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Annex II: Glossary of terms

Cableway (F.: Station téléphérique; S.: Teleférico de aforro). Cable stretched above and across a stream, from which a current meter or other measuring or sampling device is suspended, and moved from one bank to the other, at predetermined depths below the water surface. The instrument may be operated from the bank or from a cable carrying personnel.

Calibration syn rating (F.: Réglage, calage; S.: Calibración). Experimental determination of the relationship between the quantity to be measured and the indication of the instrument, device or process which measures it.

Catchment or watershed (F.: Bassin versant; S.: Cuenca). That area determined by topographic features within which rainfall will contribute to runoff at a particular point under consideration.

Data logger (F.: Appareil de télémesure; S.: Registrador electrónìco). Electronic instrument designed to read and store information, such as rainfall and water level. The memory of the instrument allows a one-month autonomy with a recording rate of 5 minute-step. The instrument is directly interrogable by a portable computer.

Drainage network (F.: Réseau de drainage; S.: Red de drenaje). Arrangement of natural or manmade drainage channels within a catchment.

Ephemeral stream (F.: Cours d'eau sporadique; S.: Curso de agua intermitente). Stream becoming dry during the dry season or in particularly dry years.

Erodibility (F.: Erodibilité; S.: Erodibilidad). Susceptibility to erosion, erosion proneness. Sands are generally more erodible than silts, and silts more than clays; no fully satisfactory soil erodibility assessment method has yet been found. Soil erodibility might change according to the soils' physical conditions (Soil wetness, frost, recent tillage or compaction). Angular soil particles are more interlocking than rounded particles; soil colloids cement particles together; compaction increases total surface contact among particles. (Hewlett, 1982)

Erodibility Map, from the current elaborated Mediterranean common mapping methodology, expresses the same practical concept by crossing the soil's qualitative erodibility with the slope factor to assess the overall land erosion susceptibility.

Erosion (F.: Erosion; S.: Erosion): The wearing away of the land by running water, rainfall, wind, ice or other external agents, including such processes as detachment, entrainment, suspension, transportation and mass earth movement.(SCS-New South Wales, 1986)

Erosion Risk (F.: Erosion potentielle; S.: Riesgo de erosion): Probability rate for an erosion process to start and develop as a result of changes of one or several erosion inducing or controlling factors. While climate, soil and topography are fairly stable, vegetation cover, land use and management are more liable to modifications. The concept of risk is equivalent to that of POTENTIAL erosion. (Giordano, 1991)

Erosion Status (F.: Etat érosif; S.: Estado erosivo): Actual and/or Potential Erosion assessment as related to the local environmental features such as topography, geology and soils, vegetation cover and land use. Rainfall and other climatic features are not taken into account.

Erosion Trend (F.: Tendance évolutive de l'érosion; S.: Tendencia de erosión): The predictable tendency of an erosion process to develop or to stabilize in terms of nature, intensity and/or area expansion.

Erosivity (F.: Erosivité; S.: Erosividad): Potential ability of physical dynamic agents such as water, wind or ice to cause erosion. Falling rain is more erosive than water moving over the surface of the ground. Drop size, falling velocity and intensity are rain features related among themselves which determine rainfall erosivity. (Hewlett, 1982).

Flume (F.: Canal d'essai; S.: Canaleta). Manmade channel with clearly specified shape and dimensions which may be used for the measurement of discharge.

Gully or Channel Erosion (F.: Erosion concentrée, Ravinement; S.: Erosion en cárcavas). The removal of soil by the formation of relatively large channels or gullies cut into the soil by concentrated surface runoff. In contrast to rills, gullies are too deep to be obliterated by ordinary tillage practices. (U.S. Soil Conservation Service, 1951)

Landslide (F.: Glissement de terrain; S.: Deslizamiento de terreno): A slope Mass Earth movement where a soil or substrata mass slides over a contact surface called sliding surface.

Lithofacies (F.: Lithofaciès; S.: Litofácies): A term used to describe the physical mechanic and organic features of local soil and subsoil conditions.

Load (F.: Charge solide; S.: Carga sólida). The weight of dry solids being transported in any mode by the action of gravity, wind or water.

Load (bed) (F.: Charriage de fond; S.: Carga de fondo). Coarse grained sediments transported don the bed of a stream.

Load (dissolved) (F.: Charge soluble; S.: Carga soluble). Sediments transported in solution.

Load (saltation) (F.: Transport solide par saltation; S.: Transporte por saltación). Sediments whose mode of transport fluctuates between suspended and bed.

