Glossary

Adaptive management
A management approach that involves monitoring the outcomes of a project or issue and, on the basis of the monitoring, improving the way the project is managed.
Agro-forestry
Cultivation of trees for profit.
Aquifer
A porous soil or rock formation which holds water.
Aquaculture
Farming of aquatic organisms including fish, molluscs, crustaceans and aquatic plants.
Aquatic ecosystem
All living and non-living elements of a water-based environment and the relationship between them.
Biodiversity
The variety of life forms, the different plants, animals and micro-organisms, the genes they contain and the ecosystems they form.
Biomass
The total amount of living substance in a given area. It can include animals, micro-organisms and vegetation, such as wood or crop residue.
Biophysical
A word that jointly refers to the biological and physical elements of an environment.
Break of slope
The line across a landscape where the hill slope flattens out and where the hydraulic conductivity of the underlying material decreases.
Capillary rise
The upward movement of water through soil caused by molecular attraction between soil particles and water. Dry soils can act like a sponge to bring groundwater to the surface.
Carbon sequestration
The removal of greenhouse gasses from the atmosphere by plants, soils or technological measures.
Catchment
The area of land drained by a river and its tributaries.
Connate salt
Salt naturally present in the soil profile coming from marine sediments deposited in earlier geological times.
Co-benefit
An additional benefit from an action that is undertaken to achieve a particular purpose, that is not directly related to that purpose.
Cumulative impact
The incremental effects of a group of actions as they accumulate over time and space.
Cyclic salt
Salt transported from the ocean and deposited by rainfall.
Development Control Plan
A plan prepared by a local council under the Environmental Planning and Assessment Act 1979 that contains detailed guidelines that must be considered when carrying out new development.
Dieback
A general term for a significant decline in tree health and numbers, especially native trees, caused by a variety of agents including salinity, insect attack, disease and pollution.
Discharge area
An area where groundwater seeps to the surface or waterway.
Dispersion
The process where soils separate into their constituent particles in water. Dispersible soils are highly erodible.
Drainage paths
Naturally defined pathways through which water run-off flows. Generally used to describe drainage depressions, gullies, drainage lines, creeks and rivers.
Dryland salinity
Dryland salinity is mainly caused when deep-rooted native vegetation is replaced by crops and pastures that have shallower roots and different water use requirements. This leads to more water flowing into groundwater systems and the increased mobilisation of salts that are present. This saline water rises close to the ground surface in low-lying areas or at the break of slope, and/or flows underground directly into streams.
Dryland salinity is also caused by erosion exposing naturally saline soils, such as hypersaline clays.
Electrical conductivity
The most widely used and convenient method of measuring the salinity of water is by electrical conductivity. One measure of electrical conductivity is ‘micro-Siemens per centimetre’. The shorthand expression for this is the ‘electrical conductivity unit’, ‘EC unit’ or just ‘EC’. 1 EC = 1 micro-Siemen per centimetre (?S/cm), measured at 25ºC. 1 EC = 0.64 mg salt / L.
Ecologically Sustainable Development
Using, conserving and enhancing the community’s natural resources so that ecological processes on which life depends are maintained and the total quality of life, now and in the future, can be increased.
Ecosystem
Communities of organisms and their physical environment interacting as a unit.
Flocculation
The process by which very fine clay particles, suspended in water, loosely come together into larger masses.
End-of-valley salinity target
A water quality target at the end reach of a river that expresses the overall saintiy condition to aim for.
Environmental services
Land and water management practices that help preserve natural resources or ecosystems.
Episodic recharge
Where recharge occurs as a result of a number of intense or prolonged rainfall events, rather than steadily over a long period.
Evaporation basin
A shallow pond into which saline water is discharged to evaporate, leaving a residue of salt.
Evapotranspiration
Water returned to the atmosphere by evaporation and by plants emitting water vapour from their leaves.
Externality
An economic term: when the person who causes a problem (or a benefit) is not the same person who experiences it.
Frontline staff
Government agency staff who have direct contact with land managers.
Greenhouse effect
The accumulation from human activity of certain gases in the atmosphere that contribute to global warming.
Groundwater
Water beneath the surface held in or moving through saturated layers of soil, sediment or rock.
Groundwater equillibrium
Equilibrium in a groundwater flow system is achieved when discharges are equal to the recharge on average. This is a dynamic equilibrium in that the groundwater flow system status varies about a constant average condition as the system reacts to the effects of climate variability.
Groundwater Flow Systems (salinity provinces)
Another term for an aquifer, but often used in a salinity context. Where geological and geomorphic characteristics are similar, salinity provinces or groundwater flow systems give rise to similar dryland salinity issues, through similar groundwater processes, and are likely to be amenable to similar interventions. This concept helps scientific and catchment communities speak a common language with respect to dryland salinity.

