The Kiri-tó meander//Sediments and the question of floods

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Chapter 5
THE KIRI-TÓ MEANDER:
SEDIMENTS AND THE QUESTION OF FLOODS
Pál Sümegi and Sándor Molnár
Fig. 5.1. Aerial photograph of the Kiri-tó study area
□
excavated Kőrös site, ○ undisturbed cores for pollen analyses, A–A’ B–B’ the geological cross-sections
Geological and geomorphological conditions around the Kiri-tó meander
According to the results of the geomorphological investigations carried out in the surroundings
of the Kiri-tó, and the analyses of aerial photographs and satellite images (Fig. 5.1), the gradually
silting-up cut-off channel of the Kiri-tó formed an oxbow lake, whose surrounding river banks,
and adjacent backswamps, though significantly deformed as a result of erosion and sediment ac-
cumulation, are clearly distinguishable. This juvenile geomorphological state has been preserved
in an almost original condition because the study area developed a relatively elevated position
forming a fossil lag-surface at a relatively early stage, preventing further landscape evolution
(Sümegi 2000b; 2003b; Sümegi et al. 2002).
According to the geological investigations, the surface sediments are exclusively of Quater-
nary age (Fig. 5.2). On the other hand, the geological forms in the surroundings of the Kiri-tó
can be classified into two major groups. One of these is the Holocene organic-rich, clayey flood-
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Fig. 5.2. The geological map of the Kiri-tó. Late Holocene: fQa,h2 = Late Holocene alluvial clay; fQalh2 = alluvial silt;
lQal,h2 = lake silt; bQt,h2 = peat. Early Holocene: fQa,h1 = Early Holocene alluvial clay; fQal,h1 = Early Holocene
alluvial silt. Upper Pleistocene: eQl,P3 = Upper Pleistocene loess; hQil,P3 = Upper Pleistocene infusion (alluvial) loess;
fQal,P3 = alluvial silt; fQa,P3 = alluvial clay
plain deposits uniformly covering the valley of the River Berettyó. The other is made up of the
island-like segments of Pleistocene loess-covered lag surfaces elevated above the surface of the
floodplain as a result of erosion starting during the Holocene (Fig. 5.3).
Three major neotectonic depressions or sub-basins with a decisive role in this geological
evolution are located in the study area: the Körös Basin, the Szarvas Basin and the outlet of
the River Sajó (Sümeghy 1944; Rónai 1985) (Fig. 5.4). Thanks to the unique geological setting
and the differential neotectonic movement of the sub-basins, the coarser Upper Pleistocene and
Holocene gravels and sands accumulated at a larger distance from the study area, at the interface
of the foothills and lowlands (Nádor et al. 2003). Mainly fine-grained deposits of clays and silts
accumulated in the inner parts, thus in the valley of the Berettyó as well.
According to the geomorphological analysis, the channel of the Kiri-tó is a relatively ancient
one, which must have formed as early as the Pleistocene, possibly during the Würmian period
(Fig. 5.5). It must have formed as part of an ancient fluvial channel system running down from
the NE to the SW, a little bit more to the south than the present-day valley of the Berettyó. This
river must have discharged into the small neotectonic depression located in the surroundings of
Szarvas and observable even today (Rónai 1985). The emergence of the cutoff channel of the
Kiri-tó, and the birth of the present-day fluvial system of the Berettyó must have occurred during
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Fig. 5.3. The geomorphological formations depicted on a digital field map (Timár 2003).
Ecsegfalva 23 is shown by a square and an arrow
Fig. 5.4. The sub-basins of the Great Hungarian Plain
the end of the Würmian and the Holocene. During this time, the river cut itself into the older al-
luvia at a depth of 3–2 m as a result of the subsidence of the foreland (the Szarvas Basin), forming
an incised valley. The outcome of geomorphological forms are clearly observable on the digital
elevation model (DEM) of the area (Fig. 5.3) (Timár 2003).
