Classification of the Dynamics of Water Quality Changes in the Elbe River Basin

J. Hydrol. Hydromech., 53, 2005, 4, 205–218

CLASSIFICATION OF THE DYNAMICS OF WATER QUALITY CHANGES IN THE ELBE RIVER BASIN

JAKUB LANGHAMMER

Charles University in Prague, Faculty of Science, Department of Physical Geography and Geoecology, Albertov 6, 128 43 Prague 2, Czech Republic; mailto: [email protected]

With regard to the water quality changes, the area of the Czech part of the Elbe River basin is extraordinarily dynamic. In the 20th century it experienced an enormous increase of load of pollution. Since the beginning of the 1990´s due to the political and economical changes we have witnessed a particularly intensive decrease in the emission volume and a related increase in water quality of watercourses. However, positive changes in the pollution load balance have occurred mainly in the biggest watercourses and these changes have not been accompanied by similar development in the whole river system. Using a newly created classification methodology the basic models of dynamics of water quality changes in the Elbe River basin have been derived. Based on GIS geostatistical analysis, regions with analogous water quality development trends have been defined for selected parameters and critical areas have been identified. It has become apparent that the prevailing part of the Elbe River basin has been experiencing a gradual increase in pollution. In addition, after a previous decrease, a number of watercourses experienced a recurrence of the increase in load. These areas are priorities for further development and the control of surface water protection against pollution.

KEY WORDS: Hydrology, Water quality, Pollution, Elbe, GIS, Geostatistical analysis, Modelling.

Jakub Langhammer: KLASIFIKACE DYNAMIKY ZMĚN KVALITY VODY V POVODÍ LABE. Vodo- hosp. Čas., 53, 2005, 4; 17 lit., 7 obr., 1 tab.

Oblast české části povodí Labe je z hlediska změn kvality vody mimořádně dynamická. Díky intenziv- nímu vývoji antropogenních aktivit a společenským změnám zaznamenala v průběhu 20. století nejprve enormní nárůst zátěže znečištěním, od počátku 90. let jsme naopak svědky mimořádně intenzivního snížení objemu emisí a souvisejícího zvyšování jakosti vody v tocích. Pozitivní změny v látkové bilanci jsou však soustředěny především na největší toky – Labe a Vltavu a nejsou doprovázeny obdobným vývojem v celém povodí. Pomocí nově vytvořené metodiky klasifikace vývoje kvality vody prezentované v článku byly na zák- ladě geostatistické analýzy sestaveny základní modely časové dynamiky změn kvality vody v povodí Labe. Pro jednotlivé ukazatele byly na základě analýzy v prostředí GIS vymezeny regiony s analogickými trendy vývoje kvality povrchových vod a identifikovány kritické oblasti. Ukazuje se, že přes pozitivní vývoj jakosti vody v hlavních sídelních a průmyslových regionech v 90. letech převažující část povodí Labe stále zaznamenává v jednotlivých ukazatelích postupný nárůst znečištění, na řadě toků navíc po předchozím poklesu dochází k opětovnému nárůstu zátěže. Tyto oblasti představují prioritu pro další rozvoj a řízení ochrany povrchových vod před znečištěním.

KLÍČOVÁ SLOVA: hydrologie, kvalita vody, znečištění, Labe, GIS, geostatistická analýza, modelování.

1. Introduction and objectives the quality of water in Czech watercourses was sufficient for the majority of regular activities, During the 20th century, several significant mainly in the period after the World War II, the changes in surface water quality in European rivers situation has changed radically due to both the in- occurred including the watercourses in the Elbe dustrial development and insufficient consideration River basin. While at the beginning of the century, of the environment. The water importance was

