Steep Slopes Research Articles

Response of tidal dynamics and shear fronts to topographic changes in the Yellow River Delta

In recent years, the position of the Yellow River Estuary (YRE) entrance has changed frequently, and human activities such as land reclamation have contributed to the transformation of the deltaic topography. These combined factors have resulted in altered hydrodynamics and tidal shear fronts (TSFs) in the surrounding sea area. However, there are few studies on the characteristics of the TSFs before and after diversion, so this paper establishes a hydrodynamic model based on the Finite Volume Coastal Ocean Model (FVCOM) for the years 2005, 2014, and 2020 and analyzes the characteristics of the changes in the tidal currents and the TSFs before and after diversion and the long-term evolution trends. The results reveal that the M2 amphidromic point near the YRE shifted eastward by 4.9 km from 2005 to 2014 and migrated southeastward by 6.8 km between 2014 and 2020. Additionally, significant changes were observed in the maximum and residual currents within the active mouth (AM), the old Qing 8 (Q8) channel, the old QingShuiGou (QSG) channel, and the southeastern region. Notably, the residual currents exhibit vertical fronts with substantial current velocity differences across the slopes. After the diversion of the YRE, the northern TSFs disappeared. The TSFs in the AM gradually shifted landward, while the TSFs in the southeastern region shifted offshore. In the vertical direction, the frontal centerlines of the TSFs gradually moved offshore from top to bottom. The intensity of the TSFs at the same latitude was positively correlated with the offshore distance. Generally, steeper slopes were associated with larger bottom stress gradients, which in turn corresponded to stronger TSFs.

The Role of Bedrock Topography in the Runoff Process and Soil Erosion on Karst Steep Slopes

The Role of Bedrock Topography in the Runoff Process and Soil Erosion on Karst Steep Slopes

Outward depolarization of the microglia mitochondrial membrane potential following lipopolysaccharide exposure: a novel screening tool for microglia metabolomics

Microglia are non-electrogenic immune cells that respond rapidly to protect the central nervous system (CNS) from infections, injuries, or other forms of damage. Microglia mitochondria are essential for providing the requisite energy resources for immune regulation. While fluctuations in energy metabolism are regulated by mitochondria and are reflected in the mitochondrial membrane potential (ΔΨm), there remains a lack of innovation in microglia-centric tools that capitalize on this. In this study, live imaging of microglia in acute slices from EGFP reporter mice expressing EGFP under the control of the fractalkine receptor (CX3CR1) promoter is combined with loading a fluorescent reporter of ΔΨm. Depolarizations in the ΔΨm were recorded after administering the well-characterized immune stimulant lipopolysaccharide (LPS). Microglia ΔΨm increased in distinctive phases with a relatively steep slope following LPS exposure. Conversely, the ΔΨm of neurons showed minimal regulation, highlighting a distinct microglia ΔΨm response to immune stimuli. Analysis of the depolarization of the microglia ΔΨm in the soma, branches, and endfeet revealed progressive changes in each subcellular domain originating in the soma and progressing outward. The inverse agonist emapunil attenuated the depolarization of the ΔΨm across states in a domain-specific manner. These findings emphasize the contribution of mitochondrial membrane dynamics in regulating microglial responses to immune stimuli. Further, this work advances a novel drug screening strategy for the therapeutic regulation of metabolic activity in inflammatory conditions of the brain.

Thwaites Glacier thins and retreats fastest where ice-shelf channels intersect its grounding zone

Abstract. Antarctic ice shelves buttress the flow of the ice sheet but are vulnerable to increased basal melting from contact with a warming ocean and increased mass loss from calving due to changing flow patterns. Channels and similar features at the bases of ice shelves have been linked to enhanced basal melting and observed to intersect the grounding zone, where the greatest melt rates are often observed. The ice shelf of Thwaites Glacier is especially vulnerable to basal melt and grounding zone retreat because the glacier has a retrograde bed leading to a deep trough below the grounded ice sheet. We use digital surface models from 2010–2022 to investigate the evolution of its ice-shelf channels, grounding zone position, and the interactions between them. We find that the highest sustained rates of grounding zone retreat (up to 0.7 km yr−1) are associated with high basal melt rates (up to ∼250 m yr−1) and are found where ice-shelf channels intersect the grounding zone, especially atop steep local retrograde slopes where subglacial channel discharge is expected. We find no areas with sustained grounding zone advance, although some secular retreat was distal from ice-shelf channels. Pinpointing other locations with similar risk factors could focus assessments of vulnerability to grounding zone retreat.