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Fig. 5.5. Palaeochannel systems around the Kiri-tó (Nádor et al. 2003)
The location and selection of the coring sites
The infilled cut-off channel of the Kiri-tó forms a sedimentary basin linked to archaeological
sites. It has been investigated from an environmental historical aspect as well. This minor sedi-
mentary depression preserves layers from which the once prevailing environmental conditions
and the history of its development can be elucidated via the application of various sedimento-
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logical, geochemical, chronological and
paleoecological (analysis of macro- and
microfossils, pollens, charcoal, diatoms,
phytoliths and molluscs) tools (Mack-
ereth 1966; Birks and Birks 1980). These
sedimentary basins tend to preserve not
only so-called autochtonous deposits
accumulated on site, but allochtonous
ones as well, transported into the basin
from larger distances. Thus, we can iden-
tify traces of human-induced soil erosion
horizons and vegetation changes in the
deposited layers (Edwards 1979; 1982;
1991). The sedimentary basin is best suit-
ed for the investigations of the relation-
ship between people and environment
throughout the course of history, when
relevant archaeological sites are located
adjacent to the lacustrine system. No such
analysis of Neolithic sites has been pub-
lished so far from Hungary. However, the
results of such work have been presented
on a Bronze Age site (Sümegi et al. 1998;
Sümegi 2000a). The major goal of each
and every analyis was to shed light on the
surrounding environmental conditions of
the oxbow lake prevailing before the ap-
pearance of agricultural production, and
during the time of the Early (Körös cul-
ture) and Middle Neolithic (AVK: Linear
Pottery culture of the Great Hungarian
Plain), and to understand the effects these
human communities had on the environ-
ment.
Two geological cross-sections were recorded in the study area (Figs 5.1 and 5.6–9). The
northern section runs from the centre of the channel through site Ecsegfalva 18 of the AVK
group (Figs 5.6–7), while the southern section was taken across the channel at site Ecsegfalva 23
of the Körös culture (Figs 5.8–9). These cross-sections were used to determine the coring sites
for taking undisturbed samples for pollen, phytolith, malacological and radiocarbon analysis
from the channel. An auger was used for the geological mapping (32 boreholes), while undis-
turbed samples for pollen, phytolith and radiocarbon analysis were taken by a Russian corer (six
boreholes) (Bell and Walker 1992). Two further profiles were dug by hand for taking samples for
malacological analysis.
No samples were taken from the bedrock due to the high carbonate and iron content as well
as the compaction of the deposits. Several augers and Russian and Cobra bitheads were damaged
during the coring process. Despite the fact that the bedrock was not reached, the layers deposited
during the past 11–12,000 years and which are important for archaeological investigations have
been sampled. According to the results gained, the channel must have formed during the Pleis-
tocene, possibly in the early phase of the Würmian period.
Fig. 5.6. The position of the A-A’ geological cross-section
of Kiri-tó
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0 40 80 120 160 m
85
80
75
m a.s.l.
1. Neolithic
2. Recent
3. Eutrophic lake
4. Infusion loess
5. Oligotrophic lake
6. Alluvial
7. F luv ial
Fig. 5.7. The geological cross-section A-A’
of the Kiri-tó
Fig. 5.8. The position of the B-B’ geological cross-section
of Kiri-tó
m
86
84
82
80
2
3
4
5
33
2
6
Fig. 5.9. The geological cross-section B-B’
of the Kiri-tó
1. Soit within Neolithic finds
2. Infusion (Alluvial) loess
3. Fluvial sandy silt
4. Holocene organic rich silty clay
5. Pleistocene silty layers with low organic
content
6. A river regulation channel
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Lithological analysis
All samples taken from the undisturbed cores and the geological profiles created for the sampling
of the malacofauna have been analysed for grain-size composition (hydrometry: Molnár 1981),
and organic and carbonate content (Dean 1974). Furthermore, completely new approaches have
been introduced during the sedimentological analysis with regard to pollen preservation.
