Floods
During 1995-2015, floods accounted for 43 per cent of all documented natural
disasters, affecting 2.3 billion people. Climate change is projected to increase
flood hazards over more than half the planet, both through increased heavy
rainfall, and increases in the intensity and frequency of cyclones, hurricanes and
tropical storms. These risks can be exacerbated particularly in small catchment
areas and drainage basins, as larger basins have more capacity for integrating
sudden increases in river flows.
Impacts on the human rights to safe drinking water and sanitation
Infrastructure can be damaged or destroyed, with important consequences for the availability and
accessibility of water and sanitation services.
Water quality can be threatened by pollutants such as pesticides and fertilizers, residues and
sediments carried by runoff; in addition, in a coastal strip of up to 10 km, saltwater intrusion into
coastal aquifers can threaten the potability of their waters.
Individuals living or working on flooded land can suffer heavy economic consequences,
exacerbating poverty and access to water and sanitation services.
Recurring floods can cause communities to abandon safe sanitation and hygiene practices and
return to defecating in the open.
Floods can put large numbers of people into refugee camps or temporary accommodation. This
type of accommodation is less likely to be culturally acceptable, or to provide for marginalized
populations such as women and girls with menstrual needs, LGBTQ people, children, the elderly
and people with disabilities.
Floods can collapse sewage systems and produce "black floods" inside houses through toilets.
Deglaciation
Glacial and snow masses around the world are predicted to reduce significantly,
over the course of the 21st century. The seasonality of the river flows will change.
Spring melt floods will become smaller, and without regulation of these snow
masses and glaciers, runoff will depend on rain, rather than snow.
Impacts on the human rights to safe drinking water and sanitation
Melting of glacier ice and snow will have consequences for inhabitants of mountainous basins,
who will have to adapt water storage to account for changing seasonal patterns and reduced
natural storage and flow regulation capacities.
The sustenance glacier melting throughout the year, rather than with a peak in the summer,
may reduce on the summer water flows in the downstream parts of glacier basins.
Storage alternatives may be unaffordable, or culturally unacceptable in regions where
populations rely mostly on the usual river regime.
5