Scaling relations between mass components and rotational velocity in disk galaxies

Abstract In this study, we re-evaluate the baryonic Tully–Fisher relation (BTFR) by analyzing the correlations between maximum rotational velocity and various mass components, including stellar mass, atomic hydrogen (H i) mass, baryonic mass, and dark matter mass in a sample of 141 disk galaxies from the SPARC (Spitzer Photometry and Accurate Rotation Curves) database, augmented by recent data on stellar and dark matter masses. We apply multiple statistical methods, including Monte Carlo orthogonal distance regression (MCODR), Monte Carlo least-squares (MCLS), and traditional least-squares (LS), to assess the impact of different fitting techniques on the derived scaling relations between the mass components (stellar, H i, and dark matter) and maximum rotational velocities of these galaxies. We find that the selection of statistical methods significantly influences the derived slopes and intercepts the relation between maximum rotational velocity and mass components. The MCODR method that accounts for errors in both variables consistently produces steeper slopes, suggesting a stronger correlation between stellar mass and rotational dynamics compared to other methods. In contrast, the MCLS method tends to yield flatter slopes, highlighting the sensitivity of this approach to outliers. Despite the variations in slope and intercept across different methods, the fundamental relation between baryonic mass and rotational velocity remains robust. We have also compared dark matter mass derived from different halo models [NFW (Navarro–Frenk–White) versus combined NFW + Dekel–Zhao profiles] and noted that the slope from the NFW profile is slightly steeper than that from the combined profile, highlighting the sensitivity of scaling relations to the selection of halo model. Overall, this study reinforces the robustness of the BTFR across different mass components in disk galaxies while emphasizing the critical role of statistical methods and dark matter profiles in analyzing galactic dynamics.

Impact of Impedances and Solar Inverter Grid Controls in Electric Distribution Line with Grid Voltage and Frequency Instability

The penetration of solar energy into centralized electric grids has increased significantly during the last decade. Although the electricity from photovoltaics (PVs) can deliver clean and cost-effective energy, the intermittent nature of the sunlight can lead to challenges with electric grid stability. Smart inverter-based resources (IBRs) can be used to mitigate the impact of such high penetration of renewable energy, as well as to support grid reliability by improving the voltage and frequency stability with embedded control functions such as Volt-VAR, Volt–Watt, and Frequency–Watt. In this work, the results of an extensive experimental study of possible interactions between the unstable grid and two residential-scale inverters from different brands under different active and reactive power controls are presented. Two impedance circuits were installed between Power Hardware-in-the-loop (P-HIL) equipment to represent the impedance in an electric distribution line. Grid voltage and frequency were varied between extreme values outside of the normal range to test the response of the two inverters operating under different controls. The key findings highlighted that different inverters that have met the same requirements of IEEE 1547-2018 responded to grid instabilities differently. Therefore, commissioning tests to ensure inverter performance are crucial. In addition to the grid control, the residential PV installed capacity and physical distances between PV homes and the substation, which impacted the distribution wiring impedance which we characterized by the ratio of the reactive to real impedance (X/R), should be considered when assigning the grid-supporting control setpoints to smart inverters. A higher X/R of 3.5 allowed for more effective control to alleviate both voltage and frequency stability. The elimination of deadband in an aggressive Volt-VAR control also enhanced the ability to control voltage during extreme fluctuation. The analysis of sudden spikes in the grid responses to a large frequency drop showed that a shallow slope of 1.5 kW/Hz in the droop control resulted in a >65% lower sudden reactive power overshoot amplitude than a steeper slope of 2.8 kW/Hz.

