Glossary and abbreviations

adaptive capacity: is the ability of a human system or ecosystem to adjust or respond to climate change (including both variability and extremes); to moderate potential damages; to take advantage of new opportunities arising from climate change; or to cope with and absorb the consequences.
climate: average weather patterns over medium to long timescales of seasons, decades and centuries
climate change: any significant change or trend in climate over time, either the mean state of climate and/or in its variability (e.g., extremes of temperature or rainfall, retreat or advance of glaciers, more intense storms). IPCC include both 'natural' change and that attributable to human activities (e.g., use of fossil fuels).
coastal accretion: a long-term trend of shoreline advance and/or gain of beach sediment volume over several decades. In many cases, accretion is beneficial and creates a buffer against future coastal hazards, but also can be a hazard when too much sediment accumulates in dunes causing blow-outs.
coastal erosion: a long-term trend of shoreline retreat and/or loss of beach sediment volume over several decades. 'Cutback' is a more suitable term to use on a dynamically 'stable' shoreline to describe the temporary loss of beach volume or shoreline retreat during a storm, before it gets replenished over ensuing weeks and months.
coastal margin: aquatic and land environments which are potentially affected by coastal hazards including long-term impacts of climate change, in which the coast and any dune or cliff system is a significant element or part, and includes the coastal marine area.
coastal marine area: (or CMA) means that area of the foreshore and seabed of which the seaward boundary is the outer limits of the territorial sea (12 nautical miles) and the landward boundary is the line of mean high water springs, except that where that line crosses a river, the landward boundary at that point shall be whichever is the lesser of one kilometre upstream from the mouth of the river, or the point upstream that is calculated by multiplying the width of the river mouth by five. [Resource Management Act (1991)]
ENSO: El Niño-Southern Oscillation climate cycle of 2-4 years duration that governs year-to-year (interannual) climate variability in the Pacific and Indian Oceans.
hazard: a situation with the potential to cause harm or damage. A hazard does not necessarily lead to harm or damage.
IPCC: Intergovernmental Panel on Climate Change-a group set up by the United Nations Environment Programme and World Meteorological Organization to regularly assess global and regional climate change every 5-6 years.
IPO: Interdecadal Pacific Oscillation-a 20-30 year 'El Niño-like' climate cycle in the greater Pacific region that modifies the ENSO system. In the negative IPO phase, New Zealand generally experiences higher sea-levels, and more storm surges and floods in eastern areas.
MHWS: mean high water spring-which traditionally is the level of the average spring tides just after full or new moon. In central-eastern regions, a 'pragmatical' MHWS or perigean-spring tide level (MHWPS) is a better hazard measure of upper-level high tides than the traditional MHWS, because the spring-neap effect is weak.
MSL: mean sea level survey datum set down in the 1930s to 1950s. Because of the sea-level rise since then, MSL datum values around New Zealand are usually a few cm below the current mean level of the sea.
natural character: means the qualities of the coastal environment that together give the coast of New Zealand recognisable character. These qualities may be ecological, physical, spiritual, cultural or aesthetic in nature, whether modified or managed or not.
natural hazard: means any atmospheric or earth or water related occurrence (including earthquake, tsunami, erosion, volcanic and geothermal activity, landslip, subsidence, sedimentation, wind, drought, fire, or flooding) the action of which adversely affects or may adversely affect human life, property, or other aspects of the environment. [Resource Management Act (1991)]
risk: relates to both the likelihood and the magnitude of the impact (or consequence). It also has an element of choice by humans.
sea level: the actual level of the sea over a certain averaging period (days, weeks, years, decades) after removing the tides (not to be confused with mean sea level or MSL, which usually refers to a set vertical survey datum).
sea-level rise: trend of annual mean sea level over timescales of at least 3 or more decades. Must be tied to one of the following two types: global-overall rise in absolute sea level in the world's oceans; or relative-net rise relative to the local landmass (that may be subsiding or being uplifted).
significant wave: height the average height of the highest one-third of waves during a short recording interval (typically 10-20 minutes). Generally considered the height that a trained observer would report for a given sea state.
storm surge: temporary increase in ocean level above the predicted tide height caused during storms by a combination of low barometric pressure and winds that cause a set-up in sea level.
storm tide: the total elevated sea height at the coast above a datum during a storm combining storm surge, wave set-up in the surf zone and the predicted tide height. Note that wave run-up needs to be added to the storm-tide level at any locality to get the final storm inundation level, but care is needed to ensure the wave run-up formula doesn't already include wave set-up.
vulnerability: susceptibility to potential harm or damage, considering factors such as the ability of a system to cope or absorb stress or impacts and to 'bounce back' or recover.
weather: what we see happening or about to happen 'out the window', on timescales of hours to weeks
wave run-up: (for storms or tsunami) the ultimate height reached by waves after running up the beach and coastal barrier (see also wave set-up)
wave set-up: (for storms) the super-elevation in water level across the surf zone caused by energy expended by breaking waves (see also wave run-up)

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Glossary and abbreviations