205 J. Langhammer gradually reduced to a raw material and rivers were 2. Material and methods gradually forced to absorb more and more waste. The same process could have been seen in most of Within the research project, the author has de- the developed countries. On the worldwide basis, signed a new method for the classification of the therefore, the decades of the 60s and 70s represent dynamics of water quality changes for the purpose periods of the highest level of water pollution that of determining the spatial trends in water quality had been practically uncontrolled until this time. changes. The methodology is based on the combi- Since the 70s, Western Europe and North America nation of methods of geostatistical and spatial have gradually started to seek solutions for the most analysis in the GIS environment. The research is urgent problems related to the pollution of water- stemming from the previous analyses of water qual- courses (De Wit, 1999, EEA, 2002). In the Czech ity changes in the Elbe watercourse and its river Republic, things have changed only after the politi- basin where methods of mathematical modelling cal changes in the year 1989. During one decade, and spatial analysis were applied (Langhammer, there was a significant decrease in pollution of our 2000, 2004a). The assessment is based on a com- most important watercourses thanks to systematic plete set of water quality profiles observed in the investment in wastewater treatment plants at the Czech part of the Elbe River basin during the as- biggest industrial sources and settlements. Until sessment period 1970–2002 covering the main then, the pollution level had been critical stages of water quality changes. (Langhammer, 2000). In this respect, the first half of the 90s was a turning point - new wastewater 2.1.Assessment methodology treatment plants were put in operation at the biggest direct pollution sources on the Elbe and the Vltava The methodology is based on the application of watercourses. During ten years, the concentrations the geostatistical analysis to the data of long-term of the main balance indicators related to water qual- records concerning the concentrations of selected ity in the Elbe mouth profile decreased to the level water quality indicators. that was in a number of cases even lower than at the The assessment principle consists in the deriving beginning of monitoring in the 60s. This was a con- of the trend slopes of water quality development on sequence of the massive building and the intensifi- all assessed profiles, subsequent identification of cation of wastewater treatment plants at main pollu- related features of the development and their group- tion sources. However, positive changes had not ing into basic models. For this purpose, the meth- occurred in the whole area of the drainage pattern. ods of regression and cluster analyses are applied. When taking a closer look at the dynamics of the The time progressions of annual average concentra- load development related to the whole hydro- tions of selected indicators for individual profiles graphical pattern of the Czech Elbe River basin, we are, at first, divided into homogenous time periods find out that, in a number of watercourses, different corresponding to significant periods of water qual- water quality indicators stagnate or sometimes even ity changes. deteriorate. The classification methodology is summarised in The paper is focused on classification of the dy- Figure 1. With the use of regression analysis, the namics of water quality development in the Elbe guidelines of change trends have been calculated River basin with regard to quality, time and space. for individual main periods of quality development. The objective of the presented research is to define These trend lines are entered into the cluster analy- a methodology that would allow objective differen- sis as source data. The output of clustering repre- tiation of the Elbe River basin into areas with dif- sents groups of profiles with similar dynamics of ferent dynamics and trends associated with water water quality changes in the assessed periods. The quality changes. With the use of this methodology, final data is transported into GIS where it is ana- the classification of particular river basins was car- lysed with regard to the spatial distribution. The ried out in accordance with the identified main mo- calculation is subsequently repeated for all assessed dels of development dynamics and areas with criti- water quality indicators. cal water quality development were defined with the application of individual indicators.

206 Classification of the dynamics of water quality changes in the Elbe River basin

Fig. 1. The methodology of the analysis of space water quality changes in the Elbe River basin. Obr. 1. Metodika analýzy prostorových změn kvality vody v povodí Labe.

2.2 Application of the methodology − 1991 – 2000 changes after the year 1989 that to the Elbe River basin reflect both system changes (the construction of wastewater treatment plants at big pollution The information on the average annual concen- sources) and changes of economic and social trations of selected water quality indicators out of conditions (a number of production plants were all profiles of the CHMI pattern within the Elbe closed down, new plants were established, the River basin from the year 1970 to the year 2002 development of settlements, changes in agricul- were used as the enter data (CHMI, 2004, Rieder et ture). al., 2000). For each period, a trend line slope of linear re- The data set was divided into three periods that gression trend was calculated out of the average are crucial with regard to the water quality devel- annual values of concentrations of the main pollu- opment in the Elbe River basin: tion indicators for all profiles. The slope shows the − 1971 – 1980: the starting period of monitoring trend in water quality changes in the particular in- and, at the same time, the beginning of intensive dicator for this period. Through this procedure, pollution of surface water, broken lines for each profile and each indicator − 1981 – 1990: is characterized by the highest pol- were designed that characterize the process of water lution load of watercourses, its sources being quality changes during the whole period. both industrial and municipal, The combination of development trends in these three periods was used as entry information for the

207 J. Langhammer cluster analysis. The K-means algorithm was used changes within individual models and the analysis as the clustering method through which from the of spatial distribution of trends in change dynamics total number of 160 profiles have been derived 6 in the Elbe River basin. basic clusters. The XLStat software was used as the main tool for the statistical analysis and GIS Map- 3.1 Basic models of water quality development Info Professional/Vertical Mapper was used for the in the Elbe River basin spatial analysis. The regression analysis was carried out for the Through the application of regression analysis, whole set of profiles and indicators of water quality the guidelines of water quality changes to the as- including the total number of 160 profiles and 12 sessed main periods were derived for the total water quality parameters –BOD-5, COD, N-NH4, number of 160 profiles and the whole set of consid- N-NO3, Total phosphorus, Dissolved and Undis- ered quality indicators whereby a total number of solved solids, Saprobity index, conductivity, Pb, 1920 model types of courses or water quality Cd, Hg. The representativeness of data sets was changes were created. This entry data was used as assessed for the purpose of further processing the entry for a subsequent cluster analysis. through the cluster analysis. Subsequently, the indi- Based on the analysis of water quality develop- cators that did not provide the sufficient coverage ment trends through the application of cluster of the assessed period were rejected. They were analysis, 6 basic models of water quality develop- mainly the parameters concerning the load by ment trends were defined for individual assessed heavy metals at which the data sets do not start indicators (Tab. 1). Altogether, 24 types of change until the 90s and even there, they are incomplete. dynamics of water quality were generated for the The total phosphorus indicators was also rejected as main indicators supplemented by further 24 types again only the values for the period after the year for supplementary indicators. 1990 were available for most of the profiles. Data Subsequently, 6 main models of water quality sets of profiles with the beginning of monitoring in development, occurring across the spectrum of the 70s were in a number of cases interrupted dur- assessed indicators, were derived from individual ing the decade of the 80s (e.g. in the Ohře River types of courses of water quality time changes that basin). had been generated through the application of clus- The water quality parameters BOD-5, N-NO3 ter analysis for individual quality parameters. and N-NH4 were selected as the main indicators for These models indicated as A – F describe the ba- the performed spatial analysis. sic patterns of change dynamics relating to water quality in the Elbe River basin (Fig. 2). They reflect 3. Results the main causing factors in changes and they are mutually different regarding both the space – for The project results are represented by the estab- different River basins and watercourses – and the lishment and classification of basic models of water structure – for individual pollution indicators. quality development in the Elbe River basin, the assessment of the causality relating to water quality

T a b l e 1. The results of the cluster analysis of the water quality changes classification for individual indicators. T a b u l k a 1. Výsledky zhlukové analýzy klasifikace změn kvality vody pro jednotlivé ukazatele.

