Iraqi Geological

Abstract


Introduction
Morphometry is the measurement and mathematical analysis of the configuration of the earth's surface, shape and dimensions of its landforms (Clarke, 1966); it is also used to describe and evaluate drainage networks, as well as to determine the components that influence the creation of various river systems (Ali and Khan, 2013;Sakthivel et al., 2019). Morphotectonics is regarded as a method for detecting the degree of tectonic activity in tectonically active places (Beaumont et al., 2004). Its research is vital for evaluating the risk of earthquakes in the area with relatively high activity, such as the Holocene and Late Pleistocene (Pinter and Keller, 2002). According to the Koppen-Geiger climate classification (Kottec et al., 2006), the study area is located in the primary arid climatic region, with steppe precipitation and warm arid temperature conditions. The emphasis was on the lithology and tectonic activity of the fact that climate has an equal or semi-equal influence on the evolution of geological forms in the area. By using morphometric analysis, watersheds could be organized and defined in relation to their physical characteristics, which is important for many investigations including such environmental science, soil degradation, water recycling, the influence of geology variables on the production of different stream systems, and planning or management for Land Cover and Land Use (LCLU) (Aravinda and Balakrishna, 2013;Arabameri et al., 2018). Many research have effectively employed remote sensing in association with GIS approaches to investigate morphometric characteristics of watersheds in recent years. According to Aziz et al. (2020), the collection of information as well as morphometric analyses utilizing GIS would be highly essential in water harvesting selected sites with the least time and cost when compared to conventional techniques; moreover, all of this produces correct results. As a consequence, in this work, remote sensing and GIS techniques were used to assess the morphometric features and manage significant basins in the Kurdistan Region such as Rawanduz basin as the case study. The aim of the study will be to compute the basin's morphometric parameters including (Linear, Areal and Relief parameters), and comprehend the geologic, hydrologic, and geomorphic characteristics of the basin, and establish the morphometric location of the drainage within that network in order to contribute to watershed management preparation.

Description of the Study Area
The study area is situated approximately 110 kilometers northeast of Erbil city. The area was delineated by longitudes and latitudes of 44°30'E and 45°0'E and 36°20'N and 36°50'N respectively. In the research area, the Rawanduz River flows from the northeast to the southwest and has a length of 65 kilometers from Haji-Omaran to the Kawlokan district. The basin's total area is 977.68 km 2 as Fig.  1. The river passes through Rayat and Choman districts. Near Naopurdan Village, it joins another main branch that flows down between the higher ridges of Sakran Mountain. The river flows further, passing near the Galala Gorge, the third main branch that heads between the slopes of Halgurd and Hassar-Roast near the intersection of Smilan Road and Hamlton Road. Thereafter, over through the Barsarin Gorge to Jundian, and finally to the Rawanduz Valley (Khara-Rash Valley; on the west of Rawanduz Town) (Abdullah et al., 2020). After its conjunction with the Balakiyan and Alana Streams, it flows through Galy Ali Beg to Khalan Valley, where it joins the Greater Zab River. According to Jassim and Goff, (2006), Tectonically, the study area positioned in three major tectonic zones (High Folded Zone to Imbricate Zone and Zagros Suture Zone). The area of study bounded by four mountains; Korek mountain in the southern part, Handreen mountain in the east, Zozik mountain in the northern part, and Bradost mountain in the western part.

Materials and Methods
This research conducted by using DEM (ALOS PALSAR DEM) with 12.5 m resolution, topographical map with 1: 25,000 -1: 100,000 scale data would be used. The Arc GIS 10.8 from Spatial Analyst Tools has been used to outline the basin and perform morphometric analyses such as linear, aerial, and relief characteristics. Moreover, DEM was used to obtain hydrological information such as drainage networks, primary drainage pattern types, and the Rawanduz river basin border. The graphic below represents the diagram and basin stream orders delineation (Fig 2 and 3).

