Batman Çayı’nın taşkın analizinin HEC-RAS programıyla yapılması

Year 2015, Volume: 6 Issue: 2, 83 - 92, 01.12.2015

Hüseyin Efe Fevzi Önen

Abstract

Taşkınlar, tropikal iklim kuşağında yer alan ülkelerin yanı sıra Türkiye gibi bu iklim kuşağının dışında yer
alan ülkelerde de hem sayı olarak hem de verdiği zararlar açısından bir artış göstermektedir. Artan nüfus
yoğunluğuyla beraber çarpık yerleşim bölgelerinin artmasıyla bu taşkınlar sonucu can ve mal kayıplarının
da yaşanmasını kaçınılmaz hale getirmektedir. Özellikle son yıllarda hayatın her alanına girmeye başlayan
Coğrafi Bilgi Sistemiyle, taşkın risk analizlerine dayalı risk haritaları yerleşim planlamalarında esas alınan
öncelikli etmen olmaya başlamıştır. Bu çalışmada, Batman Çayı’nın Yeni Malabadi Köprüsü ile Diyarbakır
– Batman Karayolu Köprüsü arasında kalan kesimine ait taşkın analizi yapılmıştır. Düşük bir eğimle
(J≈0.00019) menderesler çizerek sık sık akım yatağı değişen Batman Çayı’nın, Batman İl merkezi de dahil
olmak üzere birçok yerleşim yerine sınırı bulunmaktadır. Bu da, yüksek bir debiye sahip olan Batman
Çayı’nda zaman zaman can ve mal kaybına neden olmaktadır. Çalışma yapılan bölgeye ait 1/1000 ölçekli
haritada AutoCADCivil 3D programıyla toplamda 165 adet enkesit alınmıştır. Elde edilen bu enkesitlerle,
HEC-RAS (Hydrologic Engineering Centers River Analysis System) programı yardımıyla Batman Çayı’nın
tek boyutlu taşkın hidrolik analizi yapılmıştır. Değişik feyezan değerlerine bağlı taşkın zararlarının alansal
değişimleri göz önüne alınarak mevcut dereye ait doğal yatakta Q5, Q10, Q25, Q50, Q100 ve Q500 taşkın tekerrür
debilerinde su üst yüzünün geldiği kotlar belirlenmiştir.

Keywords

Batman Çayı, HEC-RAS, taşkın analizi

Floodplain analysis of Batman river with HEC-RAS program

Abstract

Since the beginning, people have preferred
residential areas close to the water resources of the
indispensable qualities for permanent living. As a
result, it is made interfere with the natural water
beds. Beside of meteorological and geomorphological
structure of the basin, flood under
human intervention cause losses of life and property
inevitability.
As a result of global warming, besides the
meteorological events such as extreme weather
events it is expected that the frequency can be of
significant increase in the activity area of floods.
Floods are seen as the greatest natural disaster in
the worldwide after earthquakes. Especially country
like Turkey, as well as in terms of both climate and
geographical features changing in a short distance,
flood is the most decisive parameter in the
localization planning. With the increasing
awareness, there are more accurate studies intend to
on early warning systems and reduce damage of
flood under the "Flood Risk Management".
Especially in the case that permeates every aspect of
life are increasingly, the Geographic Information
System is use with flood plain analysis.
In nature, the size of river does not cause excessive
flood. However, as a result of human intervention
river cross-section area is decrease and major flood
can occur. The main cause of this problem is
incorrect application of zoning and land use as
settlement.
Depend on founding petroleum there have been
major and rapid growth in Batman city. After this
unplanned growing, there have been disorder in
urbanization of the city and people settle in river bed
areas. As a result of this situation, there are a
significant amount of life and property losses. In
2006, the flood in the city centres, there were 10
people dead and great material damage.
In this study, the floodplain analysis of Batman
River between New Malabadi Bridge and
Diyarbakır – Batman Highway Bridge was
performed. With a lower slope ( J=0.00019) and a
lot of meanders Batman River, which close to the
several settlements including the city centres of
Batman, frequently changes its current bed. High
flow rate in Batman River cause loss of life and
property. 165 cross-sections is taken from the map
of the study area with AutoCAD Civil 3D program.
After export these cross-sections to the HEC-RAS
(Hydrologic Engineering Centres River Analysis
System), one-dimensional floodplain analysis of
Batman River is obtained. Under the different flow
rate, a spatial variation of flood damage is provided.
Floodplain risk analysis determine water surface
profile in the natural bed of the river under Q5,Q10,
Q25, Q50, Q100ve Q500 flow rates.
According to the analysis result, capacity of crosssections
of Batman River isn’t passed more than Q50
flow rates. Because of its geological formation is
semi-permeable and impermeable, flood infiltration
to the ground water is prevented. As a result of river
bed is used by human as sand pits, residential or
agricultural areas, there can be losses of life and
property every rain season. Especially the area
between station km: 20+700 – 21+211 and 9+300 –
9+950 is have higher water depth because of the
flatness of the section base, it was observed that
inundated a large area. This part of the river bed to
the corresponding Şerbet and Bıçakçı Villages is
under serious risk of flooding.

Keywords

Batman River, HEC-RAS, floodplain analysis