Search Results (19)

Understanding the interactions among mountain snow resources, river discharge, and irrigated agriculture is essential for sustainable water management in transboundary river basins of Central Asia. This study evaluated the relationships among high-elevation snow conditions, hydroclimatic factors, summer river discharge, and agricultural vegetation dynamics in the transboundary Chu River Basin during 2001–2025 using MODIS snow-cover, snow-persistence, and NDVI products together with meteorological and hydrological observations. The results showed that snow cover was widespread during winter but declined substantially during spring, while the Mann–Kendall analysis indicated that no statistically significant trend predominated across most of the high-elevation snow zone, although significant decreases in snow persistence occurred across 12.83% of the analyzed area. For summer cropland NDVI, 61.15% of the analyzed area showed no significant trend, while significant decreases and increases occurred across 26.24% and 12.62%, respectively. Spring temperature exhibited a significant negative correlation with snow persistence (r = −0.64, p < 0.001), indicating the sensitivity of mountain snow resources to warming conditions. Summer river discharge was strongly correlated with summer precipitation (r = 0.77, p < 0.0001), vegetated cropland area (r = 0.76, p < 0.0001), and mean summer NDVI (r = 0.69, p < 0.001). In addition, snow persistence showed a significant positive relationship with summer river discharge (r = 0.63, p < 0.001), vegetated cropland area (r = 0.52, p = 0.008), and mean summer NDVI (r = 0.42, p = 0.036), suggesting a linkage between high-elevation snow conditions, seasonal water availability, and downstream agricultural vegetation. Canonical correlation analysis further revealed a strong multivariate association between hydroclimatic and hydroagricultural variables (Rc = 0.900, Rc² = 0.810). Overall, the findings indicate significant statistical linkages among climate conditions, snow resources, river discharge, and irrigated agriculture, providing a scientific basis for water-resource management and climate-change adaptation in transboundary mountain-fed basins. Full article

Based on the high relevance of climate change issues and the extent of their investigation at global and regional levels, this study aims to quantify current changes in average annual air temperature, relative humidity, and precipitation within the Chu River watershed, and to identify patterns of their spatiotemporal variability under conditions of intensifying global warming. The study is based on long-term observational data from 18 meteorological stations collected during the period 1940–2024 under diverse physical and geographical conditions across the basin. The analysis of climatic dynamics within the Chu River basin catchment during the period 1940–2024, conventionally divided into four physiographic-altitudinal zones (high-mountain, mid-mountain, low-mountain, and plain regions), and conducted using a linear trend assessment approach with the application of statistical criteria, revealed the presence of multidirectional trends in climatic variables. It was established that the spatial and temporal variability of the trend coefficients for mean annual air temperature ranged from −2.50 to 2.45, for mean annual relative humidity from 0.93 to 1.03, and for annual atmospheric precipitation from 0.59 to 1.42. The identified positive trend in mean annual air temperature, occurring simultaneously with negative trends in relative humidity and atmospheric precipitation, is characterized not only by a stochastic component but also by a pronounced deterministic component manifested in the form of persistent positive and negative trends. These observed patterns are associated with the complex nature of climatic responses occurring in the northern part of the Tien Shan mountain system and along the eastern periphery of the Turan Lowland. Full article

Shiga toxin–producing Escherichia coli (STEC) are important zoonotic pathogens that can disseminate through environmental water systems, yet data from Southern Italy remain scarce. The aim of this study was to investigate the occurrence and genetic characteristics of STEC isolated from surface water samples collected from rivers and lakes in the Apulia region (Southern Italy). A total of 120 samples were processed according to ISO/TS 13136:2012, followed by whole genome sequencing (WGS) for isolate confirmation and characterization. Overall, 20% of the samples were stx-positive in screening. STEC strains were isolated from 4.2% of stx-positive enrichments, corresponding to one sample out of a total of 120 (0.8%). The isolate was identified as O139:H1, carrying the stx2e subtype and belonging to sequence type ST1. Genomic analysis revealed multiple virulence-associated determinants, including the complete F18 fimbrial operon (fedA-F), hlyA, csgA, gad, chuA, yehA-D, and ompT, along with stress-resistance and tellurite-resistance genes. The strain was susceptible to all antibiotics tested. The genomic profile suggests a swine-associated lineage with multiple environmental persistence traits but limited antimicrobial resistance. The detection of a swine-associated STEC strain in surface waters highlights potential environmental dissemination pathways and underscores the importance of continued monitoring within integrated water–livestock surveillance frameworks. Full article