These corings in the channel of the Kiri-tó were complemented by the analysis of the sedi-
ments at and within the surroundings of the archaeological sites by boring over a 5 by 5 m grid
to an average depth of 2 m (196 boreholes). Plough horizons, the soil infills made during the
industrial age to prevent alkalisation, as well as the disturbed soil and undisturbed hidromorphic
woodland (which developed under gallery forest) and black soil horizons of the Neolithic and the
bedrock horizons, were identified within these boreholes along with their morphological posi-
tions (Fig. 5.10). Then by separating human-induced infilling in the area and removing the cul-
ture layers, which formed as a result of human activities of the individual periods (for example,
the Sarmatian earthwork, and medieval and modern historical trenches) from the digital model,
and the restoration of the original soil horizon, which was eroded later on, the original geomor-
phological conditions have been reconstructed for the Neolithic (Fig. 5.11).
Radiocarbon analysis
A significant amount of shell material of the species Planorbarius corneus and Unio pictorum
available from a depth of 1.6–1.5 m enabled the radiocarbon analysis of an open mass sample. The
preparation of the shells necessary for the analysis was carried out in accordance with Hertelendi
et al. (1992).
The results of the sedimentological analyses
The layers from the base of the borehole towards the surface correspond to the deposits of a grad-
ually silting-up oxbow lake (Fig. 5.12). The lowermost horizon between the depths of 2.2–2.0 m
is made up of brownish-yellow, carbonate-rich silts with a minimal organic and clay content. This
sediment type corresponds to the aeolian minerorganic deposits accumulating in a cold-water,
oligotrophic lake (Oldfield 1978), which is highly characteristic of the loose-bound sediments
which accumulated in Hungarian ponds and oxbow lakes during the Late Glacial (Willis et al.
1995; Sümegi 1996; 1998; 1999a; 2004; Sümegi et al. 1999).
There is a sudden increase in the clay and organic content in the overlying horizon between
2.0–1.6 m, accompanied by a significant drop in the carbonate content and the deposition of or-
ganic-rich, yellowish-brown clayey silts. This sedimentary facies is closely linked to the environ-
mental changes which occurred at the end of the Pleistocene and the beginning of the Holocene
as a result of the global warming-induced intense weathering and the emergence of a new type of
vegetation cover in Hungary (Willis et al. 1995; 1997; Sümegi 1998; 1999a; Sümegi et al. 1999;
Juhász 2002; Magyari et al. 2002). The Pleistocene oligotrophic lake gradually turned into a mes-
otrophic lacustrine system via eutrophisation at the start of the Holocene. Another significant in-
crease in the clay and organic content in the near-surface layers must be related to the emergence
of agricultural production in the area at the end of the Early Holocene, resulting in a disturbance
of the original vegetation and the erosion of the clay and organic fraction of the soils, which had
developed in the surroundings of the Kiri-tó.
At a depth of 1.6–0.4 m, right above the zone of soil erosion, a blackish-brown, organic-rich
silty clay layer has been identified corresponding to eutrophic lacustrine deposits. The signifi-
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Fig. 5.10. Recent surface around the Körös site of Ecsegfalva 23
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Fig. 5.11. Neolithic Age surface around the Körös site at Ecsegfalva 23
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cant amount of brownish-red limonite and goethite spots in the layers must indicate the former
fluctuations of the groundwater level, and the intensive falls and rises in the water level within
the lacustrine system. According to the transformations identified in the deposits, the silting-up
of the channel and the erosion of the soils in the surrounding areas must have accelerated during
this time, resulting in a rapid eutrophisation of the Early Holocene lake and the emergence of an
organic-rich eutrophic lacustrine system with highly fluctuating water levels during the second
half of the Holocene.
From a depth of 0.4 m up to the surface, we have come across a layer of blackish-brown peaty
clay embedding reed (Phragmites), bulrush (Typha), and sedge (Carex) remains. According to the
composition of the deposits, the lacustrine system must have turned into a periodically drying-
out marshland during this time.