BOD-5 N-NO3 N-NH4 71-80 81-90 91-00 Size 71-80 81-90 91-00 Size 71-80 81-90 91-00 Size 71-80 81-90 91-00 Size Cluster 1 –5.47 4.51 –7.83 1 –0.33 0.86 –4.89 2 –0.62 –0.75 0.10 61 0.08 0.27 –1.64 9 Cluster 2 1.49 –4.15 –4.51 2 0.74 –0.45 –1.97 11 0.43 –0.38 1.94 16 0.27 0.17 0.39 105 Cluster 3 0.31 0.16 –0.65 34 0.34 0.15 0.59 86 1.84 0.36 –1.53 15 0.17 0.19 –0.37 29 Cluster 4 –4.16 –3.25 0.28 4 –4.13 –5.11 0.34 4 –0.55 0.53 –0.23 41 –5.25 –5.11 –4.75 4 Cluster 5 0.22 0.07 0.34 109 0.09 0.12 –0.25 43 0.55 3.85 –1.78 3 –0.56 0.44 0.12 7 Cluster 6 –1.56 0.42 0.13 10 –1.69 0.38 –0.71 14 1.01 0.54 0.02 24 –1.43 –1.40 0.45 6

208 Classification of the dynamics of water quality changes in the Elbe River basin

Fig. 2. The main models of water quality changes in the Elbe River basin. Obr. 2. Hlavní modely změn kvality vody v povodí Labe.

Model A describes the development without any Model C indicates a continual decrease in the significant trend in water quality changes during the watercourse load level during the whole period. It whole monitored period. We can observe this type usually occurs in areas with traditional settlements of distribution of water quality changes on a num- and economic activities where wastewater process- ber of watercourses of medium size, mainly in rela- ing and treatment is carried out systematically and tion to the indicators of organic pollution. Such where watercourses have not been affected by in- insignificant trends usually appear in areas with a tensive industrialization. generally low level of economic activity along the Model D describes a significant decrease in pol- River basin where watercourses are not impacted lution in the 90s of the 20th century. This model by distinct point sources of pollution and have not characterizes the most distinct changes in water gone through intensive changes. quality that appeared in the Czech part of the Elbe Model B describes a gradual increase of load dur- River basin after the year 1990. They are mainly ing the whole assessed period. With regard to the the indicators and regions affected by significant statistics and space, this is definitely the most fre- point sources of pollution. quent model of development at all assessed water Model E reflects the situation of the load de- quality parameters. It occurs across the spectrum of crease before the year 1990. Radical changes in assessed indicators as well as geographic regions. It watercourses water quality in the 70s and 80s have generally reflects high intensity of use of the terri- to be assigned to the first constructions of wastewa- tory without the adoption of corresponding mea- ter treatment plants mainly at big industrial and sures focused on the water protection against pollu- municipal sources. The purpose of this tool was to tion. remedy the emergency conditions caused by the

209 J. Langhammer water discharge when entirely untreated waste wa- − Model B characterizes a continuous increase of ter or waste water that had received only minimum load during the whole assessed period (the clus- treatment was release into watercourses. ter 5, 109 profiles) Model F describes the situation of a recurred in- − Model D represents a decrease in the concentra- crease of watercourses load in the 90s of the 20th tions of BOD-5 after the year 1990 (the clusters century after a previous period of a decrease. The 3, 2, 1 that include the total number of 37 pro- recurrence of an increase in surface water pollution files) after the previous period of decrease indicates the − Model F represents an increase of load after a development that appeared as a consequence of previous decrease (the clusters 6 and 4 that in- changes in the structure of economic activities. The clude the total number of 14 profiles). decrease in watercourses load at the beginning of The basic models of water quality development the 90s was caused by a depression in production in the BOD-5 indicator show significant spatial and not by systematic measures designed for water organization (Fig. 4). The development type with protection. Therefore the current economic revival the most frequent representation is the Model B that causes an increase of pollution load in water- characterizes a continuous increase of organic pol- courses. With regard to the future development, this lution load during the whole assessed period. This model of changes is critical. If it occurs in the as- type of development is typical for the area of the sessed River basins, it has to be devoted maximum south-west and the north-west of Bohemia – the attention. Vltava, Otava, Berounka and Ohře River basins. With regard to the space, the increase of water- 3.2 Spatial distribution of trends of water quality courses load in the BOD-5 indicator occurs on the changes for individual indicators most of the territory. The watercourses concerned are generally the watercourses of small or medium Multiple indicators describing the changes of wa- size in urbanized areas or areas transformed in an tercourses load by point sources of pollution were anthropogenic way that have been experiencing selected for the assessment purposes. In the paper economic development. there are selected following water quality parame- The areas with a significant decrease in organic ters describing the main driving forces in the pro- pollution load after the year 1990 are represented cess of water pollution change: Biochemical oxy- by the Model D. Such areas are concentrated in the gen demand, reflecting the organic pollution mainly regions of central and lower parts of large water- from communal sources, ammonia nitrogen as the courses that are represented by significant settle- indicator reflecting the load from industrial point ment and industrial regions, specifically the central sources and nitrate nitrogen as parameter reflecting and lower Elbe course and the lower Vltava course. the pollution from non point sources. The third type of water quality changes is represented by the Model F. This model indicates the 3.2.1 Biochemical oxygen demand (BOD-5) watercourses that experienced a recurrence of the increase of pollution load after a previous decrease. With help of the cluster analysis, the water qual- The main areas concerned are settlement and indus- ity development in the BOD-5 indicator in individ- trial regions on central watercourses – the Berounka ual quality profiles during the period of 1970 – course as well as the area of the north-east Bohe- 2000 was divided into six groups according to the mia. mutual relation. With regard to the area range of individual River Individual clusters (Fig. 3) differ in frequency basins according to the relevant models of change while the cluster 5 is being dominant, the clusters 3 dynamics (Fig. 7), we can clearly see a prevailing and 6 can be considered significant, other clusters proportion of areas with negative development fea- marginal. tures. Positive changes occur just on 20% of the The clusters represent the generated typology area of the Elbe River basin. The whole 80% of the groups of water quality development. According to area experiences a continuous increase or experi- the frequency of representation and according to the enced an increase during the 90s. With regard to the character of the course of trends of changes, we can spatial distribution, however, we can also see high subsequently assign these the clusters into three effectiveness of the adopted measures. The con- groups corresponding to the main models of devel- struction of sewage works at the largest point pollu- opment (see chapter 3.1):

