Search Results (114)

Temperate Highland Peat Swamps on Sandstone (THPSS) are wetlands in the Blue Mountains, south-eastern Australia. The wetlands have legislative protection as endangered ecological communities. They have long-standing cultural significance for Gundungurra Traditional Custodians. Previous studies document their degradation by urban development and vulnerability to extreme weather. Water quality in our study was assessed at wetlands in protected areas and compared with others exposed to urban development. We derived water quality guidelines that are intended to help future water quality assessment at THPSS and, in particular, to detect any impact from urban development on these wetland systems. Water quality in urban swamps was consistent with the freshwater salinisation syndrome despite all the swamps having relatively low electrical conductance (<140 µS cm⁻¹). Urban swamp water had salinity (mean 87.3 µS cm⁻¹) three times that of non-urban swamps (mean 28 µS cm⁻¹). The ionic composition of urban swamp water was dominated by calcium and bicarbonate, consistent with urban alkalisation syndrome. Our guidelines instead recommend limits for pH, salinity, turbidity, dissolved oxygen, and metals detected in greater concentrations that were found in urban swamps (iron, manganese, barium, and strontium). Our results support the theory that the dissolution of urban concrete materials is a degradation process that contributes to the impairment of urban swamp water quality. Full article

This study develops a numerical model to simulate groundwater flow and contaminant transport in a “typical hydrogeological environment” of northern New Jersey, addressing freshwater decline. Focusing on the Lower Passaic water management area (WMA), we model chloride transport in a fractured-rock aquifer, where fracture networks control hydraulic conductivity and porosity. The urbanized setting—encompassing Montclair State University (MSU) and municipal wells—features heterogeneous groundwater systems and critical water resources, providing an ideal case study for worst-case contaminant transport scenarios. Using MODFLOW and MODPATH, we simulated flow and tracked particles over 20 years. Results show that chloride from MSU reached the Third River in 4 years and the Passaic River in 10 years in low-porosity fractures (0.2), with longer times (8 and 20 years) in high-porosity zones (0.4). The First Watchung Mountains were identified as the primary recharge area. Chloride was retained in immobile pores but transported rapidly through fractures, with local flow systems (MSU to Third River) faster than regional systems (MSU to Passaic River). These findings confirm chloride in groundwater, which may originate from road salt application, can reach discharge points in 4–20 years, emphasizing the need for recharge-area monitoring, salt-reduction policies, and site-specific assessments to protect fractured-rock aquifers. Full article

With the intensification of human activities, the water resource environment in the karst mountainous area of central Shandong has undergone significant changes, directly manifested in the cessation of karst spring flows and the occurrence of karst collapses within the spring basin in the Laiwu Basin. To support the scientific development and management of karst water, this study utilizes comprehensive analysis and deuterium-oxygen isotope test data from surveys and sampling of 20 typical karst springs conducted between 2016 and 2018. By integrating mathematical statistics, correlation analysis, and ion component ratio methods, the study analyzes the genesis, hydrochemical ion component sources, and controlling factors of typical karst springs in the Laiwu Basin. The results indicate that the genesis of karst springs in the Laiwu Basin is controlled by three factors: faults, rock masses, and lithology, and can be classified into four types: water resistance controlled by lithology, by faults, by basement, and by rock mass. The karst springs are generally weakly alkaline freshwater, with the main ion components being HCO₃⁻ and Ca²⁺, accounting for approximately 55.02% and 71.52% of the anion and cation components, respectively; about 50% of the sampling points have a hydrochemical type of HCO₃·SO₄-Ca·Mg. Stable isotope (δ¹⁸O and δD) results show that atmospheric precipitation is the primary recharge source for karst springs in the Laiwu Basin. There are varying degrees of evaporative fractionation and water–rock interaction during the groundwater flow process, resulting in significantly higher deuterium excess (d-excess) in the sampling points on the southern side of the basin compared to the northern side, indicating clear differentiation. The hydrochemical composition of the karst groundwater system is predominantly governed by water–rock interactions during flow processes and anthropogenic influences. Carbonate dissolution (primarily calcite) serves as the principal source of HCO₃⁻, SO₄²⁻, Ca²⁺, and Mg²⁺, while evaporite dissolution and reverse cation exchange contribute to the slight enrichment of Ca²⁺ and Mg²⁺ alongside depletion of Na⁺ and K⁺ in spring waters. Saturation indices (SI) reveal that spring waters are saturated with respect to gypsum, aragonite, calcite, and dolomite, but undersaturated for halite. The mixing of urban domestic sewage, agricultural planting activities, and the use of manure also contributes to the formation of Cl⁻ and NO₃⁻ ions in karst springs. Full article

