Glossary
 

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Agenda 21 (Agenda for the 21st Century) was passed by the UN Conference on Environment and Development (UNCED) in Rio de Janeiro, 1992. Agenda 21 is a global programme that committed 118 countries to environmental restoration, preservation and social development. Their aims were to meet the challenge of global warming, pollution, biodiversity and the inter-related social problems of poverty, health and population. Article 18.9 of Agenda 21 deals with integrated water resources management: 'Integrated water resources management, including the integration of land- and water-related aspects, should be carried out at the level of the catchment basin or sub-basin. Four principal objectives should be pursued, as follows: (a) To promote a dynamic, interactive, iterative and multisectoral approach to water resources management, including the identification and protection of potential sources of freshwater supply, that integrates technological, socio-economic, environmental and human health considerations; (b) To plan for the sustainable and rational utilisation, protection, conservation and management of water resources based on community needs and priorities within the framework of national economic development policy; (c) To design, implement and evaluate projects and programmes that are both economically efficient and socially appropriate within clearly defined strategies, based on an approach of full public participation, including that of women, youth, indigenous people and local communities in water management policy-making and decision-making; (d) To identify and strengthen or develop, as required, in particular in developing countries, the appropriate institutional, legal and financial mechanisms to ensure that water policy and its implementation are a catalyst for sustainable social progress and economic growth.'

Alluvial: Formed by river sediments. An alluvial river flows in a landscape formed by its own sediments

Analysis (of data): Processing, involving a sometimes comprehensive transformation and interpretation, in order to arrive at some desired knowledge. Data analysis is often carried out stage-wise and in different contexts. In general, it involves both hidden and explicit assumptions about the relation between primary data and final results. Such assumptions can affect both the accuracy and the validity of the results. A suitable quality is supported by an adequate transparency of the analysis

Basic minimum needs: These can comprise food and water, shelter, primary education, vital health care, and personal integrity. In Thailand, Department of Rural Development has defined 39 indicators of basic minimum needs, which are applied for monitoring of social development

Benthic: Growing/living on or in the river bed

BOD: Biological oxygen demand, meaning the amount of oxygen required for biological mineralisation of organic (or inorganic) degradable matter in sewage or in a natural watercourse. This indirect unit is widely applied because it is easy to measure in the laboratory for samples that contain a variety of (perhaps unknown) compounds. BOD is harmless in itself, but excessive supplies can cause oxygen depletion. BOD is expressed as a mass (g or kg oxygen), a concentration (mg oxygen per litre), or as a supply rate (oxygen mass per time unit)

Catchment area (or drainage area, or watershed): An area that drains through a specific river cross-section

Consistency (of data): Compliance between the quality of different data sets, produced by different methods, or at different places, or at different times

Cost (of water): Can be divided into operation and maintenance costs of supply and distribution system, capital costs, opportunity costs, external costs, and environmental costs. (External costs are consequential costs or benefits, or simply opportunity costs in a wider sense). See also valuation of water

Crop intensity: In the present study, the crop intensity (for a given cultivated area) has been taken as 100 percent (representing the wet season) + xx percent (representing the part of the area that is actually cultivated in the dry season)

Crop requirement (of water): The amount of water required for cultivation of one crop, as available to the crop in the field where it grows (supplied by rainfall and irrigation). The crop requirement can be estimated as the potential evapotranspiration multiplied by a crop coefficient (reflecting the crop species and the stage in its cultivation cycle). Often expressed in mm per crop

Demand (of water): The amount of water required for a given purpose, for example litre per person per day, or mm per crop. The demand can be present or future, and it can be actual (i.e. related to an available infrastructure) or potential (assuming full infrastructural development and no water shortage). The serviceable (part of the) demand is limited both by infrastructure and water availability

Demand satisfaction (of water for irrigation): The water that is available (at the intake from the river), in percent of the withdrawal demand, at a given time for a given crop and a given cultivation routine. Today, in the Kok River Basin, the demand satisfaction is lowest in July, because the cultivation practices are in general accordance with the water availability

