Comparison of natural and differently urbanized sections of Rák Stream in Sopron
Zoltán Gribovszki, Péter Kalicz, Péter Csáfordi, Géza Király, Renáta Szita, Andrea Pődör
University of West Hungary, Institute of Geomatics and Civil Engineering , Sopron, Hungary, corresponding
author: zgribo@emk.nyme.hu
Abstract
Urbanization has great influence both on the drainage system of a catchment, especially in
case of small streams. The changes manifest both in the water quality and the water
quantity. Generally the water quality becomes worse and the water regime becomes more
extreme. The negative changes have an effect on the broader environment, so on the
neighbouring ecosystems also, and significantly decrease the biodiversity (GayerLigetváry 2007). The assessment of these effects is very important and not only from the
ecological viewpoint, but also from safety of the humans.
The water status changes of a small stream are examined in the natural and urban
environment of the Rák brook stream system in Sopron (Western Hungary). We assigned
seven monitoring points in the watershed from the headwaters to the stream mouth.
Surface cover characteristic parameters of natural and differently urbanized subcatcments
are determined from remote sensed dataset. Samples were taken fortnightly or for floodlinked in the period 01.09.2010-01.05.2012. The following features were determined:
catchment characteristic, discharge, physico-chemical, chemical and biological parameters.
Simple and multivariate statistical methods were used for data processing. Based on the
results the effect of the different degree of urbanization on the watershed and the hydromorphological interventions in the stream bed was well demonstrable.
Introduction
The nowadays dominating social-economical processes, such as the urbanization and the
extension of suburban regions, intensify the alteration of hydrologic cycle. The urban water
management infrastructure is responsible for the qualitative changes as well the
quantitative modification, furthermore the cities have impact on the whole spectrum of
hydrometeorology. Gayer and Ligetvári (2007) summarize the most important factors and
processes, which have negative influences on the hydrological conditions. Pavements,
channel control and canalisation reduce the surface roughness, the surface storage capacity,
and the infiltration rate. The consequences are the increased surface runoff, the larger flood
peaks, the shorter time of concentration, and the reduced travel time.
Experiments of several authors confirm that the impermeable pavements significantly raise
urban rainfall-runoff. Corbett et al. (1997) modelled the non-point source runoff from a
forested and an urban watershed. The urban watershed runoff ratio was on average 14.5 %
higher than the forested watershed, and the urban watershed generated the highest runoff
ratio (66%). Brattebo and Booth (2003) investigated the long-term effectiveness of four
permeable and an impervious asphalt surface for runoff quantity, and they found, that
while the runoff from the asphalt stall closely followed precipitation rates during all rain
events, all four permeable pavement systems infiltrated virtually all precipitation, even
during the most intense storms experienced during the study period. White and Greer
(2006) asserted that the increase of urbanization resulted significant increases in flood
magnitudes and geomorphic changes to stream channel morphology. Since the hydrologic
conditions are modified, the increased discharges need larger cross-sections, increasing the
channel erosion (Gayer and Ligetvári 2007). Urban surfaces and constructions also modify
the natural watershed boundaries. Therefore there is a need to develop reliable delineation
techniques of urban watersheds. The alteration of hydrological conditions may include the
lowering of groundwater level (Cho et al. 2009). However Barron et al. (2012) give an
example when the groundwater recharge rates, and subsequently the groundwater
discharge on the urban drainage network was higher due to the direct infiltration of roof
and road runoff.
Degradation of water quality in urban areas is the consequence of increased water intake,
sewage disposal, contaminated runoff through the canal systems, and non-point pollution
by rainfall-runoff (Buzás 2009, Gayer and Ligetvári 2007, ÖKOTECH 2005). The
contaminated urban runoff may lead to following characteristic chemical and biological
problems. The dissolved oxygen concentration declines in the receiving water due to the
high oxygen demand of sewage disposal and runoff water. High nutrient input, such as
phosphorous and nitrogen compounds may trigger eutrophication. Accumulated heavy
metals and toxic materials may cause acute or chronic intoxication of the aquatic
ecosystems.
Not only the quantitative, but also the qualitative alteration of hydrological conditions may
have ecological consequences, such as changes of the biodiversity and habitat degradation.
