Water is fundamental for our lives, society and ecosystems. In the next decades population growth is expected to amplify current pressures on water resources, intensify the stress on freshwater ecosystems and potentially increase environmental pollution and its impacts on human health and biodiversity in many regions of the world. These problems will be further exacerbated by global warming and the likely impacts of climate change in the water system, including more frequent and intense extreme events such as floods, heat waves or droughts, which are expected to have a significant impact on human lives and property, especially on most vulnerable populations.

Responding to these challenges requires a quantum leap in the way we observe, understand, and predict the evolution of the water cycle and its interactions with human activities and ecosystems.

In this decade ESA, several other space agencies and private organisations are developing a unique observation infrastructure in space, including an extraordinary and complementary suite of sensors on board Copernicus Sentinels series, ESA’s Earth Explorers, coming meteorological missions and different EO observation satellites planned to be launched by national space agencies and private operators in Europe.

This comes at a time where novel information and computing technologies, Artificial Intelligence, cloud computing and digital platform capabilities are opening the door to new and advanced ways to implement open science and develop novel applications and services.

The unprecedented potential for water science and hydrology of this exceptional set of capabilities is far from being reached and needs to be fully explored and exploited.

HYDROSPACE 2023 aims at bringing together the international EO and water science and the practitioners community to review the latest advances in the use of EO technology and tools for water cycle research and identify new opportunities and challenges that may drive future ESA science activities in the years to come.