The changes in the natural-artificial dualistic water cycle system have triggered the inconsistency of hydrometeorological time series. Continuing to use traditional frequency calculation methods would affect the accuracy of water resource planning and flood-drought management decisions, underscoring the need for (in)consistency testing before performing hydrological calculations. To address the misjudgement issues of current methods, this study proposes a hydrological (in)consistency testing method (CT) based on correlation coefficients. The CT method applies a discrete wavelet transform to extract high-frequency pure random components from the original time series, then calculates the correlation coefficients between these components and the original time series to determine (in)consistency. Statistical experiments indicate that the CT method significantly reduces false positive rates compared with traditional methods like the Bartels test. Its accuracy and stability improve as the time series length increases, making it especially effective at identifying inconsistent time series. These promising results confirm that the CT method is a valuable tool in (in)consistency test, ensuring robust and reliable outcomes. A case study of the surface water resources amount modulus coefficient time series of 10 major river basins in China (1956-2020) shows that surface water resources in the Southeastern, Yangtze, Huaihe, Pearl, and Southwestern river basins are consistent. In contrast, the Songhua, Haihe, Yellow, Liaohe, and Northwestern river basins display pronounced inconsistency characteristics. Existing studies, based on external driving factors such as climate change and human activities, have validated the inconsistency of hydrological time series in regions like the Songhua River Basin, indirectly confirming the effectiveness of the CT method. For consistent time series, consistent hydrological frequency analysis can be directly applied, whereas for inconsistent time series, researchers should analyze the characteristics of inconsistent components or conduct inconsistent hydrological frequency calculations. These approaches aim to predict and plan for potential risks, thereby providing robust support for scientific water resource management decisions.

This study systematically investigates the impact of elevated atmospheric CO₂ on streamflow at the global scale, using control experiments from the TRENDY project, a coordinated ensemble of global dynamic vegetation models. These models incorporate key processes such as vegetation growth, carbon uptake, and water use under changing CO₂ conditions. Our analysis reveals that the majority of global dynamic vegetation models simulate an increase in streamflow under elevated CO₂, driven by vegetation-mediated mechanisms such as reduced stomatal conductance. This effect is particularly pronounced in tropical, cold, and temperate regions. To evaluate the reliability of these modeled responses, we further employed an observational-based approach that isolates CO₂-vegetation-induced streamflow changes using a fully differential method. This method was applied to 1116 catchments that are minimally impacted by human activities. These observational results were then compared with the modeled outputs. Our findings show that most global dynamic vegetation models consistently project increased streamflow under elevated CO₂ levels, which tend to overestimate the magnitude of this increase, especially in temperate forest and cold forest regions as well. Notably, nine out of the fourteen models exhibit an average absolute overestimation exceeding 20% in these catchments. These findings point to notable discrepancies between model simulations and observation-based estimates. They highlight the need to improve and validate global dynamic vegetation models, especially regarding their responses to atmospheric CO₂ changes. Enhancing the reliability of such models is essential for accurate assessments of future water resources and climate change impacts.

A comparative analysis of the brGDGTs distribution, their variations with altitude, and the dispersion in the surface sediments of the Kelan River in the southern Altai Mountains and the adjacent topsoil (all samples were collected in July 2018), indicates that the brGDGTs of the river sediments are primarily derived from autochthonous sources, rather than from allochthonous inputs. The MBT'_5ME index, which is calculated based on brGDGTs and is widely used for temperature reconstruction, shows a variation of only 0.07 in the surface sediments of the Kelan River over a vertical altitudinal gradient of 1735 m (from 702 m to 2437 m). The variation of MBT'_5ME, represents a temperature variation of no more than 2.5 ℃ and is significantly smaller than the actual air temperature variation (around 11.1 ℃), indicating that the MBT'_5ME index in the surface sediments of the Kelan River cannot be used for air temperature reconstruction and is more likely to represent the temperature changes of the river water itself. Since meltwater from ice and snow is a significant water source for the Kelan River, the autochthonous brGDGTs in surface sediments of the river are likely to be strongly influenced by it. Therefore, we propose that in high-altitude or high-latitude regions, the temperature changes in geological archive caused by ice and snow meltwater can directly affect the distribution of autochthonous brGDGTs. This, in turn, impacts the reliability of "air temperature" reconstructions based on brGDGTs indices. This understanding highlights the importance of fully considering the impact of meltwater on sedimentary environment when using brGDGTs for paleotemperature reconstructions, and it provides valuable insights for future brGDGTs-based research in high-altitude or high-latitude regions.