Demonstration projects are intended for confirming the site-specific, practical value of new technology (for example new crops or new cultivation routines)

Development objective (or overall objective, or development goal, or mission): A desired future situation, which is supported by a plan (or programme or project) that is targeted towards it. The plan (or programme or project) cannot in itself assure achievement of the development objective - this is subject to a number of assumptions on related developments that are outside the control of the plan (or programme or project). Some authors recommend that only one development objective be applied from case to case, and that it be specified in time, space and quantity

Discharge: Net flow (or net sediment transport) through a fixed cross-section of a river

Driving force: A circumstance that has a major (positive or negative) influence on pursuance of a set of planning goals. It can appear as a trend, a cycle, an analogy, or an event. A driving force cannot be fully controlled by the participants in the planning process. A driving force can be unpredictable, or not well understood, or even unknown

Dry season (in the present study): December through May

Dublin Principles (from International Conference of Water and the Environment, Dublin 1992): (1) Freshwater is a finite and vulnerable resource, essential to sustain life, development and the environment; (2) water development and management should be based on a participatory approach, involving users, planners and policy-makers at all levels; (3) women play a central role in the provision, management and safeguarding of water; (4) water has an economic value in all its competing uses and should be recognised as an economic good

Ecological demand (of streamflow): The minimum flow that is required for preventing significant (medium- or long-term) flow-related ecological damage. The ecological demand varies along the river and over the year. Sometimes, the waterlevel can be critical, rather that the flow rate

Effective rainfall: The part of the direct rainfall that can actually be used by the crop. For rice, the effective rainfall equals the direct rainfall. For other crops, the effective rainfall is the direct rainfall minus surface runoff minus seepage to the underground (below the root zone)

Eutrophication: Excessive supply of nutrients, resulting in a high primary production. Eutrophication can have negative ecological effects, such as large fluctuations of dissolved oxygen between night and day, or damage to benthic vegetation due to shading by algae

Evapotranspiration is the loss of water from the ground to the atmosphere by evaporation and by transpiration (of plants). The rate is determined by the energy supply (by sunlight radiation), the wind speed, and the moisture of the air. Potential evapotranspiration is the capacity of the atmosphere to remove water from the ground, if water is available without constraints

Fish yield: In reservoirs: 100 kg/ha/year (large and medium size reservoirs), 250-500 kg/ha/year (small reservoirs); cage culture in canals: 100-150 kg/year/mē of cage, or 50-60 tonnes/year/km of (primary) canal; rice paddy production: 100-200 kg/ha/year; flood plain yield 50 kg/ha/year; integrated farming systems: up to 5-15,000 kg/ha/year (based on experience from China)

Flow: Volume transport per time unit (for example through a cross-section of a river)

Gauging: Measuring at a fixed point; a gauge is a measuring device (e.g. for water-level)

Global Water Partnership (GWP): An international network (established in 1996) of organisations involved in integrated water resources management: Governments of developing as well as developed countries, UN agencies, multilateral banks, professional associations, research organisations, the private sector and NGOs. The activities of GWP build on the Dublin Principles

Goal: Same as objective

Greater Mekong Sub-region (GMS): Cambodia, Yunnan Province of China, Myanmar, Laos, Thailand and Vietnam. In terms of area and population, the GMS is much larger than the Mekong River Basin, because it comprises the entire countries (or province in the case of Yunnan), and not only the parts that are located in the Mekong drainage area

Green taxes: Taxes that are levied in order to regulate consumption, production or behaviour that affects pollution or utilisation of sparse resources. They aim at a better concordance between actual, immediate, direct (market) costs and total, long-term social costs (including public health, environmental impact and preservation of important resources). The can serve a fiscal purpose as well, or they can be fiscally neutral, for example if the green taxes are used for subsidies of the same sector. Green taxes can for example be levied on cars, fuel, energy, pesticides, fertilisers, water, sewage discharges, and carbondioxide emissions

Groundwater recharge: The replenishment of groundwater with surface water

Holistic (view, analysis): (A view, analysis) of an entire system (with all its elements, states, processes and relations)

