Hydrology, Morphometry and Hydrochemistry study of Gibbel Stream in Dinarta / Akre area, Iraqi-Kurdistan Region.

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The studied area is 24km away from Akre city and situated in the
Kurdistan Region of Iraq between latitudes (407524 to 409705) and longitude
(4074824 to 4049779). The study focuses on Gibbel stream which extend from
the NE to SE of Akre city. A (26)km longer and has a total stream area of (390)
Km2. Satellite images as well as a Digital Elevation Model with topographic,
geologic, and structural maps were used in addition to field investigations to
perform a geomorphological analysis and classification. Tectonically, the studied
area is located in the high folded zone in its northern part and in the foot hill
zone of low folded zone in its southern part. All the lithological units that are
encountered and crops out in the area are sedimentary and belonging to the
Cretaceous and Tertiary in which Sarmord formation being the oldest formation,
while Quaternary deposit (Holocene) are the youngest.
The studied area is part of a region influenced by the Mediterranean
climatological system. The climatic data were obtained from the Agrometeorological
of Aqra stations because it is the nearest station to the study area.
The obtained data for the period of (2004-2014) were used to determine the
meteorological parameters of the study area. Water balance calculated for this
period showed that the average of the annual rainfall is 717.50mm/year, the
relative humidity is 46.40 %, the temperature is 19.25°C, the wind speed is
1.67m/Sec, the sunshine duration is 8.17 hours and the annual pan evaporation is
1708.68 mm/year. The annual surface runoff and recharge are 364.82 mm and
32.73 mm, respectively. Therefore, the coefficient of variation values indicates
that the rainfall variation of winter and spring seasons were nearly uniform and
consistent and of minimum contrast. The rainfall of winter and spring is the most
effective for creation of discharge in the Gibbel stream which means that the
stream discharge will reflect the same characteristic of consistency and
Detailed morphometric analysis was applied to the Gibbel stream, using
variable geomorphological and hydro geomorphological parameters, depending
upon DEM (digital elevation model) (30m) as a base map with GIS and
Collecting required data and information related to the case study. All groups of
morphometric parameters were used, including: linear, relief, aerial and other
parameters related to the studied area. Morphometric analysis results are
discussed and correlated with each other and with standard values to evaluate
fluvial-geomorphic evolution of the stream. The study shows that the Gibbel
stream is of the 5th order drainage stream type, with relatively moderately values
of drainage density and high stream relief value. This implies that high run-off,
and consequently low infiltration rate in the stream. According to the elongation
ratio and the circularity ratio the stream, is semi-elongate to elongate in shape,
which reflects strong structural controls on its morphology; and smoother
hydrograph curve because of the greater time lag for the water. Drainage pattern
is dominated by dendritic and parallel types which reflect structural controls in
addition to variable lithologic characters of the stream rocks.
The hydrochemical study of the surface water in the Gibbel stream for 20
water samples in two periods comprised the major cations, anions and trace
elements concentration, salinity, temperature, electrical conductivity, and pH.
The ionic concentrations were calculated in (ppm and epm) units. The surface
water in Gibbel stream is meteoric and the type of water is bicarbonate in both
periods. Gibbel stream water is suitable for drinking purposes and suitable for
many other purposes, including industrial, building, livestock, poultry,
agricultural crops, and irrigation.

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