⁸⁶Sr ratios (0.7113–0.7122) confirm silicate weathering contributions, with intercrystalline brines acting as key intermediate end members. B, S, and Cl isotopes further highlight deep fluid ascent along faults and anticlines, driving K co-enrichment, while sandy–gravel brines inherit highly evolved paleo-lake signatures. These multi-isotope constraints define an integrated evolutionary model involving surface runoff recharge, evaporation-driven concentration with water–rock interaction, deep fluid mixing, lateral migration, and final potash precipitation. Full article

Humans tend to mark their presence and thus their lands by naming charismatic places such as mountains, canyons, rivers, and lakes. Toponyms is the term for marking places with names. In doing so, cultural groups claim the lands and the recognition of their presence through names in their language and behaviors reflecting their culture. When other cultures occupy these lands, they similarly mark them with their own place names, thus replacing earlier names and evidence of occupation. A conflict of toponyms occurs when one cultural group uses their power to maintain a superior attachment to the land. This chapter uses six toponym ethnographic studies to understand the origins of debates between Native American and settler colonial peoples in North American. Research findings from these studies define both the importance of toponyms to cultural groups and possible resolution of heritage conflicts. All studies have been reviewed and approved for public use for place interpretations, visitor education, and culturally appropriate management by funding agencies and participating Native American tribes and Pueblos. Full article

The Atlantic City–South Pass (ACSP) orogenic gold district, Wind River Mountains, Wyoming, occurs in the Archean South Pass Greenstone Belt primarily within greywackes and igneous rocks metamorphosed to the upper greenschist–lower amphibolite facies. Approximately 10 Mt of gold has been produced from pyrite and arsenopyrite-bearing quartz veins in deformation zones at the brittle–ductile transition. Multiple generations of primary and/or pseudosecondary fluid inclusions in gold-bearing quartz veins include one- and two-phase gaseous CO₂-CH₄ ± N₂ inclusions and two- and three-phase gaseous CO₂-CH₄-H₂O inclusions with rare NaCl daughter minerals. These primary/pseudosecondary inclusions show a broad range of homogenization temperatures (T_h) of 177.2 to 420.0 °C, with salinities of halite-bearing inclusions of >26 wt. % NaCl, with a high concentration of CaCl₂. Secondary aqueous inclusions formed at lower values of T_h (80.9 to 243.4 °C, with one outlier of 301.1 °C). Carbon from graphitic schists associated with gold-quartz veins yields values of δ¹³C = −28.5 to −19.1 per mil, suggesting that the light C isotope compositions of some carbonates (δ¹³C = −11.0 to −1.5 per mil) involved exchange reactions with graphite in the schists. Isotopic compositions of sulfur in sulfides (δ³⁴S = −1.0 to 3.6 per mil), oxygen in vein quartz (δ¹⁸O = 7.36 to 10.38 per mil), and hydrogen in fluid inclusions in vein quartz (δD = −125 to −55 per mil) are permissive of both magmatic-hydrothermal and metamorphic dehydration models for the origin of gold mineralization. However, a potential source of magmatic–hydrothermal fluids, the post-metamorphic Louis Lake granodiorite was unlikely to transport gold in a vapor state to become focused into shear zones as previously proposed. We favor a metamorphic dehydration model in which gold was derived from the South Pass supracrustal sequence and deposited in second-order shear zones that are spatially related to the first-order Roundtop Mountain Deformation Zone. Full article

The Ebinur Lake Basin, a key ecological security barrier for windbreak and sand control in northern Xinjiang, is crucial to the ecological safety of western China and the northern sand-prevention belt. Combining the basin’s geographical characteristics, this study comprehensively evaluated ecosystem service functions from four dimensions: water conservation, soil and water conservation, windbreak and sand-fixation, and biodiversity maintenance. Simultaneously, it conducted an ecological sensitivity assessment from four aspects: soil erosion, desertification, land use, and salinization sensitivity. The assessments of the importance of ecosystem service function and ecological sensitivity results were combined to create a tiered zoning plan for the basin. The basin was divided into four first-level zones: the Ebinur Lake Water Area and Wetland Biodiversity Protection Zone, the Desert Vegetation Windbreak and Sand Fixation Ecological Restoration Zone, the Oasis Agricultural Ecological Function Protection Zone, and the Mountain Water Conservation Zone. Six second-level zones were also delineated: the Ebinur Lake Wetland National Nature Reserve, Gobi Vegetation Distribution and Soil Erosion Sensitive Zone, Desert Vegetation Restoration Zone, Jinghe-Bortala Valley Oasis Agricultural Ecological Function Zone, Mountain Water Conservation and Forest-Grass Protection Zone, and Sayram Lake Water Body. This assessment and zoning plan provide support and scientific basis for the basin’s comprehensive ecological management, integrated protection and governance of mountains, rivers, forests, farmlands, lakes, grasslands and deserts, as well as regional ecological development. Full article

This study uses high-frequency monitoring across a river–barrier lake–reservoir continuum in the upper Minjiang River, southwestern China, to quantify the spatiotemporal dynamics and drivers of aquatic CO₂ partial pressure (pCO₂) and to identify the dominant controls under contrasting lotic and lentic conditions. River reaches were CO₂-supersaturated throughout the year, with higher pCO₂ in the wet season (mean 521 ppm) than in the dry season (421 ppm), indicating persistent CO₂ evasion to the atmosphere. In contrast, the downstream canyon-type reservoir showed a pronounced seasonal reversal. During the wet season, surface-water pCO₂ averaged 395 ppm, about 24% lower than that of the river and below atmospheric levels (~419 ppm); more than 55% of observations were undersaturated, with minima as low as 141–185 ppm, indicating temporary CO₂-sink behavior. In the dry season, mean pCO₂ increased to 563 ppm, exceeding both riverine and atmospheric levels and returning the reservoir to a CO₂ source. The reservoir pCO₂ variability was governed by the interaction of hydrology and metabolism: rising water levels and longer residence times likely enhanced CO₂ accumulation from the decomposition of inundated organic matter, while warm temperatures, high light and monsoon-driven nutrient inputs promoted phytoplankton growth that removed dissolved CO₂ and elevated dissolved oxygen, producing temporary sink behavior. In the river, short residence time and strong turbulence limited in-stream biological regulation, and pCO₂ variability was mainly driven by catchment-scale carbon inputs along the elevation gradient. Overall, our results demonstrate that dam construction and impoundment can substantially modify carbon cycling in high-mountain rivers. Under specific conditions (warm water, sufficient nutrients, high algal biomass), lentic environments may strengthen photosynthetic CO₂ uptake and temporarily transform typical riverine CO₂ sources into sinks, with important implications for carbon-budget assessments and reservoir management in mountainous basins. Full article