65. defining river types in a mediterranean area munne

8/8/2019 65. Defining River Types in a Mediterranean Area MUNNE

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ENVIRONMENTAL ASSESSMENT

Dening River Types in a Mediterranean Area:A Methodology for the Implementation of theEU Water Framework DirectiveANTONI MUNNE *

Department of EcologyUniversity of BarcelonaDiagonal, 645E-08028, Barcelona, SpainandPlanning Department Catalan Water AgencyProvena 204-208E-08036, Barcelona, Spain

NARCI S PRAT

Department of EcologyUniversity of BarcelonaDiagonal, 645E-08028, Barcelona, Spain

ABSTRACT / The Water Framework Directive (WFD),approved at the end of 2000 by the European Union,proposes the characterization of river types through two

classification systems (A and B) (Annex II of the WFD),thereby obtaining comparable reference sites andimproving the management of aquatic systems. System Auses fixed categories of three parameters to classify rivers:three altitude ranges, four basin size ranges, and threegeological categories. In the other hand, System B pro-poses to establish river types analyzing different factors

considered as obligatory and optional. Here, we testedSystems A and B in the Catalan River Basin District (NESpain).

The application of System A results in 26 river types: 8 inthe Pyrenees and 18 in the IbericMacaronesian ecore-gions. This number would require the establishment of acomplex management system and control of the ecologicalstatus in a relatively small river basin district. We propose amultivariant system to synthesize the environmental de-scriptors and to define river types using System B. We usefive hydrological, seven morphological, five geological, andtwo climatic variables to discriminate among river types.This method results in fewer river type categories thanSystem A but is expected to achieve the same degree ofdifferentiation because of the large number of descriptorsconsidered. Two levels are defined in our classificationmethod using System B. Five river types, defined at largescale (1:1,000,000), are mainly discriminated by annualrunoff coefficient, air temperature, and discharge. This level

is useful and could facilitate comparisons of results amongEuropean river basin districts. The second level defines 10subtypes of river management, mainly discriminated bygeology in the basin and flow regime. This level is moreadequate at local scale (1:250,000) and provides a usefultool for management purposes in relatively small andheterogeneous river basin districts.

The morphological, geological, and climatic featuresof river basins are highly variable and therefore affect riverine ecosystems and their functioning (Richardsand others 1996; Lammert and Allan 1999; Gergel andothers 2002; Molnar and others 2002). In addition,characteristics at the reach level, such as local habitat features (Schlosser 1991), riparian structure and quality (Petersen and others 1987; Gregory and others 1991;

Naiman and others 1993), or local land uses (Nerbonneand Vondracek 2001), can lead to differences betweenbiological communities. Moreover, hydrodynamic andbiological processes vary along watercourses, from theirheadwaters to the lower reaches and the river mouths(Illies and Botosaneanu 1963; Vannote and others1980). Thus, complex relationships at multiple scales(ecoregion, catchment, reach, and site levels) arepresent along rivers, and hierarchical inuences oper-ate at distinct spatial scales (Frissell and others 1986; Allan and Johnson 1997). Large-scale elements (geol-

ogy, land cover, runoff, or basin size, shape and slope)at the catchment level affect watercourses with multiplepathways by modifying water chemistry (Omernik andothers 1981; Lenat and Crawford 1994; Johnson andothers 1997), soil erosion, sediment composition (Wa-

KEY WORDS: Water Framework Directive (WFD); River manage-ment; River types; Mediterranean rivers; Catalan

River Basin District

Published online December 2, 2004*Author to whom correspondence should be addressed; email: [email protected]

Environmental Management Vol. 34, No. 5, pp. 711729 2004 Springer Science+Business Media, Inc.

DOI: 10.1007/s00267-003-0098-y


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ers 1995), and hydrology (Poff and others 1997). Incontrast, reach-scale elements at the river buffer levele.g.. local riparian forest) are strongly related to

microhabitat composition and stream bank stability Nerbone and Vondracek 2001). The hierarchicaltructure of rivers should be considered for manage-

ment purposes. A review of classications systems based on land-

cape spatial scales for aquatic bioassessments andiver community response (Hawkins and others 2000)howed that the amount of variation related to land-cape features is not large and concluded that the use

of local habitat attributes leads to greater accuracy inhe prediction of freshwater communities than larger-cale landscape features. However, large-scale features

and upstream catchment processes determine the

habitat structure at reach level (Molnar and others2002), and river ecosystems and aquatic community tructure can be affected (Minshal 1988). Therefore,tream classi cation attempts to organize the vari-

ability of aquatic habitats at site-speci c level (Bryceand Clarke 1996), and catchment-scale factors, such asgeology and land use, might make a greater contri-bution than stream buffers and local-scale factors inexplaining mesohabitat composition (Townsend andothers 2004; Richards and others 1996). The sub-equent changes in environmental conditions and

morphological characteristics at the basin scale pro-vide a wide range of conditions along watercoursesMontgomery 1999) and between basins and could be

used to de ne homogeneous environmental unitsuseful for river bioassessments (Hawkins and Norris2000).

Regionalization and classi cation procedures havebeen developed to facilitate research, assessment, andmanagement of ecosystems (Bailey 1987; Omernik1987; Hughes and Larsen 1988). These procedures

have been widely used together with reference condi-ions (Hughes and others 1986; Reynoldson and others

1997; Bailey and others 1998) to determine biologicalcommunities (Van Sickle and Hughes 2000; Marchant and others 2000) and to de ne water quality goals forextensive areas (Resh and others 1995; Marshall andothers 1996; Rabeni and Doisy 1998). To establishappropriate management practices for the variety of iverine ecosystems in Europe, the Water Framework

Directive (WFD) (2000/60/EC) proposes the differ-entiation of rivers by ecoregions [using the classi ca-ion of Illies (1978)] and by surface water body ypesin our case, river types (European Commission

2000). This measure aims to establish management practices adapted to the geographical characteristics of iverine ecosystems and serves to target adequate con-

trol and follow-up programs and policies (e.g.,instream ow regimes or restoration programs that aretype-specic) and to facilitate the analysis of ecologicalstatus by using the reference conditions (Wallin andothers 2003) of each type.

Using this approach, classi cation of river systemsis done through the characterization of the hydro-morphological and environmental heterogeneity of basins that contribute to local changes in river mor-phology and habitat. Human activity or other relateddescriptors should not be considered. This classi ca-tion de nes areas or groups of rivers with similarnatural conditions, the communities of which willconsequently show a similar structure (Omernik andBailey 1997). By analyzing the reference conditions of each river type, this classi cation allows the quali ca-

tion of disturbances of anthropogenic origin and thedesign of restoration policies and protection pro-grams.

Two systems of river classication (A and B) havebeen proposed by the WFD using hydromorphological,climatic, and geological factors (for more details, see WFD Annex II) (European Commission 2000). System A is based on 25 preestablished surface water body ecoregions according to the distribution of Europeanfreshwater communities (Illies 1978). For each ecore-gion, river types are de ned by xed criteria usingaltitude (three classes), size typology based on catch-ment area (four classes), and geology (three classes).In contrast, System B uses several descriptors that determine the structure and composition of the bio-logical communities of the watercourses. In this system,seven descriptors are obligatory and have to be used;the others are optional.