Gradient variations of formation mechanisms and sources of PM1 at the steep slope from western SiChuan Basin to eastern Tibetan Plateau

Vertical distributions of chemical components of particulate matter (PM) are essential for better understanding the climate, environmental and health effects. The steep slope from western SiChuan Basin (SCB) to eastern Tibetan Plateau (TP) provides a good platform for obtaining the gradient variations of PM chemical components. Daytime and nighttime PM1 (particulate matter smaller than 1 μm) samples were collected with the medium-volume sampler at six sites with elevation ranging from 500 m to 3500 m (Chengdu, Sanbacun, Wenchuan, Lixian, Maerkang and Hongyuan). The secondary inorganic ions and carbonaceous aerosols were the largest contributor to PM1 concentrations. The chemical components from the anthropogenic sources existed strong stratification with high concentrations inside the basin, while primary natural ions showed little discrepancy among the sites. The concentrations of primary inorganic ions from anthropogenic sources were much higher at nighttime than daytime, which was contrary to the diurnal cycle of secondary inorganic ions. Spatial heterogeneity of PM chemical components was large between basin and plateau sites, especially for NO3− and NH4+, large depending on season and daylight. The excess NH4+ concentrations existed in spring, summer and fall, while SO42− and NO3− cannot be completely neutralized by NH4+ in winter. The proportion of secondary formation in all sources significantly increased from about 10 % to 30 %–40 % with the increased elevation, while the contribution of motor vehicles declined from western SCB to eastern TP. This study will fill the scarce observations of PM chemical components at the sloped terrain and deepen the understanding of formation mechanism of heavy pollution inside the basin.

Geophysical characterization of the bedrock and regolith in the Pranmati basin critical zone, Uttarakhand Himalaya

The young active Himalayan mountain is characterized by steep slope and dissected topography in overall compressive tectonic setting. The mountain belt has primarily coarse textured soil with poor water holding capacity and is highly prone to erosion. The erosion not only affects many ecosystems located at downstream but also has detrimental effects on the critical zone (CZ). In the present study, we have carried out DC electrical resistivity study in the Pranmati catchment of the Alaknanda basin, a Himalayan critical zone in the Lesser Himalaya, to understand the pattern of soil erosion, transportation and deposition by characterizing the bedrock architecture and hence regolith thickness. A total of 6 electrical resistivity tomogram (ERT) profiles were laid at two locations in the catchment, one in a plain grassland and another at a crop field located on a hill slope of >25o. The study area in the Baijnath klippe, consists of quartz-biotite gneisses with layers of quartz mica-schist enclosed by thrust faults. Electrical resistivity sections of the downslope grassland site show a sharp resistivity contrast between the southwest and northeast transects suggesting south-eastern increase in dip of the bedrock, oblique to the north-east facing surface topography and a thick regolith (> 10 m). The resistivity sections of the site located on the hillslope yield a very thin layer of regolith (< 2 m) indicating significant soil erosion and high weathering of the bedrock. We propose that the water–rock interaction within the porous regolith facilitated by subsurface water circulation might be a potential source for the thick regolith. The observations substantiate existing hypotheses for the evolution and development of deep critical zones. From the results, it has been hypothesized that the bedrock architecture and water channel paths within the CZ together control the regolith thickness.

Effect of transcutaneous electrical nerve stimulation on maximum mouth opening after orthognathic surgery: a randomised controlled trial

Background: The present study aims to determine the effect of transcutaneous electrical nerve stimulation (TENS) on maximum mouth opening (MMO) after orthognathic surgery. Materials and methods: This study is a randomised clinical trial. The samples of this study were class III patients who are candidates for Le Fort I osteotomy surgery for maxillary advancement and bilateral sagittal split osteotomy (BSSO) for mandibular setback surgery due to the lack of maxilla growth and mandibular prognathism using the Dalpont method. On the day following surgery, the intervention group received TENS physiotherapy and instructions to take analgesics. In the control group, patients only received analgesics. MMO was measured in both groups using a digital caliper preoperatively, 1 month, and 6 months postoperatively. Results: A total of 82 patients participated in this study, who were divided into two groups of 41, intervention and control. The difference in the mean MMO in different periods after surgery of the intervention group (F=59733.350, P&lt;0.001) and the control group (F=32.480, P&lt;0.001) was significant. The pattern of MMO increase over time was not the same in the two groups. There was a steeper slope in the increase of MMO in the intervention group than in the control group. Conclusion: It can be concluded from the results of this study, that the use of TENS after orthognathic surgery can be effective along with analgesics in reducing pain intensity and, subsequently, recovery in MMO in the short term.