Delineation Types of Drainage Patterns
The drainage system, also known as the river system in geomorphology, is the patterns formed by the streams, rivers, and lakes in a specific drainage basin. They are regulated by the land's topography, whether a specific area is influenced by hard or soft rocks and the land's gradient (Ritter, 2006). Streams are frequently viewed as part of drainage basins by geomorphologists and hydrologists. The landform region from which a stream receives runoff, through flow, and groundwater flow. The number, size, and shape of drainage basins vary, and the more information available, the wider and more accurate a topographic map will seem to be (Pidwirny, 2006). Dendritic to sub-dendritic type is more common in my study area. Fig.4 illustrates the major types of drainage patterns.

Morphometrical Parameters Analysis
Mathematical quantitative analysis (morphometry) has been used to describe the linear, area, relief, and other characteristics of the basin in order to infer the interrelationship among numerous different drainage basin parameters and their influence on the evolution of the basin stage. The different main equations of morphometric parameters are represented in Table 1.

Types of Drainage Patterns
A number of types of drainage patterns have been identified, within the Rawanduz basin, (Fig. 4), namely:

Dendritic drainage and Sub-dendritic pattern
Dendritic to sub-dendritic type is more common in my study area. The dendritic system form in Vshaped valleys, the rock types must be impervious and non-porous (Sissakian, 2013). In study area this type of pattern representing in the NW-part such as in the Roste District area as shown in Fig. 4.

Parallel drainage pattern
This form is structurally managed and it is most frequently known on the limbs of major structures such as the Korek, Handren, Zozik, Bradost, and Halgurd mountains. In the study region, the Parallel pattern indicting in the NE Limb of Korek Anticline representing Kawlokan area as shown in Fig. 4.

Rectangular drainage pattern
The rectangular drainage pattern is being located in areas controlled by structural joints and faults. Streams take the path of least resistance and thus congregate in areas where exposed rock is even at its weakest (Sissakian, 2013). This type of pattern in my study area represents in Rayat and Hajeomaran district areas as shown in Fig. 4.

Radial drainage pattern
The radial drainage pattern, also known as the centrifu-gal pattern, is formed by streams that diverge greatly in all directions from a central higher point. Dome formations, volcanic craters, batholiths and laccoliths, residual ridges, minor plains, mesas and escarpments, and individual highlands all appear to encourage the formation of perfect radial patterns (Sissakian, 2013). This kind is found in the Warte syncline region as shown in Fig. 4.

Linear morphometric parameters
Twelve linear morphometric parameters are evaluated in this study to identify various linear features of the Rawanduz basin as represent in Table 2. The linear morphometric aspect is concerned with stream order, number, length, bifurcation ratio, RHO coefficient, main channel length, basin width, lemniscate factor, and basin length. The length of Rawanduz river is about 65.52 km, a boundary of the basin is 164.46 km and the value of basin width is 14.92 Km represented in Table 1. Basin length is the maximum length of the river basin inside the largest circle drawn around at the basin's boundary that runs parallel to the main stream and it is indicating that the basin length is increasing comparative to its width (Rawat et al., 2017). The variation in average width is caused by variation in erosion rate, which is influenced by lithology and slope. The average width and erosion in the basin have a proportional relationship (Al-Assadi, 2015). The basin's stream order is seventh-order (Table 2 and Fig. 5). The Rawanduz basin has a total of 6376 streams. In general, total stream length, stream numbers and stream order have an opposite relationship; as increasing in stream order, total stream length and stream numbers drops and vice versa Fig. 6. The stream length ratio of basin ranged between 0.47 for the first stream order to 3.98 for the sixth stream order. This variation might be due to changes in slope and topography. Horton (1945) considered the bifurcation ratio as an index of relief and dissections and this ratio value for the study area differ from 1.64 to 53, with an average of 10.91 Table 2, which is indicating a higher value of Rb (Strahler, 1964). Moreover, according to Iron, (1985) which is the best classification in this study, such estimates reveal that structural disturbances have a significant impact on basin, from which drainage morphology is heavily influenced by geological structure expressed by faults and the resulting lineaments (Al-Bakri and Al-Jahmany, 2013). Rho coefficient (RHO) is an important variable that influences the correlation between Dd and the geomorphic evolution of a drainage basin. As a result, it is important to estimate the drainage network's storage capacity (Horton, 1945). It is influenced by climatic, geologic, biologic, geomorphologic and anthropogenic factors.The RHO coefficient value for the study area is about 1.12 (Table 2), which indicates a high value that is recommending increased hydrologic reservoir throughout overflows and amplification of degradation influence through high discharge (Fatah et al., 2020). Lemniscate factor is the expression provided by Chorley et al. (1957), would be used to evaluate the slope of the watershed and to denote the similarity between the shape of the basin and a pear shape.The value of Lemniscate factor is 3.45 (Table 1), which represents a high value and indicate increasing the basin elongation.