China is the world’s leading producer of molybdenum–copper concentrates, an industry noted for its high energy demand and considerable environmental burdens. This study applies a cradle-to-gate life cycle assessment to the production of molybdenum–copper concentrate in the Lesser Khingan Mountains, utilizing the ReCiPe 2016 midpoint method coupled with Monte Carlo uncertainty analysis. The results indicate that human carcinogenic toxicity represents the greatest environmental risk, followed by marine and freshwater ecotoxicity. Contribution analysis reveals that the grinding stage is the dominant impact driver—particularly due to hexavalent chromium emissions—affecting carcinogenic risk, climate change potential, and fossil resource depletion. Scenario testing demonstrates that upgrading grinding technology, enhancing electricity efficiency, and substituting conventional energy with renewable sources can markedly mitigate these impacts. However, because of implementation barriers, such as high capital costs, retrofit downtime, and uncertainties in the supply chain, a pilot phase is necessary before deployment at full scale. Quantitatively, the production of one tonne of molybdenum–copper concentrate corresponds to 0.05 DALYs of human health damage, 1.11 × 10⁻⁴ species.year of ecological loss, and USD 3488.82 of resource depletion. These results provide constructive references for the sustainable development of the mining industry and contribute to achieving China’s dual carbon targets through energy transformation and low-carbon technological innovation. Full article

Water resources are vital for sustainable development in arid regions, where glacial runoff plays a significant role in maintaining water supply. This study quantitatively assesses the sustainability of water resources in the Manas River Basin (MnsRB) and the Muzati River Basin (MztRB), situated on the northern and southern slopes of the Tianshan Mountains, respectively, over the period from 1991 to 2050. Freshwater availability was simulated and projected using the Variable Infiltration Capacity Chinese Academy of Sciences (VIC-CAS) hydrological model. Furthermore, three development modes—traditional development, economic growth, and water-saving—were established to estimate future water consumption. The levels of water stress were also applied to assess water resources sustainability in the MnsRB and MztRB. Results indicate that from 1991 to 2020, the average annual available freshwater resources were 13.94 × 10⁸ m³ in the MnsRB and 14.27 × 10⁸ m³ in the MztRB, with glacial runoff contributing 20.24% and 65.58%, respectively. Under the SSP5-8.5 scenario, available freshwater resources are projected to decline by 10.94% in the MnsRB and 4.37% in the MztRB by 2050. Total water withdrawal has increased significantly over the past 30 years, with agriculture water demand accounting for over 80%. The levels of water stress during this period were 1.14 for the MnsRB and 0.87 for the MztRB. Glacial runoff significantly mitigates water stress in both basins, with average reductions of 21.16% and 69.84% between 1991 and 2050. Consequently, clear policies, regulations, and incentives focused on water conservation are vital for effectively tackling the increasing challenge of water scarcity in glacier-covered arid regions. Full article

Riverbed sediments act as potential retention reservoirs or transport corridors for microplastic particles (MPs) from river water to groundwater. Vertical concentration profiles of MPs, together with river water and groundwater analysis, provide insight into their fate and transport behavior in freshwater systems. However, such data remain scarce. This study provides a depth-specific analysis of MPs ≥ 100 µm (abundance, type, and size) in gravelly riverbed sediments down to 200 cm, along with river water and groundwater analysis. Three sediment freeze cores were collected from the Alpine Rhine, a channelized mountain stream with high flow velocities and permanent losing stream conditions. The average MP abundance in the riverbed was 3.1 ± 2.3 MP/kg (100–929 µm); in the river, 92 ± 5 MP/m³ (112–822 µm); and in the groundwater, 111 ± 6 MP/m³ (112–676 µm). The dominant polymer types in the riverbed were polypropylene (PP), polyvinyl chloride (PVC), and polyethylene terephthalate (PET) (>70%), while polyamide (PA) dominated in the river water (56%) and the groundwater (76%). The comparable MP concentration, particle sizes, and polymer types between river water and groundwater, as well as the vertical MP concentration profiles, indicate that even large MPs up to 676 µm are transported from river water to groundwater without significant retention in the gravel sediment. Full article