Strong decline in grasshopper abundance over 20 years without major land-use changes: Is soil drying one of the drivers?

Strong declines in insect numbers have been described for different taxa and regions. These observations are of great concern such that broad scientific and public attention has been raised. Among other urgencies, the need for long-term insect data has been identified. Here, we present data on grasshopper (Caelifera) abundances recorded between 1992 and 2011 at over 600 sites in north-western Switzerland. While vegetation type, often semi-natural grasslands, had remained largely constant, total grasshopper abundance declined by around 50 % (while many other taxa showed much less decline). Numbers in July remained relatively stable until about 2003 but then declined similar to the declines seen in August–October already before. Greatest losses were observed for drier habitats and steeper slopes, suggesting that soil drying might be an important factor for the decline. Second, more nutrient-rich habitats suffered greater losses; possible reasons for this include small-scale vegetation changes in these habitats e.g. due to atmospheric nitrogen deposition, or isolation of sites. Other than abundance, species richness decreased much less, illustrating that important ecological changes may be strongly underestimated when only species lists are available. The strong declines at our sites, which often are in an agri-environmental scheme, is alarming. Apart from being yet another call to fight climate change, our results also point to the urgent need to reduce atmospheric nitrogen deposition and to continue extensive farming, but also to adapt it in preparation of expected effects of climate change, with the aim to favour a divers, ecologically robust insect community.

Submarine Groundwater Discharge at a Mega‐Tidal Beach

ABSTRACTTidally influenced groundwater systems in coastal environments represent important mixing zones of fresh groundwater and circulating seawater, manifesting as submarine groundwater discharge (SGD). Water circulation induced by tidal pumping enhances the exchange of chemicals between aquifers and coastal waters and thereby influences the biogeochemistry of coastal zones. Here, we report the results of an SGD field study conducted at a steep, mega‐tidal sand and gravel beach along the Canadian coast of the Bay of Fundy, a region with the world's highest tides (semi‐diurnal tidal ranges exceeding 10 m). Several physical and geochemical measurement techniques were employed to document the spatiotemporal SGD variability. SGD was directly sampled from seepage meters installed over multiple tidal cycles and two summer campaigns. SGD rates were estimated from tracer mass balances for radon (August 2020) and radium isotopes (July 2021) over multiple tidal cycles. Tidally averaged SGD estimates from seepage meters ranged from 12 to 87 cm d−1, with an average of 42 cm d−1, while radon tracing yielded a tidally averaged rate of 86 cm d−1. SGD estimates from radium tracing ranged from 23 to 43 cm d−1 along the shoreline and 6 to 71 cm d−1 offshore, depending on the estimated residence times. Radionuclide analyses of seepage meter waters suggest that the residence time of seawater circulation through the aquifer is less than 1 day. SGD measurements in mega‐tidal settings are rare, and the results suggest that the combination of the steep slopes, highly permeable sediments and high tidal range drive very high seepage rates for diffusive SGD. Salinity gradients in the intertidal zone demonstrate that SGD is primarily comprised of circulated seawater with negligible fresh groundwater. Although the freshwater proportion of SGD is relatively low, the large volumetric rates of total SGD can still contribute large amounts of terrestrially derived and remineralized nutrients to coastal waters.

