Understanding the influence of landscape characteristics and climate on water security in a mountain river basin: a case study in the Adige River basin (Italy)

Mountains are complex social-ecological systems and key components of the global hydrological cycle, acting as “water towers” that supply freshwater to downstream regions. These systems are increasingly exposed to global changes, including climate change, land abandonment and agricultural intensification, which threaten the stability and functioning of mountain ecosystems. Understanding how land-use change reshapes landscape structure and affects ecosystem resilience to climatic pressures and, consequently, the provision of water-related ecosystem services, is critical as millions of people rely on mountain water resources for their livelihoods and well-being.

Water quantity and quality are commonly assessed separately, despite being intrinsically linked. When both dimensions are considered, global water scarcity emerges as a more severe challenge than suggested by quantity-based assessments alone. In the EU, only 26.8% of surface waters currently achieve good chemical status, largely due to unsustainable land use and management, agricultural pressures and hydro-morphological alterations. These pressures are expected to intensify under future climate and land-use change, with potential impacts even on water bodies traditionally considered pristine.

This study examines how landscape composition and configuration, land-use intensity and climatic factors jointly influence water quality and availability in a mountain catchment, with particular attention to non-linear responses and tipping points. A three-step statistical framework is applied to: (i) identify the most influential landscape, topographic and climatic drivers of water quantity and quality; (ii) evaluate how these relationships vary under different climatic conditions; and (iii) detect threshold values in landscape metrics that are relevant for management and planning. The approach is tested in the Adige River basin, a large alpine catchment in Northern Italy, characterized by strong elevation gradients, heterogeneous land-use patterns and increasing climate and anthropogenic pressures.

By moving beyond simple land-use percentages, this work demonstrates the critical role of landscape configuration in shaping hydrological processes and ecosystem service provision. The results provide quantitative evidence to support integrated land and water management in mountain regions, contributing to a systems-level understanding of socio-ecological dynamics and offering actionable insights for enhancing water security and ecosystem resilience under ongoing and future global change.