Snow cover is an important freshwater source in many mountain ranges around the world and is heavily affected by climate change, often leading to reduced overall snow cover availability and duration as well as shifts in seasonality. To monitor these changes and long-term trends, the analysis of remote sensing is a commonly used tool, as data are available consistently and for long time series. In this study we acquired and processed the whole archive of available Landsat data between 1985 and 2024 for two catchments in the Chilean Andes, Aconcagua and Río Maipo, located in the Valparaíso and Santiago de Chile metropolitan regions, respectively. We generated monthly Snow Line Elevation (SLE) time series from the entire archive for both catchments and performed trend analyses on these time series. Strong positive long-term SLE change rates of 11.25 m per year for the Aconcagua catchment and 9.85 m to 15.65 m per year for the Río Maipo catchment were detected, indicating a decrease in snow cover as well as available freshwater from snowmelt. The projection to the year 2050 revealed a potential loss of snow covered area of up to 42% during summer months, with the SLE receding up to 231 m. Full article

Chironomidae are characterised by cosmopolitan distribution, high abundance and diversity in different aquatic environments, which makes them ideal for studying changes in freshwater ecosystems. To understand the environmental factors influencing chironomid communities, we analysed how altitude and waterbody type (hydromorphological features) affect their composition at 75 study sites from 49 watercourses. A total of 110 chironomid taxa from five subfamilies were identified, with Prodiamesa olivacea, Rheocricotopus fuscipes and Cricotopus bicinctus being the most frequent species. The lowest values of all alpha diversity components were recorded in communities collected from watercourses at altitudes up to 500 m a.s.l., while the highest values were observed in small mountainous rivers and streams. Beta diversity showed that taxa turnover was the dominant component in all situations analysed. Communities in large rivers with fine substrate were characterised by the lowest taxa turnover and the highest levels of nestedness, indicating the existence of an ecological gradient that reduces the number of taxa from one site to another. We identified indicator taxa for different altitudes, as well as groups of taxa that are typical for different waterbody types. Furthermore, the combination of four water parameters (oxygen saturation, conductivity, concentration of ammonium and nitrates) had the strongest influence on the chironomid community composition in the studied watercourses. Full article

Mountain regions are particularly sensitive and vulnerable to the impacts of climate change. Over the past three decades, mountain temperatures have risen significantly faster than those in lowland areas. The Hindu Kush–Karakoram–Himalaya region, often referred to as the “water tower of Asia”, is the largest freshwater source outside the polar regions. However, it is currently undergoing cryospheric degradation as a result of climatic change. In this study, the Normalized Difference Glacier Index (NDGI) was calculated using Landsat and Sentinel satellite images. The results revealed that glaciers in Chitral, located in the Eastern Hindu Kush Mountains of Pakistan, lost 816 km² (31%) of their total area between 1992 and 2022. On average, 27 km² of glacier area was lost annually, with recession accelerating between 1997 and 2002 and again after 2007. Satellite analyses also indicated a significant increase in both maximum (+7.3 °C) and minimum (+3.6 °C) land surface temperatures between 1992 and 2022. Climate data analyses using the Mann–Kendall test, Theil–Sen Slope method, and the Autoregressive Integrated Moving Average (ARIMA) model showed a clear increase in air temperatures from 1967 to 2022, particularly during the summer months (June, July, and August). This warming trend is expected to continue until at least 2042. Over the same period, annual precipitation decreased, primarily due to reduced snowfall in winter. However, rainfall may have slightly increased during the summer months, further accelerating glacial melting. Additionally, the snowmelt season began consistently earlier. While initial glacier melting may temporarily boost water resources, it also poses risks to communities and economies, particularly through more frequent and larger floods. Over time, the remaining smaller glaciers will contribute only a fraction of the former runoff, leading to potential water stress. As such, monitoring glaciers, climate change, and runoff patterns is critical for sustainable water management and strengthening resilience in the region. Full article

