A robust regional soil moisture estimation method based on spatiotemporal two-stage data-driven models

The record of environmental and climatic change through the late Norian stage in paleoequatorial settings has so far received limited attention. Here we present new geochemical and sedimentological data to investigate the depositional and environmental changes through the late Norian into the earliest Rhaetian in the marine carbonate Milaha and Ghalilah Formation exposed in Wadi Milaha, Ras Al-Khaimah, UAE. The upper part of the Milaha Formation studied in Wadi Milaha, comprises sediments deposited in a shallow marine environment, with some evidence of high-energy shoal deposition. Restricted conditions are present in the basal and middle part of the Asfal member of the Ghalilah formation, followed by high diversity faunal content, indicating the development of open marine conditions in the late Norian-early Rhaetian. Development of the restricted conditions upwards suggests changes in the relative sea level. Our results show that the succession is comprised of regressive-transgressive cycles, which include minor depositional cycles influenced by changes in clastic input. Sedimentological and elemental data indicate fluctuations in clastic input throughout the sedimentary succession studied. The increase in siliciclastic input coincides with a major regressive sea level cycle during the middle-late Norian. Our results suggest that the increased coarse terrigenous input is likely due to enhanced weathering and an associated warming episode during the late Norian. Very low correlation of δ 13 C carb and δ 18 O indicates little diagenetic influence on the isotopic record. The δ 13 C carb records an overall negative trend during the middle-late Norian with small-scale fluctuations of −2.8‰ magnitude and coincides with increased clastic input. A small positive excursion in δ 13 C carb is recorded at the Norian-Rhaetian boundary. The observed variations in sedimentary succession, relative sea level, and bulk carbonate carbon isotopic record are similar to those of other Tethyan sections. This comprehensive and comparably high-resolution record very likely indicates far-reaching or global ecological changes during the middle-late Norian. • Study area occupied a paleo-equatorial position during the mid-late Norian • Sedimentological investigations allowed the interpretation of sea level cycles • Enhanced siliciclastic input suggest intensification of hydrological cycle • Comparison of the carbon isotope trends suggests ecological changes in late Norian

Global oxygen distributions at the Earth's surface.

The advancement of urbanization intensifies soil impermeabilization, alters the natural hydrological cycle, and increases the occurrence and severity of urban flooding. Mitigating these impacts requires adopting territorial planning strategies that reconcile urban densification with the preservation of permeable areas. This study aimed to identify and analyze the legal instruments that municipalities in Santa Catarina implemented to control and mitigate flood risk, examining their regulatory frameworks and providing a statewide overview. Its methodology consisted of documentary research in official and legal sources, including the collection and systematization of normative instruments and the identification of municipalities with specific regulations in place. This study also surveyed the mandated permeability percentages and other sustainable urban drainage strategies in municipal legislation. The results show that requiring minimum areas of permeable surfaces on urban lots is the primary regulatory mechanism, although more than 30% of municipalities still lack specific regulations on the subject. The wide variation in minimum permeability percentages also indicates the absence of unified technical criteria to guide the definition of these thresholds. This scenario reinforces the need for more consistent, integrated regulatory guidelines aligned with the principles of sustainable urban drainage and nature-based solutions.

Climate change intensifies the hydrological cycle, and reservoir responses to meteorological forces are vital for water sustainability, but long-term quantitative assessments remain scarce. In this study, we extracted the water surface area of Xinfengjiang Reservoir from 1990 to 2024 using multisensor Landsat/Sentinel imagery and a random forest classifier (RFC) on the Google Earth Engine (GEE) platform. Furthermore, we established an interpretable modeling framework that combined random forest regression with Shapley additive explanations (RFR-SHAP) to elucidate the nonlinear influences of meteorological drivers on multidecadal reservoir dynamics. The RFC model achieved high accuracy (OA = 96.90%, KC = 0.95) and efficiency (processing time = 1.17s per image), enabling the generation of a reliable 35-year time series dataset. Further analysis of the underlying mechanisms revealed that total precipitation (TP) was the most significant driving factor for the hydrological dynamics of reservoirs, with mean |SHAP| values for annual and monthly assessments recorded at 3.33 (16.15%) and 4.32 (20.36%), respectively. The synergistic and antagonistic effects of meteorological variables constituted the nonlinear adaptation mechanisms of reservoir systems to climate forcing. These findings quantify the hydrological dynamics and the driving mechanisms of meteorological variables on the water surface area of Xinfengjiang Reservoir, providing a basis for proactive reservoir operations based on precipitation forecasts.