Here, we test the river classi cations using System A,and a methodology proposed by System B, in the Cat-alan River Basin District, a Mediterranean climate area

located in NE Spain. Using a large set of physical andenvironmental parameters, this article provides a sys-tematic methodology to de ne river types following the WFD proposals, which might be exportable to otherMediterranean River Basin Districts or many parts of the world by changing variables according to the localfeatures. Although biological data are not consideredby WFD river classication, the measurement of thesefactors, in nonperturbed areas, might also be necessary for river classication adjustment and validation in thefuture.

Study Area

We tested the ability of Systems A and B to de neriver types in the Catalan River Basin District, located

712 A. Munn and N. Prat


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in NE Spain (Figure 1). This river basin district consistsof several small watersheds (Table 1) that drain to theMediterranean Sea and comprise a total area of 16,424km 2 . These basins make up a water management unit

that is under the authority of the Autonomous Gov-ernment of Catalonia and managed by the Catalan Water Agency. The watershed environmental variablesand hydrological, morphometric, geological, and cli-

Table 1. Main descriptors of the basins that form the Catalan River Basin District

Basins Area(km 2 )

Discharge(m 3 s

) 1 )Main riverlength (km)

Maximumaltitude (m)

Mean annual airtemperature inthe basin ( C)

Precipitation(mm y

) 1 )Number of sitesconsidered

Muga 758 4.65 69 1390 10 767 8Fluvia 974 8.37 107 1520 12 1006 8Ter 2941 26.79 216 2900 11 767 22Daro 314 1.43 45 510 13 634 0Tordera 865 5.39 62 1670 12 860 12Besos 1024 4.09 60 1360 13 697 13Llobregat 4923 22.19 173 2530 12 712 34Foix 312 0.29 55 910 15 617 2Gaia 423 0.79 70 915 14 567 1Francoli 854 1.43 64 1140 13 574 7Riudecanyes 72 0.22 20 690 15 697 1Littoral basins 2964 8.75 6 18 1050 15 582 0

Note: Littoral basins are a group of small basins with high flow variability (temporal and ephemeral watercourses), that drain to the MediterraneanSea. The number of sampling sites considered in the analysis is shown for each basin (see Figure 1).

Figure 1. The Catalan River Basin District (in gray) is managed by the Catalan Water Agency in Catalonia (NE Spain). This

river basin district is composed of several small watersheds that drain to the Mediterranean Sea. The sites (108) used to obtainsite-specific variables and to define the drained area used to obtain the environmental variables at basin-scale are shown.

Defining River Types in a Mediterrean Area 713


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matic parameters used in this study were provided by his agency.

MethodsUsing System A to Define River Types

The ecoregions in the Catalan River Basin District were rst determined using the 25 preestablishedecoregions described in Annex XI of the WFD. Basedon this classi cation, this district holds two ecoregions:he Pyrenean and the Iberic Macaronesian. The rst tep of our analysis was to de ne the limit between thewo ecoregions, which is brie y outlined in the Direc-ive and in Illies work (Illies 1978). This was done

using morphological, climatic, geological, and biogeo-graphical criteria selected from numerous local refer-ences (Table 2).

Next, we used the three main WFD criteria for Sys-em A to establish the river types for each region (Ta-

ble 3). Three coverages were built using the riverdefinition criteria for System A: altitude, surface area of basin, and geological surface. By crossing these cover-ages using Arc/Info GIS tools, we obtained a classifi-cation of river types.

Using System B to Define River Types

We analyzed the obligatory variables proposed by he WFD for System B, plus several optional variablesor which information was already available or easily

obtained (e.g., from the database of the Catalan Water Agency, the Catalan Meteorological Survey, or otheragencies) (Table 4). The spatial variables (X and Y UTM) proposed by the WFD were not considered be-cause they do not offer any discriminatory informationin this small study region. Similar work performed inthe Ebro River Basin District (a neighboring watershedthat is larger than the Catalan River Basin District)demonstrated that spatial variability is not a significant influence on the community distribution of macroinvertebrates at the family level (Munne and Prat 1998).However, these variables might be relevant in largebasins or other river basin districts with more complexbiogeographic distributions. To exclude the effect of

Table 3. Criteria used to establish river types usingSystem A in the two ecoregions of the Catalan RiverBasin District, according to Annex XI of the WaterFramework Directive (2000/60/EC)

Factors used to differentiateriver types for each region Criteria to differentiateriver types

Altitude High (>800 m)Mid-altitude (200 800 m)Lowland (10,000 km 2 )Large (1000 10,000km 2 )Medium (100 1,000 km 2 )Small (10 100km 2 )

Geological surface CalcareousSiliceousOrganic

Table 2. Parameters used to define the borders Pyrenean and IbericMacaronesian regions in the Catalan RiverBasin District

Criteria used to define boundaries between ecoregions

Descriptors Pyrenees Iberic Macaronesian Ref

Morphological Altitude > 600 m Variable Bolos and others (1993)Sole (1958)Riba (1976)

Mean catchment slope > 25%

Climatic Annual runoff > 850 mm Variable Catalan meteorological serviceMean annual

temparature


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or each site. Geological data was obtained as relative

values (percent of the drained area for each geologicalype) in order to remove the influence of drainage

area. With these data, we developed a method to select epresentative descriptors that did not contain redun-

dant information and that explained spatial variability Figure 2).

To identify variables with similar characteristics, aPearson correlation analysis was performed individu-ally for the ve groups of variables (Table 4) to ex-clude those that were redundant or highly correlated.Previously, a normalization test using Q-Q plot analysiswas performed for each descriptor and some distri-butions were normalized using adequate algorithmslog y + c , o r ( y + c ) 1/2 ) (Legendre and Legendre

1998). A correlation coefficient over 0.8 ( P < 0.05) wasused as the criterion to reduce the number of

variables in each group. For further analysis, only one

variable from those highly correlated was retained,thereby removing redundant information from eachgroup of variables.

Next, to summarize environmental complexity andto explain spatial variability, we performed a principalcomponents analysis (PCA), using the CANOCO pro-gram (Ter Braak and Smilauer 2002). PCA is an ordi-nation method that consists of plotting object-pointsalong axes that represent an ordered relationshipamong several descriptors (Jongman and others 1996).This method summarizes most of the variability of adispersion matrix of a large number of descriptors in afew dimensions (Legendre and Legendre 1998). Weselected the PCA scores for each site (the projection of each sampling site on the principal axis) as new vari-ables.

Figure 2. Procedure followed to classify rivers types in the Catalan River Basin District using WFD System B.



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The correlation analysis and PCA were performedfor all the groups of variables (Table 4). The principalaxis that explained a high percentage of variance andhad an ecological interpretation for each analysis wasselected as a new descriptor. We used a PCA for eachgroup of variables to maintain a meaningful descriptor

unit with the same origin (hydrological, morphologi-cal, geological, and climatic) (Table 4).

For each site, the scores of the selected axis from thePCA analysis were corrected for the variability per-centage explained by each axis (the eigenvalues) by simple multiplication. We thus obtained PCA scores of signicant axes for the four PCAs for each group of variables corrected by their eigenvalues. Consequently,more discriminant power was given to each samplingsite. Using these values, we then performed a K -meansanalysis (Jain and Dubes 1988) to group the sites intoriver types. This cluster method allowed us to prede-termine the number of groups (river types), whichshould be internally homogeneous, distinct from eachother, and without a hierarchical structure. We grad-

ually analyzed different numbers of clusters ( n + 1 rivertypes), and the selection finishes previous the numberof river types show a fuzzy distribution pattern. Twoscales were tested: 1:1,000,000 which in our opinion isuseful for reporting by the WFD at European level, and1:250,000 which is more useful for management pur-poses in the relatively small Catalan River Basin Dis-trict.