Mountain watersheds play a crucial role in sustaining freshwater resources, yet they are highly vulnerable to climate change. In this study, we investigated the summer water temperature of 35 alpine springs in the highest part of the Retezat Mountains, Southern Carpathians, between 2020 and 2023. During the four-year monitoring period, water temperatures across all springs ranged from 1.2 °C to 10.5 °C. Springs emerging from rock glaciers had the lowest average temperature (2.37 °C), while those on cirque and valley floors were the warmest (6.20 °C), followed closely by springs from meadow-covered slopes (6.20 °C) and those from scree and talus slopes (4.70 °C). However, only four springs recorded summer temperatures below 2 °C, suggesting a direct interaction with ground ice. The majority of springs exhibited temperatures between 2 and 4 °C, exceeding conventional thresholds for permafrost presence. This challenges the applicability of traditional thermal indicators in marginal periglacial environments, where reduced ground ice content within rock glaciers and talus slopes can lead to spring water temperatures ranging from 2 °C to 4 °C during summer. Additionally, cold springs emerging from rock glaciers displayed minimal daily and seasonal temperature fluctuations, highlighting their thermal stability and decoupling from atmospheric conditions. These findings underscore the critical role of rock glaciers in maintaining alpine spring temperatures and acting as refugia for cold-adapted organisms. As climate change accelerates permafrost degradation, these ecosystems face increasing threats, with potential consequences for biodiversity and hydrological stability. This study emphasizes the need for long-term monitoring and expanded investigations into water chemistry and discharge dynamics to improve our understanding of high-altitude hydrological systems. Furthermore, it provides valuable insights for the sustainable management of water resources in Retezat National Park, advocating for conservation strategies to mitigate the impacts of climate change on mountain hydrology and biodiversity. Full article

Revealing taxonomic, functional, and phylogenetic dimensions of biodiversity is critical for the effective conservation and management of aquatic organisms in freshwater ecosystems subjected to multiple threats. Fish biodiversity patterns in river ecosystems exhibit complex spatiotemporal variation influenced by hydrological connectivity and the dispersal ability of species within the river network. This study utilized eDNA metabarcoding to investigate fish communities in three subtropical mountain rivers, aiming to uncover the community structure and spatiotemporal dynamics of the multidimensional biodiversity of fish communities across varying positions within the river network. The three biodiversity indices of the fish communities at the confluence were significantly greater than those of the mainstream community in the dry season, whereas the phylogenetic diversity of the fish community at the tributaries during the wet season was significantly greater than that in the mainstream. This likely reflected the unique spatial configuration of confluences and the seasonal dispersal of fish in the river network. The results of this study highlighted the important role of confluences and tributaries in river networks and the fact that they need to be prioritized to conserve riverine fish diversity. Full article

The interplay between terrestrial water storage and vegetation dynamics in arid regions is critical for understanding ecohydrological responses to climate change and human activities. This study examines the coupling between total water storage anomaly (TWSA) and vegetation greenness changes in the Hexi Corridor, an arid region in northwestern China consisting of three inland river basins—Shule, Heihe, and Shiyang—from 2002 to 2022. Utilizing TWSA data from GRACE/GRACE-FO satellites and MODIS Enhanced Vegetation Index (EVI) data, we applied a trend analysis and partial correlation statistical techniques to assess spatiotemporal patterns and their drivers across varying aridity gradients and land cover types. The results reveal a significant decline in TWSA across the Hexi Corridor (−0.10 cm/year, p < 0.01), despite a modest increase in precipitation (1.69 mm/year, p = 0.114). The spatial analysis shows that TWSA deficits are most pronounced in the northern Shiyang Basin (−600 to −300 cm cumulative TWSA), while the southern Qilian Mountain regions exhibit accumulation (0 to 800 cm). Vegetation greening is strongest in irrigated croplands, particularly in arid and hyper-arid regions of the study area. The partial correlation analysis highlights distinct drivers: in the wetter semi-humid and semi-arid regions, precipitation plays a dominant role in driving TWSA trends. Such a rainfall dominance gives way to temperature- and human-dominated vegetation greening in the arid and hyper-arid regions. The decoupling of TWSA and precipitation highlights the importance of human irrigation activities and the warming-induced atmospheric water demand in co-driving the TWSA dynamics in arid regions. These findings suggest that while irrigation expansion cause satellite-observed greening, it exacerbates water stress through increased evapotranspiration and groundwater depletion, particularly in most water-limited arid zones. This study reveals the complex ecohydrological dynamics in drylands, emphasizing the need for a holistic view of dryland greening in the context of global warming, the escalating human demand of freshwater resources, and the efforts in achieving sustainable development. Full article

