Construction of a typology system for rivers in Chile based on the European Water Framework
Directive (WFD)
Rodrigo Fuster1*, Cristián Escobar1, Gloria Lillo1, Andrés de la Fuente1
1
Department of Environmental Sciences and Renewable Natural Resources, FacultyofAgricultural Sciences,
Universidad of Chile, Av. Santa Rosa 11315, La Pintana, Santiago de Chile, Chile
*Corresponding author: E-mail: rfuster@uchile.cl, telephone number: (+56 2) 29785926, Fax (+56 2)
29785929
Journal of Environmental Earth Sciences
General descriptions of freshwater ecoregion of Chile
Atacama ecoregion. It extends from the northern limit of Chile (~ 17°30’S) up to the coastal basins of Salado
and Copiapó rivers (~ 26°S). It is located within the Hyper Desertic Zone (Santibañez et al. 2008) which is
characterized by having mean annual precipitation rate below 30 mm year -1 with a long dry season between
eleven and twelve months. Above 3,000 masl the mean annual precipitation is concentrated in summer and
can be higher than 100 mm year-1. Because of the low rainfall rate below 3,000 masl, the surface runoff is
scarce and erratic (Santibañez et al. 2008). The mean annual temperature is about 16°C; decreasing below
10°C above 3,000 masl.
The main basins located in this region are: Lluta river basin, San José river basin, Pampa del Tamarugal river
basin, Camarones river basin, Loa river basin and Salado river basin. All the rivers are born in the Andes, and
Lluta and Loa rivers are the only rivers that have permanent flow reaching the Pacific Ocean. It is important
to mention that most of the rivers in this ecoregion have high values of electric conductivity due to high
concentrations of borates, sulphates and others inorganic compounds (Vila et al., 2006).
The ictic biodiversity is very low and all the species belong to genera Basilichthys (Basilichthys cf semotilus,
Basilichthys spp; Dyer 2000; Dyer 2001).
Altiplano ecoregion. It is placed in the Andes plateau (Altiplano), above 3,500 masl, and includes the
Altiplanic basins (northern zone) and the Andean endorheic basins of the Salt flat of Atacama (southern
zone). The northern part of this ecoregion is located in the Cold Steppe Arid Zone with mean annual
precipitation rates around 50-300 mm year-1 concentrated in the summer season. The dry period lasts between
eight and twelve months and mean annual temperature is about 3.5°C (Santibañez et al. 2008). In the southern
part the rainfall occurs during summer months but the mean annual rate does not reach the 100 mm year -1.
The mean annual temperature decreases from west to east reaching 4.5°C above 4,000 masl.
The hydrological regimen is strongly influenced by summer precipitation and the variability in flow rates
during the year depends on the snow accumulation. All the basins located in this ecorregion are endorheic and
the waterlosses are produced through evaporation that explains the presence of Sal flats. Most of the rivers in
this ecoregions have high salinity levels due to which there are high concentrations of borates, sulphates,
carbonates and chlorides (Vila et al., 2006). The ictic species (e.g. Trichomycterus chungaraensis, Orestias
chungarensis, Orestias parinacotensis, Trichomycterus laucaensis, Orestias laucaensis) are restricted to lakes
and wetlands (bofedales).
Mediterranean ecoregion. It extends from the Copiapó river basin (~ 26°S) to Imperial river basin (~ 38°S).
Based on its climate and hidrology this ecoregion can be subdivided in three subecoregions:
Subecoregion I. It is located between the Copiapo river basin and the Ligua river basin and it is characterized
by a Mediterranean-type climate with a rainy season of approximately one month. The rivers have high flow
variability within the year having their maximum flow rate during summer and winter, depending on the
amount of accumulated snow in the headwaters and the precipitation rate, respectively (Vila et al. 2006). The
mean annual precipitation rate is around 10 mm; however the precipitation increases southward reaching
values higher than 400 mm year-1. The mean annual temperature varies between 12°C (Coastal Cordillera
and Central Valley) to 4.5°C (Andes Cordillera).
Subecoregion II. It extends from the Aconcagua river basin to the Mataquito river basin. It has a
Mediterranean-type climate with a dry season between seven and eight months (Santibañez et al. 2008). The
mean annual precipitation rate is higher than 600 mm and the mean annual temperature decreases from
Coastal Cordillera (15°C) to Andes Cordillera (3°C). The basins are characterized by having mixed
hydrological regimen and torrential runoff with the highest flow rate during winter (high rainfall) and spring
(snow melting). Vila et al. (2006) recognizes four natural sections within these basins:
1.
2.
3.
4.
Altoandean zone: The main stream is turbulent, with a steep slope and substrate made up of big
stones and rocks
Middle high zone: The water bodies are deep with stones and gravel as a dominant substrate.
Middle low zone: The water bodies have clear waters and are relatively wide and shallow.
Mouth zone: The water bodies are wide and influenced by seawater.