210 Classification of the dynamics of water quality changes in the Elbe River basin

Fig. 3. The clusters of types of water quality changes in the Elbe River basin generated for the BOD-5, N-NH4 and N-NO3 indicators. Obr. 3. Vygenerované zhluky modelů změn kvality vody pro ukazatele BSK5, N-NH4 a N-NO3.

Fig. 4. The spatial distribution of trends of water quality changes in the Elbe River basin in the BOD-5 indicator. Obr. 4. Prostorové rozložení trendů změn kvality vody v povodí Labe v ukazateli BSK5.

211 J. Langhammer

tion sources lead to a significant increase of water Positive changes associated mainly with the de- quality in the Elbe River mouth profile. At the same crease in load concerning watercourses after the time, the analysis shows the potential for further year 1990 are almost always concentrated to the decrease in organic pollution load of surface water. areas of watercourses that are affected by big indus- We can understand the differences in water quality trial pollution sources – the central and lower development described by individual models as course of the Elbe, the lower courses of the Vltava, principal system differences affecting the changes Berounka and Bílina Rivers. in emission load of watercourses. On the contrary, the major part of the Elbe River With regard to the Model D, we can observe a basin experienced a gradual increase in load in the sharp decrease in load mainly in the period after the N-NH4 indicator during the whole assessed period. year 1990, however, at some profiles, this trend can There is the total number of 105 profiles concerned. be observed even earlier. The adopted system Further, there are 13 profiles that experienced an measures are the main driving force for this devel- increase in load during the 90s after a previous opment, mainly the building and intensification of decrease. wastewater treatment plants at significant pollution The spatial differentiation of the dynamics of sources. water quality changes in this indicator is associated The model F that describes an increase of load with the character and spatial concentration of pol- after a previous decrease corresponds to the situa- lution sources. The most significant sources of the tion when the previous decrease was caused by the N-NH4 pollution are represented by industrial depression in production rather than by system sources that are located mainly in the areas of lower measures. The current re-increase of pollution in parts of watercourses of the Elbe, the Vltava and in load is therefore caused by the revival of economic the Bílina River basin. The ten biggest producers of activities in the region. The model B represents a the N-NH4 emissions in these areas (the SVHB continuously increasing load. The river basins with database, VÚV, 2000) including the pollution these types of development therefore represent risk sources as ČOV Praha, Synthesia Semtín, Spolana areas and areas that, with regard to water protec- Neratovice, Lovochemie Lovosice, Draslovka tion, should be given priority. Kolín, Chemopetrol Litvínov, etc., represent over 55% of the total amount of N-NH4 released into the + 3.2.2.Ammonia nitrogen (N-NH4 ) Elbe River basin. A significant decrease in the volume of pollution released from these sources during Both quantitative and spatial analysis of change the 90s was made thanks to massive investment of dynamics concerning water quality in the ammonia these companies into the wastewater treatment in nitrogen indicator show distinctly asymmetric dis- the framework of the national and international tribution. The generated groups (see Tab. 1) are projects. prevailed by the cluster 2 relating to 105 out of the This development within the Elbe River basin, total number of 160 quality profiles. The second however, was not followed by other parts of the most frequent cluster is the cluster 3 that together river basin. Therefore, these parts of the river basin with genetically related cluster 1 include the total have been fighting not only high pollution load of number of 38 profiles. With regard to their size, the watercourses but mainly an unfavourable trend of remaining clusters are assessed as supplementary. the development that does not show any possibili- Having allocated the generated clusters to the ties for fast improvement in the near future unless main models of water quality development, we can strict measures are adopted. reduce their number to 4 main groups: The proportions of partial areas of the River ba- − Model B – a continuous increase in load during sins with the analogous dynamics of load develop- the whole period (the cluster 2, 105 profiles) ment in the N-NH4 indicator prove the above men- − Model C – a decrease in load during the whole tioned mechanism. Only less than a quarter of the period (the cluster 4, 4 profiles) area of the Elbe River basin has been experiencing − Model D – a decrease in load in the 90s (the clus- a decrease in the level of load, more than two thirds ters 1 and 3, 38 profiles) of the river basin area have been experiencing a − Model F – an increase in load in the 90s after a continuous increase in concentrations and further previous decrease (the clusters 5 and 6, 13 pro- 10% of the river basin experienced an increase in files) load in the 90s.