Results

River Types Using System AThe criteria in Table 2 were used to define the two

river ecoregions in the Catalan River Basin District (Py-renees andIberic Macaronesian) (Figure 3), accordingto the WFD. Next, the intersection of the three coverage

Figure 3. Pyrenees and Iberic Macaronesian ecoregions.Boundaries are defined using geological, morphological, andclimatic criteria, and biogeographical distribution of natural vegetation (from Illies 1978).

Figure 4. Classification of river types using the size of drainage area in the Catalan River Basin District. Three riversizes are shown according to the WFD System A classification.

Figure 5. Classification of river types using a simplified sur-face geology in the Catalan River Basin District. Two geo-logical areas are shown according to the WFD System A classification.



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ayers (altitude typology, size typology on the basis of catchmentarea, andgeology typology), according to thecategories in Table 3 (Figures 4, 5, and 6), was used todefine river types in each ecoregion.

A maximum of 72 potential river types might bedenti ed, 36 per region (Table 5). However, not all of he categories were present in each of the two regions.

The Pyrenean region did not have river systems below 200 m of altitude, nor the Large (>1000 km 2 ) and Very Large (>10,000 km 2 ) surface area categories. Further-more, neither region had a high percentage of theorganic geological classification. Of the 72 potentialiver types, only 26 were present (Table 6): 8 in the

Pyrenees and 18 in the Iberic Macaronesian region.This classification gave a mosaic of territorial units andiver types spread over 16,424 km 2 . Furthermore, these

types were formed by small units and short water-courses scattered throughout the region (a situationthat is difficult to synthesize and show in a figure).

River Types Using System B

The variables used to de ne river types using SystemB are shown in Table 4. Pearson correlation analysisrevealed that distance from origin, stream order, andbasin shape were highly correlated ( r > 0.8) with sur-face drainage area; distance from the origin and basinshape with stream order; and basin shape with distancefrom the origin. Also, energy of flow and monthly flow variability index were highly correlated ( r > 0.8) withannual discharge and dry-period index, respectively (Table 6). Therefore, 14 variables were selected forfurther analysis after the Pearson s correlation

(Table 4). We used all of the obligatory variables asrequired by Annex II of the WFD (altitude, surfacedrainage area, and geologic typology), except longi-tude and latitude because of the small size of the Cat-alan River Basin District, and five optional variablesincluded in the same Annex. In addition, we added thedry-period index and the annual runoff coefficient.

The four PCA analyses, performed for each group of variables, resulted in a scatter diagram in which eachsite occupied a position in the space de ned by thePCA axis (e.g., Figure 7). This procedure determinesthe gradients along which the sites vary with respect toeach group of variables. The PCA scores for every sitein the axis were used as new variables for furtheranalyses. We selected seven PCA axes that were easily interpreted and explained a high percentage of varia-tion (Table 7). These new variables, corrected by theireigenvalues, were used to perform a nonhierarchicalcluster ( K -means analysis) and to define the group of sampling sites that belong to the same river type. Usingthe characterization of the sampling sites grouped

(Table 8), we classified the river water bodies belong-ing to the Catalan River Basin District into four rivertypes.

The discriminant level suitable for the Catalan RiverBasin District was established in four groups (rivertypes), which were clearly spatially de ned at 1:1,000,000 scale. We assumed that the four river types were environmentally homogeneous with similarhydrological and morphological conditions and, pre-sumably, very similar biological communities. This level of discrimination might be suitable to makecomparisons among European rivers (Wasson andothers 2002) and with other Mediterranean areas(Dallas and Fowler 2000). The small coastal streamsowing directly to the Mediterranean Sea were not included in the analysis because of a lack of data, such

Figure 6. Classification of river types using the altitude inhe Catalan River Basin District. Three areas are shownccording to the WFD System A classification.

Table 5. Number of river types in the two ecoregionsof the Catalan River Basin District according to WFDSystem A

EcoregionsusingSystem A

Types by altitude

Types by surface areaof basin

Types by surfacegeology

Totaltypes by ecoregion

Pyrenees 2 (3) 2 (4) 2 (3) 8 (36)beric

Macaronesian3 (3) 3 (4) 2 (3) 18 (36)

Total river types 26 (72)

Note: The number of categories are shown for the three main de-criptors (altitude, size on the basis of catchment area, and geology).

Numbers in brackets show the potential number of overall categoriessing System A.



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T a b l e 6

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N o t e :

* P 0.4 hm 3 /km),Mediterranean climate mountains have moderate (0.2 0.4 hm 3 /km 2 ) annual runoff, and dry Mediterraneanclimatic areas have low ( 20m3 /s) (Figure 9). Coastal streams were character-ized by their small drainage area (120 dry days per year).

Use of System B to Define Subtypes of RiverManagement

Given the heterogeneous characteristics of the Cat-alan River Basin District and the availability of reliabledata, we analyzed the level of distinction between rivertypes at a more detailed scale than that suggested by the WFD. Thus, we distinguish between river types, which might be useful for comparison at Europeanscale, and subtypes of river management, whichmight be useful at local scale, such as in the small andheterogeneous Catalan River Basin District. T a

b l e 8

.

C h a

r a c t e r i s t i c s o f r i v e r t y p e s i n t h e C a t a l a n R i v e r B a s i n D i s t r i c t u s i n g t h e v a r i a b l e s s e l e c t e d

( T a b l e 4 )

G r o u p o f

s a m p l i n g

s i t e s

N o . o f

s a m p l i n g

s i t e s

D i s c h a r g e

( m 3 / s )

R u n o

( h m

3 / k m

2 )

A l t i t u d e *

D r a i n a g e

a r e a *

( k m

2 )

C o v . o f c a l c a r e o u s

g e o l o g y *

( % o f d r a i n e d

a r e a )

C o v . o f

e v a p o r i t i c

g e o l o g y *


a r e a )

C o v . o f

s i l i c i c

g e o l o g y *


a r e a )

T e m p e r a t u r e

( C )

A n n u a l

r a i n f a l l

( m m )

N a m e o f

g r o u p o f

s a m p l i n g

s i t e s

( r i v e r t y p e s )

1

1 1

2 . 3 ( 2 . 6 )

0 . 6 ( 0 . 3 )

7 3 2

( 2 8 9 )

1 2 2

( 1 4 3 )

2 0 ( 1 9 )

0 7 ( 1 . 3 )

4 3 . 8

( 4 1

. 7 )

8 . 8 ( 1 . 7 )

9 8 7

( 1 2 0 )

W

e t m o u n t a i n

r i v e r s

2

3 8

3 . 5 ( 3 . 9 )

0 . 3 ( 0 . 1 )

3 2 0

( 1 8 5 )

3 7 4

( 4 1 4 )

1 5 ( 1 4 )

0 . 4 ( 0 . 7 )

1 9 . 8

( 3 0 2 } 1 2

. 1 ( 1 . 2 )