Sustainable small hydropower (SHP) is central to the clean-energy transition of mountainous Central Asia, yet its long-term reliability depends on a rapidly changing cryosphere. Winter river-ice dynamics—an underappreciated control on run-of-river generation—remain poorly characterized owing to the collapse of in situ hydrometeorological networks since 1991. We use a 112-month Sentinel-1 C-band SAR time series (February 2017–May 2026) over a 5320 km² headwater catchment of the Chu River basin, northern Tien Shan, Kyrgyzstan, to quantify river-ice phenology at 20 m resolution using a per-pixel summer-baseline anomaly approach. Mid-winter (December–February) ice cover declined significantly at −0.51%·yr⁻¹ (p = 0.013; Mann–Kendall p = 0.029), with the 2026 winter recording an unprecedented 2.6–2.8 σ departure from the 2017–2025 climatology. Contrasting the cold 2022 and warm 2026 winters revealed bidirectional climate sensitivity—early breakup versus persistent thin ice—posing distinct SHP hazards. ERA5-Land reanalysis (1992–2026) showed significant winter warming with no precipitation or snowfall trend, indicating thermally forced ice decline. Interpreted within a conceptual Peak Water scenario, this signals a closing window of opportunity for SHP generation, with direct relevance to sustainable water–energy management and the UN Sustainable Development Goals (SDG 7; SDG 13). Our results provide the first decadal, satellite-based evidence of river-ice loss for Central Asian mountain rivers and a transferable monitoring framework to support climate-resilient, sustainable hydropower planning in ungauged basins. Full article

The hydrological prediction in transboundary river basins is difficult because of their heterogeneous data distribution, restrictions of data sovereignty, and the irregular nature of the discharge pattern. In this paper, Federated Learning (FL) with an LSTM neural network is proposed for next-day predictions of discharge in the Chu–Talas transboundary basin. The basin area belongs to both Kazakhstan and Kyrgyzstan. In an FL scenario, two hydrological stations from the basin were selected as client nodes, representing two different discharge regimes. Station 15125—the Chu main channel is characterized by the highest discharge regime among stations located in the basin, while Station 15233—Merke tributary represents a small catchment with an irregular regime. The federated LSTM model is compared against a centralized LSTM and a local-only LSTM baseline model. The training process is based on nearly three decades of daily discharge measurements. The preprocessing step includes synchronization, lag calculation, and windowing operation. The models are trained using three metrics: root mean square error, mean absolute error, and Nash–Sutcliffe Efficiency, as well as using Monte Carlo Dropout for estimation of the probabilistic uncertainty. The results demonstrate that the federated model demonstrates comparable performance with the centralized one for the Chu main channel. It also improves prediction accuracy for the smaller Merke tributary compared with both centralized and local-only models. These findings show that FL can work effectively with non-IID and heterogeneous hydrological data. The study makes three main contributions: (i) it implements the FedAvg algorithm on transboundary, heterogeneous hydrological data, proving that decentralized optimization can effectively capture autoregressive temporal hydrology without data centralization; (ii) it systematically compares federated, centralized, and local-only models, demonstrating that the federated approach eliminates the scale bias that traditionally neglects smaller, high-variance catchments; and (iii) it utilizes Monte Carlo Dropout to translate deterministic AI outputs into risk-aware probabilistic bounds. Ultimately, the results of this study demonstrate the practical and scientific usefulness of FL in operational water management, as the method presents a privacy-saving means of increasing predictive capacity and enabling risk-based decision-making in transboundary river basins. Full article

Groundwater in uranium mining areas is highly sensitive to pollution by radionuclides and toxic elements, especially under in situ leaching mining, which increases their mobility. This study assesses the radiological and chemical features of water sources in the Chu-Sarysu uranium province (Kazakhstan) by evaluating the annual effective dose (AED) from radionuclide ingestion. In total, 98 water samples from boreholes, wells and rivers were analyzed for total alpha and beta activity, followed by radionuclide and chemical analysis of selected samples. High total alpha activity was detected mainly in groundwater and was associated with radium mobilization. On average, ²²⁸Ra constituted between 50% and 60% of the total AED, whereas ²²⁶Ra contributed between 35% and 45%, with uranium isotopes contributing less than 5%. The total AED value for the groundwater ranged from 0.14 to 0.52 mSv/year at average water use, but only one borehole sample had 9.07 mSv/year, reflecting a localized anomaly. Additionally, arsenic, manganese, and mercury displayed high spatial variability. These findings underscore radium’s significant role in radiation exposure and emphasize the need for comprehensive monitoring of both radiological and chemical contaminants in groundwater systems. Full article