212 Classification of the dynamics of water quality changes in the Elbe River basin

Fig. 5. The spatial distribution of the trends of water quality changes in the Elbe River basin in the N-NH4 indicator. Obr. 5. Prostorové rozložení trendů změn kvality vody v povodí Labe v ukazateli N-NH4.

- 3.2.3 Nitrate nitrogen (N-NO3 ) − Model D – a decrease in load in the 90s (the clusters 3, 4 and 5, the total number of 59 profiles) In comparison to the previous indicators, the ni- − Model F – an increase in load in the 90s (the trate nitrogen load of surface water reflects a differ- clusters 1 and 2, the total number of 77 profiles). ent pollution mechanism. While the primary With regard to the statistical and spatial distribu- sources of emissions at the BOD-5, N-NH4 indica- tion (Fig. 6), the changes in the nitrate load of sur- tors are point pollution sources, non-point pollution face water in the Elbe River basin are not favour- sources and mainly agriculture are the main sources able. The statistically most frequent type of change of nitrate nitrogen. is represented by the F type. This type is character- The classification results of the dynamics of the ized by re-increase of load during the 90s. The ar- development of watercourses load by nitrate nitro- eas concerned are vast areas of peripheral parts of gen (see Tab. 1) and their spatial distribution there- river basins in the north-west of Bohemia, the mid- fore differ in character. dle and lower course of the Elbe and the areas of The generated clusters describing the dynamics the south and south-east of Bohemia. The total of water quality changes in the Elbe River basin number of 24 profiles belongs to the B type that could be allocated into three main groups of the shows a continuous increase in the load of water- water quality development stated for the Elbe River course in the particular indicator. Specifically, the basin: areas concerned are areas of Bohemian Highland as − Model B – a continuous increase in load (the well as the areas of the Berounka and central Vltava cluster 6, the total number of 24 profiles) River basins.

213 J. Langhammer

Fig. 6. The spatial distribution of trends of water quality changes in the Elbe River basin in the N-NO3 indicator. Obr. 6. Prostorové rozložení trendů změn kvality vody v povodí Labe v ukazateli N-NO3.

Both models that reflect a strongly negative trend We can observe a long-term increase in load of an existing increase in pollution can be observed mainly in the areas of the central Elbe River, Bo- at almost two thirds of profiles – the total number hemian Highland and partly also in the western of 101 profiles out of 160 assessed. On the con- Bohemia. These areas are regions with intensive trary, a decrease in load after a previous increase in agricultural production. With regard to the assess- pollution in the 90s occurred at 59 partial river ba- ment of temporal dynamics of changes, a reduction sins representing 39% of the Czech area of the Elbe of pollution load during the recent ten years is a River basin. These river basins are situated in the positive fact. A decrease in the intensity of agricul- area of the central Vltava River basin, the Jizera tural production represents the main factor of the River basin and in the area of the north-east of Bo- decrease in the level of nitrate load of watercourses hemia. The stated decrease in load at the total num- in the areas of the south of Bohemia, the upper part ber of 15 quality profiles (the cluster 3) is very of the Sázava and Jizera Rivers. We can observe an moderate. In the long-term view, the overall level increase in nitrate nitrogen load of surface water in of pollution is stable and therefore the current de- vast peripheral areas of the Elbe River basin – in crease does not have to indicate a positive trend. the north-west of Bohemia covering basically the The increase of pollution level in the peripheral whole Ohře River basin, in the areas of Bohemian areas of the Elbe River basin is typical for the de- Forest, the south-east of Bohemia and the upper and velopment in the N-NO3 indicator. Further, the central course of the Elbe. For the interpretation trends of continuous increase in the level of con- purposes, the heterogeneity of the environment of centrations in traditionally agricultural areas and a individual water basins must be taken into consid- decrease in load in the areas of the south and partly eration. These are areas with distinctly different the north-east of Bohemia persist. physicogeographical features, different intensity of

