The Global Centre for Risk and Innovation (GCRI)
Water science studies how water moves through the atmosphere, land, rivers and aquifers, and how people capture, treat, use and return it. As a risk field it asks a sharper question: how failures in water availability, quality or services travel into human health, energy, food and the economy. This page defines the field, explains why it matters, sets out what experts study and shows how it connects to other risks.
The Water Nexus field covers the interdependence of water services, watersheds, human health, energy, food and economic resilience. Experts in it study questions such as catchment hydrology and groundwater and aquifers, with methods such as hydrology and water science as well as water and environmental engineering. Its counterparts at GRF and GRA look at the same systems through governance and finance.
Fig.How GCRI, GRF and GRA share one field while the authorities decide. Design, not a record.
The working screen behind this subject: its structure, terms and states. Names are placeholders and values illustrative.
Precipitation, evaporation, infiltration, runoff and recharge, studied through hydrology and water science.
Abstraction, treatment, storage, distribution and sanitation, studied through water and environmental engineering.
Gauges, wells, satellites, models and statistics, with uncertainty quantification to state confidence.
The field joins hydrology, the physical science of the water cycle, with water and environmental engineering, the design and operation of the systems that store, treat and distribute water and carry away wastewater. It draws on climate science for changing precipitation and evaporation, on ecology for the freshwater ecosystems that regulate flow and quality, and on public health for the burden of unsafe water and poor sanitation.
What makes it a risk field is the focus on consequences under stress. A water balance that closes on average can still fail in a dry season, a contaminated well can affect a whole town, and a single substation outage can stop the pumps that supply a city.
Safe water and sanitation underpin public health. Agriculture is the largest user of freshwater in most regions. Thermal power generation needs cooling water and hydropower needs flow. Industry, cities and ecosystems all compete for the same resource.
How much water is there, where and when, and how is that changing? See Catchment hydrology and Groundwater and aquifers.
How likely are droughts and floods, and what can forecasts tell us? See Drought and flood.
Are water and sanitation services safe, continuous and fairly distributed? See Drinking water and sanitation and Water utilities.
How is evidence produced and used where basins cross borders or jurisdictions? See Shared river basins.
How do water, energy, food and ecosystems constrain each other? See Water and energy interdependence and Water, food and ecosystem links.
Each term as this page uses it. Where a standard-setting body defines the term, the wording follows that body.
| Term | Definition |
|---|---|
| Integrated water resources management | A process that coordinates the development and management of water, land and related resources across sectors and levels of government; SDG indicator 6.5.1 tracks how far it is implemented. |
| Environmental flows | The quantity, timing and quality of freshwater flows needed to sustain river, wetland and estuarine ecosystems and the livelihoods that depend on them. |
| Return period | The average interval between events of a given size, equal to the inverse of the annual exceedance probability; a one-in-a-hundred-year flood has a one in a hundred chance of being exceeded in any year. |
| Systemic risk | Risk arising from the interactions and dependencies within and between systems, where a shock can propagate and threaten the functioning of the whole. |
Water links to energy, food, health, nature and the financial system. Dependencies and consequences explains those links. Governance of water and adaptation is convened at The Global Risks Forum (GRF) through Climate and Nature Governance, and its financial dimensions are studied at The Global Risks Alliance (GRA) through Climate and Nature Financial Risk.
The current service level is R0: information and enquiries. An enquiry receives a reference and names the next step; applications, payments, compute allocations and registrations open only when their team, terms and review capacity exist.