Pipe-jacking construction technology is favored in urban construction due to its advantages of high safety and being a non-excavation technique. However, instability of the tunnel face often occurs due to unfavorable conditions, such as pipe jacking across the river channel, shallow soil cover, and improper control of the support pressure. In this study, we made a use of the limit balance method and mud–water balance theory. At this moment of passive damage and active destruction occurring at the pipe-jacking tunnel face, the general mathematical expressions of the tunnel-face support pressure (with lower limit value P_min and upper limit value P_max) are derived. In the non-river impact area and river impact area, the optimal value P_o of support pressure at the tunnel face is thus derived. Then, based on the Y25-Y26 pipe-jacking project across the Chu River channel in Hefei North District, a numerical simulation method is used to support further discussion. The results indicate that, when the river overburden is 3 m, the ultimate support pressure calculated by means of numerical simulation is 881.786 kN, and the optimal support ratio $\mathsf{\lambda }$ is taken in the interval of 1.0~1.5. Secondly, the upper limit value P_max, lower limit value P_min, and optimum value P_o calculated using the theoretical equations are 2669.977 kN, 309.910 kN, and 1044.870 kN, respectively. These results leads us to recommend setting the support pressure of the tunnel face in a reasonable range between the upper limit value P_max and the lower limit value P_min, to ensure that the tunnel-face support pressure and resistance during pipe jacking always remain in a balanced state. The relevant research results from this study provide an important technical guarantee for the successful implementation of the examined project and, at the same time, can serve as a reference example for similar projects. Full article

Swimming is crucial to fish survival and reproduction, and is usually influenced by species, morphology, habitat environment and physiological condition. Understanding the changes in fish swimming ability and identifying the driving factors behind these changes is vital. In this study, seven endemic fish species from the Qingshui River, an important tributary of the upper Pearl River in Southwest China, were used to explore the effects of biological and environmental factors on fish swimming ability. The results indicated that the body length parameters had a minimal effect on the induced swimming speed (U_ind) but played a positive role in critical and burst swimming ability (U_crit and U_burst). Weight (W) and W/SL (the ratio of weight to standard body length) correlated more highly with swimming ability than body length parameters. Fish preferring the lotic environment exhibited higher U_crit and U_burst, and fish with a streamlined morphology had a smaller U_ind. The U_ind, U_ind/SL, U_ind/W and U_ind/(W/SL) of Discogobio yunnanensis (Regan, 1907) and Pseudocrossocheilus tridentis (Cui & Chu, 1986) were significantly higher during the spawning period. Acrossocheilus yunnanensis (Regan, 1904) performed better during the spawning period in U_crit and U_crit/SL. The U_burst of fish during the spawning period was smaller than that during the non-spawning period. Generally, the species difference had the greatest contribution to the swimming ability difference, followed by environmental conditions and fish morphology. Full article