The West Kunlun Mountains (WKL) gather lots of large-scale glaciers, which play an important role in the climate and freshwater resource for central Asia. Despite extensive studies on glaciers in this region, a comprehensive understanding of inter-annual variations in glacier area, flow velocity, and terminus remains lacking. This study used a deep learning model to derive time-series glacier boundaries and the sub-pixel cross-correlation method to calculate inter-annual surface flow velocity in this region from 71 Sentinel-2 images acquired between 2016 and 2024. We analyzed the spatial-temporal variations of glacier area, velocity, and terminus. The results indicate that, as follows: (1) The glacier area in the WKL remained relatively stable, with three glaciers expanding by more than 0.5 km² and five glaciers shrinking by over 0.5 km² from 2016 to 2024. (2) Five glaciers exhibited surging behavior during the study period. (3) Six glaciers, with velocities exceeding 50 m/y, have the potential to surge. (4) There were eight obvious advancing glaciers and nine obvious retreating glaciers during the study period. Our study demonstrates the potential of Sentinel-2 for comprehensively monitoring inter-annual changes in mountain glacier area, velocity, and terminus, as well as identifying glacier surging events in regions beyond the study area. Full article

This article argues that indigenous knowledge is significantly resourceful for ecological sustainability, without which humanity will not survive. It addresses the intersection between the 15th United Nations Sustainable Development Goal (SGD) “Life on Land” and African indigenous knowledge systems, including the fundamental support system that can sustain the livelihoods of communities. It reconstructs the vision of ecological sustainability from the indigenous knowledge perspective by first analyzing the inadequacy of the United Nations carbon-pricing approach to reforestation and conservation in developing countries. Then, it uses the ethnosphere methodological approach, affirming the ecological ethical warrants found in indigenous epistemology and cosmology in regard to land protection in dialogue with the sustainability vision of Laudado Si’, Querida Amazonia, and Laudate Deum. This article explores indigenous knowledge’s wellspring for ecological sustainability and what it offers for a more sustainable “Life on Land”. It suggests an approach to ecological sustainability that goes beyond a market-based instrument to CO₂ reduction to embrace a view of the “sacramental universe” as essential theological input, without which sustainable “Life on Land” cannot be met. It concludes by showing how African mountain region conservancy practices are not essential in sustaining “Life on Land” not solely because they provide the earth’s freshwater but also because they contain valuable ecologically sensitive cultural and religious wisdom. Full article

Ongoing global warming and water regime disturbances have a major impact on the natural environment. Algae phytoremediation is one option to monitor environmental changes at an elemental level. In this study, we monitored heavy metals and other elements accumulated by the genus Oscillatoriales. This research was conducted at two sites in the foothills of the High Tatras between 2020 and 2023. Annual differences showed the impact of drought and lack of rainfall on the accumulation of elements in cyanobacteria. The results show how global warming affects the movement of heavy metals and other elements in the natural environment. The Standardized Precipitation Index (SPI) showed very dry to extremely dry weather in 2022. The drought in 2022 induced a decrease in the concentration of Ti, Cr, Mn, Zn, Rb, Zr, Ba, and Pb due to low rock weathering and sediment distortion. The decrease in heavy metals, particularly Zn, resulted in an increase in S concentration due to increased biological activity. Principal component analysis (PCA) showed, in the first component, discharge depended on the accumulation of many elements. The third component of the PCA described the accumulation of S and K in an increased way during the same year, suggesting increased biological activity. Full article