9 2 8

( 9 7 )

M

e d i t e r r a n e a n

c l i m a t e

m o u n t a i n r i v e r s

3

5 0

1 . 1 ( 1 . 3 )

0 . 1 ( 0 . 1 )

1 5 2

( 1 3 3 )

2 6 9

( 2 6 5 )

1 5 ( 1 7 )

8 . 8 ( 8 . 3 )

2 6 . 8

( 2 9

. 1 )

1 3 . 7

( 0 . 9 )

6 9 7

( 9 7 )

D r y M e d i t e r r a n e a n

c l i m a t e r i v e r s

4

9

2 2 . 9

7 ( 3 . 5 8 ) 0 . 2 ( 0 . 1 )

9 8 ( 1 2 3 )

3 1 0 3

( 1 2 3 0 )

1 7 ( 5 )

0 . 8 ( 0 . 8 )

1 6 . 1

( 1 5

. 5 )

1 4 . 3

( 0 . 7 )

8 1 4

( 9 6 )

L a r g e w a t e r c o u r s e s

N o t e :

W e s h o w t h e

a v e r a g e a n d t h e s t a n d a r d d e v i a t i o n ( i n p a r e n t h e s i s ) . A n a m e f o r e a c h g r o u p o f s a m p l i n g s i t e s i s s h o w n .

* T h e o b l i g a t o r y f a c t o r s s u g g e s t e d b y W F D t o d e f i n e t h e

r i v e r t y p e s u s i n g t h e S y s t e m B .

Figure 8. Box plot of annual runoff coefficient for each river

type (except the coastal streams) defined in the Catalan RiverBasin District: (1) wet mountain rivers, (2) Mediterraneanclimate mountain rivers, (3) dry Mediterranean climate riv-ers, (4) large watercourses. Outliers (5th and 95th percentile)are shown.



12/19

Using the same axes selected from the PCA used tode ne the river types (Table 7), we obtained a moredetailed classification. We increased the number of conglomerates, using K -means analysis, until types lost homogeneity and were divided in several disconnectedpatches. This occurred after the definition of nine landunits. Including coastal streams as a separate riverype, 10 subtypes of river management were identified.

Next, we used the Wilk s lambda statistic to select actors from Table 4 that discriminated among groups

and better defined these subtypes. We characterizedubtypes using discriminant factors (Table 9) and their

box plots (Figure 10), and a clear and simple definitionwas also established by introducing the coastal streamscategory (Table 8). Among the wet mountains type, we

identified two subtypes by differences in the percentageof cover of siliceous geology in the basin. In the Medi-terranean climate mountains type, the three subtypes were differentiated by annual discharge and by thepercentage of cover of siliceous and evaporitic geology in the basin. Finally, in the dry Mediterranean climaticarea, we differentiated three subtypes mainly by the flow variability (the dry-period index) and the percentage of siliceous and evaporitic geology in the basin.

Discussion

Regionalization and classi cation is a process usedto simplify complex geographical phenomena by

Figure 9. Box plots of discriminant variables for each subtype of river management in the Catalan River Basin District: (1a)iliceous wet mountain rivers, (1b) calcareous wet mountain rivers, (2a) siliceous Mediterranean climate mountain rivers, (2b)alcareous Mediterranean climate mountain rivers, (2c) Mediterranean climate mountain rivers with high discharge, (3a)owlands Mediterranean climate rivers, (3b) siliceous dry Mediterranean climate rivers, (3c) Karst feed rivers, (4) large water-ourses. Outliers (5th and 95th percentile) are shown.



13/19

establishing distinct units or area with similar envi-ronmental characteristics. It is a method that allows the

selection of those variables with great spatial variability and the most appropriate river system habitat models(Hughes and Larsen 1988). In ecological studies,regions were rst de ned using ideographic andquantitative techniques (Bunge 1966). However, sta-tistical and mathematical procedures were progres-sively applied for classi cation purposes (Pielou 1977;Gauch 1982), using multivariate analysis to simplify and order the environmental spatial variability (Balling1984) and for evaluating ecological resources (Bryceand Clarke 1996). To de ne regions and subregions inmore detail, some authors have used a systematicmethodology with a rule-based process in a geographicinformation system (GIS) (Bernet and others 1997).Methods using statistical tools and spatial environ-mental variables improve the accuracy of river classi -

cation and provide an optimal and more objectiveprocedure (Dawson and others 2002). In our case, weused a rule-based process within a GIS, combined witha multivariate statistical methodology. Our classi ca-tion scheme allowed us to de ne and typify the main watercourses in the Catalan River Basin District using WFD System B. Heterogeneous river characteristics were simplied using multivariate analyses, and theprocess can be followed in any river basin district by using the same or other available variables with thesystematic process described in Figure 2.

We considered a large number of variables to de neriver types using System B, thus introducing a highcapacity of differentiation. The results of the multivariate analysis showed that a low number of river typesgenerated from the signi cant variables explained

spatial variability. The discriminant capacity to distin-guish river types (required in the WFD Annex II)should not be understood as a different number of these, but by the quality and quantity of variables usedin the analysis. System A distinguished a greater num-ber of river types in the Catalan River Basin District (8in the Pyrenees and 18 in the Iberic Macaronesianregion, a total of 26 river types) than did System B (5types and 10 subtypes). Using System A, a large num-ber of speci c reference sites (several for each rivertype) will be necessary to de ne ecological status, which would result in a complex reference site net- work. Also, many of the river types de ned could have very similar environmental conditions and biologicalcommunities. The differentiation of 26 river typesusing System A makes the measurement of the eco-logical status of the river systems complex and expen-sive for the Catalan River Basin District. Similarconclusions were drawn in studies that tested System A for the characterization of Iberian watersheds(Marchamalo and Garcia de Jalo n 2000). An effective

and economic management of a small river basin dis-trict of this kind requires a relatively simple classi ca-tion system, with a limited number of river types that reect the natural variability of river systems, like theSystem B proposed in this article.

The discrimination power of Systems A and Bshould be further validated using biological commu-nities from reference sites. In the study area, the highlevel of human disturbance in many aquatic systems(Prat and Munne 2000) makes this validation dif cult,except for headwater streams. Also, typologies basedon biological communities might not be concordant using different taxonomic groups (Paavola and others2003). For this reason, in this work we used only envi-ronmental factors to de ne river types and subtypes ashomogeneous systems according to the WFD criteria.

Figure 9. Continued.



14/19

T a b l e 9

.

C h a

r a c t e r i s t i c s o f r i v e r t y p e s a n d s u b t y p e o f r i v e r m a n a g e m e n t

i n t h e C a t a l a n R i v e r B a s i n D i s t r i c t a c c o r d i n g t o b o x - p

l o t s a n

a l y s i s ( F i g u r e 9 )

R i v e r t y p e s

S u b t y p e s o f r i v e r

m a n a g e m e n t

N o . o f

c a s e s

D i s c h a r g e

( m 3 / s )

D r y -

p e r i o d

i n d e x

( s e e

T a b l e 4 )

C o v . o f

e v a p o r i t i c

g e o l o g y

( % o f

d r a i n e d

a r e a )

C o v . o f

s i l i c i c

g e o l o g y

( % o f

d r a i n e d

a r e a )

T e m p e r a t u r e

( C )

A n n u a l

r a i n f a l l

( m m )

M a j o r

d i s t i n g u i s h i n g

f e a t u r e s

1 a W e t m o u n t a i n

r i v e r s

S i l i c e o u s w e t


5

A v e r a g e

M a x

M i n

.