Hydrograph: A time series of water-levels at a fixed location (either measured or calculated by a model)

Hydrology: The study of the water cycle

Immediate objective: The intended situation that is achieved as the direct result of orderly implementation of a plan (or programme or project). The immediate objective is the result of a number of outputs, which, between them, are necessary and adequate for achieving the immediate objective. Some authors recommend a maximum of 3 immediate objectives, and that these are specified in time, space, quantity, quality and target group

Incremental planning: Planning in (small) steps, for example when development goals are unclear, uncertain, or in conflict with each other

Infiltration: Loss of surface water by absorption and seepage into the ground. Infiltration capacity is the ability of the soil to absorb surface water. Deep infiltration is seepage from the root zone to the underlying soil layers, whereby the water becomes lost to the vegetation

Integrated farming: An area-intensive and labour-intensive combination of different parallel productions, like a fish pond, paddy, fruit trees, livestock, cash crops and vegetables. Integrated farming can give yields that highly exceed monoculture yields

Integrated water resources management (or IWRM) (as defined by Global Water Partnership): A process which promotes the co-ordinated development and management of water, land and related resources, in order to maximise the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems

Irreversible: That cannot be changed back to the original state

Irrigable area: The area that can actually be irrigated with a specific (present or future) infrastructure (disregarding the finite availability of water)

Irrigation efficiency: The ratio between the crop water requirement and the irrigation requirement. In the present study, a value of 0.3 has been applied

Irrigation requirement (or withdrawal demand for irrigation): The required gross amount of water needed to be withdrawn (from the river) to cultivate a crop, often expressed in mm per crop. It equals the crop requirement, minus direct rainfall, plus the return flow from the field to the river, plus miscellaneous losses (distribution, conveyance, and infiltration out of the root zone)

Kor-Chor-Chor 2 Kor: A socio-economic data base compiled by National Rural Development Committee in 1996

Mekong River Commission (MRC) is a permanent regional body formed by Cambodia, Laos, Thailand and Vietnam. Its mandate is laid down in the 'Agreement on the Cooperation for the Sustainable Development of the Mekong River Basin', or the 'Mekong Agreement', which was signed by the member countries in Chiang Rai on April 5, 1995. The Mekong Agreement includes articles on intra-basin and inter-basin use of the Mekong River in the dry and the wet season, and charges the MRC Joint Committee with preparing and proposing rules for water utilisation and inter-basin diversions. The predecessor of MRC, the 'Committee for the Coordination of Investigations of the Lower Mekong Basin', was established by the same countries on 17 September 1957

Model: (i) A simplified description of a part of reality; (ii) a structure of selected, assumed relations within a system (used for analysis of that system); (iii) a computer programme for analysis of natural phenomena

Morphology (of a landscape or a river): (1) its shape, (2) the study of states, processes and effects related to the shape

Nutrients (in a special meaning often applied within aquatic ecology): Dissolved salts that are essential for primary production in the aquatic environment. They are supplied by sewage or by agricultural runoff. A nutrient can control the rate of the primary production, if all other necessities (like other nutrients, light and carbon) are plentiful. Key nutrients are nitrogen and phosphorus. In the aquatic environment, nutrients appear in nature in low concentrations, but they can cause eutrophication and ecological damage if supplied in large quantities. Fertilisers are pure nutrients, and their residues can contaminate streams, rivers and lakes, if carried by overland flow or irrigation tailwater

Objective (1) (same as goal): Please refer to development objective or immediate objective; (2) (about criteria) (opposite of subjective): Clear, unambiguous, undistorted by arbitrary judgement

Operational, (1) (about criteria): Measurable, or otherwise objectively verifiable; (2) (about strategies): Clear, objectively implementable

Opportunity costs: The costs of one course of action, relative to the 'best' course of action. In a wider sense, the implications of one course of action, relative to a strategy that is 'ideal in terms of benefits'. In development projects, the opportunity costs can reflect the time lag from when a new technology emerges and until it becomes available to the target group. There is often an opportunity cost related to doing nothing