Load (suspended) (F.: Sédiments en suspension; S.: Sedimentos en suspensión). The total sediments moving in water-combination of wash load and bed load.

Load (wash) (F.: Transport en suspension; S.: Transporte en suspensión). Fine grained sediments moving in water entirely in suspension.

Managed Area (F.: Milieux exploités; S.: Medios intervenidos): Area of land where one or several human interventions take place which are directly related to the land, making use of its resources, or having an impact upon it.

Mass Earth Movements (F.: Mouvements de masse; S.: Movimientos en mesa): Erosion where main causative agents are waterlogging and gravity. Heavy and/or prolonged rains are usually the triggering factors. Landslides, mudflows, rock falls and soil creep, are mass movements.

Morphology (of a basin) (F.: Morphologie; S.: Morfología). Characteristics of a drainage basin, e.g. basin area, longitudinal stream profile, topography etc.

Mudflow (F.: Lave torrentielle; S.: Lava torrencial): Muddy flow composed of water and a very high concentration of sediments and solid weathering debris and which has been generally originated by mass earth movements such as landslides in the upstream sections of the catchment.

Perennial stream (F.: Cours d'eau pérenne; S.: Curso de agua permanente). Stream which flows continuously all through the year.

Rainfall simulator (F.: Simulateur de pluie; S.: Simulador de lluvia). Device to apply water in a form and at a rate comparable with natural rainfall.

Reach (F.: Tronçon; S.: Tramo). Long straight stretch of a river in which the hydraulic elements remain rather uniform.

Recurrence (interval) (F.: Recurrence, intervalle de ~; S.: Recurrencia, intervalo de ~). The average time interval between actual occurrences of a hydrological event of a given or greater magnitude.

Rill Erosion (F.: Erosion en rigoles; S.: Erosión en regueros): Removal of soil by the cutting of numerous small, but conspicuous water channels or tiny rivulets by concentrated surface runoff. The marks of rill erosion may be obliterated by ordinary tillage practices. (U.S. Soil Conservation Service, 1951)

Sediment concentration (F.: Concentration en sédiments; S.: Concentración de sedimentos). Quantity of sediment carried in a unit volume of water. The preferred symbol is Cs. With units of kg/m3.

Sediment delivery ratio (F.: Pourcentage de sédiments transportés; S.: Porcentaje de acarreo). Percentage between the sediment transported by a river and the total quantity of erosion material in movement, both relative to the drainage area at one particular section.

Sediment (solid) discharge (F.: Débit solide; S.: Acarreo sólido). The quantity of sediment, measured in dry weight per unit time, transported through a channel cross-section. (It is obtained by multiplying the sediment concentration by the stream discharge).

Sediment (siltation) (F.: Sédimentation; S.: Sedimentación). Deposition by water of sediment. Technically the term siltation refers to the deposition of silt particles, but it is more commonly used to refer to the deposition of sediment.

Sheet Erosion (F.: Erosion en nappe/Laminaire; S.: Erosion laminar): The removal of a fairly uniform layer of soil from the land surface by runoff or wind. (Soil Conservation Society of America, 1970)

Stable Area (F.: Milieux stables; S.: Medios eatables): Area of land with no evidence of any active erosion processes, because of the predominant stabilizing effect of one or several landscape components thus generating a state of morphodynamic equilibrium.

Stilling pond (F.: Bassin de décantation ou de tranquillisation; S.: Tanque de decantación). Pond connected with a stream in such a way as to permit the measurement of the sedimentation in relatively still water.

Soil Crusting (F.: Encroûtement; S.: Sellado del suelo): Process of compaction and cementation of fine soil surface particles removed and accumulated by splash and sheet erosion processes which can lead to a complete sealing of soils pores.

Splash/Raindrop Erosion (F.: Erosion pluviale/aréolaire; S.: Erosion pluvial): The spattering of soil particles caused by the impact of raindrops on the soil. The loosened particles may or may not be subsequently removed by runoff; splash erosion is an important component of sheet erosion.

Terracetting (F.: "Pieds-de-vaches"; S.: Pisoteo): The characteristic pattern formed by numerous gently inclined steps or ledges traversing a hill slope. It is apparently caused by the combined action of soil creep and the tread and trampling of animals

Thalweg (F.: Thalweg; S.: Talweg/Vahuada): A term frequently used to designate the longitudinal profile of a river, i.e. from source to mouth following the line of the lowest points of a valley.

Torrential (F.: Torrentiel; S.: Torrencial). Flow in a watercourse having a steep slope with great velocity and turbulence.