2 . 9 7

( 3 . 2 4 )

6 . 7 6

0 . 0 4

0 . 4 9

( 0 . 1 4 )

0 . 6 5

0 . 3 8

0 . 0 4

( 0 . 0 9 )

0 . 2 0

0 . 0 0

7 6 . 7

9

( 2 5

. 6 2 )

1 0 0 . 0 0

4 4 . 6

9

8 . 5

( 1 . 5 )

9 . 9

5 . 9

1 0 5 8

( 1 1 3 )

1 2 0 3

9 4 8

M o d e r a t e t o l o w a n n u a l d i s c h a r g e

H i g h p e r c e n t a g e o f s i l i c e o u s s u r f a c e

g e o l o g y i n t h e c a t c h m e n t

L o w a n n u a l a v e r a g e t e m p e r a t u r e

H i g h a n n u a l r a i n f a l l i n t h e c a t c h m e n t

1 b

C a l c a r e o u s w e t


6

A v e r a g e

M a x .

M i n

.

4 . 1 2

( 2 . 3 4 )

6 . 9 4

0 . 2 6

0 . 3 8

( 0 . 0 0 )

0 . 3 8

0 . 3 8

2 . 1 5

( 1 . 1 4 )

3 . 0 5

0 . 0 0

8 . 6 6

( 7 . 6 2 )

1 7 . 0

1

0 . 0 0

8 . 7

( 1 . 4 )

1 0 . 3

6 . 3

9 3 8

( 3 1 )

9 6 8

8 8 6

M o d e r a t e t o l o w a n n u a l d i s c h a r g e

L o w p e r c e n t a g e o f s i l i c e o u s s u r f a c e

g e o l o g y i n t h e c a t c h m e n t

M o d e r a t e t o l o w a n n u a l a v e r a g e


M o d e r a t e a n n u a l r a i n f a l l i n t h e

c a t c h m e n t

2 a M e d i t e r r a n e a n

c l i m a t e

m o u n t a i n

r i v e r s

S i l i c e o u s

M e d i t e r r a n e a n


1 0

A v e r a g e

M a x .

M i n

.

0 . 9 5

( 0 . 5 4 )

1 . 9 5

0 . 2 4

0 . 6 4

( 0 . 0 1 )

0 . 6 5

0 . 6 3

0 . 0 0

( 0 . 0 0 )

0 . 0 0

0 . 0 0

7 7 . 6

8

( 1 5

. 0 2 )

9 7 . 2

9

5 5 . 7

1

1 3 . 2

( 1 . 2 )

1 4 . 2 1 0

. 4

8 7 9

( 6 3 )

9 5 8

7 5 0

L o w a n n u a l d i s c h a r g e

H i g h i n d e x o f f l o w v a r i a b i l i t y


g e o l o g y

H i g h a n n u a l a v e r a g e t e m p e r a t u r e

M o d e r a t e a n n u a l r a i n f a l l i n t h e

c a t c h m e n t

2 b

C a l c a r e o u s



1 7

A v e r a g e

M a x .

M i n

.

0 . 9 8

( 1 . 0 4 )

4 . 4 4

0 . 1 1

0 . 5 0

( 0 . 1 8 )

0 . 6 5

0 . 2 9

0 . 2 2

( 0 . 5 8 )

1 . 8 1

0 . 0 0

8 . 0 5

( 1 4

. 0 9 )

4 4 . 3

5

0 . 0 0

1 1 . 8 ( 1 . 3 )

1 3 . 6

8 . 5

9 4 5

( 1 0 9 )

1 1 2 5

7 9 0


L o w p e r c e n t a g e o f s i l i c e o u s s u r f a c e

g e o l o g y

M o d e r a t e t o h i g h a n n u a l a v e r a g e


M o d e r a t e t o h i g h a n n u a l r a i n f a l l i n

t h e c a t c h m e n t

2 c


m o u n t a i n r i v e r s w i t h

h i g h d i s c h a r g e

1 1

A v e r a g e

M a x .

M i n

.

1 0 . 8

0

( 4 . 7 9 )

1 9 . 7

6

4 . 0 4

0 . 3 0

( 0 . 0 4 )

0 . 3 8

0 . 2 9

0 . 4 8

( 0 . 3 8 )

1 . 0 4

1 3 . 6

5

( 1 6

. 3 1 )

4 7 . 9

6

0 . 0 0

1 2 . 7

( 0 . 8 )

1 4 . 5 1 1

. 6

9 0 0

( 1 1 3 )

1 0 5 3

7 5 2

M o d e r a t e t o h i g h a n n u a l d i s c h a r g e

L o w i n d e x o f f l o w v a r i a b i l i t y

H i g h p e r c e n t a g e o f e v a p o r i t e w i t h

c h l o r i n e s u r f a c e g e o l o g y

M o d e r a t e t o h i g h a n n u a l a v e r a g e


M o d e r a t e t o h i g h a n n u a l r a i n f a l l i n

t h e c a t c h m e n t



15/19

3 a D r y M

e d i t e r r a n e a n


L o w l a n d s



3 5 A v e r a g e

M a x .

M i n .

1 . 1 5

( 1 . 5 4 )

6 . 0 1

0 . 0 2

0 . 6 3

( 0 . 0 4 )

0 . 6 5

0 . 3 8

1 . 2 3

( 2 . 9 0 )

1 . 4

0 . 0 0

2 1 . 2

1

( 2 5

. 8 9 )

7 9 . 1

6

0 . 0 0

1 3 . 6

( 1 . 0 )

1 5 . 0 1 1

. 7

7 0 0

( 8 3 )

8 6 9

5 5 8




L o w a n n u a l r a i n f a l l i n t h e c a t c h m e n t

3 b

S i l i c e o u s d r y


r i v e r s

3 A v e r a g e

M a x .

M i n .

0 . 7 4

( 0 . 9 4 )

1 . 8 1

0 . 0 5

0 . 6 5

( 0 . 0 2 )

0 . 6 6

0 . 6 3

0 . 0 1

( 0 . 0 2 )

0 . 0 4

0 . 0 0

8 2 . 5

9

( 2 . 1 5 )

8 4 . 1

9

8 0 . 1

4

1 4 . 1

( 0 . 2 )

1 4 2

1 3 . 9

7 2 8

( 2 9 )

7 5 5

6 9 7




g e o l o g y



3 c

K a r s t f e e d r i v e r s

1 2 A v e r a g e

M a x .

M i n .

1 2 1

( 0 9 9 )

3 . 0 2

0 . 1 2

0 . 2 6

( 0 . 1

7 )

0 . 6 3

0 . 1 8

1 3 . 6

7

( 1 3

. 0 8 )

3 7 . 3

7

0 . 0 0

1 1 . 5

4

( 9 . 4 1 )

2 9 . 5

4

0 . 2 2

1 4 . 0 ( 0 . 6 )

1 4 . 8 1 3

. 0

6 1 8

( 7 5 )

8 3 9

5 5 1


L o w i n d e x o f t h e f l o w v a r i a b i l i t y

H i g h p e r c e n t a g e o f e v a p o r i t e s u r f a c e

g e o l o g y



4 a L a r g e

w a t e r c o u r s e s

L a r g e w a t e r c o u r s e s 9 A v e r a g e

M a x .