Understanding drought and water availability requires integrating multiple components of the hydrological cycle. Satellite observations enable consistent monitoring of water storage, groundwater variability, and water budget components at continental scales. This study synthesises results from several satellite-based analyses to examine hydrological signals across Europe within the Köppen–Geiger climate zones. Indicators were analysed jointly, including the Combined Climatologic Deviation Index (CCDI), Water Budget (WB), Water Storage Deficit Index (WSDI), and Groundwater Drought Index (GDI). The comparison of these indices reveals consistent spatial and temporal patterns of water deficit across Europe, with the strongest drying signals observed in temperate and Mediterranean regions. In contrast, northern climatic zones show higher retention capacity. The integrated approach highlights relationships among groundwater variability, water storage anomalies, climate anomalies, and water budget dynamics, providing a broader perspective on hydrological responses to climate variability. The results demonstrate the value of multi-indicator satellite analysis for large-scale drought monitoring and water resource assessment.

Hydrovoltaic technology harnesses the ubiquitous and perpetual hydrologic cycle for solid–liquid interfacial energy conversion. However, contemporary hydrovoltaic systems exhibit multifaceted performance degradation, which includes dopant dissolution, destabilization of the electric double layer, and interfacial recombination. These factors collectively impair operational consistency and commercial viability. To address these limitations, we have developed sunlight-regenerable generators based on p-/n-type carbon nanotube (CNT) organic fabrics fabricated via scalable drop-casting techniques. The doped p-/n-type CNT organic fabrics facilitate photo-triggered recovery effects under AM 1.5 G irradiation (100 mW/cm2). Spectral and thermal analyses confirm that the recovery mechanism is primarily photo-triggered and is cooperatively assisted by photothermal effects, thereby restoring interfacial functionality. The system achieves markedly improved sustained voltage/current output, a higher peak power density of 16.46 μW at a 10 kΩ load resistance, and scalable integration with an output of 8.7 V from 20 serially connected units and 15.5 mA from 40 parallelly connected units. This work establishes a solar-hydro synergistic strategy for resolving the stability-compatibility dilemma in hydrovoltaic energy harvesting.

Abstract The Madden–Julian oscillation (MJO) produced by an idealized general circulation model (GCM) is studied. The model is a spectral dynamical core with a simple treatment of the hydrological cycle; MJO-like variability is induced by forcing zonal sea surface temperature gradients in the tropics using a prescribed ocean heat flux. Surface friction in the model is perturbed by altering the roughness length for momentum. The MJO weakens and eventually disappears entirely as the roughness length is decreased from its control value. The MJO is found to be sensitive to the roughness length in both the tropics and extratropics. Composite disturbances are constructed; the MJO has an associated vortex dipole straddling the equator. A similar vortex dipole exists when the roughness length is small, where disturbances have a closer connection to Rossby modes than to the MJO. In the lower- and midtroposphere, the main difference in the vorticity budgets of these two modes is in the rotational advection of vorticity, though the rotational terms are not dominant in the upper troposphere where the absolute vorticity is small. It is argued that greater nonlinearity relative to the mean rotational flow when the roughness length is large causes the transition of Rossby modes into the MJO. Connections to theories for the MJO which focus on the role of nonlinear Rossby wave dynamics are explored. Despite the strong influence on MJO variability, the statistics of the leading principal components of the velocity potential and the structure of the corresponding empirical orthogonal functions are insensitive to changes in the roughness length.

This study clarifies the hydrological cycle structure of the Pingjiang underground river system using hydrogeological mapping (1:50,000), tracer tests, automated groundwater monitoring, and RTK surveys. The obtained results indicate the following: (1) The Pingjiang underground river basin covers an area of 110.66km² and consists of five tributary conduits, forming a dendritic-network composite structure dominated by unilateral recharge; (2) The threshold rainfall required to generate surface runoff is around 20mm, which may exceed even 50mm under prolonged drought conditions. When the daily rainfall exceeds 50mm, the discharge at the underground river outlet increases significantly. The karst conduit system demonstrates a pronounced flood attenuation effect, capable of delaying the flood peak by up to 21h. (3) The flow dynamics at the sinking stream inlet and underground river outlet exhibit strong consistency. The discharge at the outlet ranges from 0.35m3/s to 25.57m3/s, displaying flashy characteristics. The Bujing sinking stream inlet contributes 18.86% of the annual runoff to the underground river. (4) The underground river has a baseflow runoff modulus of 3.21L/s·km2 during the dry season.

