Morphotectonic Analysis of Euphrates River Basin / Iraq

Morphological and morphotectonic analysis have been used to obtain information that influencebasins. Study area includes the Euphrates river basin in Iraq. Tectonically this area within Stable shelf,The Stable Shelf which covers the vast majority of focal south and west of Iraq reaches out into Syria and Jordan and Southwards into Kuwait and Saudi Arabia. It is separated in Iraq into three considerable structural zones. Discrimination of morphotectonic indices of Euphrates basin by using sevenindices. The Euphrates basin (main basin) was divided into four sub basin (s.b) Wadi Horan, Wadi Ubaiyidh, Shuab Hwaimy and Shuab Qusair.Which have been completed for each drainage basin utilizing remote sensing and GIS techniques. So as to identify tectonic activity, different indices including Drainage density (D), Sinuosity index (S), Hypsometric integral (HI), Drainage basin asymmetry (AF), Basin Shape (BS), Transverse Topographic Symmetry (T) and Active tectonic index (Iat). The study demonstrates that intensity of tectonic activities in different parts of the basin and sub basins are different. The values of Drainage density (D) main basin and sub basins are in high classes which mean that the study area has resultant of slight or impermeable subsurface material, little vegetation as well as a good discharge for water and sediments. The Sinuosity index (S) of all study area are sinuous and its semi equilibrium. Hypsometric integral (HI) of Horan, Ubaiyidh and shuab Hwaimy sub basins shows high values of HI which means high rates of geological erosion while the shuab Qusair and main basin shows moderate of erosion rates, HI high values shows that study area is tectonically uplifted. According to calculation of Drainage basin asymmetry (AF) the study area reflects inactive tectonic activity. The Basin Shape (BS) all of basins are in third class and it reflects inactive tectonic activity. After compute Transverse Topographic Symmetry (T) index in the area of investigate, the outcome demonstrate that all the sub basins lies in low active tectonics except wadi Horan and the main basin were moderate active tectonics. Based on Active tectonic index (Iat) all the basins were moderate active tectonics except Horan sub basin is active tectonically. These basins have evolved as a result of plate movements, subsidence, uplift and various erosional processes. The study shows variable relationship between faulting and valleys but most of the trends of faults are subparallel to Euphrates River. Faults orientations in the study area are parallel to NE-SW direction and NW-SE direction. And also the type of drainage network in study area which is varied from dendritic to parallel with SW-NE trending and its indicate that study area may be structurally control.


Introduction
The crash of the Arabian plate with the Iranian and Turkish plates continues to present day because the Red Sea divergent and the Arabian Plate Movement towards North and Northeast, which is in charge of the neotectonic and seismic events in the region (Al-Janabi, 1996).The area under investigate is part of the stable shelf, so its tectonic evolution was associated with the tectonic evolution of the stable shelf.The region was influenced by the pre-cambrian tectonic movements (Kibaran, Hajaz and Najd).These movements were affecting in the basement rocks appears of faults in the direction northeast-southwest, northwest-southeast.These faults have an essential role in the structural and structural development of the study area.Water resources of Iraq historically have depended largely on the surface water of the Tigris and the Euphrates Rivers since the Mesopotamian civilization.More than 75% of the available water of Iraq comes from outside the territory.Both the Tigris and the Euphrates are international rivers, their sources originating in Turkey.[1].
Euphrates River, The longest river in southwest Asia, it is one of the two main constituents of the Tigris-Euphrates river system.The river rises in Turkey and flows southeast across Syria and through Iraq.Formed by the confluence of the Karasu and Murat rivers in the Armenian Highland, the Euphrates descends between major ranges of the Taurus Mountains to the Syrian plateau.It then flows through western and central Iraq to unite with the Tigris River and continues, as Shatt Al-Arab, to the Arabian Gulf.The length of the Euphrates from the source of the Murat River to the confluence with the Tigris at 3,000 kilometers (1,900 mi), of which 1,230 kilometers (760 mi) is in Turkey, 710 kilometers (440 mi) in Syria and 1,060 kilometers (660 mi) in Iraq.In length of the Shatt al-Arab, which connects the Euphrates and the Tigris with the Gulf, is given by various sources as 145-195 kilometers (90-121 mi).Euphrates River is located between the Sedimentary Plain in the east and the Western desert of Iraq in the west.[2] Describes the Sedimentary Plain as a large sedimentary basin that represents a large syncline with active tectonic surface.This basin passes through a subsidence or depression, with small local elevation motions, which is associated with the Alpine movement of the mountains that occurred in the highlands Zagros, which is still active.So far, this basin receives the products of erosion and weathering of the mountainous area as the downward movement continues.

Methodology and Materials
In this searchDigital Elevation Model (DEM) with 30 m resolution, geological map 1:1000000 are utilized to investigation and extraction of vigorousindicators and drainage networks.Arc GIs 10.Excel software's were utilized to get distinctive maps..The methodology was done by following steps.

Morphotectonicsindices
It has been known that the study area lies in Western and the Southern Deserts.There are no structural or physiographic boundaries between the two deserts, and the distinction is strictly geographic.[4].