Nyenje et al. (2010) summarized studies related to nutrient contamination of African water
bodies, drawing the conclusion, that eutrophication induces the reduction of dissolved
oxygen concentration, the disappearance of certain fish species, furthermore the
multiplication of toxic and nosogenic bacteria. Researches of O’Hare (2010) prove that the
increased biological production, promoted by long-term human phosphorous pollution,
may lead to macrophytic eutrophication. Fuma et al. (2003) investigated the effect of
several toxic substances and radiation (Al, Cu, Mn, Ni, Gd, γ- and UV-radiation,
acidification) to three kind of aquatic organism, such as Euglena gracilis, Tetrahymena
thermophila, and Escherichia coli.
The study area, Sopron also presents the typical urbanisation processes, such as sewage
disposal, non-point-pollution by surface runoff, extension of suburban region,
intensification of greenfield investments, building of industrial zones, and shopping
centres. This study focuses on the quantitative and qualitative alteration of Rák Stream in
Sopron. To demonstrate different degree of urbanization on the watershed and the hydromorphological interventions in the stream bed, changes in hydrological conditions,
physico-chemical, chemical, and biological parameters have been investigated from the
nearly undisturbed forested headwater catchment along the differently urbanized sections,
to the stream mouth.
Matherial and methods
In the first phase of the work the data sources was collected about the urban section of the
Rák brook: hydrology, hydrogeology (Kárpáti (1955), Kisházi-Ivancsics (1981-85), KVT
(1981), MTA FKI (1990)), water chemistry (Klinger (1993), Keller (1998), GuttmannImrik (2010)), map data sources and other studies (Kondor (1991), Tóth (2005), Farkas
(2008), NYME KKK (2009)). On the basis of the collected data sources the drainage basin
was divided into different parts (eg. what is the dominant surface cover and what kind of
and how intensive human activities going on there). The sampling points were settled on
the basis of the former informations (Figure 1). The coordinates of the measurement points
and the basic informations about the drainage sub-catchment belonging to them can be
seen in Table 1.
Table 1. Basic informations of the examined sub-catchments and coordinates of outlet
sampling points
Sampling point
(Code)
EOV-X
EOV-Y
Ac (km2)
Asc (km2)
Outlet point of an undisturbed, totally
forested research catchment. Only one
5,76
former immigration officer house on the
catchment.
4,34
The outlet point of the Brennberg
reservoir to study the effects of the
Brennberg
457955,77
10,10
reservoir in an undisturbed water system.
reservoir (TO)
262192,94
On the watershed only 1-2 hunting house.
The catchment is almost totally forested.
13,56
EDUKOVIZIG-NYME gauging station
Sopronbánfalva
on the upper part of the town Sopron. 2
461420,27
gaging station
23,66
small villages and some farm houses on
262175,24
(BAN)
the sub-catchment. The dominant surface
cover of the catchments is forest.
3,37
Hajnal Square. On the sub-catchment
Hajnal Square
462422,36
27,03
only suburban areas: private houses with
(HAJNAL)
262364,38
garden.
4,65
At the end of the Erzsébet Public Garden,
before the brook flows into the 1.6 km
long tunnel under the city. On the subFasor Street
464591,68
catchment mainly suburban areas with
31,68
(FASOR)
262897,20
some sport-grounds and one small
building estate. The brook flows in a 0.6
km long tunnel in one part of the subcatchment.
4,27
After the long tunnel under the city. The
Győri Road
466163,02
sub-catchment is mainly densely built
35,95
(GYORI)
261919,33
downtown area. The brook flows in a
tunnel all along the sub-catchment.
1,38
Bridge on Industrial Area (near Tesco
TESCO Bridge
466955,82
37,33
supermarket). Sub-catchment belonging
(TESCO)
261189,69
to it is mainly industrial area.
Ac: Total catchment area belongs to the sampling point, Asc, Sub-catchment between the actual and upper
sampling point.