Toponyms reflect the multifaceted relationship between humans and nature, recording and transmitting important cultural information. A toponymic cultural landscape (TCL) is the comprehensive embodiment of the cultural connotations and landscape significance carried by toponyms, reflecting various factors such as regional culture, historical memory, and social values. Wuhan, as the hinterland of Jing-Chu culture, carries a profound geo-culture and brings together numerous toponymic cultural heritages. Studying the spatial distribution characteristics of Wuhan’s toponymic cultural heritage and their association with landscape elements is of great significance in promoting the inheritance of intangible cultural heritage and realizing the orderly continuation of local culture, and it also confers deeper cultural connotations and local characteristics to the process of landscape characterization. This study analyzes 3638 toponyms in Wuhan as the research objects, utilizing geospatial analysis methods, including kernel density analysis, standard deviation ellipse analysis, and average nearest neighbor analysis, to visualize the spatial distribution of Wuhan’s TCL. It further combines these methods with the optimal parameter geographic detector (OPGD) model to explore the influence of landscape elements on the spatial distribution of different types of toponyms and their interaction effects. The results show the following: (1) The TCL of Wuhan is divided into two basic types, the natural landscape (61.16%) and the humanistic landscape (41.37%), of which hydrological-related toponyms occupy a significant proportion, reaching 35.02% of the total number of toponyms in Wuhan. (2) The distribution of Wuhan’s TCL is characterized by aggregation, mostly in the core area of the city, with the Yangtze River as the main axis, and the density of the spatial distribution of humanistic landscape toponyms varies greatly. (3) The results of a single-factor analysis show that construction land (X2) is an important influencing factor in both natural and humanistic landscape toponyms, which indicates the central role of human activities in the formation of toponyms. (4) The explanatory power of the interaction effect of two factors on the spatial differentiation of Wuhan’s TCL is stronger than that of the single factors, which suggests that the spatial differentiation characteristics of the TCL of Wuhan are formed under the joint influence of the respective variables. Full article

This research aimed to analyze the relationship between deforestation (DFT) and climatic variables during the rainy (CHU+) and less-rainy (CHU−) seasons in the Tapajós River basin. Data were sourced from multiple institutions, including the Climatic Research Unit (CRU), Center for Weather Forecasts and Climate Studies (CPTEC), PRODES Program (Monitoring of Brazilian Amazon Deforestation Project), National Water Agency (ANA) and National Centers for Environmental Prediction/National Oceanic and Atmospheric Administration (NCEP/NOAA). The study assessed anomalies (ANOM) in maximum temperature (TMAX), minimum temperature (TMIN) and precipitation (PREC) over three years without the occurrence of the El Niño–Southern Oscillation (ENSO) atmospheric–oceanic phenomenon. It also examined areas with higher DFT density using the Kernel methodology and analyzed the correlation between DFT and climatic variables. Additionally, it assessed trends using the Mann–Kendall technique for both climatic and environmental data. The results revealed significant ANOM in TEMP and PREC. In PREC, the highest values of ANOM were negative in CHU+. Regarding temperature, the most significant values were positive ANOM in the south, southwest and northwestern regions of the basin. Concerning DFT density, data showed that the highest concentration was of medium density, primarily along the highways. The most significant correlations were found between DFT and TEMP during the CHU− season in the Middle and Lower Tapajós sub-basins, regions where the forest still exhibits more preserved characteristics. Furthermore, the study identified a positive trend in TEMP and a negative trend in PREC. Full article

With the rapid development of IoT, big data and artificial intelligence, the research and application of data-driven hydrological models are increasing. However, when conducting time series analysis, many prediction models are often directly based on the following assumptions: hydrologic time series are normal, homogeneous, smooth and non-trending, which are not always all true. To address the related issues, a solution for short-term hydrological forecasting is proposed. Firstly, a feature test is conducted to verify whether the hydrological time series are normal, homogeneous, smooth and non-trending; secondly, a sequence-to-sequence (seq2seq)-based short-term water level prediction model (LSTM-seq2seq) is proposed to improve the accuracy of hydrological prediction. The model uses a long short-term memory neural network (LSTM) as an encoding layer to encode the historical flow sequence into a context vector, and another LSTM as a decoding layer to decode the context vector in order to predict the target runoff, by superimposing on the attention mechanism, aiming at improving the prediction accuracy. Using the experimental data regarding the water level of the Chu River, the model is compared to other models based on the analysis of normality, smoothness, homogeneity and trending of different water level data. The results show that the prediction accuracy of the proposed model is greater than that of the data set without these characteristics for the data set with normality, smoothness, homogeneity and trend. Flow data at Runcheng, Wuzhi, Baima Temple, Longmen Town, Dongwan, Lu’s and Tongguan are used as input data sets to train and evaluate the model. Metrics RMSE and NSE are used to evaluate the prediction accuracy and convergence speed of the model. The results show that the prediction accuracy of LSTM-seq2seq and LSTM-BP models is higher than other models. Furthermore, the convergence process of the LSTM-seq2seq model is the fastest among the compared models. Full article