The loess in arid-semiarid regions is facing soil erosion under climate change and human activities. Quantitative assessment of surface erosion in loess region is of great significance for understanding environmental change and achieving sustainable development goal. There is a large area covered by loess in Tajikistan with serious soil loss, but the study is relatively less. Utilizing remote sensing data produced by Landsat 8 and Random Forest algorithm, based on the field investigation and Google Earth Engine (GEE) platform, this study identified the loess accumulation area in Tajikistan, quantitatively studied the temporal and spatial characteristics of surface erosion rate in Tajikistan's loess regions. The loess in Tajikistan is mainly distributed in Afghan-Tajik Basin, along Zarafshan River, and lowlands north of Alai Mountains, covering an area of approximately 37400 km². The RUSLE model was used to evaluate the surface erosion rate in the loess regions of Tajikistan from 1901 to 2023, in which the area of weak erosion accounted for the most 44.96%, 16.68% of the area was near the tolerable erosion rate (250-750 t·km^-2·a^-1 ), and the area of intense erosion or above accounted for 14.25%. Geomorphology has a significant effect on the surface erosion intensity. Erosion rate of loess in plain area is lower, while that of mountain area is higher. The average soil erosion rate from 1901 to 2023 was 1690.99 t·km^-2·a^-1, showing a fluctuating upward trend, and the erosion rate increased by 708.77 t·km^-2·a^-1. The areas with weak and slight erosion are decreasing, while the areas with stronger erosion are increasing. By comparing different loess sedimentary regions in the Northern Hemisphere, it is found that the modern soil erosion rates in the Loess Plateau of China and the Great Plain of the United States are decreasing significantly after the implementation of ecological restoration and soil conservation projects. Therefore, in the case of increasing surface erosion in the loess regions of Tajikistan, appropriate soil and water conservation policies should be formulated and implemented in the study area and other arid-semiarid regions, taking into account both the restoration of the natural environment and the needs of human production and life, so as to achieve the Sustainable Development Goals.

Characterized by its distinct river-lake topology and watershed geomorphology features, the Endorheic Qiangtang Basin is an essential component of the Qinghai-Xizang Plateau (QXP). However, the shortage of high-precision watershed and river system data has hindered a thorough understanding of the hydrological structure and fluvial geomorphology characteristics in this region. With the application of an innovative extraction method, a high-precision watershed and river system dataset within the Endorheic Qiangtang Basin is developed. This dataset enables an analysis of the spatial distribution of endorheic rivers and associated geomorphological features in this region. Furthermore, the spatial correlations between the endorheic river development and watershed geomorphology, climate conditions, and hydrological inputs are systematically examined. The results show that the Endorheic Qiangtang Basin comprises approximately 430 independent sub-watersheds and 1373 endorheic rivers with catchment areas exceeding 50 km². The average length of endorheic rivers is 32.62 km and the erosion base levels predominately concentrate between 4000 and 5000 m in elevation. Based on sub-watersheds as statistical units, the average drainage density is calculated as 0.10 km/km², and the average weighted river longitudinal gradient is 5.56‰. The river longitudinal profiles predominantly display slightly concave to nearly linear shapes throughout the study area. Compared to climate conditions and hydrological inputs, watershed area and geomorphological attributes exert a more significant influence on river development in the Endorheic Qiangtang Basin. A larger watershed area is beneficial to the development of larger river networks and concave river longitudinal profiles, and watersheds with greater elevation drop and gradient have steeper river longitudinal profiles. This study provides insights into the spatial distribution, development characteristics, and influencing factors of the endorheic rivers on the QXP. The findings provide basic data and regularity characteristics of river geomorphology, contributing to further research on earth surface processes of the Qinghai-Xizang Plateau under the background of climate change.