As can be seen on the cross-sections (Figs 5.8–9), the riverbanks, with a bedrock of sands and
clayey silts, are uniformly covered by silt- and carbonate-rich Pleistocene infusion loess layers.
These loess horizons must have formed from aeolian dust deposited under humid conditions in
wet areas (Földvári 1958; Pécsi 1993) and are stratigraphically closely linked to the carbonate-
and silt-rich oligotrophic lacustrine deposits of the Kiri-tó channel. Thus the silt or carbonate,
which accumulated in the lacustrine basin, or at least a part of it, must have derived from the
syngenetic inwash of these infusion loess layers.
The facies of the Holocene organic-rich lacustrine deposits on the other hand seems to cor-
respond lithostratigraphically to the soil layers, which formed on top of the infusion loess layers.
Fig. 5.12. Sedimentological results of the Kiri-tó geological profile at Ecsegfalva
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Consequently, the deposition of the Holocene lacustrine sediments and the formation of these soils
must have been isochronous or coeval. According to the results of the radiocarbon analysis (from
the shells of Planorbarius corneus sampled between 1.6–1.5 m: 7400±70 BP, 6362–6270 cal BC,
and from the hypostracum layers of Unio pictorum: 7010±100 BP, 5979–5798 cal BC; and see
the following chapter), the section between 1.6–1.5 m within the channel of the Kiri-tó must cor-
respond to the period of the Early Neolithic. As the grain-size composition revealed, there is a
slight increase in the clay and organic content of the deposits within this part of the profile, most
likely as a result of the emergence of agricultural production in the area, and the accompanying
transformation of the vegetation, the creation of arable and pasture, as well as the establishment
of permanent settlements and continuously trodden trails. All these human influences must have
enhanced the acceleration of soil erosion in the area and the eutrophisation of the Early Holocene
mesotrophic lake. According to the composition of the sediments, a mesotrophic lake with waters of
an average depth of 1.5 m must have formed during this time within the channel of the Kiri-tó.
Similar changes could be observed in all boreholes in the channel. However, the thickness of
the deposits was different in the centre compared to the marginal littoral areas.
The effects of river regulations
In order to get an understanding of the original hydrological conditions and drainage patterns
prevailing in the area of the Great Hungarian Plain, the hydrogeological systems present before
the nineteenth-century river regulations should somehow first be understood, along with other
minor water control works affecting the natural system of waters within the Carpathian Basin.
The Romans were the first to implement comprehensive river regulations within the Car-
pathian Basin with the establishment of the so-called Principal channel in the province of former
Pannonia, today Transdanubia, creating a hydrological link between the Mura and Zala rivers,
and draining the surrounding marshlands. Furthermore, the predecessor of today’s Sió channel
was used for the regulation of the water level within Lake Balaton (Szalai 1985).
During medieval and modern times, the regulation of rivers and the drainage of wetland
areas became gradually more and more desirable and were thus frequently advocated. Initially,
only earthworks of local importance were erected, but successively more water courses were
constrained between artificial levées from the eighteenth century onwards. The regulation of the
watercourses of the Vág, Lajta, Rába, Sárvíz, Sió and Kapos along with the certain parts of the
Danube was initiated, sometimes regardless of the objections of the local population.