Areal morphometric parameters
Thirteen areal morphometric factors were used to identify various areal features of the Rawanduz basin, as indicated in Table 1. The total area of study basin is about 977.68 km2, (Table 1). The stream frequency value in study area equals 5.6 km 2 (Table 1), which is indicate a high value and denotes that has impermeable lithology and higher surface runoff in the basin area (Melton, 1957). The study basin has a drainage density of 2.43 Km-1 Table 3. Thus, according to the Horton, 1945 classification, the Rawanduz river basin high drainage density value reveals fine drainage texture and the drainage density map was drawn based on the drainage system of the study area, Fig.7. Over such a wide range of environmental conditions and geologic types, the elongation ratios usually range between 0.6 and 1.0. Circular >0.9, oval 0.8-0.9, and slightly elongated to elongated < 0.7 values are further classified (Pareta and Pareta, 2011). Elongation ratio value of the study basin is 0.54 (Table 1), which is indicating slightly elongated to elongated basin. The circularity ratio value of study basin is 0.45 Table 1, which is indicating a slightly elongated-elongate shape because the main basin extended to the Southern direction in the area and which is revealing of the low permeable material, high relief, steep slopes and drainage pattern is controlled by the lineaments and the fracture traces (Abboud and Nofal, 2017). Form factor value of the studied area is 0.23 (Table 1), which indicates the shape of the basin from semi elongate to elongate and flow for longer duration. In present study of the basin, value of infiltration number is about 15.80 (Table 1), which is indicating high number which represents the lower infiltration rate and therefore higher runoff with high relief in the area (Bhatt and Ahmed, 2014). According to Horton, 1945, the length of overland flow value of the study basin is about 0.21 km (Table 1), which is indicate a low value of overland flow is an indication of high relief and faster the runoff process. The Constant of channel maintenance value of the study basin is about 0.41km (Table 1), and this value is less than one which is representing dense drainage network and a smaller area ability to maintain 1 km of drainage (Manoj, and Anilkumar, 2015). The Compactness ratio value in the study area is about 1.48 Table 1, which is indicate a high value and representing slightly elongated to elongated shape of the basin and needs longest time of concentration before peak flow is occur in the drainage (Horton, 1945)

Relief morphometric parameters
Ten relief morphometric factors were used in order to identify numerous relief features of the Rawanduz basin, as showed in Table 1. The Total basin relief value in the study basin is 3046 m (Table  1), which is high value denote the highly potential energy in the basin and the gravity of water movement, low infiltration and high runoff environments (Reddy et al., 2004). The relief ratio normally increases with decreasing drainage area and size of given drainage basin (Gottoschalk, 1964). The value of relief ratio of Rawanduz basin 0.05, it has low ratio due to the study area has less permeability material, and the relative and absolute reliefs of the basin are 1852.12 m and 3619 m respectively. The values of each relief class, which comprises the relief categories based on heights, land area, and the percentage of each class (Fig. 8 and Table 4). The Dissection index value of the study basin is 0.84, as shown in (Table 1), and which is indicating that the basin is considerably dissected. However, that's not the case throughout the basin and it is only shown in the upper reaches or mountainous regions of the basin characterized by first order streams (Rawat et al., 2017). Classify basins at least in our region and based on ruggedness values into six categories in the study basin and which is denoting in the Fig. 9 and Table 5. The extensive high ruggedness number occurs for a high relief region with high stream density (Shah and Patel, 2009). The ruggedness value in study area is about 1.25 (Table 1), which have a high value, and the region is more susceptible to soil eroding, which would also be associated with the area's increasing slope and drainage density. The concentration time value in the studied area is (5.17 hrs. and is equal to 310.2 minutes) as Table 1, indicating a high value because of the basin is semi-elongate to elongate with highly relief and slope.