Outlet of research
catchment
(HAZ)
5,76
Characterization
455886,22
261941,60
Figure 1. Location of the examined stream catchment (natural and differently urbanized
parts in the area of city Sopron, West Hungary)
On the sampling points (which are also the settling places of the permanent gages), the
water sages have been recorded continuously (in every minutes) since the end of April
2011. On the same places the geometry of the cross section and the discharge, which is
very important for calculation of rating curve (for each gage), have been measured together
with basic physical-chemical parameters (temperature, pH, conductivity (K), suspended
sediments (SS)) since fortnightly September 2010. Since February 2011 other water
chemistry parameters have also been determined (COD, ammonium (NH4+), nitrate (NO3), total phosphorus, sulphate, chloride). So as to eliminate seasonal effect not the total
dataset but a shorter one year time period (from 2011.02.01 to 2012.01.31) was selected for
analysis of fortnightly samplings.
On the basis of remote sensing data surface cover characteristics are determined for the
watersheds (Table 2.). The following categories were used for classifications: Urban
(artifically modified) area, Agricultural land, Grassland, Forest and bushy area.
Table 2. Surface cover characteristics of the examined catchment and subcatchments
Catchments
[km2(%))]
Urban
(artifically
modified) area
Agricultural
land
Grassland
TESCO
GYORI
FASOR
HAJNAL
BAN
TO
HAZ
6.97
(18.67)
5.81
(16.17)
2.05
(6.48)
0.36
(1.34)
0.29
(1.24)
0 (0)
0 (0)
1.23
(5.18)
1.12
(4.73)
21.02
(88.85)
BAN-TO
0.03
(0.29)
0.59
(5.86)
9.48
(93.84)
TO-HAZ
0 (0)
0.29
(2.16)
0 (0)
0 (0)
1.20
(8.83)
0.53
(3.89)
11.54
(85.14)
0.03
(0.67)
0.39
(8.89)
3.93
(90.41)
0 (0)
3.04
2.79
2.64
1.72
(8.15)
(7.75)
(8.32)
(6.38)
1.13
1.12
1.12
1.12
(3.02)
(3.12)
(3.54)
(4.14)
Forest and
26.19
26.23
25.87
23.82
bushy area
(70.16)
(72.95)
(81.66)
(88.14)
Subcatchments TESCO- GYORIFASORHAJNAL[km2(%))]
GYORI
FASOR
HAJNAL BAN
Urban
1.16
3.76
1.69
0.07
(artifically
(83.69)
(88.09)
(36.34)
(2.10)
modified) area
Agricultural
0.26
0.15
0.91
0.50
land
(18.60)
(3.51)
(19.62)
(14.81)
Grassland
0.00
0.00
0 (0)
0 (0)
(0.23)
(0.07)
Forest and
0 (0)
0.36
2.05
2.80
bushy area
(8.33)
(44.02)
(83.71)
Numbers in brackets (x.xx) mean surface cover in percentage.
0.21
(3.57)
5.55
(96.43)
HAZ
0.21
(3.57)
5.55
(96.43)
Results
Streamflow
The discharge measurements and parallel water quality samplings have been taken
generally in low flow (baseflow) period. Therefore the measurements give information
principally about groundwater replenishment from a quantitative viewpoint. From a
qualitative viewpoint the samplings characterize primarily the contamination of the
groundwater resources and the illegal sewage loadings into the stream channel. Figure 2.
shows the results of the discharge measurements in the form of box plot diagram. The box
plot can be edited (based on the sample dataset) using the minimum, the maximum and the
three quartiles (which divide the dataset into four parts). On the basis of the figure can be
seen, that discharges increase monotonous from the headwater region to the Hajnal Square
(effluent section). Between Fasor Street and Hajnal Square however discharge values
decrease a little (about 10%). This discharge reduction may relate that this section of the
brook is generally influent, which means that stream gives water to the groundwater body
(inflow to groundwater). On the lower section of the stream, between Fasor Street and
Tesco sampling point, the discharges show a similar increase than above the town (effluent
section). Table 3 shows the above mentioned changes calculated specific discharge values
based on the length of the stream and based on the watershed area. The specific discharges
concerning to the unit watershed area more typical, therefore at the analysis of the
qualitative features the same method was applied to the calculation of the specific values.
