Search Results (1,047)

River ice is a common feature in most Canadian rivers and streams during the cold season. River channel hydraulics under ice conditions may cause higher water levels at a relatively lower discharge compared to the open-water flood events. Elevated water levels resulting from river ice processes throughout fall freeze-over, mid-winter, and spring break-up are important hydrologic events with diverse morphological, ecological, and socio-economic impacts. This study analyzes the timing of maximum water levels (occurring during freeze-over, spring break-up, and open-water periods) and the typology of maximum ice-related events (at freeze-over, mid-winter, and spring break-up) using data from the Canadian River Ice Database. The study also compares annual maximum water levels during the river ice and open-water periods at selected hydrometric stations from 1966 to 2015, divided into two 25-year windows: 1966–1990 and 1991–2015. A return period classification method was applied to define ice-influenced, open-water, and mixed-regime conditions. The results indicate that the majority of ice-influenced maximum water levels occurred during spring break-up (~79% in 1966–1990 and ~69% in 1991–2015), followed by fall freeze-up (~13% and ~23%) and mid-winter break-up (~8% and ~7%) for the two periods, respectively. Among 15 stations analyzed for 1966–1990 and 42 stations for 1991–2015, the proportion of annual maximum water levels dominated by open-water conditions increased from 47% to 55%, while ice-dominated events decreased from 13% to 12%, and mixed-regime events dropped from 40% to 33%. However, a focused comparison of eight common stations revealed minimal change in the distribution of water level-generating events between the two periods. The findings offer valuable insights into the spatial distribution of maximum water level-generating mechanisms across Canada. Full article

Ochetobius elongatus, a critically endangered (CR) fish species of the Yangtze River Basin in China, has experienced a severe decline in its wild population. Understanding its mechanisms of phenotypic variation is essential for developing effective conservation and restoration strategies. Using geometric morphometrics based on 14 landmarks, we examined the phenotypic difference among five populations from the mainstem, the tributary, and the river-connected lakes of the middle Yangtze River. The results showed that significant phenotypic divergence was detected between river and lake populations. River individuals exhibited a more elongated body, smaller head, inferior mouth position, larger operculum, and narrower caudal peduncle, whereas lake individuals showed a deeper body, and anterior shift in the origin of pelvic fin. The first canonical variable effectively distinguished river and lake populations, with the accuracy of both original and cross-validation classification exceeding 90%, indicating that habitat heterogeneity was the primary driver of phenotypic differentiation. No significant correlation was found between morphological distance and geographical distance. Water temperature, flow velocity, water depth, and food abundance significantly influenced phenotypic variation, but their individual effects were limited, which suggested that environmental shaping of morphology depended more on synergistic effects. Our findings provide important insights into the adaptive evolution of this critically endangered species and offer a scientific basis for conservation efforts. Full article

This study aims to establish an energy assessment system and provide low-carbon design strategies for block-scale science and technology industrial parks in the Yangtze River Delta region of China. To investigate low-carbon design strategies for these parks, the impact of solar energy utilization potential and heat island effect on the energy consumption of buildings is taken as the entry point. Through an analysis of the spatial characteristics of twenty block-scale science and technology industrial parks in the Yangtze River Delta region of China, two types of idealized park models comprising a total of eighteen variations were established. The simulation process involved six key morphological parameters to describe the specific shape of the parks quantitatively. The Ladybug Tools 1.6.0, Radiance 5.4a, and URBANopt v0.9.2 software were used to simulate the potential for photovoltaic power generation and the energy consumption of the parks. Net Energy Use Intensity (NEUI) and Potential Utilization Ratio of Renewable Energy (PURRE) were selected as the final evaluation indexes to represent the integrated energy performance of the park. The results show that for the park with a circular layout, the optimal integrated energy performance is achieved when the building density is between 35% and 40%; the average building height is designed with lower values within the range of 20 m to 24 m, and the height-to-depth ratio is around 0.3. Finally, based on the results of the analysis, four major low-carbon design strategies were proposed: high-density development, courtyard layout, supporting-function centralized layout, and carbon sink enhancement. Full article

Understanding sediment transport timescales is essential for predicting morphological evolution, pollutant accumulation, and ecosystem health in estuaries. This study examines seasonal hydrodynamics and sediment transport in the Pearl River Estuary using a well-calibrated numerical model. The results indicate that plume dynamics largely control sediment transport in both the wet and dry seasons. During the wet season, sediments are exported along both estuary flanks with the expanding freshwater plume. Under the combined effects of topography and the Coriolis force, a greater proportion of sediments exits via the confluence of the West Channel and West Shoal. In the dry season, prevailing northeasterly winds suppress sediment export along the East Channel, redirecting most of the riverine sediment westward. Sediment transport timescales, quantified by sediment age, further show that, during the wet season, export via the East Channel requires approximately 30 days, whereas export along the western flank takes about 45 days due to the weaker dynamics over the West Shoal. Reduced river discharge in the dry season increases sediment age overall; offshore delivery within the plume region takes roughly 50 days, while transport via the East Channel may require an additional 30–60 days. Comparative simulations with and without wind forcing reveal that southerly winds during the wet season weaken plume intensity and prolong transport timescales, whereas northeasterly winds in the dry season enhance plume dynamics, accelerating sediment export from the estuary. Collectively, these findings clarify the mechanisms underlying the seasonal variability in sediment transport and provide a scientific basis for estuarine management and engineering. Full article