Hydrodynamically triggered landslides remain a major concern in reservoir regions, where the mechanisms controlling displacement evolution are still not fully understood and the multi-scale deformation responses induced by individual hydrodynamic factors remain difficult to quantify. To address these issues, this study establishes a TSD-TET composite framework by integrating time-series signal decomposition with deep learning for multi-scale displacement prediction and the mechanism-oriented interpretation of hydrodynamically triggered landslides. The monitored displacement sequence is first decomposed into physically interpretable components, including trend, periodic, and random terms. Each component is subsequently predicted using deep temporal learning models to capture different deformation characteristics at multiple temporal scales. Meanwhile, key hydrodynamic driving factors, including rainfall, reservoir water level, and groundwater level, are decomposed within the same framework to examine their statistical associations with different displacement components. The proposed approach is applied to the Donglingxin landslide located in the Sanbanxi Hydropower Station reservoir area. Results show that the model achieves high prediction accuracy under both long-term forecasting horizons and limited-sample conditions, with a cumulative displacement coefficient of determination reaching R2 = 0.945. Mechanism analysis further indicates that trend deformation is mainly controlled by geological structure and gravitational loading, periodic deformation is strongly modulated by hydrological cycles associated with reservoir water level fluctuations, and random deformation is more likely to reflect short-term disturbances and transient hydrodynamic forcing. These findings provide new insights into the deformation mechanisms of hydrodynamically triggered landslides and offer a promising technical pathway for improving displacement prediction, monitoring, and early warning of reservoir-induced landslide hazards.

Biological soil crusts (biocrusts) develop vertical redox-microbial-nutrient stratification that regulates hydrological and elemental cycles and contributes to ecological restoration in extreme environments, including mining regions. However, the roles of this heterogeneity in metal(loid) immobilization remain unclear, particularly in humid regions, where pronounced redox and microbial stratification may foster unrecognized stabilization mechanisms. We integrated physicochemical characterization with bioinformatic analysis to reveal stratified microbial communities and metabolic potentials in humid tailings biocrusts. Biocrusts exhibited stratified functionality through the upper photoautotrophic layer (PL) and the lower heterotrophic layer (HL). In the PL, Cyanobacteria and SWB02 formed a self-reinforcing oxygen barrier through clay-silt enrichment (2.8-fold higher than bare tailings sand) and extracellular polysaccharide accumulation (18-fold), which swelled upon hydration to physically hinder oxygen infiltration, confining Gammaproteobacteria-associated iron-manganese oxide immobilization to this layer. Beneath this barrier, the HL harbored sulfidogenic potential through microbes enriched in hydB (17.4-fold) and phsC (3.4-fold) genes, including Bacteroidota and Desulfobacterota, supporting a potential mechanism for metal(loid) sequestration via sulfide formation in underlying tailings, where sulfur occurred exclusively as sulfides at 5 cm depth. This barrier-mediated effect may outweigh metal(loid) immobilization within biocrusts. Our findings elucidate biocrust-mediated protection against metal(loid)s and provide theoretical support for remediation in humid mining regions.

ABSTRACT Soil moisture is critical for understanding the hydrological cycle and managing climatic extremes such as floods and droughts. This study evaluates the accuracy of satellite-derived soil moisture estimates from remote sensing satellite products Soil Moisture Active Passive (SMAP), Soil Moisture and Ocean Salinity (SMOS), and Advanced Microwave Scanning Radiometer-2 (AMSR-2) in the absence of ground observations. A selective fusion algorithm is introduced that enhances accuracy by fusing data only in regions where it improves the precision of soil moisture estimates, rather than applying a uniform fusion approach across all regions. Using Extended Triple Collocation (ETC) analysis, the error characteristics of individual satellite products are assessed across spatial, temporal, and meteorological aspects. Additionally, Mutual Information (MI) analysis with precipitation data quantifies the information content of each product to validate their effectiveness. Our results demonstrate that SMAP consistently exhibits the lowest error characteristics and highest information content. Notably, AMSR-2 shows superior performance in hot desert and semi-arid regions, highlighting the need for a spatially adaptive fused soil moisture product. An integrated fusion algorithm, guided by a decision map based on these analyses, optimizes the selection of soil moisture products across India’s diverse regions. This decision map revealed the highest spatial coverage by SMAP (62.5%), followed by AMSR-2 (25.7%) and SMOS (5.6%), with the remainder attributed to various combinations of products that provide superior soil moisture estimates in specific contexts. This modified fusion approach is implemented using a Linear Weight Fusion (LWF) technique, significantly enhancing the reliability of the resultant soil moisture product, particularly evident from its validation against data from three in-situ stations. The integrated approach not only refines the accuracy of satellite-derived soil moisture data but also provides a robust framework for enhancing hydrological model predictions, especially in drought monitoring.