On the other hand, the construction of mill-dams and entrenchments surrounding fortresses
contributed to the expansion of wetland areas. The site of the breach in the natural levée called
the Mirhó crevasse-splay (‘Mirhó-fok’), which served as a hydrological link towards the Middle
Tisza was cut off in 1787. Formerly, floodwaters from the Tisza managed to reach as far as the
area of the Nagy-Sárrét via this crevasse-splay, and its elimination rendered a major part of the
Nagykunság north of the River Berettyó flood-free. Regulation works on the River Tisza were
initiated during the second half of the nineteenth century, the Age of Hungarian Reformism,
based on the plans and concepts of Pál Vásárhelyi, enjoying both intellectual and material sup-
port from István Széchenyi. The first sod cut on the 27th August 1847 at the village of Tiszadob
marked the start of one of the most significant landscape transformations in Europe, lasting with
minor intermissions until 1905. 94 bends were cut off from the main channel from the village of
Tiszaújlak down to the mouth of the river, taking away a section of about 453 km from the full
river length, and reducing the area of the floodplain to one tenth of its original size (Fig. 5.13). For
the same ends, tributaries were also regulated. The twentieth century marked the establishment
of dams and hydro-electric powerplants. The total length of primary dams along the rivers today
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in Hungary equals to 4.211 km, and the former floodplain areas of 21,251 km2 have been reduced
to a size of 700 km2 (Hamar 2000).
The negative, undesired consequences of the river regulation works were emphasised by Lász-
ló Dapsy as early as 1869. His achievement was to acknowledge the differences between Hungary
and other countries like Germany, compiling a list of advantages and disadvantages of the out-
come of the regulation works. Although some of his reasoning is questionable, his work is out-
standing and fundamental (Dapsy 1869). The task of the generations of the twenty-first century is
to establish a water management system, taking into consideration the erroneous steps made in the
past as well, which not only provides safety from floods to those living along the watercourses, but
is also in accordance with the natural processes and treasures prevailing in the area.
Floods before and after the river regulations
The large-scale river regulations initiated in the nineteenth century have fundamentally altered
the natural evolution of Hungarian rivers, creating active floodplains which represent only a
minor fraction of the former extensive floodplain areas. The cutoffs increased the velocity of the
streams, bringing about a larger rate of incision of the original riverbed. The difference between
the high and low waters of floods has also increased. Without any accurate data on the water lev-
els at hand, one can only give an estimate on the magnitude of these changes. Data on four major
flood events from the profile of the city of Szeged are known for the River Tisza preceding the
river regulations, with highest waters of approximately 620 cm above normal levels in all cases.
These are generally 2.5–3 m higher today. The highest waters during floods were recorded
at Szeged to be 960 cm and 929 cm in 1970 and 2000 respectively. The low water level has also
been greatly reduced because of the deepening of the active riverbed. These changes are around
2.5 m at Szeged. The magnitude of change is different not only for the rivers, but the individual
reaches of a single watercourse as well. The increased stream velocity and incision created ex-
treme stream flows. The highest water measured at Szolnok on 18th April 2000 was 1041 cm.
In just under two months, the water level dropped to –134 cm (17/06/2000), reaching an absolute
minimum of –230 cm at the end of August. The water level remained extremely low in the chan-
nel till the end of that year. These fluctuations in the water level during the year of 2000 are by
no means ordinary. However, no such differences could have been observed between the high
and low waters preceding the river regulations. At the same time, the floodwaters extended over
Fig. 5.13. Changes in the length of the River Tisza following the water-regulations (1847–1905) (modified)
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larger areas, and the floods tended to last longer
as well. However, these somehow all contributed
to the creation of a more balanced water regime
(Fig. 5.14).
Even fewer data are available regarding the
high and low waters of the tributaries of River
Tisza, and thus the rate of alterations can only be
estimated. Finding an accurate value for the River
Berettyó is especially hard, as the present-day
watercourse is totally different from the one that
existed before river regulations. The lower reach
has completely lost its connection to the upper
reach of the river, presently acting as a drainage
channel of inland waters under the name Horto-
bágy-Berettyó (Figs 5.15–19).
However, those elevated regions which were only a couple of metres high, referred to as
‘laponyag’ in Hungarian, and which must have served as sites of human settlement, were either
totally free of floods or affected only by the most extreme flood waters. These island-like seg-
ments were the cores of the former medieval and present-day settlements (Túrkeve, Szerep), and
sometimes were inhabited during ancient times as well. The Pleistocene lag-surface near the area
of Kiri-tó can be regarded as a good example of these.