Figure 2. Discharges at the sampling points (characterize baseflow periods)
Table 3. Specific discharges valid for unit length and unit sub-watershed area between
sampling points.
q
HÁZTÓFORRÁS HÁZ
BANTÓ
HAJNAL- FASOR- GYORIBAN
HAJNAL FASOR
TESCOGYORI
(l/s/fkm)
13.04
12.65
6.30
41.56
-3.24
14.15
20.02
(l/s/km2)
6.25
10.29
2.43
5.39
-2.73
8.70
13.38
From flood protection point of view peak discharges have a significant meaning. Therefore
the high frequency measured discharge dataset was also analysed. Good quality dataset for
peak discharge analysis has been available only from three gages (Figure 3.):
 Natural headwater catchment (HAZ), almost totally forested,
 Rural catchments with dominant forest cover (BAN [inflow to the city]) small
villages, a reservoir and some farm houses on the catchment,
 Urbanized area is remarkable (19%) and close to the outlet point of the catchment
(TESCO [outflow from the city]).
Figure 3. Discharge time series of HAZ (natural, totally forest covered, headwater), BAN
(rural, but mainly forest covered) and TESCO (significantly urbanized) catchments.
On Figure 3 can be seen that the streamflow regimes are very similar in case of HAZ and
BAN catchments. However the discharge time series of the urbanized catchment (TESCO)
is significantly different from the other two. The runoff processes is much quicker and the
peak discharges are much higher on the TESCO catchment.
So as to compare the runoff regime of three catchments quantitatively peak discharges
were analysed (since these peaks cause inundations, which is one of the biggest problem in
the neighbourhood of urban steams). As a first step of the analysis peak discharges and
inducing precipitation events were selected from the dataset. So as to compare catchments
in different sizes, specific discharges were calculated and used for regression. A simple
linear regression was fitted to points and regression parameters were determined (Figure
4.).
Figure 4. Regression of selected daily peaks vs. precipitation and the regression lines
Figure 4 shows that regression slope is similar in case of natural headwater [HAZ] and
rural [BAN] catchments. It is interesting that in case of rural catchment (slope: 0.66,
R2=0.8) a gentler slope (smaller flood peaks [expressed in specific discharge]) can be
detected than in case of the natural one (slope: 0.95 R2=0.7). This is probably the effect of
the reservoir, which can be found between HAZ and BAN sampling points. The reaction of
the urbanized catchment is significantly different from the others. The slope parameter is a
magnitude bigger (slope: 9.11 R2=0.69) than the other two catchment’s, meaning much
stronger runoff response to precipitation. Our results are confirmed by field experiences
that inundations are frequently happened after big, high intensity rainfall events on the
lower part of the city (in the neighbourhood of TESCO sampling point).
Chemical parameters
Suspended solids, water temperature, and pH change to a small degree from among the
physicochemical parameters, however the conductivity significantly increases in the urban
area (Figure 5). Only the standard deviation of suspended sediment concentration (SSC)
rises to the Fasor Street, nevertheless the mean of SSC remarkably increases on the vaulted
section under the Deák Square (GYORI) and the industrial territories (TESCO).
Figure 5. Change of the conductivity along the stream
Effect of urbanisation is reflected mostly in salts (sulphate and clorid) and nitrogen forms
(ammonium and the nitrate), therefore from our measured parameters these are the most
characteristic indicator of the water pollution (Figure 6.).
a,
c,
b,
d,
Figure 6. Changes of salts (Clorid [a] and Sulphate [b]) and Nitrogen forms (Ammonium
[c] and Nitrate [d]) concentrations along the stream.
The load-based calculation completes well the concentration-based computation supporting
also the contamination estimation:
Ci  Qi  Ci 1  Qi 1
(1)
Ai  Ai 1
where gi, is the specific load in a given subcatchment (relating to a unit subcatchment
area); Ci, resp. Qi are the SSC, resp. discharge measured at the outlet point of a given subcatchment, Ci-1, resp. Qi-1 are the SSC, resp. discharge measured at the upper boundary of a
given subcatchment; az Ai, resp. Ai-1 subcatchment areas belonging to the sampling points
located at the lower, resp. upper boundary of sub-catchment.
gi 
Figure 7. shows different representation of salt loads (valid for the total and unit
catchment/sub-catchment area). On the basis of the graphs it can be seen that the most
representative for a given stream section between two sampling points the load datasets of
unit sub-catchment.
a,
b,
c,
Figure 7. Different representation of salt loads along the stream system: Salt Load [g/s] (a) ,
Specific Load [g/s/km2] relating to each catchment (b), Specific Load [g/s/km2] relating to
each sub-catchment (c).
