Publication Name

Glossary

Disaster: A serious disruption of the functioning of a community or a society involving widespread human, material, economic or environmental losses and impacts, which exceed the ability of the affected community or society to cope using its own resources. Disasters are often described as resulting from the combination of exposure to a hazard, existing conditions of vulnerability, and insufficient capacity or measures to reduce or cope with the potential negative consequences. Disaster impacts may include loss of life, injury, disease and other negative effects on human physical, mental and social wellbeing, together with damage to property, destruction of assets, loss of services, social and economic disruption, and environmental degradation. 128 Baseflow: The sustained flow of a stream in the absence of direct runoff. It includes natural and human-induced stream flow. Natural baseflow is sustained largely by groundwater discharge. 129 Discharge: The volume of water that passes a given location within a given period of time. Usually expressed in cubic feet or cubic metres per second. 130 Ecosystem services: The benefits that people and communities obtain from ecosystems. These include ‘regulating services’ (of floods, drought, land degradation and disease), ‘provisioning services’ (food and water), ‘supporting services’ (soil formation and nutrient cycling) and ‘cultural services’ (recreational, spiritual, religious and other non-material benefits). The integrated management of land, water and living resources that promotes conservation and sustainable use and provides the basis for maintaining ecosystem services, including those that contribute to reducing disaster risks. 131

Emission scenarios: These describe future releases into the atmosphere of greenhouse gases, aerosols and other pollutants and, along with information on land use and land cover, provide inputs for climate models. They are based on assumptions about driving forces such as patterns of economic and population growth, technology development and other factors. Levels of future emission are highly uncertain, and so scenarios provide alternative images of how the future might unfold. They are an appropriate tool with which to analyse how driving forces may influence future emission outcomes and to assess the associated uncertainties. They assist in climate change analysis, including climate modelling and the assessment of impacts, adaptation and mitigation. The possibility that any single emissions path will occur as described in the scenarios is highly uncertain. 132 Flood: An overflow of water onto lands that are used or usable by man and not normally covered by water. Floods have two essential characteristics: The inundation of land is temporary and the inundation is due to overflow from an adjacent river, stream, lake or ocean. 133 Hydrological cycle: The cycle in which water evaporates from the oceans and the land surface, is carried over the Earth in atmospheric circulation as water vapour, condenses to form clouds, precipitates over the ocean and lands as rain or snow, which on land can be intercepted by trees and vegetation, provides runoff on the land surface, infiltrates into soils, recharges groundwater, discharges into streams and ultimately flows out into the oceans, from which it will eventually evaporate again. The various systems involved in the hydrological cycle are usually referred to as hydrological systems. 134

Peak flow: The maximum instantaneous discharge of a stream or river at a given location. 135

Precipitation: Rain, snow, hail, sleet, dew and frost. 136

Representative Concentration Pathways (RCPs): Scenarios that include time series of emissions and concentration of the full suite of greenhouse gases and aerosols and chemically active gases, as well as land use/land cover. 137 The word ‘representative’ signifies that each RCP provides only one of many possible scenarios that could lead to the specific radiative forcing characteristics. The term ‘pathway’ emphasises that not only the long-term concentration levels are of interest, but also the trajectory taken over time to reach that outcome. 138 Reservoir: A pond, lake, or basin, either natural or artificial, for the storage, regulation, and control of water. 139 Resilience: The ability of a system, community or society exposed to hazards to resist, absorb, accommodate and recover from the effects of a hazard in a timely and efficient manner, including through the preservation and restoration of its essential basic structures and functions. The resilience of a community in relation to potential hazard events is determined by the degree to which the community has the necessary resources and is capable of organizing itself both prior to the shock and during times of need. 140 Runoff: Total discharge from the part of precipitation, glacier melt, snow melt or irrigation water that appears in uncontrolled surface streams, rivers, drains or sewers. Runoff may be classified according to speed of appearance after rainfall or melting snow as direct runoff or base runoff,

90