Slope Analysis
The slope was determined in degrees and/or percentage. slope components are influenced by climate morphogenic methods in regions with different resistance to rock (Gayen et al. 2013). Surface runoff is slower in gentle slope areas, allowing more time for rainwater to flow, whereas high slope areas facilitate high runoff, enabling fewer residence time for rainwater and thus comparatively less infiltration (Sreedevi et al., 2005). The study basin slope map is created in GIS using ASTER DEM data with a resolution of 12.5 m. Calculating slope from a DEM is relatively simple, but attention must be given when selecting an algorithm (Bety, 2013). The degree of slope displayed from study basin which is varies from < 10° to 80.02° (Figs. 10, and 11) and (Table 6).

Aspect Analysis
The direction that a mountain slope faces is referred to as its aspect. Aspect influences the distribution of vegetation, rainfall pattern, and biodiversity in the research region (Magesh et al., 2011). The aspect's compass direction was computed by using output raster data value. The appearance of the study basin is represented in the Figs. 12 and 13. This study clearly indicates that the southern part of the basin, such as the south-west S-W and south-east S-E facing slopes, have a higher moisture content and a lower evaporation rate, and so have a high vegetation index (Magesh and Chandrasekar, 2012).

Lineament distribution analysis
These are linear geomorphic features also on earth's surface that represent regions of softness or structural displacement in the earth's surface. Deep seated faults, master fractures and joint sets, drainage lines, and boundary lines of various rock formations are examples of such features. Lineaments are hydrogeologically significant because they provide mechanisms for groundwater movement (Sankar, 2002). Lineaments are significant in rocks because secondary permeability, porosity, and inter-granular properties all influence groundwater motion. Lineaments are described as one of the tectonic elements in the structural analysis (Bety, 2013) Lineament intersections are thought to be great groundwater potential zones. The better aquifer horizons can also be based on the combination of fractures and topographically low grounds. Manual lineament extraction or (visual interpretation) is technique for lineaments generate using satellite data Aster DEM 12.5*12.5m from the Aspect view (Fig. 12). A  (Fig.15) is necessary for determining groundwater recharge, flow, and improvement (Nag and Saha, 2014) ( Fig. 13 and Table 7). Rose diagrams are used to evaluate lineament orientation. Because the direction of the fractures is frequently equal to the orientation of the favored flow line, this study is essential for understanding groundwater movement. The faulty rose plot shows two groups of orientation. The primary and secondary classes have NE and SW strikes, whereas the other two courses have NW and SE strikes. The majority of lineaments run in the SE-NW direction (Fig.  14).

Conclusions
Analyzing the specific characteristics of the stream orders would imply understanding the significance of preserving any area's unique natural and agricultural qualities. Remote sensing and geographic information system (GIS) techniques are useful tools for morphometric evaluation of the Rawanduz River basin. A large number of morphometric regression linear, areal, and relief parameters were counted and analyzed in relation to the hydrological process. As a result, this research is critical for watershed management and sustainability. The drainage patterns in the studied region are Subdendritic and Dendritic, Parallel, Rectangular, and Radial patterns, with 7th stream orders. Streams order was calculated for 6376 streams with a length 2376.4 km. The values of stream number and length are adversely related to the value of stream order in the basin. According to the results, variations in the stream length ratio indicate changes in the basin's slope and topography. Furthermore, the elongation ratio (0.54), circulatory ratio (0.45), and form factor (0.23) values for the basin indicated that the basin was semi-elongated to elongated in nature, which is displaying of the low -permeability material, high relief, steep slopes, and drainage pattern is managed by the lineaments and fracture traces. The stream frequency value in the study area is (5.6 km-2), which is a high value indicating impermeable lithology and increased surface runoff in the basin area. The drainage density in the studied region is 2.43 km-1. The high drainage density value of the Rawanduz river basin demonstrates fine drainage texture. To summarize, morphometric analysis assists in precisely studying landforms for any planning and development reasons. It is also highly useful since it computes the landform characteristics for evolutionary significance, which is essential nowadays. Such information would help to establish a stable, economical, and sustainable agriculture, hence improving food security. It also safeguards the natural environment and rural livelihoods.