Figure (4) Shows the main & sub basin in study area
Some of indices were calculated by using geometry and measure tool in Arc GIS program such as (the basin area, basin length, basin perimeter, Maximum & Minimum elevation, Form parameter whichis the ratio of Basin area (A) divided by (length of the Basin) 2 and Percentage of the basins).As in table (1).

Drainage Density index (D)
The drainage density shows the closeness of distance of channels, hence giving a quantitative measure of the normal length of stream channel for the entire basin.High drainage density is the resultant of feeble or impermeable subsurface material, inadequate vegetation.Low drainage density prompts coarse seepage surface while high drainage density prompts fine waste surface.[5].

Figure (5) System of stream ordering
Ten stream orders were adapted in this study for main and sub basin, the length was calculated to each basin separately.As well as the Euphrates basin (main basin).Low density is below0.6,average between 0.6 and 0.9, high if it is above 0.9 [6].Appling equation no.1 on table no.1 we get the result as in table 2.

:
Rivers that have turns are near to be harmony, while the immediate river course speaks to more youthful and presence of neotectonic exercises in the territory.Rivers having a sinuosity of 1.5 are called sinuous, or more 1.5 are called meandering [8].Appling equation no.2 on table no.1 we get the outcome as in table 3.

Hypsometric integral (HI)
The hypsometry may reflects the interaction between tectonic and level of non stability in the balance of erosion, beside it could provide a valuable geomorphic index that constrains the relative importance of these processes, In general, land areas with higher rates of tectonic uplift have higher HI values as basins are less concave, and land areas that have been subject to net long-term erosion have lower HI values and basins are less convex.[9].And it calculated by equation: HI= (mean elevation -Min.elev)/ (Max.elev-Min.elev)-----3 Classified this parameterinto three categories: 1) Hi≥0.5, 2) 0.4 ≤Hi>0.5, and 3) Hi >0.4.[10].Appling equation no.3 on table no.1 we get the result as in table 4.

Transverse Topographic Symmetry Factor (T)
Regards to present search, we were indicate class 1 for T >0.4high, class 2 for T between 0.2 and 0.4 moderate and class 3 for T < 0.2 low.[12].Appling equation no.6 on table no.1 we get the result as in table 6. Active Tectonics Index (Iat) [10].Appling equation no.7 on indices we get the result as in table (7).

Faults and Drainage network in study area
The study area contains several sub-basins that lie in the western and southern of Iraq.These sub-basins were observed from the interpretation of using Digital elevation model processing, these basins have evolved as a result of plate movements, subsidence, uplift and various erosional processes.
The observation of Figure (7) shows different and variable relationship between faulting and valleys but most of the trends of faults are sub-parallel to Euphrates River.Faults orientations in the study area are parallel to NE-SW direction and NW-SE direction.Besides the type of drainage network in study area which is varied from dendritic to parallel with SW-NE trending and it's indicate that study area may be structurally control.

Discussion &Conclusion
In present research, in view of geomorphic parameters the aspects of tectonic activities in Euphrates basin territory were discussed.
1. Seven indices were achieved as well as the basins characteristic as in table (1) so as to elicit tectonic efficiency for Euphrates basin.
2. Ten stream order recognized in study area for main basin (Euphrates basin) starts with tenth order and end with second order, Horan sub basin starts with ninth stream order and end with second order, Ubaiyidh sub basin starts with tenth order and end with second order, Shuab Hwaimy sub basin starts with tenth order and end with second order, Shuab Qusair starts with tenth order and end with second order.
3. With regard to the value of Drainage density (D) main basin and sub basins are in high classes which mean that the study area hasconsequence of slight or impermeable subsurface material, little vegetationas well as a good discharge for water and sediments.The Sinuosity index (S) of all study area are sinuous and its semi equilibrium.Hypsometric integral (HI) of Horan, Ubaiyidh and shuab Hwaimy sub basins shows high value of HI which means high rates of geological erosion while the shuab Qusair and main basin shows moderate of erosion rates, HI high valuesshows that study area is tectonic uplift.According to calculation of Drainage basin asymmetry (AF) the study area reflects inactive tectonic activity.TheBasin Shape (BS) all of basins are in third class and it exhibit inactive tectonic activity.Aftercompute Transverse Topographic Symmetry (T) parameter in the area under investigate, 10 isolated areas were estimated and the outcomedemonstrate that all sub basins lies in low active tectonics except wadi Horan and the main basin were moderate active tectonics.Basedon Active tectonic index (Iat) classification as in table (7) all the basins were moderate active tectonics except Horan sub basin is active tectonically.4-Overall, intensity and tectonic vigor in different parts of the Euphrates basin and sub basinswere differentia, the results of morphotectonics parameters and the tectonic assessments demonstrate that study area considered as a modestlyvigor's territory as far as tectonic activity.
5-Different and variable relationship between faulting and valleys but most of the trends of faults are sub-parallel to Euphrates River.Faults orientations in the study area are parallel to NE-SW direction and NW-SE direction.Moreover the type of drainage network in study area which is varied from dendritic to parallel with SW-NE trending and it's indicate that study area may be structurally control.