Spatiotemporal characteristics of non-seismically fatal landslides in Northwest China: A case study from Shaanxi province

Landslides are one of the devastating geo-hazards that result in severe casualties in Northwest China (NW China) every year. However, a comprehensive landslide database is yet to be available for quantitatively assessing the distribution of fatal landslides in NW China. To investigate the spatiotemporal characteristics of non-seismically fatal landslides in NW China, we carried out a study using fatal landslides that occurred in Shaanxi province as an example to construct a new database by incorporating data of fatal landslides that occurred in the period between 1996 and 2018. A total of 332 non-seismically fatal landslides that claimed 1132 lives were compiled in this database. Additionally, a thorough study of spatial and temporal variations of fatal landslides reveals that anthropogenic landslides occur approximately evenly throughout the year. Natural fatal landslides, however, rise noticeably in July, August, and September. The spatial distribution analysis showed that fatal landslides in Shaanxi province of China were mainly distributed in the An’ kang, Yan’an, and Shangluo regions. Additionally, areas with relatively high relief (46.1 to 123 m), steep–slope topography (19.2 to 26.1°), and intense precipitation (465 to 937 mm) are more vulnerable to naturally-triggered landslides. The spatiotemporal analysis of the fatal landslides revealed increasing trends in zones such as Yan’an and Yulin cities (in northern part), and in An’kang city (in southern part). When combined with other information, the Fatal Landslide Database of Shaanxi Province can be used to provide a guide for risk assessment and spatial planning studies to mitigate geo-hazard risks.

Assessing watershed vulnerability to erosion and sedimentation: Integrating DEM and LULC data in Guyana's diverse landscapes

This study assesses watershed vulnerability to erosion and sedimentation in Guyana using Digital Elevation Model (DEM) and Land Use/Land Cover (LULC) classification. It aims to assess erosion risk by examining rainfall erosivity, soil types, and spatial variability. The integration of DEM-derived slope data with LULC and rainfall erosivity shows a strong correlation between high rainfall (20,809.02–31,262.35 mm) and erosivity (21,433.29–32,200.22 MJ mm ha−1 h−1 yr−1), indicating increased erosion potential, particularly in southwestern regions. Soil analysis reveals Plinthic Acrisols, with high clay content, are more prone to erosion, whereas Orthic Ferralsols are less vulnerable. Slope analysis suggests flat terrain (89.16 %) has low erosion risk, but steeper slopes require interventions. Conservation strategies like reforestation, sustainable agriculture, contour plowing, and terracing are recommended to reduce erosion impacts. This integrated assessment provides insights for prioritizing soil conservation and adaptive management to address erosion risks in Guyana.

Southeastern Ohio Hemlock Stands Prior to Hemlock Woolly Adelgid Infestation: Baseline Conditions from 2 Surveys a Decade Apart

The Hocking Hills of southeastern Ohio are situated at the western range boundary of eastern hemlock, where this foundation species occurs in isolated pockets in ravines and on steep slopes. The goal of this study is to characterize these hemlock stands prior to infestation by hemlock woolly adelgid (HWA), which recently entered the state and is likely to cause high mortality if untreated. Individuals in 30 plots established from 2008 to 2011 were resurveyed in 2020, allowing determination of growth rates and mortality rates. Each plot was paired with an upslope transect in the resurvey to record non-hemlock species likely to seed in from above. Tree species diversity in the plots is low (Shannon H’ &lt; 1), as eastern hemlock remained the dominant species in all plots; storm damage and competitive thinning appeared to account for most mortality across all species. Hemlock growth rates were comparable to deciduous species. Common co-occurring species are statistically associated with particular topographic and soil properties on the plots. Following future hemlock mortality, tulip-poplar, chestnut oak, white oak, sweet birch, and red maple may be among the first species to dominate the canopy; Japanese stiltgrass currently appears to be the invasive species of greatest concern. An understanding of pre-HWA composition, structure, and forest dynamics can inform restoration efforts, if in the future long-term, sustainable HWA control or host-tree resistance is developed; this understanding can also apprise management and conservation efforts in the unique hemlock stands of southeast Ohio.