M i n .

2 2 . 9

7

( 3 . 5 8 )

2 9 . 0

7

1 8 . 1

9

0 2 9

( 0 . 0 0 )

0 . 2 9

0 . 2 9

0 . 7 7

( 0 . 8 5 )

1 . 9 4

0 . 0 2

1 6 . 0

7

( 1 5

. 4 8 )

3 4 . 3

7

1 . 1 6

1 4 . 3 ( 0 . 7 )

1 5 . 6

1 2 . 9

8 1 4

( 9 6 )

9 3 3

7 1 2

H i g h a n n u a l d i s c h a r g e

L o w i n d e x o f f l o w v a r i a b i l i t y

H i g h a v e r a g e a n n u a l a v e r a g e


5 a C o a s t a l

s t r e a m s

C o a s t a l s t r e a m s

I n t e r m i t t e n t a n d

l o w ( < 0 . 3 )

V e r y h i g h

( > 0 . 7 )

V a r i a b l e V a r i a b l e H i g h ( > 1 4 ) V a r i a b l e S m a l l r i v e r s p l a c e d a l o n g t h e

l i t t o r a l C a t a l a n W a t e r D i s t r i c t

a n d d r a i n e d t o t h e M e d i t e r r a n e a n

S e a . S m a l l d r a i n a g e a r e a ( < 2 5 0 k m 2 )

I n t e r m i t t e n t f l o w r e g i m e

( > 1 2 0 d r y d a y s p e r y e a r )

N o t e :

W e s h o w t h e a v e r a g e , t h e s t a n d a r d d e v i a t i o n ( i n p a r e n t h e s i s )

, a n d t h e m a x i m u m a n d m i n i m u m v a l u e s f o r e v e r y d i s c r i m i n a n t f a c t o r . F

o r t h e

c o a s t a l s t r e a m s

r i v e r t y p e , w

h i c h a r e n o t

i n c l u d e d i n t h e a n a l y s i s , t h e q u a l i t a t i v e c h a r a c t e r i s t i c s a r e g i v e n .



16/19

The Catalan Water Agency is currently setting up anetwork of reference sites, where it is possible. Alter-natively, if reference sites are not present in a type, thebest quality site for a given subtype of river manage-ment should be de ned.

Why is System B more adequate than System A foriver typology? Using System A, the river types are dis-inguished by altitude (up to 800 m, between 200 and

800 m, and below 200 m), geology type of drainagearea (calcareous or siliceous), and size of drainage areaup to 10,000 km 2 , between 1000 and 10,000 km 2 ,

between 100 and 1000 km 2 , and below 100 km 2 ), but hydrological and climatic variables are not used. UsingSystem B, following the method explained in this arti-cle, river types are mainly distinguished by the annualunoff coefficient, the flow regime and discharge, the

geology type of the drainage area (nonanthropogenic water chemistry), and climatic variables (the annualrainfall and air temperature). The discharge and its variability, usually generated by rainfall patterns, are akey element of the community structure in river eco-systems (Poff and Allan 1995) and should be used todefine river types, specially in Mediterranean areas.

It might be agreed that drainage area is correlated with discharge (as used in System A) in regular rainfallregions and homogeneous runoff coef cients, but inMediterranean areas, mean ow is not indicative of theriver characteristics as a result of high intra- andinterannual variability in the ow regime. Therefore,ow variability and runoff coef cient are betterdescriptors for classifying river types in the Mediterra-nean areas and are not considered in System A. In our

Figure 10. River types and subtypes of river management in the Catalan River Basin District using the WFD System B (2000/60/EC) (see Table 9). Groups of small watercourses corresponding to the same river type or subtype (siliceous and calcareous wet mountain rivers, siliceous and calcareous Mediterranean mountain rivers, lowlands Mediterranean rivers, siliceous dry Medi-erranean rivers, and coastal streams) are shown in the figure in a shaded area. This map is available in color at www.gencat.net/ca/.



17/19

case, using System B, different river types and subtypesof river management were distinguished by the runoff coef cient (low, 0.4 hm 3 /km 2 ), the dry-periodindex (low variability flow regime, 0.6), and thedischarge category (see Table 9).

Different types and scales of data have a greaterinuence on river classi cation, depending on the variable measured (Frissell and others 1986; Allan and Johnson 1997; Lammert and Allan 1999), and distinct scales should be analyzed to manage water integrity. Watershed conditions have been used to predict bio-logical communities (Roth and others 1996) and rivermesohabitat conditions (Harding and others 1997;Cohen and others 1998) and, in contrast, several au-

thors show that local and near landscape conditions of site-specic rivers might be signi cantly correlated withbiological habitat structure and biological quality indi-ces, which are not related to catchment conditions(Vinson and Hawkins 1998; Nerbonne and Vondracek2001; Dovciak and Perry 2002). In our opinion, largeclassication units or ecoregions are not useful for localmanagement, because biological measures might not be comparable (Moog and others 2004) and decision-making should be at local scale. In our study, we pro-pose that watercourses delimited at more detailed scale(subtypes of river management) contribute to improvemanagement practices in heterogeneous environments(e.g., Mediterranean river basin districts), while a low detailed scale, such as river types, is useful for reportsand also for comparing diagnostics at the Europeanlevel. The ve river types dened in the Catalan RiverBasin District (16,424 km 2 ) provide a good spatial def-inition at European management level (1:1,000,000scale) (Bryce and Clarke 1996; Wasson and others2002) and are enough for reporting the river ecological

status to the European Commission (Wallin and others2003). This level is in accordance with the classificationdefined in similar and nearby river basin districts usingSystem B (Ivol-Rigault 1998; Munne and Prat 2000) andin other Mediterranean zones (Dallas and Fowler2000). However, for better river ecosystem manage-ment in small and heterogeneous water districts, espe-cially in Mediterranean areas, a more detailedclassification is necessary (Vidal-Albarca and others1990). We subdivided these 5 types into 10 subtypes of river management using the same multivariate meth-odology. Although the coastal stream type might be anheterogeneous group, it is included here as a uniquemanagement unit.

Our river classi cation process using System B offersa coherent division and establishes a spatial river clas-

sication where boundaries are drawn around areas with similar characteristics (Wright and others 1998).Reference conditions should be assigned in the futurefor each subtype of river management to correctly design tools for their management. For this task,undisturbed or minimally disturbed sites of river arerequired for each subtype of river management (Warry and Hanau 1993).

AcknowledgmentsFinancial support was provided by the Catalan Water

Agency, the Water Authority of the Catalan River BasinDistrict managed by the Autonomous Government of Catalonia (Generalitat de Catalunya). Special thanks goto Llu s X. Gode and Gervasi Benito for data from the

Catalan Water Agency, Alex Rocas for interpretation of geologic data, and the ECOBILL scienti c group of theDepartment of Ecology (University of Barcelona)(Maria Rieradevall, Nu ria Bonada, Carolina Sola, Mireia Vila, Rosa Casanovas, and Marc Plans) for support. Fouranonymous referees improved the original text.

Literature Cited Allan, J. D., and L. B. Johnson. 1997. Catchment-scale analysis

of aquatic ecosystems. Freshwater Biology 37:107111.Bailey, R. C. 1987. Mapping ecoregions to manage lands.