The joint operation of cascade reservoir systems significantly influences river sediment dynamics and geomorphological changes, particularly in downstream hubs that are critical for understanding riverbed channel evolution. This study focuses on a 108 km stretch of the Hanjiang River downstream of the Xinglong Hydraulic Hub, analyzing runoff, sediment, and topographic data from 1977 to 2023. We investigate the characteristics of riverbed scouring/deposition intensity, bar-pool distribution, cross-sectional morphology, flow conditions from normal to low-water levels, and autumn flood processes. The results reveal that: (1) Following the joint operation of the South-to-North Water Diversion Project and the Xinglong Hydraulic Hub, with reductions in runoff and sediment transport of 11.42%-15.40% and 69.2%-73.9%, the proportion of flow levels between 500 m³/s and 800 m³/s at Xinglong Station increased from 21.10% (1980-2013) to 43.12% (2014-2023). (2) From 1977 to 2023, the total erosion volumes in the low-water and bankfull channels from Xinglong to Xiantao reaches were 1.24×10⁸ m³ and 1.57×10⁸ m³, with 78.52% of the riverbed scouring concentrated in the low-water channel. (3) From 1977 to 2016, the riverbed exhibited a "uniform scouring of bars and deep-water channel" pattern, which shifted to a "deep-water channel scouring and lower-bar deposition" pattern from 2016 to 2023, indicating that navigation projects have stabilized the lower-bars and deep-water channel. (4) During 2014-2023, flow conditions from normal to low-water levels showed a decreasing trend downstream of the Xinglong Hydraulic Hub, influenced by riverbed scouring, navigation engineering, and flow processes. This resulted in a synchronous reduction in the differential between normal and low-water levels near the dam and the riverbed in deep-water channel. (5) The decrease in sediment content transport is the primary driver of riverbed scouring in the low-water channel from Xinglong to Xiantao reaches, followed by waterway management project, with runoff having the least impact. During 2016-2023, the contributions of these factors to riverbed scouring were 63.33%, 25.79%, and 10.88%, respectively. Additionally, the relative increase in autumn flood intensity has intensified riverbed scouring. This study enhances our understanding of how the operation of large-scale hydraulic hubs and waterway management projects impact downstream riverbed evolution and water level fluctuations.

Global warming has led to a significant shrinkage of the cryosphere over the Qinghai-Xizang Plateau, affecting the water quality and safety of the river source area. To assess these impacts, 126 river water samples were collected from the Buqu River Basin located at the source of the Yangtze River during June-October of 2021 and 2022. The chemical characteristics and controlling factors of river water were analyzed across different underlying surface basins using methods such as the Piper trilinear diagram, Gibbs diagram, correlation analysis, and the ion ratio assessment. Results indicated that: (1) The total dissolved solids (TDS) values of river water in the study area were higher at the downstream than those of the upstream. The hydrochemical composition differed with varying underlying surface coverages. The Dongkemadi Basin, with a higher proportion of glacier coverage, exhibited Ca²⁺ and HCO₃^- as the primary hydrochemical ions. In contrast, other basins with lower glacier coverage exhibited water chemistry types primarily characterized by HCO₃^-·SO₄^2--Ca²⁺·Mg²⁺and $HC{O}_{3}^{-}$·$S{O}_{4}^{2-}$-Ca²⁺·Mg²⁺·Na⁺. (2) A negative correlation was observed between ion concentration and runoff, likely due to dilution effects. (3) The Gibbs diagram indicated that rock weathering was the primary factor influencing ionic concentration in river water samples. Based on the ion ratio analysis, the Buqu Basin was concluded to be mainly influenced by the weathering of silicate rocks, with contributions from carbonate rocks and sulfuric acid interactions. Furthermore, the railway station basin was mainly influenced by evaporite and carbonate rocks, while the river water in the upstream Dongkemadi Glacier basin was predominantly affected by carbonate rocks. (4) The forward geochemical model calculations revealed that the carbonate rocks accounted for 73.2% of the cation sources in the Dongkemadi Basin, followed by silicate and evaporite rocks, with precipitation showing the least influence. (5) The ionic concentrations of river water at the outlets of the Buqu and Dongkemadi basins exhibited a significant negative correlation with temperature. This indicates that in the context of global warming, changes in glacier permafrost may affect the chemical composition of river water in the cryosphere watershed, and consequently impact the water quality and safety of the river source area. These findings provide a scientific basis for the protection of the ecological environment and the development and utilization of water resources in the river source area.

