Dear Colleagues,

Water in an integral part of human survival, energy and food production and maintaining sustainable development of natural ecosystem. With the impact of climate change, increase in population and conflicting demands, water availability in many catchments across the world has changed significantly. The demand of freshwater resources is growing, water quality and aquatic ecosystem health deteriorating and water stress and risk are increasing at the global and local scales. Therefore, the challenges in water resources research are to put forward new theories, develop new models, tools and systems, understand hydrological processes due to climate change that will safeguard access to clean water and managing water security for human populations and environmental water flow for ecosystems.

In this Issue focuses on some of these research challenges through exploring new models, tools and systems. Topics of interest may include, but not limited to, the following:

• Climate changes on water resources: What are the dynamics and      relationships between hydrology, aquatic ecosystems, land use and land      cover changes on landscape water balance and climate?

• Water security and assessment: How can the conflicting and      increasing demands of different water-user communities be reconciled      during scarcity and abundance?

• Hydrologic modelling: How the new models can represent the process      of non-stationarity, uncertainty and extreme events due to climate change,      in particular prolonged periods of droughts and floods?

• Data science and technology: How the new technologies (big data,      machine learning, earth observations) can be used to develop models and      systems that support better water management and planning decisions?

Please submit papers addressing the research topics mentioned above. Your papers will go through peer-review process before publishing. We look forward to receiving your contributions.

Dr. Mohammed Bari

Section Editor