Opportunity window: A shift between 'technological regimes', represented by access to a new technology, which can change the balance between for example centralised/decentralised development, or large-scale/small-scale development. The new technologies can for example be within agriculture, food processing, information technology, etc. One example is high-yield varieties of rice. The outcome need not be positive in all respects

Overland flow: The flow of water on the ground from precipitation to streams located at lower elevations. Occurs when the infiltration capacity of an area soil has been exceeded

Pelagic: Living in the free water column

Photosynthesis: The primary production (by plants, algae and some bacteria) of simple carbohydrates (such as sugar), normally from (inorganic) carbondioxide, and using energy supplied by the sun

Phytoplankton: Photosynthetic aquatic microorganisms (algae)

Pilot projects are intended for testing solutions to new and complex problems. They are typically small-scale, implemented in a short time, and with low costs

Precipitation: Rainfall and snow reaching the ground

Pollution: Release to the environment of a substance that can harm it

Quality: The compliance between an actual and a desired property (or set of properties) (for example an actual biodiversity as compared with a desired biodiversity)

Reference: A basis for comparison (for example 'present situation', or 'future situation without intervention'

River basin: The catchment area of a river

Rice yield (1997): Cambodia 1.5 t/ha (steady), Lao 2.7 t/ha (increasing), Thailand 2.3 t/ha (steady), Vietnam 3.8 t/ha (increasing); world average (1994) 3.7 t/ha

Seepage: Slow movement of water in the ground, or from the ground to the surface

Scenario: A hypothetical (but preferably consistent) combination of events and physical conditions, describing a possible future situation

Sector planning: Planning for a specific income generation, like agriculture, industry, fisheries, tourism, hydropower, etc.

Simulation: A specific reproduction, by numerical modelling, of the time variation of a natural system

Stakeholder: A person, group or institution that has a particular interest in an activity, project, programme or policy. This includes both intended beneficiaries and intermediaries, winners and losers, and those involved and/or excluded from the decision-making process. A key stakeholder is one who can significantly influence or who is otherwise important to the success of the activity, project, programme or policy

Strategy (same as action plan): A plan for how to reach a goal

Sustainability (1) (according to the UN World Commission on Environment and Development, the 'Brundtland Commission', as reported in 'Our Common Future'): Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs; (2) environmental sustainability means avoidance of irreversible conflicts with a desired state of the environment (for example groundwater being suited for drinking); (3) a donor agency consider a project as sustainable if it provides adequate benefits to the target group for a certain period of time (preferably many years) after project completion

Synergy: Mutual stimulation or amplification of two parallel processes, whereby their joint (positive or negative) effect becomes larger than the sum of the effects of each individual process. The existence of synergy effects is a part of the background for integrated planning

Thematic planning: Planning for a specific topic that affects different sectors, like water resources, the environment, education, public health, poverty alleviation, etc.

Trend (in a data record): A gradual change of the general level of values

Valuation (of water): The direct value to users of water can be expressed in terms of crop yield, production output, generated energy, environmental quality, or money, expressed per unit of water, or as a function of quantity. The total value of water is the direct value, plus a net benefit of return flows, benefits from indirect uses, a societal value, and an intrinsic value (reflecting access, ownership, amenity, etc). See also cost of water

Water pricing: A tool for management of water allocation between areas, sectors and individual users, assuming that an 'optimal' allocation (or just a sustainable allocation) can be determined on the basis of a water price that reflects the full costs (and hereby the full value) of water (for example, in economic theory, by charging the full costs and relying on free market mechanisms for allocation). Such a strategy can improve water efficiencies and reduce waste of water. It will often give preference to industrial allocations rather than irrigation. See valuation and cost of water

Wetland: An area that (for natural reasons) is covered by water in at least a part of the year. A wetland can represent a special ecological habitat, sometimes with a high biodiversity, and can serve as a fish breeding ground

Wet season (in the present study): June through November

Withdrawal demand: The required amount of water needed to be withdrawn (from the river) for a given purpose

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