Ice disasters in the Yellow River’s Inner Mongolia reach exhibit sudden onset and high destructiveness, driven by climatic and channel constraints. The Shisifen Bend, within this reach, is particularly prone to initial ice jamming during freeze-up periods annually. This susceptibility arises from channel narrowing, increased upstream ice influx, and complex river morphology. To address persistent ice flood risks and mitigation challenges at Shisifen Bend, this study developed a coupled ice-transport numerical model. Utilizing MIKE21’s hydrodynamic and particle tracking modules alongside measured bathymetric and depth data, the model simulates ice movement under three distinct flow conditions: 2000, 2500, and 3000 m³/s. Analysis of ice trajectories and distribution patterns under varying flow conditions reveals key transport mechanisms for both ice and water. These findings provide critical insights for enhancing ice flood prevention and disaster reduction strategies along the Inner Mongolia Yellow River during freeze-up period. Full article

Different sampling techniques were evaluated to assess potential differences in species richness and the abundances of phytoplankton across several lowland aquatic environments. Five sampling methods were used, including a bucket, narrow- and wide-mouth bottles, a 10 µm plankton net, and a vertical Van Dorn bottle. These sampling methods were applied in subtropical streams, shallow lakes, and rivers. The results were compared using a two-way ANOVA to evaluate differences in total density by considering the morphological group and major phytoplankton phyla. Similarity analyses (SIMPER) and a permutational multivariate analysis of variance (PERMANOVA) were performed to compare the relative abundances of the species. The results showed, in general (except with Cyanophyta, Chrysophyta, and colonies—coenobia), significant differences in the effect of the sampling method but without interaction with the kind of environment. Particularly, the plankton net always reported lower density estimations, with the bucket having the highest values and the wide–narrow bottle methods having similar values. SIMPER and PERMANOVA indicated differences, especially with the plankton net and the other methods, particularly the bucket. These findings suggest that the sampling method can influence species counts and registration in subtropical water ecosystems, highlighting the need for standardized procedures across countries to obtain comparable and reliable results. Full article

The presence of metallic pollutants presents a significant risk to human health, making their removal crucial. Magnetic halloysite nanotube (HNT@Fe₃O₄) nanocomposite was synthesised via co-precipitation, and then magnetic hydrogel (Fe₃O₄@HNT-SA and Fe₃O₄@HNT-CTS) nanocomposites were prepared using chitosan (CTS) and sodium alginate (SA) biopolymers. The structural, morphological, crystalline, surface, and thermal properties of the hydrogels were determined. The favourable adsorption performance of Fe₃O₄@HNT-SA and Fe₃O₄@HNT-CTS hydrogels towards As, Cd, Cr, Mo, Pb, Sb and V was established by optimising the factors affecting the sorption process. The results indicated that Fe₃O₄@HNT-CTS was suitable for the adsorption of As, Cr, Mo, Sb and V, while Fe₃O₄@HNT-SA had high adsorption affinity for Cd and Pb. The data for the adsorption of target analytes onto the hydrogels were mostly explained by both the Langmuir isotherm model and the pseudo-second order model. The maximum adsorption capacities of Fe₃O₄@HNT-SA hydrogel for Cd and Pb were 52.2 mg/g and 57.7 mg/g, respectively. On the other hand, the maximum capacities of the Fe₃O₄@HNT-CTS hydrogel for As, Cr, Mo, Sb, and V were 30.3 mg/g, 28.4 mg/g, 22.2 mg/g, 24.7 mg/g, and 19.9 mg/g, respectively. The Fe₃O₄@HNT-SA and Fe₃O₄@HNT-CTS hydrogels effectively removed the respective target analytes from river water samples. Full article