Southeastern Ohio Hemlock Stands Prior to Hemlock Woolly Adelgid Infestation: Baseline Conditions from 2 Surveys a Decade Apart

The Hocking Hills of southeastern Ohio are situated at the western range boundary of eastern hemlock, where this foundation species occurs in isolated pockets in ravines and on steep slopes. The goal of this study is to characterize these hemlock stands prior to infestation by hemlock woolly adelgid (HWA), which recently entered the state and is likely to cause high mortality if untreated. Individuals in 30 plots established from 2008 to 2011 were resurveyed in 2020, allowing determination of growth rates and mortality rates. Each plot was paired with an upslope transect in the resurvey to record non-hemlock species likely to seed in from above. Tree species diversity in the plots is low (Shannon H’ &lt; 1), as eastern hemlock remained the dominant species in all plots; storm damage and competitive thinning appeared to account for most mortality across all species. Hemlock growth rates were comparable to deciduous species. Common co-occurring species are statistically associated with particular topographic and soil properties on the plots. Following future hemlock mortality, tulip-poplar, chestnut oak, white oak, sweet birch, and red maple may be among the first species to dominate the canopy; Japanese stiltgrass currently appears to be the invasive species of greatest concern. An understanding of pre-HWA composition, structure, and forest dynamics can inform restoration efforts, if in the future long-term, sustainable HWA control or host-tree resistance is developed; this understanding can also apprise management and conservation efforts in the unique hemlock stands of southeast Ohio.

Multi-year performance of white clover oversown into eastern North Island hill country

Animal performance on summer-dry North Island hill country pastures is limited by soil fertility and the challenge of establishing and retaining a strong legume base in swards on steeper slopes. However, this can be overcome by 1. selecting legume species adapted to the various slope, aspect and soil type combinations; and 2. following well-recognised establishment and management techniques developed in the 1980s. We broadcast white clover in two large southerly aspect paddocks on Tangihanga Station, Gisborne, in the autumn of 2019. Establishment methods involved resident pasture control by hard grazing and selective herbicide to supress dominant low-fertility grasses, broadcasting at high sowing rates and trampling of seed with sheep. We followed white clover persistence and animal performance over the subsequent 5 seasons of rotational cattle grazing with heifers and steers, in comparison with adjacent unsown paddocks. The cost of establishment was c. $220/ha. White clover abundance remained high throughout the 5 years, between 25-40% of cover, compared with 7-17% in unsown paddocks. This increase in clover content of the pastures translated into both increased stocking rates and per head growth rates, with overall annual LWG increasing by 67-169% depending on season. The investment was paid back within the first year.

Research on the Identification of Rock Mass Structural Planes and Extraction of Dominant Orientations Based on 3D Point Cloud

The different spatial distribution forms of rock mass structural planes create weak zones in the rock mass, which is also a key factor in controlling rock mass stability. Accurately and efficiently identifying rock mass structural planes and obtaining their dominant orientations is critical for rock mass engineering design and construction. Traditional surveying methods for high and steep rock mass structural planes pose high safety risks, offer limited data, and make comprehensive statistical analysis difficult. This paper utilizes complex rock mass surface 3D point cloud data obtained through 3D laser scanning technology and uses the Hough space transform method to calculate the normal vectors of the 3D point cloud. Based on the difference in normal vectors and surface variation, region growing segmentation is applied to identify and extract rock mass structural planes. Additionally, the fast search and density peak clustering method (CFSFDP) is used for clustering analysis of the rock mass structural planes to obtain dominant orientations. This method was applied to a highway’s high and steep rock slope, successfully identifying 281 structural planes and two sets of dominant structural planes. The orientation of the dominant structural planes identified through RocScience Dips 7.0 analysis showed a deviation of no more than ±3°, complying with engineering standards. The research results offer a feasible solution for the identification of high and steep rock mass structural planes and the extraction of the orientation of dominant structural planes.

Multi-Source Monitoring and Numerical Simulation Deformation on Highway Steep Slopes Under Rainfall Effects

Rainfall is one of the most important factors affecting slope stability. This study employed multi-source monitoring devices to observe the slope displacements in real time under rainfall infiltration and performed numerical simulations to investigate the effects of different rainfall conditions and anti-slip pile configurations on slope stability. Specifically, multi-source monitoring operations were conducted on the high and steep slopes along the Yunmao Expressway. Real-time data on slope deformation, rainfall, and displacement at the tops of anti-slip piles were collected and analyzed, and numerical simulations were conducted using Geo Studio finite-element software. The findings indicated that abrupt deformation of slopes occurs once a threshold rainfall amount is surpassed and sustained over a specific duration. Slope displacement decreased with increasing slope depth above the potential slip fracture surface, with a more rapid reduction in deformation rates observed in slopes reinforced with anti-slip piles. For equivalent rainfall amounts, short-duration, intense rainfalls led to a rapid decrease in the slope safety factor, which also recovered rapidly once the rainfall ceased, in contrast to long-duration, mild rainfalls. The presence and location of anti-slip piles significantly influenced slope stability; therefore, project implementation should carefully consider factors such as cost and duration for optimal decision making.