214 Classification of the dynamics of water quality changes in the Elbe River basin anthropogenic activities and, last but not least, also − economic tools with a different level of existing load of water- − educational programmes. courses. As far as the field of legislation tools is con- With regard to the proportion of the River basin cerned, the Czech Republic has done a lot – the area according to the relevant models of the dynam- European environmental EU standards have been ics of water quality development (Fig. 7), an overall adopted and harmonized with the existing national unfavourable spatial distribution is apparent. Only legislation system. However, individual legislation 29% of the Elbe River basin area belongs to the tools and rules will have to be applied and enforced group of areas in which a decrease in nitrate nitro- more consistently. gen concentrations in the watercourse occurs. A With regard to the involvement of business enti- more or less intensive increase occurs in the re- ties and investors in water protection, economic maining areas while during the 90s, we can observe tools have to be adjusted in such a way that consis- an increase in load at the whole 42% of the Czech tent care of water protection represents a competi- area of the Elbe River basin. tive advantage rather than a burden. A significant element here is a possibility of gaining access to 4. Discussion European funds. Beside the direct financial partici- pation, among other things, the role of the govern- The experience gathered through the analogous ment should consist in the facilitating and support- development in large European River basins, par- ing of the access to external financial resources for ticularly in the Rhine River basin (Behrendt, 1996, individual entities. De Wit, 1999, Thyssen, 2001, Langhammer, 2004a, In order the implemented measures were suc- etc.) show that comprehensive changes in surface cessful, both direct and indirect measures, the over- water quality in the whole of the River basin repre- all level of investment in the water protection sent a long-term process. The reduction of pollution against pollution, will be one of the main factors. A load from the main pollution sources that occurred continuous decrease in the volume of investment in in the Czech part of the Elbe River basin in the last the area of water protection has to be considered as decade of last century is, however, only the first a risk factor. The investment level has been on the step that has to be followed by a number of system decrease since the middle of the 90s and it concerns measures, that are less visible but inevitable in the the means provided from the state budget, from the long term prospect, within the whole river basin private sector and abroad. If the Czech Republic is area (Jurča, 1997, Mohaupt et al., 1998, Rosendorf to ensure not only the fulfilment of the current wa- et al., 1998, Langhammer, 2004b). ter protection objectives arising out of the obliga- The knowledge of the temporal and space dy- tions within the EU and international programmes namics of the whole system development obtained but also to support strategically the protection of through the performed analysis allows a more pre- water component of the environment, the invest- cise definition of the structure of priorities concern- ment in the water protection area has to be sup- ing the control of water protection against pollu- ported systematically. In part, the support is related tion. It also helps to find adequate tools for the so- to the stimulation of the increase in the overall in- lution of different problems. The direct measures – vestment volume and, in part, to structural changes investment subsidies and research and organization in the composition of financial resources. In par- support of national and multinational structures ticular, the proportion of financial means from for- played the key role in the implementation of urgent eign sources should be increased as currently, their and priority measures in the middle of the 90s. In proportion in the overall volume of investment in the subsequent process in the whole of the river the environmental protection is minimal. basin area, a significant role will be played mainly Educational and training programmes form an by indirect tools while the direct measures will be important complement and they condition long- focused on the starting of wastewater treatment term sustainable development when sustaining ac- plants at small and medium pollution sources and ceptable quality of the environment. Their target on their intensification. Based on the experience of should be to achieve the general level of acceptance the analogous development in the western Euro- and sharing of responsibility among the involved pean river basins, the following measures should be individuals and organizations with regard to the propped on three main pillars: state of the environment components that are influ-

− legislation tools

215 J. Langhammer

Fig. 7. The shares of areas of the Elbe River basins according to the relevant models of the BOD-5, N-NH4 and N-NO3 change dynamics. Obr. 7. Podíly plochy povodí Labe podle vývoje kvality vody odpovídajícímu jednotlivým modelům v ukazatelích BSK5, N-NH4 a N-NO3. enced by them. In spite of the fact that this is a big watercourses as a consequence of system long-term objective and the results are difficult to measures adopted for the prevailing pollution measure in practice, the experience of foreign coun- sources. tries show that this component cannot be underes- − The positive development that started in the first timated as mainly the voluntary acceptance of re- half of the 90s and lead to a radical decrease in sponsibility for the state of the environment on the the level of load of our biggest watercourses has level of each individual or a business entity is an slowed down considerably. In the first stage, the essential condition of harmonious and long-term system investment measures related to wastewa- sustainable development. ter treatment focused on the biggest industrial and municipal pollution sources. However, this 5. Conclusions trend has not been followed by measures designed for pollution sources of regional and local A research project has introduced a new assess- importance within the whole area of the Elbe ment methodology concerning the dynamics of River basin. On the contrary, we can observe a water quality changes that allows both qualitative, recurrent increase in load in a number of areas time and mainly spatial view at the water quality since the middel of the 90s. development within a complex river basin. Basic − In a number of areas, the temporary decrease in models of water quality changes in the Elbe River the load level at the beginning of the 90s was basin in the period of 1970 – 2002 were derived via caused simply by the depression of industrial and this methodology. The changes were assessed with agricultural activities without the adoption of regard to the quantity and spatial distribution for system measures designed for water protection individual indicators. Based on the analysis in the against pollution. Therefore the current economic GIS environment, regions with analogous devel- revival in these regions is followed by an in- opment in water quality in individual indicators crease in pollution load of watercourses. were identified. The analysis of the dynamics of − With regard to organic pollution from municipal water quality changes resulted in following find- sources, long-term absence of wastewater treat- ings: ment plants in settlements of small and medium − The major part of the Elbe River basin in the size is a significant problem. The current post- most of the assessed indicators has been experi- ponement of the application of the EU legislation encing a continuous increase in the pollution requirements concerning the treatment of waste- level during the last 30 years. water released from the above sources interferes − Most of the positive changes in the area of sur- with the opportunity of effective improvement in face water quality are concentrated in the area of