This study investigates how landcover change between 1935 and 2020 have shaped hydrological responses in the semi-arid highlands of Tigray, Ethiopia. Focusing on the Tsili catchment (27.5 km²), it examines links between landcover change, drainage network evolution, and river channel width under conditions of population growth and climate variability. Landcover and drainage maps were derived from historical aerial photographs and satellite imagery for four time steps, and surface runoff was simulated using the SWAT model with uniform meteorological forcing to isolate landcover effects. Results show a 37.6% increase in cropland and substantial declines in shrubland (−29.3%) and forest (−10.1%). River channel width at the outlet widened from 7.5 to 10.5 m, while drainage density increased 1.5-fold. These physical changes aligned with modelled increases in surface runoff. Strong correlations were found between runoff, channel width, drainage density, and landcover types. The findings highlight that cropland expansion—at the expense of natural vegetated land—has intensified runoff and erosion risks. As climate change is expected to bring more intense rainfall to East Africa, this underscores the need for land management strategies that reduce hydrological connectivity and support sustainable agriculture in data-scarce regions. Full article

Thermal discharge from power plants causes significant concerns in aquatic environments. The purpose of this study is to evaluate how river mouth morphodynamics, particularly spit development and removal, influence the dispersion of thermal plumes. To achieve this, a case study was carried out at a coastal power plant in southwest Türkiye, where thermal effluent is conveyed to the sea through a low-flow river. Field measurements combined with numerical modeling were used to analyze plume dynamics under varying spit configurations. Results revealed that the evolution of a spit on one side of the river mouth influences plume dispersion and redirects the mixing zone toward the opposite shoreline. Numerical simulations demonstrated that spit development reduces dispersion efficiency (by over 75%), while the physical removal of the spit significantly improves it, reducing temperature excess from 4–5 °C to 0–1 °C within the mixing zone, meeting safe environmental standards. The findings highlight the pivotal role of morphological changes in governing thermal discharge behavior and emphasize the importance of continuous monitoring and management strategies, such as periodic dredging, to ensure compliance with environmental regulations. Full article

As fluvial deposition features, river islands originate from persistently exposed sandbars. Their morphological evolution responds to hydrological dynamics, sediment budgets, and human modifications of river systems. This study conducts a quantitative analysis of the spatiotemporal evolution of four river islands in China’s Yangtze River Estuary (YRE), utilizing multitemporal Landsat imagery (MSS, TM, ETM+, and OLI) at five-year intervals from 1974 to 2024. This analysis employed thresholding, binarization, image registration, cropping, and cluster analysis. Hydrological data (runoff and sediment flux) from Datong Station were concurrently evaluated to explore the driving factors of evolution. The findings suggested the following: (1) MSS/TM/ETM+/OLI images were effective for accurately extracting river island information, and the results were consistent with the accuracy verification. (2) The cumulative area and growth rate of the river islands have exhibited an upward trend over time, with Jiuduansha growing the fastest. (3) Runoff and sediment discharge are the primary natural controls on morphological evolution, with a weak positive correlation (R = 0.293) and a strong negative correlation (R = −0.915) with the area of river islands, respectively. Anthropogenic drivers such as land reclamation, sediment enhancement projects, and the Three Gorges Dam are equally critical. Full article

A total of 700 broiler chicks (350 Indian River and 350 Ross 308) were obtained from a local hatchery. Birds were randomly allocated in a completely randomized design by strain into two dietary groups: a control group (corn–soybean meal) and a treatment group in which 7.5% of soybean meal (SBM) was replaced with fermented soybean meal (FSBM). Each group included 175 birds, distributed across seven replicates (pens) with 25 birds per pen. Birds were weighed at the start of the trial and at the end of each rearing phase (starter (1–14 days of age), and grower phases (15–35 days of age)). Mortality was monitored daily throughout the experiment. Weekly feed intake was recorded for each pen. On day 35, 14 birds were randomly selected from each treatment–strain combination for carcass and meat quality evaluation. Data were analyzed with linear models; strain, diet, and their interaction were the investigated effects. No strain–diet interaction was detected for growth performance, carcass and meat quality, and intestinal morphology traits (p > 0.05). Significant interaction effect on crude protein digestibility is found (p < 0.001). The FSBM improved crude protein digestibility for the Indian River broiler strain, while the opposite occurred in the Ross 308 strain. Fermented soybean meal supplementation did not significantly affect body weight gain, feed conversion ratio (FCR), or feed intake during the study period (p > 0.05). The Ross strain exhibited a higher dressing percentage (p = 0.04) and greater cooking loss (p = 0.01), whereas the Indian River strain showed higher abdominal fat percentage (p = 0.04) and shear force (p = 0.003). The dressing percentage, pH, color parameters, cooking loss, water-holding capacity, and breast fillet yield for FSBM and control groups did not differ (p > 0.05). Ileum villus length and width were significantly higher (p < 0.05) in the FSBM group compared to the control group. In conclusion, Fermented soybean meal can enhance intestinal morphology and crude protein digestibility in a strain-specific manner; however, its impact on growth and carcass attributes is limited at this inclusion level. Full article