Pages 8285 in 1987 Yearbook of agriculture. US Depart-ment of Agriculture. Washington, DC.

Bailey, R. C., M. G. Kennedy, M. Z. Dervish, and R. M. Taylor.1998. Biological assessment of freshwater ecosystems usinga reference condition approach: comparing predicted andactual benthic invertebrate communities in Yukon streams. Freshwater Biology 39:765774.

Balling, R. C. 1984. Classification in climatology. Pages 81 108 in G. L. Gaile, C. J. Willmott (eds.), Spatial statistics andmodels. D. Reidel, Dordrecht.

Bernert, J. A., J. M. Eilers, T. J. Sullivan, K. E. Freemark, andC. Ribic. 1997. A quantitative method for delineatingregions: An example for the Western Corn Belt Plainsecoregion of the USA. Environmental Management 21(3):405 420.

Bolos, O., J. Vigo, R. M. Masalles, and J. M. Ninot. 1993.Flora. Manual dels Pa sos Catalans. Portic, S.A., Barcelona.

Bryce, S. A., and S. E. Clarke. 1996. Landscape-level ecologicalregions: Linking state-level ecoregion frameworks withstream habitat classifications. Environmental Management 20(3):297 311.

Bunge, W. 1966. Theoretical geography. Lund studies ingeography series C, 2nd ed. General and MathematicalGeography No. 1. Gleerup, Lund, Sweden.

Cohen, P., H. Andriamahefa, and J. G. Wasson. 1998.Towards a regionalization of aquatic habitat: distribution of mesohabitats at scale of a large basin. Regulated Rivers Research and Management 14:391404.



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Dallas, H., and J. Fowler. 2000. Delineation of river types of Mpumalanga, South Africa: Establishing a spatial framework for selection of reference sites. Institute for WaterQuality Studies, Department of Water Affairs and Forestry,Pretoria, South Africa, 111 pp.

Dawson, F. H., D. D. Hornby, and J. Hilton. 2002. A

method for the automated extraction of environmental variables to help the classification of rivers in Britain.Aquatic Conservation: Marine and Freshwater Ecosystems 12:391403.

Dovciak, A. L., and J. A. Perry. 2002. In search of effectivescales for stream management: Does agroecoregion, watershed, or their intersection best explain the variancein stream macroinvertebrate communities? Environmental Management 30(3):365 377.

European Commission. 2000. Directive (2000/60/EC).Establishing a framework for community action in the fieldof water policy. Pages 1 72 in Official Journal of the

European Communities (22/12/2000) L327.Frissell, C. A., W. J. Liss, C. E. Warren, and M. D. Hurrey.1986. A hierarchical framework for stream habitat classifi-cation: Viewing streams in a watershed context. Environ- mental Management 10(2):199 214.

Gasith, A., and V. H. Resh. 1999. Streams in Mediterraneanclimate regions: Abiotic influences and biotic responses topredictable seasonal events. Annual Review of Ecology and Systematics 30:5181.

Gauch, H. G. 1982. Multivariate analysis in community ecol-ogy. Cambridge University Press. Cambridge.

Gergel, S. E., M. G. Turner, J. M. Miller, J. M. Melack, and E.H. Stanley. 2002. Landscape indicators of human impactsto riverine systems. Aquatic Sciences 64:118128.

Gregory, S.V., F. J. Swanson, W.A. McKee, and K. W.Cummins.1991. An ecosystem perspective of riparian zones: Focus onlinks between land and water. BioScience 41:540551.

Harding, J. S., M. J. Winterbourn, and W. F. McDiffent. 1997.Stream faunas and ecoregions in South Island, New Zea-land: Do they correspond? Archiv fu r Hydrobiologie 140(3):289 307.

Hawkins, C. P., and R. H. Norris. 2000. Performance of dif-ferent landscape classifications for aquatic bioassessments:

Introduction to the series. Journal of the North American Benthological Society 19(3):367 369.Hawkins, C. P., R. H. Norris, J. Gerritsen, R. H Hughes,

S. K. Jackson, R. K. Johnson, and R. J. Stevenson. 2000.Evaluation of the use of landscape classifications for theprediction of freshwater biota: Synthesis and recommen-dations. Journal of the North American Benthological Society 19(3):541 556.

Hughes, R M., and D. P. Larsen. 1988. Ecoregions: Anapproach to surface water protection. Journal of the Water Pollution Control Federation 60:486493.

Hughes, R. M., D. P. Larsen, and J. M. Omernik. 1986.

Regional reference sites: A method for assessing streampotentials. Environmental Management 10:629635.llies, J 1978. Limnaufauna Europaea, a checklist of the ani-

mals inhabiting European inland waters, with accounts of their distribution and ecology (except protozoa). Vol. II.Fisher-Verlag, Stuttgart.

Illies, J., and L. Botosaneanu. 1963. Problemes et methodesde la classification et de la zonation ecologique des eauxcorantes, considerees surtuout du point de vue faunistique.Mitteilungen der Internationale Vereinigung fu r Theoretische and Angewandte Limnologie 12:157.

Ivol-Rigault, J. M. 1998. Hydro-ecore gions et variabilite des

communaute s du macrobenthos sur le bassin de la Loire.Essai de typologie re gionale et referentiel faunistique. PhD,University of Lyon I, 271 pp.

Jain, A. K., and R. C. Dubes. 1988. Algorithms for clusteringdata. Prentice-Hall, Englewood Cliffs, New Jersey.

Jongman, R. H. G., C. J. F. Ter Braak, and O. F. R. Tongeren.1996. Data analysis in community and landscape ecology.Cambridge University Press, Cambridge.

Johnson, L. B., C. Richards, G. E. Host, and J. W. Arthur.1997. Landscape influences on water chemistry in mid- western stream ecosystems. Freshwater Biology 37:193208.

Lammert, M., and J. D. Allan. 1999. Assessing biotic integrity of streams: Effects of scale in measuring the influence of land use cover and habitat structure of fish and macroinvertebrates. Environmental Management 23:257270.

Legendre, P., and L. Legendre. 1998. Numerical ecology.Elsevier. Science B.V., Amsterdam.

Lenat, D. R., and J. R. Crawford. 1994. Effects of land use on water quality and aquatic biota of the three North CarolinaPiedmont streams. Hydrobiologia 294:185199.

Marchamalo, M., and D. Garc a de Jalon. 2000. Clasificacio necotipolo gica de los r os espan oles peninsulares segu n la

Directiva Marco de Pol tica de Agua Europea. Page 244 in Libro de resu menes del X Congreso de la Asociacio nEspan ola de Limnolog a y II Congreso Ibe rico de Limno-loga. Valencia, Spain.

Marchant, R., F. Wells, and P. Newall. 2000. Assessment of anecoregion approach for classifying macroinvertebrateassemblages. Journal of the North American Benthological Society 19(3):97 500.

Marshall, I. B., C. A. S. Smith, and C. J. Selby. 1996. A nationalframework for monitoring and reporting on environmentalsustainability in Canada. Environmental Monitoring and Assessment 39:2538.

Minshal, G. W. 1988. Stream ecosystem theory: A global per-spective. Journal of North American Benthological Society 7:263288.