Trap efficiency (F.: Pourcentage de sédiments capturés; S.: Porcentaje de sedimentos retenidos). Ability of a reservoir to trap and retain sediment, expressed as a percent of sediment yield (incoming sediment) which is retained in the reservoir.

Turbidity (F.: Turbidité; S.: Turbidez). Presence of fine visible material in suspension in a liquid which is not of sufficient size to be seen as individual particles but which prevents the passage of light through the liquid.

Unstable Area (F.: Milieux instables; S.: Medios inestables): Area of land where one or several active erosion processes occur.

Vegetation Cover (F.: Couvert végétal; S.: Cobertura vegetal): Portion of soil which is covered by the plant canopy.

Water Divide Line (F.: Ligne de partage des eaux; S.: Divisoria de aguas): Dividing ridge between two catchments.

Waterlogging (F.: Engorgement; S.: Anegamiento). Condition of land when the water table stands at or near the land surface and may be detrimental to plant growth.

Weir (F.: Seuil; S.: Vertedero). Overflow structure which may be used for controlling upstream water level or for measuring discharge or for both.

Glossary Bibliography

Soil Conservation Service, New South Wales, 1986: Glossary of terms used in Soil Conservation

Chambers Science and Technology Dictionary, Editor T.C. Collocott, MA, 1984.

Soil Conservation Society of America, 1970: Resource Conservation Glossary. Journal of Soil and Water Conservation No. 25 (supplement).

U.S. Soil Conservation Service 1951: Soil Survey Manual. USDA Washington D.C.

Hewlett, J.D., 1982: Principles of Forest Hydrology. University of Georgia Press. Athens, Georgia.

Giordano, A. and Marchisio C., 1991: Analysis and Correlation of the existing Soil Erosion Maps in the Mediterranean Basin. Quaderni di Scienza del Suolo, Vol III, Firenze.

Griesbach, J.C., 1980: Vocabulario Básico de las Ciencias de la Tierra, TRANARG, CA, Caracas, Venezuela.


Arnoldous, H.M.J: Methodology used to determine the maximum potent/al average annual soil loss due to sheet and rill erosion in Morocco. FAO Soils Bulletin no. 34. FAO, Rome, 1977.

Bos, M.G (Ed.): Discharge measurement structures. Int. Inst. for Land Reclamation and Improvement. P.O. Box 45, 6700AA Wageningen, Netherlands pub. no 20, 1976. 464 p.

Boughrara, A.: Mésure de l'erosion dans le bassin versant de l'oued El Khairat et ses deux sous-bassins: oued El Maleh et oued Eddhieb. Rapport final. Agence Nationale de Protection de l'Environement, Direction des sols, PNUE, PAM PAP. Tunis, 1994. 65pp + annexes.

Brakensiek, D.L., Osborn, H.B. & Rawls, W.J. (Coord.): Field manual for research in agricultural hydrology. Agriculture Handbook n° 224, U.S.D.A., 1979. 550 pp.

CEMAGREF: Les bassins versants expérimentaux de Draix. Grenoble, 1988.

Clark, J.: Integrated Management of Coastal Zones. FAO Technical Fisheries Paper 327. FAO, Rome, Italy, 1992.

Crickmore, M.J., Tazioli, G.S., Appleby, P.G., Oldfield, F.: The use of nuclear techniques in sediment transport and sedimentation problems. Technical Documents in Hydrology. Unesco, Paris, 1990.

Dogan O., Sevinç,, N.: Measurement of rainfall-induced erosion processes in Mediterranean coastal areas: The Turkish Case Study. General Directorate of Rural Services, UNEP MAP PAP. Ankara, 1995.73 pp.

European Commission: Desertification in a European context. Physical and socio-economic aspects. Proceedings of the European School of Climatology and Natural Hazards, Final report, EUR 15415EN, 1995.

FAO: Arid zone hydrology for agricultural development FAO Irrigation & Drainage Paper No. 37. Food and Agriculture Organization of the United Nations, Rome, 1981.

Gazzolo, T., Bassi, G.: Carta delle isolinee di ugual erosione in Italia. In: Contributo allo studio del grado di erodibilità del terreni costituenti i bacini montani dei corsi d'acqua italiani. Memorie e studi idrografici - Ministero di LL.PP. Servizio idrografico - Publ. no. 2 - vol IV. 1966.

Giordano, A., Marchisio, C.: Analysis and Correlation of the Existing Soil Erosion Maps in the Mediterranean Coastal Zones. PAP, Malaga, Spain. 1989.

Gregory, K.H. & Walling, D.E.: Drainage basin form and processes. Edward Arnold, London, 1973.458 pp.