Figure 8. demonstrates the load-based calculation with the example of ammonium
concentration. The surplus information given by this calculation method is visible
compared with the Figure 6.c. Load of ammonium decreases after the GYORI place (outlet
point of the paved section) because of the nitrification processes, according to the
computation Equation 1.
Figure 8. Specific load of ammonium ion (g/s/km2) relating to each sub-catchment
Biological results
The sampling of biologic conditions was performed in 2011, in spring (30.04-01.05.),
summer (30.07-31.07.), and autumn (24.09-25.09). Sampling point ‘TO’ was neglected at
the biologic analyses, because it was not eligible for the macroinvertebrates examinations.
The results of the analysis can be found in Table 4.
The biotic index was applied to the biologic assessment of the water body, which describes
the habitat based on the existing aquatic organisms in a given time. The MMCP method
was used for the assessments, which is the Hungarian adaptation (Csányi 1998) of the
international BMWP (Biological Monitoring Working Party) technique. The Biological
Monitoring Working Party (BMWP) scoring system is a method of assessing water quality
using the families of insects - e.g. mayflies and stoneflies - and other aquatic invertebrates
such as freshwater shrimps present in a river. The method is based on the principle that
different aquatic invertebrates have different tolerances to pollutants. The presence of
mayflies or stoneflies for instance indicates the cleanest waterways and is given a tolerance
score of 10. The lowest scoring invertebrates are worms (Oligochaeta) which score 1. The
number of different macroinvertebrates is also an important factor, because a better water
quality is assumed to result in a higher diversity. The sum of score allotted to each insect
family is the total sample value. The mean value of each insect family is coming from the
samples of different stream sections with slow and high flow velocity. The quality index is
determined according to the total and mean value, and the arithmetical average of both
indexes gives the water quality category.
Table 4. Biological water quality based on average value of three sampling periods
Sampling point
TESCO
GYORI
UT
FASOR
HAJNAL
BAN
TO
HAZ
Taxon number
15
9
17
21
23
NA
22
Total score
68
35
91
102
125
NA
117
Index based on
total score
4
3
5
6
7
NA
6
Mean score of
taxon
4.4
4.0
5.1
4.9
5.4
NA
5.3
Index based on
mean score
5
4
7
6
7
NA
7
Biotic Index
4.5
3.5
6
6
7
NA
6.5
MMCP Class
II. A
III.A
I.A
I.A
I.A
NA
I.A
Quality
Good
Fair
Excellent
Excellent
Excellent
NA
Excellent
Biological quality decreases along the stream from the excellent categories of the upper
catchments to the fair and good qualities of the lower part of the town. The degradation of
the biotic index is mostly correlate to the increase of the urban areas.
The increase of the stream water pollution induces the decrease of the number of species
and the dissapearance of the good water staus indicator species. Other effect of the water
quality reduction is the bulk proliferation of the pollution tolerant species (like:
Oligochaeta, Hirundinae, Coleoptera). These above mentioned tendencies are mostly
representative on the lower city sections.
GYORI sampling point got the worst biological water quality, because belonging
subwatershed has the highest ratio of urbanized area and the upper stream section from the
point is strongly modified and paved. The mostly nature close water qualities are detected
in points BAN and HAZ. Both of them can be found above than the town in fairly natural
conditions.
Beyond above mentioned statements, it can be said that artifical modification of the stream
channel strongly influences (decrease) the makroinvertebrates diversity.
On the basis of the average values of the three biological samplings (spring, summer and
autumn) number of taxons, number of individuals, Shannon-index (diversity) and Jaccardindex (similarity) were determined. The above mentioned diversity numbers significantly
decreasing from the headwaters to the lower sections of the city. Most diverse habitats are
HAZ and BAN sampling points, most poor stream sections are GYORI and TESCO
places.
Complex analysis
In the frame of a complex analysis hierarchical clustering was done on the basis Jaccard –
index. Figure 9. represents the result of the cluster analysis. Two main groups can be
separated, first group contains TESCO and GYORI points, and the others belong to the
second group. In the second group the most similar points are BAN and FASOR.
Figure 9. Hierarchical clustering basod ont he Jaccard-index (I. TESCO, II. GYORI, III.
