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The river Tisa has the flow
which is almost one thousand kilometers long and begins in Ukraine as two
small rivers: White and Black Tisa which join together near the town of Rahiv.
The wells of those two rivers are in the northeastern Karpats, very high in
the mountains, so in its upper flow, the Tisa is the tipical mountain river,
with no big pollution.
In its lower flow, the Tisa is typical plain river (wide and quiet, with a lot
of material which carries with itself and meanders). The Tisa is a left
tributary of the Danube, and its mouth is near Titel. Riverbed of the Tisa in
its lower flow represents a border between Banat an Backa, two parts of big
Panonian plain. With the Danube, it is also connected by channel Danube-Tisa-Danube.
By the works of famous Serbian geographer, academic Pavle Vujevic, river basin
of the Tisa has the area of 153200 km2. The Tisa had the flow of length of
1492 km which was cut with the big works of the riverbed regulations and now
it is only 977 km long. During the regulations, the most of meanders have been
artificially cut of the river and dead meanders became of them. Dead meanders
around the Tisa are now being called "The Dead Tisa" or "The
Old Tisa" and are rich with water of high quality since there are no
industry nor pollutants in the closest vicinity, and dead meanders are in no
connection with the river flow.
The Tisa waters significant area of Central Europe - its river basin is spread
over Ukraine, Slovakia, Romania, Hungary and Yugoslavia. Half of the river
basin in Hungary is under protection (dead meanders are very important natural
protected areas), and the second half represents irrigated and fertile land.
On this river, a rare phenomenon of blossom of water can be seen. Water
flowers are the ancient groups of insects, characterized by big swarming which
still can not be explained in details by science. The most famous species here
is "Tisa flower" (Palngenia longicauda). Because of very expressive
sensibility on environment changes, water flowers can be used as bioindicators:
on their presence and number, pollution degree (i.e. quality of water) can be
determined.
Unfortunately, many of
industrial plants which drop their industrial waste into the Tisa contribute
to relatively big pollution of the river water. Except "regular"
pollutions, accidents represent special danger, as two years ago, cyanide was accidentally
drop into the river which bring into danger life in the river and around it.
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