Karst springs respond quickly to environmental changes, making them crucial to understanding climate impacts on groundwater. This study analyses long-term trends in precipitation, temperature, and discharge from more than 50 springs across Europe. Results show that while historical discharge trends align with those of rivers, recent changes are driven by rising temperatures rather than precipitation. These findings highlight climate-driven shifts in groundwater recharge and storage processes.

Seasonal streamflow forecasts for snowmelt-dominated catchments often rely on snowpack data, which are not always available and are prone to errors. Our study evaluates near-real-time global snow estimates and climate oscillation indices for predictions in the data-scarce mountains of central Asia. We show that climate indices can improve prediction accuracy at longer lead times, help offset snow data uncertainty, and enhance predictions where streamflow depends on in-season climate variability.

We introduce a novel method for improving daily precipitation maps in mountain regions and pilot it across three basins in the Hindu Kush Himalaya (HKH). The approach leverages climate model and weather station data, along with statistical or machine learning techniques. Our results show that this approach outperforms traditional methods, especially in remote ungauged areas, suggesting that it could be used to improve precipitation maps across much of the HKH, as well as other mountain regions.

Urban flooding can be driven by rain and storm surge or the combination of the two, which is called compound flooding. In this study, we analyzed hourly historical rain and surge data for New York City to provide a more detailed statistical analysis than prior studies of this topic. The analyses reveal that tropical cyclones (e.g., hurricanes) have potential for causing more extreme compound floods than other storms, while extratropical cyclones cause less extreme, more frequent compound events.

This study enhances irrigation modeling in the Common Land Model by capturing the full irrigation process, detailing water supplies from various sources, and enabling bidirectional coupling between water demand and supply. The proposed model accurately simulates irrigation water withdrawals, energy fluxes, river flow, and crop yields. It offers insights into irrigation-related climate impacts and water scarcity, contributing to sustainable water management and improved Earth system modeling.

Machine learning is playing an increasingly important role in hydrological modeling. In this paper, we introduce an adaptation of existing machine learning models for simulating streamflow in river basins, redesigning them with the goal of integrating them in climate models. We demonstrate the effectiveness of our adapted model by showing that it outperforms a physics-based river model. These results motivate further studies of the use of machine-learning-based river models inside climate models.

Camera-based rainfall observation can measure rainfall with high spatiotemporal resolution and low cost. This study proposed a method for estimating rainfall intensity from images using the relationship between image information and rainfall intensity. The method was applied to outdoor cameras, and rainfall intensity could be estimated from the images. The method has the potential to facilitate the development of a camera-based rainfall observation technology that is accurate and versatile.

Propagation from meteorological droughts to agricultural droughts under climate change is analysed in the monsoon-dominant Asian regions. Next, the persistence of such agricultural droughts across seasons in a water year is determined. Finally, the spatial concurrence of monsoonal agricultural droughts across regions has been estimated. South Asia and eastern China are projected to experience intensified future drought propagation and spatial concurrence.

The glacier-expanded SWAT (Soil Water Assessment Tool) version, SWAT-GL, was tested in four different catchments, highlighting the capabilities of the glacier routine. It was evaluated based on the representation of glacier mass balance, snow cover and glacier hypsometry. The glacier changes over a long timescale could be adequately represented, leading to promising potential future applications in glaciated and high mountain environments and significantly outperforming standard SWAT models.

It is challenging to investigate flood variabilities and their formation mechanisms from massive event samples. This study explores spatiotemporal variabilities of 1446 flood events using hierarchical and partitional clustering methods. Control mechanisms of meteorological and physio-geographical factors are explored for individual flood event classes using constrained rank analysis. This gives insights into comprehensive changes in flood events and aids in flood prediction and control.

Understanding hydrological variability is essential for ecological conservation and sustainable development. Evapotranspiration influences the carbon cycle, and finding what causes its variability is important for ecosystems. This study shows that ENSO (El Niño–Southern Oscillation) influences not only South America’s rainfall, soil moisture, radiation, and evaporation but also other phenomena in the Atlantic Ocean. The impacts change regionally depending on the season analysed and have implications for heat extremes.

Impact Webs are a conceptual risk modelling tool designed to better understand and characterise complex risks. Understanding the complexity of risks is a key step in reducing and managing disaster risks. This paper outlines the rationale for Impact Webs and the steps for their co-creation and use. Impact Webs allow for an in-depth analysis while accounting for interactions within the systems in which they exist. They can be used to provide guidance for risk management options.

The unclear feedback loops of water supply–hydropower generation–environmental conservation (SHE) nexuses with inter-basin water diversion projects (IWDPs) increase the uncertainty in the rational scheduling of water resources for water receiving and water donation areas. To address the different impacts of IWDPs on dynamic SHE nexuses and explore synergies, a framework is proposed to identify these effects across the different temporal and spatial scales in a reservoir group.

We present a robust method for identification and classification of global land drought events (GLDEs) based on soil moisture. Two models were used to calculate soil moisture and delimit soil drought over global land from 1980–2022, with clusters of 775 and 630 GLDEs. Using four spatiotemporal and three motion-related characteristics, we categorized GLDEs into seven severity and seven dynamic categories. The frequency of GLDEs has generally increased in recent decades.

The study assesses the Global Precipitation Climatology Centre (GPCC) and Global Precipitation Climatology Project (GPCP) precipitation products by estimating hydrological drought recovery time (DRT) using satellite gravimetry data, Jet Propulsion Laboratory mass concentration solution (JPL mascon), and Global Gravity-based Groundwater Project (G3P) terrestrial water storage (TWS) products. The findings reveal that DRTs from GPCC and GPCP are comparable, and JPL mascon shows longer DRT, while G3P demonstrates greater consistency. These results contribute to a deeper understanding of precipitation and water storage dynamics and are essential for meteorological and hydrological research.

In the real hydrological Earth system, the relationships between variables are not constant. This study employed advanced statistical models, incorporating physical mechanisms to examine how evaporation stress responds to key factors over time. We found that stronger soil drought effects can be expected in areas undergoing rapid greening. This study may enhance the comprehension of evaporation stress, help optimize parameters in Earth system models, and promote greening initiatives.