FASOR, IV HAJNAL, V. BAN, VI. HAZ)
In the next step of the analysis three representative taxons (Baetidae, Gammaridae,
Chironomidae) were chosen from the dataset, species of which can be found in each
sampling points. The data of the taxons were combined with average phisical, chemical
water parameters and on the basis of the complex standardized data matrix cluster analysis
was employed. The result of the clustering was similar to the earlier dendrogram (Figure
9).
The elaborated data matrix was also used for calculation of Pearson correlation coefficients
(Table 5.). These coefficients showed us which parameters have significant influence of
the chosen taxons. Table 5 shows that Baetidae taxon has significant indicator values in
case of most parameters. The values of correlation (magnitude, plus or minus sign) also
allude to ecological demand of taxons (e.g. natural close values of the examined
environmental parameters have positive effect on the Baetidae taxon).
Table 5. Correlation matrix of three representative taxons and some environmental
parameters.
Baetidae
Chironomidae
Gammaridae
Discharge
Temperature
pH
Conductivity
COD
Ammonium
Nitrate
Clorid
Sulphate
Tot.Phosporous
ALP
ALK
Fe
Mn
Cu
Zn
Baetidae
1.000
0.172
-0.386
0.632
0.821
0.265
0.785
0.737
0.748
0.936
0.797
0.819
0.827
0.894
0.703
0.909
0.659
0.886
0.916
Chironomidae
0.172
1.000
0.702
-0.290
0.040
0.097
-0.077
0.289
0.095
-0.017
-0.176
-0.255
0.086
-0.090
0.193
0.280
-0.060
0.039
-0.013
Gammaridae
-0.386
0.702
1.000
-0.630
-0.294
-0.173
-0.618
0.141
-0.410
-0.497
-0.692
-0.756
-0.431
-0.562
-0.188
-0.166
-0.360
-0.454
-0.490
Summary
Influence of urbanisation on the small streams was investigated on the stream-system of
Rák Brook in Sopron, combining suitably the quantitative and qualitative changes of water
body. Seven sampling points were established from the mainly undisturbed headwater
catchment to the stream mouth – where the lower subcatchments are located in the urban
area with different character. The preliminary results also significantly demonstrate the
effects of urbanisation, furthermore that different types of settlements have divergent
impact on the runoff and water quality. The new aspect of material discharge-based
calculation gives surplus information regarding the contamination processes in the
watershed.
Acknowledgement
The research has been supported by the European Union and co-financing of the European
Social Fund. The code of the application: TÁMOP 4.2.1/B-09/KONV-2010-0006. The
authors would like to acknowledge the support of ERFARET and HAS Bolyai Scholarship.
References
BARRON, O. V., BARR, A., DONN, M., (2012): Effect of urbanisation on the water balance of
a catchment with shallow groundwater. Journal of Hydrology, doi:
http://dx.doi.org/10.1016/j.jhydrol.2012.04.027
BRATTEBO, B. O., BOOTH, D. B., (2003): Long-term stormwater quantity and quality
performance of permeable pavement systems. Water Research 37, 4369–4376.
BUZÁS, K., (2009): A közúti közlekedés hatása a felszíni csapadékvíz-lefolyás
szénhidrogén szennyezettségére. Doktori (PhD) értekezés, BME, Budapest.
CSÁNYI, B., (1998): A magyarországi folyók vízminősítése a makrozoobenton alapján.
PhD értekezés, 1-89. Kossuth Lajos Tudományegyetem, Debrecen.
CHO, J., BARONE, V. A., MOSTAGHIMI, S., (2009): Simulation of land use impacts on
groundwater levels and streamflow in a Virginia watershed. Agricultural Water
Management 96, 1–11.
CORBETT, W. CH., WAHL, M., PORTER, D. E., EDWARDS, D., MOISE, C., (1997): Nonpoint
source runoff modeling – A comparison of a forested watershed and an urban watershed
on the South Carolina coast. Journal of Experimental Marine Biology and Ecology 213,
133–149.
FUMA, S., ISHII, N., TAKEDA, H., MIYAMOTO, K., YANAGISAWA, K., ICHIMASA, Y., SAITO,
M., KAWABATA, Z., POLIKARPOV, G. G., (2003): Ecological effects of various toxic
agents on the aquatic microcosm in comparison with acute ionizing radiation. Journal of
Environmental Radioactivity 67, 1–14.