Lacquered wooden sculptures of fantastic hybrid beasts adorned with real deer antlers are among the most extraordinary examples of sculpture found in Chu tombs dated from the sixth through the third centuries BCE. Conventionally known as zhenmushou 镇墓兽 or “protecting tomb beasts”, the antlered sculptures have grotesque features, including bulging eyes, fangs, and protruding tongues. In the fourth century BCE, production and use of these sculptures increased and peaked in the Hanxi region of Hubei province. Although most of these figures have been found in tombs in Hanxi (west of the Han River), distinctive variations of antlered tomb sculptures are also documented in regional areas of the Chu polity, including the Nanyang Basin, the Upper Huai, Eastern Hubei, and Jiangnan. Through a systematic regional analysis of Chu antlered sculptures, this paper presents a spatial framework for analyzing this unique genre of Chu funerary sculpture. This approach provides fresh insight into the interregional networks of interaction across the Chu state and beyond, via waterways and the Suizao corridor from the sixth through the third centuries BCE. Full article

Thanks to the large scope, high spatial resolution, and increasing data records, satellite-based precipitation products are playing an increasingly important role in drought monitoring. First, based on the data from ground sites, the long-term Multi-Source Weighted-Ensemble Precipitation (MSWEP) precipitation product was evaluated in respect to drought monitoring. Then, based on the MSWEP product, the drought trends and the spatiotemporal characteristics of the drought events in four major basins (Amu Darya Basin, Syr Darya Basin, Chu-Talas River Basin, and Ili River Basin) in Central Asia, which have relatively dense gauge sites, were studied. The Standardized Precipitation Index (SPI) and the run theory were used to identify drought events and describe their characteristics. The results showed that MSWEP can effectively capture drought events and their basic characteristics. In the past 40 years, the study area experienced 27 drought events, among which the severest one (DS = 15.66) occurred from June 2007 to September 2008. The drought event that occurred from June 1984 to October 1984 had a drought peak value of 3.39, with the largest drought area (99.2%). Since 1881, there appeared a drying trend and a wetting trend in the Amu Darya River basin and the Ili River basin, respectively. No obvious wetting or drying trend was found in both the Chu-Talas River basin and the Syr Darya basin. Since 2016, the drought area has been on the increase. Full article

The literary representation of China’s great rivers has repeatedly been transformed by changes in religious belief and ritual. In the Book of Songs, rivers figure primarily as political boundaries and figures of separation. Though they may already play a role in religious rites, their geographical identity is paramount. However, in the “Nine Songs” of the Elegies of Chu, they appear in a new guise as sites of divine encounter and shamanistic flight. Their treatment in later works may be regarded as a peculiar synthesis of these two traditions. Once the Four Waterways were designated as the object of state ritual in the Western Han, their divine status was widely accepted, along with explicitly political ramifications. For instance, the god of the Yellow River was honored as a participant in flood control and imperial governance writ large. Meanwhile, the tradition of the epideictic fu also celebrates the awesome scale of China’s waterways, reaching a culmination not long after the fall of the Han in Guo Pu’s (286–324) “Rhapsody on the Yangzi River”. However, it is noteworthy how often the fu tradition eschews material description of rivers in favor of celebrating their numinous powers and divine inhabitants. Because of this turn towards the divine in the medieval literary tradition, it is no accident that one of the most prominent subjects of fluvial verse in the Tang is not body of water at all but rather the Sky River, or Milky Way. Full article

The frequency of glacier lake outbursts floods (GLOFs) is likely to increase with the ongoing glacier retreat, which produces new glacial lakes and enlarges existing ones. Here, we simulate the outburst of a potentially dangerous glacial lake in Bhutan by applying hydrodynamic modelling. Although the lake volume is known, several parameters connected to the dam breach and the routing of the flood are rough estimates or assumptions, which introduce uncertainties in the results. For this reason, we create an ensemble of nine outburst scenarios. The simulation of magnitude and timing of possible inundation depths is an important asset to prepare emergency action plans. For our case study in the Mo Chu River Basin, the results show that, even under the worst case scenario, little damage to residential buildings can be expected. However, such an outburst flood would probably destroy infrastructure and farmland and might even affect the operation of a hydroelectric powerplant more than 120 km downstream the lake. Our simulation efforts revealed that, by using a 30-m elevation model instead of a 5-m raster, flood magnitude and inundation areas are overestimated significantly, which highly suggests the use of high-resolution terrain data. These results may be a valuable input for risk mitigation efforts. Full article