Besides the regulation of the river, the former marshland areas were also drained along with
the accumulated inland waters on the protected side. This contributed to a significant drop in
groundwater level.
The Berettyó and the Nagy-Sárrét following the river regulations
The area of the Nagy-Sárrét is located between the settlements of Bucsa, Bakonszeg, Füzesgyar-
mat and Dévaványa along the Ó-Berettyó. Only the name of this minor landscape reminds us
today that once significant amounts of water covered these areas. Low-quality arables, alkaline
steppes and a large number of smaller-larger channels are the prevalent forms of the landscape
today. All these alterations happened during the past 150–200 years as a result of human activi-
ties and interventions aimed at draining the inland waters in every possible way (Fig. 5.19).
The density and abundance of the former aquatic flora and fauna are known from surveys
made before river regulations (Dóka 1997). The hydrographer Mátyás Huszár carried out an ex-
tensive mapping of the important marshlands along the rivers of the Körös and the Berettyó in
1825. The final results of the survey yielded a total marshland area of 1927 km2 (as a comparison
Lake Balaton today covers 595 km2).
The most important marshlands were as follows: Komádi Sárrét (Kis-Sárrét): 345 km2; Fási
rét: 129 km2; Péli and Gyulavári rét: 115 km2; Gyánti rét: 57 km2; Nagy Posár (Nagy-Körös, along
the Berettyó): 86 km2; and Berettyó Sárrét (Nagy-Sárrét): 671 km2. No wonder the forename of
this latter marshland is ‘Nagy’ or ‘Great’ in English. This low-lying depression drained not only
the waters of the Berettyó, but other rivers as well. The Kakat creek used to carry waters from the
River Tisza into this depression through the Mirhó crevasse-splay of Abádszalók. Furthermore,
the minor waterflows of the Hortobágy and the Kék-Kálló also drained into this area. The Kis-
Körös, on the other hand, transported waters from the Sebes-Körös into the River Berettyó. The
former inhabitants of the landscape, who had a good knowledge of the water courses, could tell
the origin of the waters reaching the area of the Sárrét by their colour alone. The waters originat-
Fig. 5.14. The cross-section of the channel preceding
and following the river regulations
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ing from the Körös were greenish, those from the Berettyó were brownish, those of the Kálló
were bluish, and those from the Tisza were yellowish or ‘blonde’ (Szűcs 1992).
The most influential stream in the evolution of the Nagy-Sárrét, however, was the Berettyó. The
name Berettyó comes from an ancient Hungarian word denoting a river with lush gallery forests
(Rakonczay 1987). The lower reach of the river flowing out of the Sárrét is marked under the name
Túr in medieval maps and charters, meaning auroch. This designation is still preserved in the name
of some settlements located along the River Berettyó, like Túrkeve and Mezőtúr (Fig. 5.15).
The river derives from the Meszes Hill in the Transylvanian Mid-Mountains (at a height of
582 m) with a watershed area of 64,7465 ha. The watershed area enjoys a precipitation over 900
mm in the area of the Szilágyság from the Réz Hill (Transylvania). However, the average rainfall
on the Great Hungarian Plain and at the interface of the lowland and foothill areas is around
600 mm only (Lászlóffy 1982). The rainfall peak is in June with the lowest rates in January and
February.
The total average annual rainfall is rather low in the area of the Nagy-Sárrét with values be-
tween 530–550 mm. However, these can be even lower in the western parts. The average rainfall
during the growth season is around 310–320 mm. The aridity index is between 1.28–1.33. This is
a rather arid region. This aridity has been somewhat moderated by the waters of the Keleti main
channel constructed during the second half of the twentieth century. The unfavourable soils and
the strong alkalisation make the situation even worse in the region. A significant amelioration is
necessary for the utilization of the lands in agricultural production (Marosi and Somogyi 1990).