The correlation between environmental shifts and agricultural progress during the Neolithic and Bronze Ages has garnered significant attention. The Xingyang basin stands out as a pivotal region in the genesis of Chinese civilization and early agricultural practices. Nevertheless, the connection between the spatiotemporal evolutionary trends in Neolithic to Bronze Age agriculture within the Xingyang basin and alterations in hydrogeomorphic environments remains obscure. This study focuses on reconstructing the historical distribution of lakes in the Xingyang basin at four distinct time points (~8000 BP, ~6000 BP, ~4500 BP, and ~3600 BP), utlizing two dated limnological profiles along with age and elevation data sourced from existing limnological records. Subsequently, in conjunction with available plant flotation data, we investigate the interplay between the sptiotemporal distribution patterns of agriculture and hydrogeomorphic conditions. The results show that: (1) Around 8000 a BP, lakes within the Xingyang basin were abundant, peaking approximately 6000 a BP. Subsequently, there was a significant reduction in lake size around 4500 a BP, with further diminishment and fragmengtation into smaller bodies of water by 3600 a BP. (2) During the Neolithic and Bronze Ages, the Xingyang basin adopted an agricultural framework centered on foxtail millet (Setaria italica), broomcorn millet (Panicum miliaceum) and rice (Oryza sativa). Millet-based agriculture prevailed in the surrounding hilly regions throughout the Neolithic and Bronze Ages, while the alluvial plains witneessed a mixed millet-rice cultivation. Nevertheless, transitional zones between the alluvial plains and adjacent hills experienced shifts in crop structure, alternating between millet agriculture and mixed cultivation of millet and rice across different periods. Integration of paleoclimate reconstruction data from neighboring areas reveals that the Yangshao culture era witnessed the most extensive distribution of Holocene lakes in the Xingyang basin. Notably, rice cultivation extended beyond the plains to encompass mountainous regions and certain loess terraces in proximity to the plains, representing the broadest dissemination of rice during the Neolithic-Bronze Ages. The hydrogeomorphic conditions during the Neolithic and Bronze Ages exerted discernible influence on regional agricultural evolution.

Water resources are a crucial component of the water-energy-food (WEF) nexus, making it essential to analyze the pressures faced by the WEF nexus from a water resource perspective. However, few studies have examined how China's interprovincial trade affects local WEF nexus water consumption and pressure from a regional trade viewpoint. This study first accounted for provincial WEF water use inventories and then used multi-regional input-output modeling and SSP-RCP multi-scenario analysis to assess consumption-driven water use, external water pressure contributions and pathways, and future changes in embodied water use in provincial WEF nexus. The results show that the blue water footprint embedded in domestic trade within the national WEF nexus accounts for 43% of water use in the energy and food sectors and 25% of total water withdrawals. Guangdong, Zhejiang, Jiangsu, Henan, and Beijing are the five provincial-level regions (hereafter province) with the highest embodied water flow. With regard to external impacts on water resources, the external contribution to Shanxi's water pressure is primarily driven by the energy sector, while in other provinces, it is predominantly driven by the food sector. Among provinces facing high water pressure, Inner Mongolia, Xinjiang, Gansu, Hebei, Ningxia, and Liaoning have external contributions ranging from 30% to 50%. In most of the cases, water consumption in the energy sector is higher for high-risk provinces than for low-risk ones, while the opposite is true for the food sector. By 2030 and 2050, in various scenarios, the implicit water flow in most provinces will be 1.3 to 1.6 times higher than the baseline, with an increasing trend in high-risk water pressure pathways, especially in the energy sector. This study underscores the primary modes of water pressure transmission in interprovincial trade and explores two-way mitigation measures on both the supply and consumption sides. Indigenous water conservation measures and more rational trade structures in high water-scarce provinces are essential for the integrated management of water resources and the sustainable supply and production of critical resources.