Grenon, M., Batisse, M. (eds): The Blue Plan. Futures for the Mediterranean Basin. Oxford University Press. Oxford, UK, 1989.

Hadley, R.F. & Walling, D.E. (Edrs.): Erosion and sediment yield. some methods of measurement and modelling. Geobooks, Norwich, 1984. 218 pp

Hudson, N.W.: Field measurement of soil erosion and runoff. FAO Soils Bulletin 68, Food and Agriculture Organization of the United Nations, Rome, 1993.

Lahlou, A.: The silting-up of Moroccan dams. 1st International Congress of Geohydrology "Antropization and degradation of the physical environment". Florence, Italy, 2-6 December 1987. CNR Gruppo Naz. per la Difesa delle Catastrofi Idrogeologiche. Pubbl. Nx129. Florence, 1987.

Lal, R.: Preface. in: R. Lal (Ed.), Soil Erosion Research Methods. Soil and Water Conservation Society, Ankeny, Iowa: xi-xiii. 1988.

Michaelides, P.: Rainfall-induced soil erosion in Cyprus. Ministry of Agriculture and Natural Resources, Dept. of Agriculture, Republic of Cyprus. Cyprus, 1989.

OECD: Coastal Zone Management. Integrated Policies. Organization for Economic Cooperation and Development. Paris, France, 1993.

OECD: Coastal Zone Management. Selected Case Studies. Organization for Economic Cooperation and Development. Paris, France, 1993.

PAP/RAC-UNEP: National Reports on Pilot Mapping and Measurement of Rainfall-Induced Erosion Processes in the Mediterranean Coastal Areas. PAP-8/PP/NR.1. PAP/RAC- MAP/UNEP, Split, Croatia, 1997.

Roche, M.: Hydrologie de surface. Office de la recherche scientifique et technique outre-mer. ORSTOM. Gauthier-Villars Editeurs, Paris, 1963.

Rojo Serrano, L.: Synthesis of the National Reports on the State of the Art of Erosion in the Mediterranean countries. UNEP/ICONA, Madrid. Spain, 1988.

Romero-Diaz, M.A., Cabezas, F., Lopez Bermudes, F.: Erosion and fluvial sedimentation in the River Segura Basin. Catena vol. 19. Cremlingen, 1992.

Rouse, H.: Engineering Hydraulics. John Wiley & Sons, Inc., 1949.

The World Bank: The Noordwijk Guidelines for Integrated Coastal Zone Management. The World Bank, Environment Department, Land, Water and Natural Habitats Division distributed at the World Coast Conference, Noordwijk. The Netherlands, 1993.

Thomas, W.A.: Sediment Transport Hydrologic Engineering Methods for Water Resources Development The Hydrologic Engineering Center Corps of Engineers, U.S. Army. Davis, California, 1977.

Toebes, C. & Ouryvaev, V. (Eds): Les bassins représentatifs et expérimentaux. Unesco-I.A.H.S., Paris, 380 pp. 1970.

Topraksu Koyisleri ve Kooperatifler Bakanligi: Erosion map of Turkey. Harita Mdrlgnde Hazinranmis ve Basilmistir. 1981.

UNCED (United Nations Conference on Environment and Development): Rio Declaration on Environment and Development UNCED, Rio de Janeiro, Brazil, 1992.

UNEP - Blue Plan: Systemic and Prospective Analysis for Mediterranean Sustainable Development: Activities and Outputs. UNEP(OCA)/MED IG.5/Inf.5. Athens, 1995.

UNEP: Guidelines for Integrated Management of Coastal and Marine Areas - With Special Reference to the Maditerranean Basin. UNEP Regional Seas Reports and Studies No 161. PAP/RAC (MAP-UNEP). Split, Croatia, 1995.

USDA: Field Manual for Research in Agricultural Hydrology. Agriculture Handbook No. 224. United States Department of Agriculture, 1979.

Walling, D.E. & Webb, B.W.: The reliability of suspended sediment load data in: Erosion and sediment transport measurements, IAHS Pub. no 133: 177-194. 1981.

Walling, D.E.: The sediment delivery problem. J. Hydrol. 65: 209-237. 1983.

Walling, D.E.: Measuring sediment yield from river basins in: Soil Erosion Research Methods, R. Lal (Ed.), Soil and Water Conservation Society, Ankeny, 39-73. 1988.

WMO: Guide to Hydrological Practices, Volume I: Data Acquisition and Processing. World Meteorological Organization, Geneva, Switzerland, 1981.

World Meteorological Organization: Measurement of river sediments. Operational Hydraulics Report N° 16. Geneva, Switzerland. 1981.

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