Editorial: Monitoring and Modelling of Runoff and Soil Processes in River Basins

Abstract

A major theme emerging from this collection is the increasing value of integrated monitoring, particularly in basins where field observations remain sparse or uneven. Remote sensing (RS), GIS-based analysis, and network-based metrics feature prominently across several articles, emphasizing how modern observational tools can reveal spatial-temporal complexity that conventional measurements often miss. This is exemplified by work on ecosystem service flows in the Yangtze River Basin, where network analysis uncovers long-term shifts in ecological and socio-economic linkages across 2010-2023, demonstrating how basin-scale monitoring now extends well beyond physical hydrology alone (Wang et al, 2025b).Complementing observation, the Topic highlights strong advances in hydrological and hydro-geomorphic modelling, with several papers demonstrating how hybrid modelling strategies enhance understanding of runoff generation, sediment mobility, and subsurfacesurface water interactions. A key contribution comes from the study on hyporheic-zone groundwater modelling, which incorporates stochastic representations of aquifer parameters to address their inherent heterogeneity. This approach markedly improves the accuracy of groundwater-river exchange simulations in the Huaihe River Basin, offering a robust pathway to strengthen subsurface components of watershed models (Wang. et al., 2024).Land-use change and its cascading impacts on hydrological processes represent another core thread running through the Topic. The Rwanda Hydro-Unity Network case study provides a compelling example: three decades of land-use/land-cover (LULC) transformationcharacterized by rising cropland and built-up area and declining forest cover-have substantially altered the basin's hydrological balance. The authors show increased surface runoff and evapotranspiration alongside reduced groundwater recharge (Hakorimana et al., 2025), with implications for drought exposure and seasonal water deficits. These findings underscore the need to integrate land management, water planning, and climate-adaptation strategies in regions experiencing rapid demographic and landscape change.Two additional contributions deepen our understanding of soil erosion and sediment dynamics, central components of watershed functioning. The comparative study in the Daqing River Basin provides a spatially resolved analysis of erosion processes across mountainous and lowland environments, revealing how physiographic differences shape erosion intensity and sediment pathways (Wang et al 2025a). Meanwhile, research from the Datong River Basin links LULC patterns to broader ecological effects, emphasizing that soil and vegetation transitions directly mediate hydrological and geomorphic responses (Li et al 2025). Together, these papers highlight why sediment-related processes must remain central in basin management, from reservoir sustainability to flood risk mitigation.The Topic also includes a methodological contribution that broadens the disciplinary scope of basin assessment. The Yuanshui River Basin study introduces a spatial-quality evaluation framework-using semantic differentials and entropy weighting to characterize how human perceptions and landscape attributes intersect with environmental processes (Wang et al 2025). Although distinct from hydrological modelling, this perspective is vital: socio-spatial conditions influence land-use decisions, water management acceptance, and the implementation of conservation interventions. Integrating such human-environment dimensions enhances the relevance and applicability of hydrological insights.Finally, the accepted article on estuarine channel evolution links changes in water and sediment regimes to morphological adjustments in tidal-fluvial transition zones (Su et al., 2026). Estuaries are critical nodes in sediment continuity, ecological productivity, and navigation. By identifying mechanisms and discriminating among morphodynamic responses, this research provides essential context for understanding downstream consequences of altered runoff and sediment inputs topics intimately connected to upstream land-use alterations and climate-driven hydrological extremes.Taken together, the seven articles provide a cohesive illustration of how multi-scale, multi-disciplinary approaches are needed to understand and manage river basins effectively. They show that monitoring and modelling of runoff and soil processes must now integrate: • Surface and subsurface process interactions, including groundwater-river exchanges; • Long-term land-use transitions, urbanization, and associated hydrologic shifts; • Ecosystem service flows, socio-spatial change, and landscape-planning connections;• Sediment dynamics, erosion patterns, and geomorphic adjustments; • Advanced computational methods, including stochastic modelling and RS-driven analytics.Across diverse geographic settings from East Africa to East Asia these studies reaffirm that hydrological processes are tightly interwoven with social, ecological, and geomorphic systems. The findings collectively advance the Research Topic's central aim: to deepen understanding of watershed soil and water process evolution under combined human and climatic pressures, and to support improved prediction and management across scales.As editors, we view this collection as a meaningful step toward more integrated, resilience-oriented watershed science. Future research directions highlighted across the Topic include: the need for tighter fusion of RS datasets with hydrological and geomorphic models; expanded treatment of uncertainty and stochasticity in process representation; and improved modelling of human-water feedback, particularly under rapid land-use or climate transitions. These priorities align with global calls for enhanced predictive capability in support of flood management, soil-conservation planning, ecological restoration, and water-resource governance.