Rising rainfall intensity induces spatially divergent hydrological changes within a large river basin

Global warming is expected to intensify precipitation extremes, yet the specific effects on regional hydrology remain unclear. Prior research has shown that droughts and floods are often linked to precipitation anomalies. However, the mechanisms connecting these events within a single watershed are not fully understood. Recent droughts in China's Southwest and floods in the Southeast have raised concerns about climate impacts. These events suggest a need to explore how rainfall patterns influence hydrological responses. No prior work had resolved the interplay between rainfall intensity and topography in large watersheds. This gap motivated a detailed analysis of hydrometeorological variables over a 54-year period. The study focuses on the West River Basin in South China, a region experiencing contrasting hydrological trends. By examining spatiotemporal changes, the research aims to clarify the underlying causes of divergent soil moisture patterns.

The study aims to investigate the spatiotemporal changes in hydrometeorological variables within the West River Basin. It seeks to understand the mechanism behind contrasting soil dryness and wetness patterns. The authors focus on a 54-year period from 1965 to 2018 to capture long-term trends. They examine how rainfall intensity influences hydrological responses across the basin. The study addresses the lack of understanding of how climate change affects regional water security. It explores the interaction between rainfall intensification and topography. The goal is to clarify the relationship between drought and flood risks in a single watershed. The findings aim to inform climate adaptation strategies for water and food security.

The study uses a 54-year dataset of hydrometeorological variables from the West River Basin. It analyzes spatiotemporal changes in soil water storage, water yield, and baseflow. The researchers compare upstream and downstream responses to rainfall intensity. They employ statistical methods to detect trends over time. The analysis includes topographic variables to assess their influence on hydrological patterns. The study uses a representative mega-watershed to generalize findings. It distinguishes between contrasting hydrological behaviors in different regions. The approach combines observational data with climate projections to assess future risks.

The study finds that increasing rainfall intensity leads to upstream drying and downstream wetting. Soil water storage decreases in the upper basin but increases downstream. Water yield and baseflow show similar divergent trends. The most significant changes occur in the upper reaches of the watershed. Rainfall intensification interacts with topography to produce contrasting outcomes. The results suggest a simultaneous rise in drought and flood risks. The upstream region experiences reduced water availability. The downstream area sees increased hydrological activity.

The findings suggest that rainfall intensification interacts with topography to produce divergent hydrological outcomes. The study implies that climate change may increase both drought and flood risks simultaneously. The results highlight the vulnerability of water and food security in the region. The analysis supports the idea that rainfall patterns influence regional hydrology in complex ways. The study does not propose new adaptation strategies but emphasizes the need for localized responses. The results are specific to the West River Basin but may inform broader climate adaptation efforts. The authors suggest that continued climate change will exacerbate these risks. The study underscores the importance of understanding regional hydrological responses to climate change.