216 Classification of the dynamics of water quality changes in the Elbe River basin

water quality within the whole of the Elbe River LANGHAMMER J., 2004b: Water Quality Changes in the basin. Elbe River Basin. Geografie - Sborník ČGS, 109, 2, 93–104. − The load coming from diffuse pollution and non- MOHAUPT V., SIEBER U., ROOVAART VAN DE J., VER- point pollution sources continues to be a signifi- STAPPEN G. G. C., LANGENFELD F., BRAUN M., cant problem as the level of pollution at the se- 1998: Diffuse Sources of Heavy Metals in the German lected recipients remains on the same level even Rhine Catchment, 3rd International IAWQ-Conference on Diffuse Pollution, Edinburgh. after the use of synthetic fertilizers has been re- MŽP ČR, 2004: Indikátory životního prostředí. (Environmental duced radically. Indicators. In Czech.) Online, available at: The knowledge of qualitative, quantitative, tem- http://indikatory.env.cz/, Ministry of Environment of the poral and spatial aspects of water quality develop- Czech Republic, Praha. ment is important for the management and control RIEDER M. et al., 2000: Jakost vody v tocích 1998–99 – ročenka. (Water quality in Rivers 1998–99. In Czech.) of water quality in the Elbe River basin. This CHMI, Praha. knowledge shows that in spite of the fact that the ROSENDORF P. et al., 1998: Omezování plošného znečištění current situation can be considered positive regard- povrchových a podzemních vod v ČR. Etapová zpráva za ing the balance, further investment in the surface rok 1998. (Reduction of non point pollution of surface and subsurface waters in the Czech Republic. In Czech.) VÚV water protection against pollution has to be sup- TGM, Praha. ported and specifically managed. At the same time, THYSSEN N., 2000: Rivers in the European Union: Water the results of the analysis show critical aspects of Quality, Status and Trends. River Restoration in Europe. water quality changes and identify regions that Ed. Cals, M.J.R.; Nijland, H.J. Wageningen, 63–71. should be subject to prior attention and measures VAN DIJK P., 2001: Soil erosion and associated sediment supply to Rivers. University of Amsterdam, Amsterdam. in the future. VÚV, 2000: Databáze Státní vodohospodářské bilance., VÚV Acknowledgment. Presented research was funded TGM, Praha, (State Water Management Balance database, by the Research Plan MSM 0021620831 “Geo- in Czech.) graphical structure and risk processes in conditions of global change and European integration” of the Received 8. February 2005 Scientific paper accepted 2. June 2005 Ministry of Education of Czech Republic which is fully appreciated by the author. KLASIFIKACE DYNAMIKY ZMĚN KVALITY VODY V POVODÍ LABE REFERENCES

Jakub Langhammer BEHRENDT H., 1996: Inventories of point and diffuse sources and estimated nutrient loads – A comparison for different River basins in Central Europe. Water Science and Tech- V průběhu 20. století došlo k několika významným nology, 33, 4-5, 99–107. změnám kvality povrchových vod v evropských řekách, COUSTEAU EQUIPE, 1993: The Danube…For Whom and včetně toků v rámci povodí Labe. Zatímco ještě na for What? European Bank for Reconstruction and Devel- počátku století byla kvalita vody českých toků vhodná opment, London. pro většinu běžných aktivit, s nástupem rozvoje prů- CHMI, 2004: Database of surface water quality in period myslu spolu s minimálním ohledem na životní prostředí 1970–2003. Czech Hydrometeorological Institute, Prague. tak zejména v období po 2. světové válce se situace DE WIT M., 1999: Nutrient Fluxes in the Rhine and Elbe basins. Faculteit Ruimtelijke Wetenschappen Universiteit, radikálně změnila. Voda byla postupně degradována na Utrecht. surovinu a řeky postupně byly nuceny absorbovat větší EEA, 2002a: Phosphorus concentrations in Rivers. Online, množství odpadů. Stejný vývoj zaznamenala většina available at: http://themes.eea.eu.int/ vyspělého světa. Dekády 60. a 70. let tak celosvětově EEA, 2002b: Total oxygen in River stations by River size. představují období nejvyšší úrovně do té doby prakticky Online, available at: http://themes.eea.eu.int/ nekontrolovaného znečišťování vod. V západní Evropě i JURČA V. et al.., 1997: Látkový transport z plošných zdrojů v v Severní Americe se od 70. let začaly postupně řešit České republice. (Material transport from non point pollu- nejnaléhavější problémy související se znečišťováním tion sources in the Czech Republic. In Czech.) VÚMOP, toků (De Wit, 1999, EEA, 2002). V ČR obrat ve vývoji Praha. LANGHAMMER J., 2000: Trends of water quality of the Elbe nastal až se změnou politických poměrů po roce 1989. River. Acta Universitatis Carolinae – Geographica, 35, 1, Během jednoho desetiletí se podařilo díky systema- 127–138. tickým investicím do čistíren odpadních vod největších LANGHAMMER J., 2004a: Modelling the structural changes průmyslových zdrojů a sídel rychle a významně snížit do of water quality in the Elbe River basin. Ekológia – Ecol- té doby kritickou úroveň znečištění našich nejvýznamně- ogy, 23, in print. jších toků (Langhammer, 2000). Přelomovým obdobím přitom byla první polovina 90. let, kdy byly zprovozněny nové čistírny odpadních vod