Physiological traits and population dynamics of Schizothorax niger (Heckel, 1838): Insights from Dal Lake and the Jhelum River, Kashmir, Himalayan region.

This study examines the physicochemical characteristics, morphometric features, biometric growth parameters, biological indices, physiological parameters, and biochemical profiles of Schizothorax niger population. The physicochemical analysis revealed a maximum temperature of 12.93 ± 1.33°C and hardness of 156.53 ± 12.82 mg/L in Dal Lake, whereas the Jhelum River had a minimum level of 10.94 ± 1.12°C temperature and 128.31 ± 11.62 mg/L of hardness. Dal Lake had a neutral pH (7.5 ± 0.2) and lower dissolved oxygen (6.8 ± 0.4 mg/L) compared to the Jhelum River (pH 7.2 ± 0.3; dissolved oxygen 7.5 ± 0.5 mg/L). Morphometric analysis showed significant differences (p < 0.05) in fish length (Dal Lake: 18.4 ± 2.1 cm; the Jhelum River: 21.0 ± 1.8 cm) and weight (Dal Lake: 74.5 ± 9.8 g; the Jhelum River: 92.2 ± 7.4 g) between the sites. Biometric growth parameters demonstrated a positive allometric growth pattern, with Dal Lake having a steeper slope (b = 3.15) than the Jhelum River (b = 2.98). Biological indices revealed gender-based variations in the gonado-somatic index (GSI) and hepato-somatic index (HSI), with GSI being higher in Dal Lake (0.21 ± 0.02) and HSI in the Jhelum River (1.04 ± 0.09). Haematological and biochemical analyses showed significant differences in parameters such as haematocrit (Dal Lake: 29.2 ± 2.1%; the Jhelum River: 32.4 ± 1.8%), glucose (Dal Lake: 85.3 ± 5.4 mg/dL; the Jhelum River: 68.1 ± 4.2 mg/dL), and total protein (Dal Lake: 6.2 ± 0.4 g/dL; the Jhelum River: 5.8 ± 0.3 g/dL) between sites. These findings provide valuable insights into the physiological traits and population dynamics of S. niger, informing species-specific conservation strategies and ecosystem management practices.

Unveiling the prediction model and mechanism of the collapse of bank slope in the lancangjiang area

This study takes the bank collapse at the left bank of Badi Township of the Lidi Hydropower Station in the Lancang Area as an example. To address the lack of in-depth research on the prediction model and mechanisms of bank collapse, this study conducts field drilling surveys, investigates influencing factors, analyzes causal mechanisms, and proposes prediction methods based on the geological survey data of bank collapse in the reservoir area. The study explores the stratigraphic lithology, determines the key parameters for bank collapse prediction, and studies the failure modes and bank collapse mechanisms. It also proposes the finite element method of bank collapse to predict the width and elevation of bank collapse and provides the influence on the surrounding environment. The results show that the collapsed bank on the left bank of Badi Township is a high and steep soil-like slope, and forms the collapse and retreat type of failure mode after impoundment. The Kachukin method, the bank slope structure method, and the proposed finite element method are used to predict the width and elevation of the collapsed bank. The results indicate that the Kachujin method predicts a larger range of bank collapses and is biased towards safety. In contrast, the prediction ranges of the bank slope structure method and the finite element method are close. The bank collapse position is located in the middle and rear of the residential houses in Badi Township, which is consistent with the on-site investigation and has strong reliability. The predicted width of the bank collapse is about 34 m and the elevation is about 1,845 m. The research results can be directly applied to preventing and controlling bank collapse and have powerful practical application value.