Impacts of multiple reservoirs on hydrological cycle and hydrochemical evolution in a mountainous river basin of the North China Plain.

ABSTRACT Uptake and distribution of soil water by vegetation is a dynamic phenomenon, which is of utmost importance due to its role in the hydrological cycle and terrestrial productivity. Despite the significance, the soil water–vegetation interaction remains unexplored in large parts of the world, particularly in the tropical forested regions. This study, through measurements of oxygen isotopic compositions (δ 18 O) of water in different hydrological components, such as streams, xylem, groundwater, root and soil pore water, focused on understanding the eco‐hydrological connectivity during the dry season in a tropical humid forest (Western Ghats, India—a biodiversity hotspot). The results indicated that only 12% of the riparian trees primarily accessed stream water, and the dominant portion (36%) of the trees showed lower δ 18 O than the expected (sampled) sources, indicating access to an unsampled/deeper water source, probably accessed only during the summer season to withstand low plant water potential. We explain this isotopic difference by differential access to shallow, deep and redistributed soil water, providing insights into the contribution of multiple water sources to transpiration. Hydraulic redistribution (i.e., root‐mediated transport of deep water to upper soil layers) served as a critical water source for shallow‐rooted plants, helping them meet their water requirements during dry periods. Evidence for limited percolation of water into deeper soil due to quick filling of shallow soil pores during short and heavy precipitation events was noticed, highlighting the importance of continuous moderate rainfall for effective water percolation into the deeper soil.

Enhancing run-of-river hydropower capacity assessment through integrated time series flow regime modeling and continuous wavelet transform analysis.

Functional dynamics of fish assemblages in a tropical estuary during different phases of El Niño‒Southern Oscillation.

Unveiling fDOM dynamics in shallow lakes via a coupled "spectral-thermal" XGBoost-SHAP retrieval framework: Implications for water diversion management in Lake Honghu.

ABSTRACT Water remains the most critical limiting resource for the arid and semi‐arid China's Loess Plateau (CLP). Over the past three decades, large‐scale ecological restoration (ER) has significantly increased vegetation coverage but also altered the regional hydrological cycle. This study quantifies the spatiotemporal dynamics of water resource conflicts (WRC) by integrating multisource remote sensing data and the water balance equation, and predicts future trends (2021–2100) under CMIP6 climate scenarios. The results indicate that: (1) While vegetation greening has enhanced ecosystem services, it has intensified the trade‐off between ecosystem water use and human demand, contributing to a 30% reduction in average annual runoff from 2000 to 2020. (2) WRC has become prominent, with available water resources approaching sustainable limits in 2020, particularly in Central and Northern Shanxi and Northern Shaanxi provinces. (3) However, future projections under SSP2‐4.5 and SSP5‐8.5 scenarios suggest a turning point: benefiting from a predicted warmer and wetter climate, the intense WRC is projected to be alleviated by 2100. These findings reveal the nonlinear evolution of water scarcity and provide critical insights for adaptive water management in dryland restoration.

Unraveling future hydrological and sediment dynamics through an integrated GCMs-PLUS-SWAT coupling framework.

Abstract X‐ray amorphous materials (XAMs) are observed to be prevalent on the Martian surface, though their formation mechanisms remain unclear. In this study, we utilize mineralogical data from Zhurong, China's first Mars rover, to provide a deeper understanding of this issue. The shortwave infrared spectra revealed signals of Al‐OH near 2.20 μm, and signals of the vibrations of water molecules and hydroxyl in sulfates around 1.95 μm. These findings suggest the presence of clay and possibly Al‐bearing XAM along with sulfate. Comparative studies of analog samples from the western Qaidam Basin and brine soaking experiments present a mineral evolution model for the formation of XAM through clay‐brine interactions. In this model, evaporites crystallize within the interlayers of clay minerals, impacting their structural stability. Structural ions may be continuously released due to the attack of H + ions, forming XAMs as liquid water rapidly evaporates. These findings indicate that clay‐brine interactions could extend beyond the Martian southern hemisphere, highlighting the importance of carefully considering the ancient hydrologic cycle and the resulting post‐depositional impacts on surface minerals in salt‐weathering environments on Mars.