Molnar, P., P. Burlano, and W. Ruf. 2002. Integrated catch-ment assessment of riverine landscape dynamics. Aquatic Sciences 64:129140.

Montgomery, D. R. 1999. Process domains and the rivercontinuum. Journal of American Water Resources Association 35:397410.

Moog, O., A. Schmidt-Kloiber, T. Ofenbo ck, and J. Gerritsen.2004. Does the ecoregion approach support the typological

demands of the EU Water Framework Directive ? Hydrobi- ologia 16:2133.Munne , A., and N. Prat. 1998. Delimitacion de regiones

ecolo gicas en la cuenca del Ebro. Asistencia te cnica1998-PH-08-I. Confederacion Hidrogragica del Ebro, Zar-agoza, 153 pp.



19/19

Munne , A., and N. Prat. 2000. Delimitacion de regionesecolo gicas para el establecimiento de tipos de referencia y umbrales de calidad biolo gica: Propuesta de aplicacio n dela nueva Directiva Marco del Agua en la cuenca del Ebro. Actas del II Congreso Iberico sobre Gestion y Planificacio ndel Agua. Fundacion Nueva Cultura del Agua, Oporto, 19pp.

Naiman, R. J., H. Decamps, and M. Pollock. 1993. The role of riparian corridors in maintaining regional biodiversity. Ecological Applications 3:209212.

Nerbonne, B. A., and B. Vondracek. 2001. Effects of localland use on physical habitat, benthic macroinvertebrates,and fish in the Whitewater River, Minnesota, USA. Envi- ronmental Management 28(1):87 99.

Omernik, J. M., A. R. Abernathy, and L. M. Male. 1981.Stream nutrient levels and proximity of agricultural andforest land to streams. Journal of Soil and Water Conservation 36:227231.

Omernik, J. M. 1987. Ecoregions of the conterminous UnitedStates. Map scale (1:7,500,000). Annals of the Association of American Geographers 77(1):118 125.

Omernik, J. M., and R. G. Bailey. 1997. Distinguishingbetween watersheds and ecoregions. Journal of the American Water Resources Association 33(5):935 949.

Paavola, R., T. Muotka, R. Virtanen, J. Heino, and P. Kreivi.2003. Are biological classifications of headwater streamsconcordant across multiple taxonomic groups? Freshwater Biology 48:19121923.

Petersen, R. C., Jr., B. L. Madsen, M. A. Wilzbach, C. H. D.Magadza, A. Paarlberg, A. Kullberg, and K. W. Cummins.1987. Stream management: emerging global similarities.Ambio 16:166179.

Pielou, E. C. 1977. Mathematical ecology. John Wiley & Sons,New York.

Poff, L. N., and D. Allan. 1995. Functional organization of stream fish assemblages in relation to hydrological vari-ability. Ecology 76:606627.

Poff, L. N., J. D. Allan, M. B. Bain, J. R. Karr, K. L. Preste-gaard, B. D. Richter, R. E. Sparks, and J. C. Stromberg.1997. The natural flow regime: A paradigm for river con-servation and restoration. BioScience 47:769784.

Prat, N., and A. Munne. 2000. Water use and quality andstream flow in a Mediterranean stream. Water Research.34(15):3876 3881.

Rabeni, C. F., and K. E. Doisy. 1998. The distribution of benthic macroinvertebrates among ecoregions and fishfaunal regions in Missouri streams. Journal of the North American Benthological Society 15(1):147 160.

Resh, V. H., R. H. Norris, and M. T. Barbour. 1995. Designand implementation of rapid assessment approaches for water resource monitoring using benthic macroinverte-brates. Australian Journal of Ecology 20:108121.

Reynoldson, T. B., R. H. Norris, V. H. Resh, K. E. Day,D. M. Rosenberg. 1997. The reference condition: a com-parison of multimetric and multivariate approaches toassess water-quality impairment using benthic macroinver-tebrates. Journal of American Water Resources Association 16(4):833 852.

Riba, O. 1976. El relleu dels Pa sos Catalans. Pages 7 68 in Geografia f sica dels Pa sos Catalans. Ketres, Barcelona.

Richards, C., L. B. Johnson, and G. E. Host. 1996. Landscape-scale influences on stream habitats and biota. Journal of Fisheries and Aquatic Science 53(Suppl. 1):295 311.

Roth, N. E., J. D. Allan, and D. L. Erickson. 1996. Landscape

influences on stream biotic integrity assessed at multiplespatial scales. Landscape Ecology 11(3):141 156.Schlosser, I. J. 1991. Stream fish ecology: A landscape per-

spective. BioScience 41:704712.Sole, L. 1958. El relleu. Pages 25 157 in Geografia de Ca-

talunya. Aedos, Barcelona.Ter Braak, C. J. F., and P. Smilauer. 2002. CANOCO refer-

ence manual and CanoDraw for Windows user s guide:Software for Canonical Community Ordination (Version4.5). Microcomputer Power, Ithaca, New York.

Townsend, C. R., B. J. Downes, K. Peacock, and C. J. Arbuckle.2004. Scale and the detection of land-use effects on mor-phology, vegetation and macroinvertebrate communities of grassland streams. Freshwater Biology 49:448462.

Uys, M. C., and J. H. OKeeffe. 1997. Simple words and fuzzy zones: early directions for temporary river research inSouth Africa. Environmental Management 12(4):517 531.

Van Sickle, J., and R. M. Hughes. 2000. Classificationstrengths of ecoregions, catchment, and geographic clus-ters for aquatic vertebrates in Oregon. Journal of the North American Benthological Society 19(3):370 384.

Vannote, R. L., G. W. Minshall, K. W. Cummins, J. R. Se-dell, and C. E. Cushing. 1980. The river continuum

concept. Canadian Journal of Fisheries and Aquatic Sciences 37:130137. Vidal-Albarca, M. R., C. Montes, M. L. Suarez, and L. Ram rez-

Daz. 1990. Sectorizacio n ecolo gica de cuencas fluviales: Aplicacion a la cuenca del r o Segura (SE Espan a). Anales Geografa. Universidad Computense 10:149182.

Vinson, M. R., and C. P. Hawkins. 1998. Biodiversity of streaminsects: Variation at local, basin, and regional scales. An- nual Review of Entomology 43:271293.

Wallin, M., T. Wiederholm, and R. K. Johnson. 2003. Guid-ance on establishing reference conditions and ecologicalstatus class boundaries for inland surface waters. CIS-WFD Working Group 2.3 REFCOND Version 6 (final), 93 pp.

Warry, N. D., and M. Hanau. 1993. The use of terrestrialecoregions as regional-scale screen for selecting represen-tative reference sites for water quality monitoring. Envi- ronmental Management 17(2):267 276.

Wasson, J. G., A. Chandesris, H. Pella, and L. Blanc. 2002. Leshydro-e core gions de France metropolitaine: Approcheregionale de la typologie des eaux courantes et e lementspour la definition des peuplements de re ference d inver-tebre s. Research program HYDRECO (LHQ), Cemagref,Lyon, 190 pp.

Waters, T. F. 1995. Sediment in streams. American FisheriesSociety Monograph 7. American Fisheries Society, Beth-esda, Maryland.

Wright, R. G., M. P. Murray, and T. Merrill. 1998. Ecoregionsas a level of ecological analysis. Biological Conservation 86:207213.


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