Subecoregion III. It is located between Maule river basin and the Imperial river basin. It is characterized by
having a Mediterranean-type climate with a mean annual precipitation rate above 900 mm and a dry season
between seven and eight months. The mean annual temperature decreases from Coastal Cordillera to Andes
Cordillera (5.8°C above 1500 m). The hydrological regimen is similar to the subregion II; however the mean
annual flow rate is higher and less variable during the year.
Regarding biodiversity, this ecoregion has the highest ictic biodiversity degree of the country. Some of the
main species are: Trichomycterus areolatus, Basilichthys australis, Percichthys trucha, Percichthys
melanops, Diplomystes chilensis Bullockia maldonadoi, Cheirodon pisciculus, Cheirodon galusdae,
Diplomystes nahuelbutaensis, Brachygalaxias, Odontesthes mauleanum, Aplochiton zebra and
Trichomycterus chiltoni
Valdivian Lakes ecoregion. It extends from the Tolten river Basin (~39°S) to the basins and islands located
between the Bueno river basin and Puelo river basin (~41°S). The climate is humid with a rainy season
between eight and twelve months (Santibañez et al. 2008). In the continental zone of this ecoregion, the mean
annual precipitation rate exceeds 1500 mm year-1 and the mean annual temperature fluctuates between 14 and
15°C. Above 700 masl the mean annual temperature decreases to 7.8°C. In the Chiloé Island the mean annual
precipitation and temperature reach 2,200 mm year-1 and 12.8°C respectively.
In general, the rivers located in the continental zone are characterized by having gentle slopes and constant
flow rate. Most of the rivers are born in Andean lakes. On the other hand, rivers found in Chiloé Island are
short and have low flow rate with a great amount of organic matter. Additionally a lot of rivers in the Chiloe
Island have high salinity content because intrusion of seawater (Vila et al. 2006). Between 39°S and 41°S, this
ecoregion has a system of big lakes which, in general, are deep, oligotrophic, monomictic and glacial or
tectonic origin.
Regarding ictic biodiversity, 17 species, two of them endemics (Cheirodon australe and Diplomystes
camposensis) can be found in this ecoregion.
Patagonian Ecoregion. It extends from Puelo river basin (~41°S) to the islands located southward of Beagle
Canal. The mean annual precipitation rate exceeds 4,000 mm year -1 and the mean annual temperature
fluctuates between 5°C and 6°C. In the eastern side of the Andes, in southern Patagonia and Tierra del Fuego
the precipitation decreases up to 200-400 mm year-1 with a dry period of four months.
Two main types of rivers can be identified:
1.
2.
High flow rates rivers. These rivers are born in the western side of the Andes Cordillera. The highest
flow rate occurs in summer; however the annual variability is very low. The ictic fauna is similar to
the fauna described in Valdivian Lakes ecoregion; however the richness is lower (Vila et al. 2006).
Some representative ictic species includes: Hatcheria macraei, Galaxias platei, G. maculates, G.
australis, Aplochiton taeniatus.
Rivers of the Isla Grande de Tierra del Fuego. These rivers are relatively shallow and are
characterized by having low flow rate. This water bodies has a low richness of fauna. Some species
that can be found are: Galaxias platei, G. maculatus, Aplochiton taeniatus, A. zebra; G. australis and
Caragola lapicida (Vila et al. 2006).
River classification criteria according to Annex II of European Water Framework Directive
System A
Fixed typology
Ecoregion
Type
Descriptors
Ecoregions shown on map A in Annex XI
 Altitude typology
high: > 800 m
mid-altitude: 200 to 800 m
lowland: < 200 m
 Size typology based on catchment area
small: 10 to 100 km2
medium: > 100 to 1 000 km2
large: > 1 000 to 10 000 km2
very large: > 10 000 km2
 Geology
calcareous
siliceous
organic
System B
Physical and chemical factors that determine the
characteristics of the river or part of the river and
hence the biological population structure and
composition
Obligatory factors
 altitude
 latitude
 longitude
 geology
 size
Optional factors
 Distance from river source
 Energy of flow (function of flow and
slope)
 Mean water width
 Mean water depth
 Mean water slope
 Form and shape of main river bed
 River discharge (flow) category
 Valley shape
 Transport of solids
 Acid neutralising capacity
 Mean substratum composition
 Chloride
 Air temperature range
 Mean air temperature
 Precipitation
Source: European Parliament and Council (2000)
Alternative characterization
References
European Parliament and Council (2000) Directive 2000/60/EC of the European Parliament and of the
Council of 23 October 2000 establishing a framework for Community action in the field of water policy as
amended by Decision 2455/2001/EC and Directives 2008/32/EC, 2008/105/EC and 2009/31/E
Santibáñez F, Roa P, Santibáñez P (2008) El medio físico. In: CONAMA (ed) Biodiversidad de Chile.
Patrimonio y desafíos, Santiago de Chile, pp. 21-45
Vila I, Pardo R, Dyer B, Habit E (2006) Peces límnicos: diversidad, origen y estado de conservación. In: Vila
I, Veloso A, Schlatter R, Ramírez C. (eds) Macrófitas y vertebrados de los sistemas límnicos de Chile.
Editorial Universitaria, Santiago de Chile. pp. 73-103