GAYER J., LIGETVÁRI F. (2007): Települési vízgazdálkodás, csapadékvíz-elhelyezés.
[Settlement water management, rain-water placement]. Környezetvédelmi és
Vízgazdálkodási Kutató Intézet, Környezetvédelmi és Vízügyi Minisztérium, InnovaPrint, Budapest, ps. 10-15, 26-31 (in Hungarian)
GUTTMANN E., IMRIK P. (2010): A Rák-patak vízminőségi változása Sopron belterületén.
[Water quality changes on the urban sections of Rák Brook.] Thesis. University of West
Hungary, Sopron. (in Hungarian)
FARKAS K. (2008): A Rák-patak referenciaviszonyainak meghatározása a Víz
Keretirányelv előírásainak megfelelően. [Determination of reference conditions of the
Rák Brook in accordance with the Water Framework Directive.] MSc thesis. University
of West Hungary, Sopron. (in Hungarian)
KAPUVÁRI VÍZGAZDÁLKODÁSI TÁRSULAT (1981): Brennbergi-tározó (Pisztrángos-tó)
rekonstrukciója - műszaki leírás. [Reconstruction of the Brennberg Reservoir
(Pisztrángos Lake) - technical description.] Number of the project: 8-1/1981
KÁRPÁTI L. (1955): Adatok Sopron környékének geomorfológiájához. [Data to the
geomorphology of Sopron’s surroundings] Földrajzi Értesítő, Vol. 4, No. 3, ps. 21-40
(in Hungarian)
KELLER I. (1998): A Rák-patak vízminőségi vizsgálata. [Water quality examinations at the
Rák Brook.] MSc thesis. University of West Hungary, Sopron. (in Hungarian)
KISHÁZI P., IVANCSICS J. (1981-1985): Sopron környéki üledékek összefoglaló földtani
értékelése. [Comprehensive geological evaluation of sediments in the surroundings of
Sopron.] Központi Bányászati Fejlesztési Intézet Petrográfia, Sopron. p. 48 (in
Hungarian)
KLINGER Z. (1993): A Rák-patak vízminőségi hossz-szelvénye. [Longitudinal water quality
profile of the Rák Brook.] MSc thesis. University of West Hungary, Sopron. (in
Hungarian)
KONDOR K. (1991): Vízbiológiai vizsgálatok a soproni Rák-patakban és mellékágaiban.
[Hydrobiological examinations in the Rák Brook and its tributaries.] MSc thesis.
University of West Hungary, Sopron. (in Hungarian)
MTA FTKI (1990): Magyarország kistájainak katasztere [Cadastre of the Hungarian
regions.] ps. 379-382 (in Hungarian)
NYENJE, P. M., FOPPEN, J. W., UHLENBROOK, S., KULABAKO, R., MUWANGA, A., (2010):
Eutrophication and nutrient release in urban areas of sub-Saharan Africa – A review.
Science of the Total Environment 408, 447–455.
NYME KKK (2009): Sopron Megyei Jogú Város Környezetvédelmi Programja
[Environmental Programme of Sopron 2010-2015.] (University of West Hungary,
KKK, Sopron) (in Hungarian)
O’HARE, M. T., CLARKE, R. T., BOWES, M. J., CAILES, C., HENVILLE, P., BISSETT, N.,
MCGAHEY, C., NEAL, M., (2010): Eutrophication impacts on a river macrophyte.
Aquatic Botany 92, 173–178.
ÖKO TECH KÖRNYEZETGAZDÁLKODÁSI TANÁCSADÓ ÉS SZOLGÁLTATÓ KFT., (2005): A
csapadékvíz hasznosítás korlátjai a települési vízgazdálkodásban: a város, mint diffúz
szennyezőforrás. Kutatási jelentés a Fenntartható települési vízgazdálkodás altémában.
Budapest.
TÓTH, I., (2005): Vízbiológiai vizsgálatok a Rák-patakon [Hydrobiological examinations
at the Rák Brook.] Scientific Student Conference, University of West Hungary, Sopron.
(in Hungarian)
WHITE, M. D., GREER, K. A., (2006): The effects of watershed urbanization on the stream
hydrology and riparian vegetation of Los Penasquitos Creek, California. Landscape and
Urban Planning 74, 125–138.