At the broadest level, groundwater flow systems are defined according to scale as local, intermediate and regional systems. A local groundwater flow system is one that is within a small local catchment. In most local systems the length of the flow path seldom exceeds 3-5 kilometres. An intermediate groundwater flow system is one that operates across local catchment boundaries but does not extend over the entire region of a river basin. These systems may extend over 10–20 kilometres or more. Where a groundwater flow system operates on a large scale (comparable with that of major river or groundwater basins), then it is said to be ‘regional’. Regional groundwater flow paths typically range in length from 50 to several hundred kilometres.

Groundwater mound
A bulge in the watertable, usually created by excessive recharge at that point.
Groundwater response times
The time taken for a groundwater system to fully transition from one equilibrium condition to another in response to a change in recharge regime, such as that caused by land use or a climate change.
Halophytes
Plants that have adapted to saline soils. Halophytes are often used as indicators of salinity.
Hard water
Water containing high concentrations of calcium and magnesium salts. Hard water makes soap difficult to lather and may cause scaling or corrosion in water pipes, boilers, water heaters and other appliances, and industrial equipment.
Hydraulic conductivity
The rate at which a given substance allows water to move through it.
Hydrogeology
The study of water in or moving through soils and rock formations.
Hydrological equilibrium
When the water cycle is in balance and there is no long-term trend in groundwater levels. That is, groundwater recharge and discharge are balanced over time.
Hypersaline
More saline than seawater.
Innate salt
Salts released during the process of soil and rock weathering.
Irrigation salinity
A localised rise in the level of groundwater and the associated mobilisation of salt, caused by the application of large volumes of irrigation water, compounded by the replacement of native vegetation by plants with different water use patterns.
Land managers
Those who manage land, including farmers, graziers, irrigators, cultural and environmental land holders, councils and government agencies.
Landcare
Groups of people from the same area who join together to do things to benefit the environment. They are involved in activities as wide as erosion-control, planning, planting native vegetation and awareness raising.
Land salinisation
The process by which land becomes salt-affected.
Landscape
An area of land and its physical features. A term we use to describe an area that has common features. For example, Dubbo may be in a range of landscapes, depending on whether we are looking at the type of agricultural production, vegetation or landforms.
Leaching
The downward movement of material, such as chemicals and minerals, in the soil profile by percolating water.
Local Environmental Plan
The principal legal document for controlling development at the council level. The zoning provisions establish permissibility of uses and standards regulate the extent of development. They are prepared by councils and approved by the Minister (after public exhibition).
Management actions
Action that needs to be undertaken on the ground to achieve management targets.
Management targets
What we need to have in the landscape to get desired salinity conditions locally and to achieve end-of-valley salinity targets. They are often land-based (biophysical).
Market failure
The situation where a market does not efficiently allocate resources to achieve the greatest possible good.
Native vegetation
Plants species originating in Australia.
Natural Heritage Trust
A Commonwealth Government grants program that funds community projects to improve sustainable agriculture and environmental management.
Natural resources
The assets of land, water, plants, animals and air.
Percentiles (salinity and salt loads)
Percent of time during a prescribed period where salinity (or salt load) is less than a given value. Used to describe end-of-valley salinity targets.
Perched watertable
A groundwater table that sits above (perched on top of) an impermeable rock or soil structure.
Perennial plant
Plant that continues to grow from year to year.
Permeability
The capacity of a substance (for example rock or soil) to allow water to pas through it.
Phase-farming
Alternating farming land uses – such as trees and crops.
Piezometer
A non-pumping, deep (>3m) bore used to measure groundwater pressure.
Porous/porosity
Permeability through small hoes or pores.
Priority salinity hazard landscape
An area that has been identified as needing initial attention for salinity management, due to a variety of biophysical, social and economic factors.
Property-scale
Actions and impacts at the scale of an individual farm or business.
Recharge area
An area in which surface water (from rainfall, irrigation or streams) infiltrates into the soil and is added to the groundwater (c.f. discharge area).
Regional Environmental Plan
A plan that deals with matters that are significant for environmental planning in a region, prepared under the Environmental Planning and Assessment Act 1979.
Residual salt
Salt that is left in the landscape after the water has evaporated or receded.
River salinity
Concentration of salts in rivers and creeks caused by saline discharges from dryland, irrigation and urban salinity.
Root zone
The area below the ground surface occupied by plant roots.
Saline discharge area
An area where salty groundwater is discharged at the soil surface.
Salinisation
The accumulation of salts via the actions of water in the soil to a level that causes degradation of the soil and water resources.
Salinised land
Land affected by salinity.
Salinity (in water)
The concentration of dissolved salts in water. The main salts are made up from sodium, calcium, magnesium, potassium, chloride, sulphate, bicarbonate and carbonate ions. Usually expressed in electrical conductivity (EC) units or milligrams of total dissolved solids per litre (mg/L TDS). (see Total Dissolved Solids).
Salinity hazard
The extent to which natural physical characteristics, excluding land cover, predispose a landscape to salinisation. Relevant characteristics include topography, soils, geology, climate.
Salinity risk
A measure of the likelihood of salinity occurring as a result of land use and other activities and of the severity of the impacts (economic, social and environmental costs) caused by that salinity. (Risk = likelihood x consequence). A change in land use or management practice can either reduce or increase risk.
Salt, salts
Salt causing salinity is actually a mixture of several types of chemical ‘salts’. This includes common table salt (sodium chloride). Other calcium, potassium and magnesium salts, such as gypsum (CaSO4) cause hardness in water and other problems. The sulphate salts are very corrosive to cement.
Salt concentration
Level of salts on the land surface, in soil or water.
Salt interception scheme
Usually engineering works comprising a system of pumps and drainage systems that reduce the level of the groundwater by pumping it into evaporation basins or elsewhere, thereby intercepting salt before it enters a river or reaches the soil surface.
Salt land agronomy
Land management practice in which farmers cultivate plants, principally salt bush, to reduce salt washoff and improve grazing productivity of salt-affected land.
Salt load
Amount of salt carried in rivers, streams, groundwater or surface run-off, in a given time period. Salt load is calculated from data on salinity and stream flow. It is often expressed in kg/day, tonnes/day or tonnes/year.