The region of the Sárrét, just like the majority of the Great Hungarian Plain, is not totally
smooth, but is studded with smaller or bigger morphological forms. The near-surface deposits
are exclusively of Pleistocene Age. Organic-rich clayey deposits of Holocene Age are predomi-
nant along the River Berettyó with elevated Pleistocene infusional loess-covered ridges. People
used to settle on these island-like elevated surfaces during historical times. Their importance is
well represented by the town of Biharnagybajom, which was an agricultural centre in the Middle
Ages. The low-lying meadows and pastures offered either food or very often protection for their
inhabitants during the course of history.
Fig. 5.15. Changes in the length of the Berettyó
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Afterword: possible solutions for the present day
River regulations, initiating in the middle part of the nineteenth century in the area under study,
brought about fundamental changes regarding landscape evolution. Human influences, though
observable formerly as well in the area, were rather negligible compared to the changes imple-
mented during the past 150 years. As a result of these anthropogenic effects, the formerly rela-
tively wide floodplain ceased to exist, and the regions of the Sárrét were fully drained.
Future attempts at a reconstruction of the original landscape should be aimed primarily at
eliminating these above mentioned changes in the area. The lower course of the Berettyó, located
right next to the area of the Kiri-tó, has been regulated not by the application of the traditional
cut-off of the former riverbed. Rather the original channel was preserved with a relatively wider
active floodplain constrained between artificial levees. Yet the original size of the floodplain
has been significantly reduced this way. For example, the formerly flood-influenced areas of the
Kóré-zug and the channel of the Kiri-tó got on to the inactive protected side of floodplain. Sever-
al gates were constructed within the channel of the Kiri-tó. The watercourse of the Berettyó was
directed right into the River Sebes-Körös through an artifical bed, preventing it from running
Fig. 5.16. The Berettyó dam
Fig. 5.17. High water level in Hortobágy-Berettyó next
to the area of the Kiri-tó
Fig. 5.18. Some remains of the natural vegetation
within the regulated channel
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across the area of the Nagy-Sárrét.
The reach downstream of the vil-
lage of Bakonszeg was linked to the
Hortobágy creek, and the former
outlet into the Körös at Túrtő has
been placed under control with the
help of gates as well. In this way the
water regime of the newly emerged
Hortobágy-Berettyó main channel
system has become fully adminis-
trable.
In order to preserve the flora
and fauna of the surrounding pro-
tected areas, the effects of this
artificial system should be some-
what moderated, to emphasise the
importance of natural processes in
the area. Within the framework of
international co-operations, a special emphasis is laid on the introduction of traditional and sus-
tainable production forms and methods. These principles were first conceptualized on the 1992
UN Convention on the Environment and Development in Rio de Janeiro. There, the maintenance
of sustainable growth, the protection of the biodiversity, as well as the reduction of green-house
gases has been advocated. The 1997 XLI bill on Hungarian industrial and sport fishing was
aimed at the introduction of new methods and tools, which are respecting the protected treasures
of the country, and are implemented in accordance with the needs of conservation. The manage-
ment of the Körös-Maros National Park is intending to restore the former original conditions of
aquatic life in a part of the Nagy-Sárrét as well in the near future (Fig. 4.19).
It would be highly desirable to consider the traditional medieval floodplain management meth-
ods for the reconstruction of the former drainage pattern and aquatic environments in the area of
the Kiri-tó as a possible solution for the expansion of the floodplain area, with the reestablishment
of aquatic, marshland habitats and orchards within the area of the gallery forests. This would cre-
ate new workplaces for the local workforce as well by the introduction of a sustainable form of ag-
ricultural production, besides the conservation of the close-to-natural conditions in the area. The
re-establishment of this system of crevasse splays and floodplain management based on ancient
principles would also enable us to re-evaluate the effects of floods on the landscape within the
Carpathian Basin from a brand new and totally different point of view, enhancing the exploitation
of the natural resources of soils and waters more efficiently in a nature-friendly way.
Fig. 5.19. A drained and ploughed former f lat at the edge of Ecsegfalva
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