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(dále ČOV) u největších přímých zdrojů emisí na toku − Velká část pozitivních změn v oblasti jakosti povr- Labe a Vltavy. V důsledku masivní výstavby a intenzifi- chových vod je soustředěna do oblasti velkých toků kace ČOV u hlavních zdrojů znečištění poklesly jako důsledek systémových opatření u dominantních v průběhu deseti let koncentrace hlavních bilančních zdrojů znečištění. ukazatelů jakosti vody ve výústním profilu Labe na − Pozitivní vývoj, který byl nastartován v první úroveň, která v řadě ukazatelů byla dokonce nižší než na polovině 90. let a který vedl k razantnímu snížení počátku období sledování v 60. letech. (viz obr. 1). úrovně zátěže našich největších toků, se výrazně K pozitivním změnám však nedošlo v rámci celé říční zpomalil. Systémová investiční opatření do čištění sítě. Při bližším pohledu na dynamiku vývoje zátěže celé odpadních vod se v prvním období logicky soustředila hydrografické sítě českého povodí Labe naopak zjišťu- na největší průmyslové a komunální zdroje znečištění. jeme, že na řadě toků v různých ukazatelích kvalita vody Tento trend však nebyl následován u zdrojů regionál- stagnuje nebo se dokonce zhoršuje. ního a lokálního významu v celé ploše povodí Labe. Příspěvek se zabývá klasifikací dynamiky vývoje V řadě oblastí naopak od druhé poloviny 90. let po- kvality vody v povodí Labe z kvalitativního, časového a zorujeme opětovný nárůst zátěže. prostorového hlediska. Cílem prezentovaného výzkumu − V řadě oblastí za dočasným poklesem úrovně zátěže byla definice metodiky, která umožňuje objektivní dife- na počátku 90. let stojí prostý útlum průmyslových a renciaci povodí Labe na oblasti s odlišnou dynamikou a zemědělských aktivit bez systémových opatření na trendy změn kvality vody. Pomocí této metodiky byla ochranu vod před znečištěním. Současné ekonomické provedena klasifikace dílčích povodí podle identifi- oživení v těchto regionech tak je provázeno nárůstem kovaných hlavních modelů dynamiky vývoje a byly zátěže toků znečištěním. vymezeny oblasti s kritickým charakterem vývoje jakosti − V organickém znečištění z komunálních zdrojů před- vody v jednotlivých ukazatelích. stavuje závažný problém dlouhodobá absence ČOV u Výzkumný projekt představil novou metodiku hodno- malých a středních sídel. Současný odklad aplikace cení dynamiky změn kvality vody, která umožňuje jak požadavků legislativy EU na čištění odpadních vod kvalitativní, časový, tak zejména prostorový pohled na z těchto zdrojů oddaluje možnosti efektivního vývoj jakosti vody v komplexním povodí. Metodika zlepšení jakosti vody v povodí Labe jako celku. vychází z využití kombinace metod statistické a pros- − Výrazným problémem zůstává zátěž z difúzních a torové analýzy za využití nástrojů GIS a navazuje na plošných zdrojů znečištění, kdy ani po razantním pok- předchozí analýzy změn jakosti vody v toku Labe a jeho lesu aplikace strojených hnojiv nedochází k poklesu povodí za využití metod matematického modelování a úrovně vyvoleného znečištění recipientů. prostorové analýzy (Langhammer, 2000, 2002b). Hodno- Pro management a řízení kvality vody v povodí Labe til se komplexní soubor profilů kvality vody v české jsou poznatky o kvalitativních, kvantitativních, časových části povodí Labe v období pokrývajícím hlavní etapy a prostorových aspektech vývoje kvality vody změn jakosti vody. Jako vstupní data byly použity údaje významné. Ukazují, že jakkoliv lze z bilančního hlediska o průměrných ročních koncentracích vybraných uka- považovat současný vývoj za pozitivní, je nezbytné pod- zatelů jakosti vody ze všech profilů sítě ČHMÚ v rámci porovat a cíleně řídit další investice do ochrany povr- povodí Labe od roku 1970 do roku 2002. chových vod před znečištěním. Zároveň výsledky Pomocí této metodiky byly odvozeny základní analýzy ukazují kritické aspekty změn jakosti vody a modely změn kvality vody v povodí Labe v období identifikují geografické oblasti, do kterých by do bu- 1970-2002. Změny byly kvantitativně a prostorově vy- doucna měla směrovat prioritní pozornost a opatření. hodnoceny pro jednotlivé ukazatele. Na základě analýzy v prostředí GIS byly identifikovány regiony s analo- gickým vývojem kvality vody v ukazatelích BSK5, CHSKCr, N-NH4, N-NO3, celkový fosfor a další. Redakčná poznámka Analýza dynamiky změn jakosti vody ukázala na následující skutečnosti: Autor obdržal za tento píspevok ocenenie Sloven- − Převažující část povodí Labe ve většině hodnocených ského výboru pre hydrológiu za najlepšiu prácu 16. kon- ukazatelů zaznamenává v průběhu posledních 30 let ferencie mladých hydrológov v r. 2004. kontinuální nárůst úrovně znečištění.

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