Salt load estimates are vital because they indicate the amount of salt stored in the landscape, washed from land, or entering the system from groundwater. If we only used salt concentration (measured as EC) as an indicator of salinity, we would not have a sense of the total quantity of salt in the system. For example, if a river has high flows salt concentration (EC) can be low but the salt load can still be very high. Salt loads also indicate the potential rate of salt build up in places where salt might accumulate, such as wetlands and depressions on floodplains. Load estimates are important in predicting the impacts of salinity further downstream in the system as well.

Salt scald
A bare patch of earth where the surface soil has been removed by erosion or damaged by salinity, making it hard to revegetate. Salt may form crystals on the surface.
Salt-tolerant crops
Crops that grow well in salty soils.
Seepage
The process by which water percolates downwards and/or laterally through the soil, often emerging at ground level lower down the slope.
Sodicity
Refers to a soil containing levels of sodium that affect its stability. Sodic soils are dispersible and thus vulnerable to erosion.
Soil permeability
The characteristic of a soil that governs the rate at which water moves through it. Soil properties such as texture, structure and size and distribution of pores largely determine permeability.
Soil pores
Very small spaces between soil particles often occupied by air, water or minerals.
Soil porosity
The degree to which the soil mass is permeated with pores or cavities. The number, size, shape and distribution of pores influence the soil’s ability to hold water.
Soil profile
A vertical section of earth from the soil surface to parent material, showing the different horizons of soil.
Soil sponge
The effect of plant roots drawing water from the soil, thereby drying it out and increasing water holding capacity. Prior to extensive land clearing, native vegetation provided a soil sponge to a depth of six metres or more. Increasing the organic matter in soils help mange salinity.
Subsoil
The layers of soil below the topsoil.
Terrestrial ecosystem
All living and non-living elements of a land-based environment and the relationship between them.
Top soil
The surface or upper layer of soil.
Total dissolved solids (TDS)
A measure of the salinity of water, sometimes referred to as total dissolved salts, usually expressed in milligrams per litre (mg/L). An alternative measure is total soluble salts (TSS).
Triple bottom line
An accounting system that considers more than the traditional financial “bottom line”. As well as financial outcomes, a company (or Government’s) performance should be measured against its social and environmental responsibilities.
Urban salinity
Salinisation in urban areas caused by mobilisation of salt due to raised groundwater levels and exposure of saline soils and rock. Raised groundwater levels result from clearing vegetation; the application of additional quantities of water via watering gardens and parks, leaking water, sewerage and drainage pipes; and the obstruction or modification of natural surface and sub-surface drainage paths. Exposure of saline soils and rock can occur during construction activities.
Watertable
The level below which the ground is saturated with water.
Waterlogging
Where the surface soil is saturated with water from rising groundwater or surface run-off collecting in low areas.
Wetlands
Wetlands are areas that are permanently or periodically wet or inundated. The plants and animals living in wetlands are adapted to, and often dependent on, the wet conditions for at least part of their life cycle. The pattern of inundation determines the productivity of the soils and the plant and animal communities.
Zero-till
A form of conservation farming involving no mechanical soil disturbance other than planting. Crops are planted directly in the stubble of a previous crop or into native grasses. Zero-till has been successful in managing some forms of dryland salinity by increasing the capacity of the soil to hold water and reducing recharge to the watertable.
Page last updated: 26 September 2013