Lithology identification is a critical technology for geological resource exploration and engineering safety assessment. However, traditional methods suffer from insufficient feature representation and low classification accuracy due to challenges such as weathering, vegetation cover, and spectral overlap in complex sedimentary rock regions. This study proposes a hierarchical multi-feature random forest algorithm based on Feature-Preserved Compressive Sampling (FPCS). Using 3D laser point cloud data from the Manas River outcrop in the southern margin of the Junggar Basin as the test area, we integrate graph signal processing and multi-scale feature fusion to construct a high-precision lithology identification model. The FPCS method establishes a geologically adaptive graph model constrained by geodesic distance and gradient-sensitive weighting, employing a three-tier graph filter bank (low-pass, band-pass, and high-pass) to extract macroscopic morphology, interface gradients, and microscopic fracture features of rock layers. A dynamic gated fusion mechanism optimizes multi-level feature weights, significantly improving identification accuracy in lithological transition zones. Experimental results on five million test samples demonstrate an overall accuracy (OA) of 95.6% and a mean accuracy (mAcc) of 94.3%, representing improvements of 36.1% and 20.5%, respectively, over the PointNet model. These findings confirm the robust engineering applicability of the FPCS-based hierarchical multi-feature approach for point cloud lithology identification. Full article

Phytophthora species are known as water molds and are widespread in rivers and riparian habitats, but the distribution of these oomycetes in coastal and sea ecosystems is not well explored. The present study aims to investigate salt tolerance and potential to survive in marine environment of thirteen Phytophthora species, including P. citricola, P. plurivora, P. pseudosyringae, P. inundata, P. chlamydospora, P. gonapodyides, P. bilorbang, P. lacustris, P. pseudocryptogea, P. syringae, P. polonica, P. honggalleglyana, and P. gallica. The effect of varying concentrations of sodium chloride and the impact of sea water from the Black Sea and the Aegean Sea on mycelial growth, colony type, and formation of different morphological structures by Phytophthora species were studied. The tested isolates belong to different clades of the genus and members of clade 6 stand out with more extensive colony growth on media with elevated salt content compared to the growth on the control medium. A number of Phytophthora isolates produced morphological structures for sexual and/or asexual reproduction under salt stress conditions. The ability of the studied Phytophthora species to exist in marine environment is discussed. Full article

Preferential flow in coal mining subsidence areas leads to shallow soil moisture loss, vegetation reducing and ecological degradation. However, the factors influencing the development of preferential flow remain unclear. This study analyzed the morphological characteristics of preferential flow using a staining tracer test in coal mining subsidence areas along the middle reaches of the Yellow River Basin. Characteristic parameters including the dye-stained area ratio, preferential flow ratio, length index, variation coefficient were comparatively evaluated under different initial soil moisture conditions. Results showed that shallow soils exhibited substrate flow, while preferential flow occurred in deeper soil layers below the matrix flow. As initial soil moisture increased, the extent of both substrate flow and preferential flow decreased. The dye-stained area ratio declined with increasing soil depth, and the relationship between dye-stained area and soil layer depth was best described by a cubic function. Higher initial soil moisture reduced maximum infiltration depth and length indices while increasing the coefficient of the stained pattern. Furthermore, a higher of initial soil water content corresponded to a lower preferential flow index. Overall, increased initial soil moisture may reduce the extent of preferential flow and the rapid infiltration of water into soil. These findings provides a basis for further hydrological studies in coal mining subsidence areas in arid and semi-arid regions and offer scientific support for ecological restoration efforts in mining areas. Full article

Sinibotia species, investigated for morphology and species divergence owing to comparable body patterns and frequent sympatric occurrences, show high morphological similarity and close phylogenetic relationships, which challenge their accurate distinguishing via conventional morphological methods. Hence, multivariate morphometric (MM) and geometric morphometric (GM) analyses were used to assess the morphological differences between Sinibotia species (S. superciliaris, S. reevesae, S. robusta, S. pulchra, and S. zebra) habiting the Tuo River (Zizhong County) and Li and Lipu Rivers (Pingle County) based on 40 morphological traits and 34 landmarks. The morphological traits of S. robusta contrasted with those of S. pulchra and S. zebra, whereas S. superciliaris and S. reevesae showed similar morphologies, consistent with the cluster results. MM analysis using discriminant function analysis along with GM methods such as canonical variate analysis and relative distortion analysis enabled the differentiation between the Sinibotia species. Morphological variations were primarily reflected in snout length, nasal snout distance, head depth, body depth, caudal fin length, and dorsal fin length. MM effectively quantified linear size differences, whereas GM better captured and visualized complex variations in overall shape. The combined morphological evidence presented in this study contributes significantly to the identification of species, phylogenetic relationships, and ecological adaptations of Sinibotia species, thereby strengthening the theoretical rationale for the conservation and sustainable utilization of this genus. Full article