Why is arid zone hydrology a scientific desert - and how does the hydrological community move forward?

Abstract

While the world's hot arid climates are, by definition, water stressed, many of these regions face existential challenges as population growth, economic development and climate change exacerbate both the natural water scarcity and the risks from extreme flood events. A strong science base and effective modelling tools are needed for effective water management but hydrological processes in these regions remain poorly understood and quantified. This personal reflection aims to answer the key questions: What are the challenges for hydrological science in hot desert zones, why have they arisen, and how should the hydrological community move forward to address them?

There remains a critical need for: a) high quality observational basins across the arid regions to provide consistent long-term data and a platform for detailed experimental work to elucidate critical processes, b) improved quantification of spatial rainfall, infiltration into desert soils and groundwater recharge from ephemeral flows, c) integrated assessment of stream-aquifer interactions, and d) modelling tools that recognize uncertainty in process representation and parameterization. We note the potential for remote sensing to provide new insights, particularly in data-scarce areas, and stress the importance of traditional knowledge and stakeholder engagement in water management for these highly stressed regions.