Journal of Spatial Analysis

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Tectonic geomorphology is part of Earth Sciences, which deal with study of the interaction of tectonic and geomorphology. In other words it studies the effective tectonic processes in forming and changing the landforms. Geomorphic and morphometric indicators are suitable tools to the morphotectonic analysis for different areas. These indicators are used as the base tool to identify and recognition of tectonic deformation or estimates of the relative instability of tectonic activity in a particular region. Some of geomorphic indicators has been widely used, then the results of research projects are used to obtain comprehensive information about active tectonics. Full assessment of contemporary tectonics and tectonic activities, especially the young tectonic and its hazards need to Full understanding of geomorphologic processes speed and made for this purpose, geomorphological methods play an important role in this context.

     This research uses a descriptive-analytical approach, using library studies and aims at determininge the activity of Neotectonic in 7 Watersheds of Tehran metropolis (from west to east: Kan, Vesk, Farahzad, Darakeh, Velenjak, Darband and Darabad). In the first step, using topographic and geological maps of  under the studied area, faults, drainage networks and watersheds are identified, then to evaluation  the indicators of Mountain Front sinuosity (Smf), the main river sinuosity (S), the drainage watershed asymmetry (Af), rivers density index (D), hypsometric integral (HI), the ratio of the watershed shape (BS), the ratio of valley floor width to valley height (Vf), river longitudinal gradient index (SL) and Index active Tectonic(IAT) have been determined. Survey of these indicators by topographic and geologic maps and Google Earth images of the under studied area using software of Google Earth, Arc GIS and Global Mapper are derived and calculated. In the following, parameters and how they are calculated are given:

-Mountain Front sinuosity is the result from equation (1):

Smf = Lmf / Ls     (1)

In the equation (1), Smf is index of sinuosity Mountain Front. Lmf is the front along the foothills and mountains of the specified slope failure and Ls: straight line along the front of the mountain.

- The main river sinuosity index is as follows: S = C / V.  In this formula, S is main river sinuosity.  C: along of the river. V: valley along of the straight line.

- Rivers density index, drainage density is obtained from the formula:

                            µ=  

Li is length in kilometers of drainage Watershed, A is area in square kilometers, μ is total drainage watershed in terms of kilometers per square kilometer.

- Hypsometric integral is an indicator which represents the distribution of surface heights variation from equation (2) is obtained:

HI= H - Hmin / H max – H min    (2)

In this equation Hi is hypsometric integral, Hmin and Hmax respectively are the minimum and maximum height and H is the height of watershed.

- The ratio of width to height of the valley floor is another geomorphologic parameters to investigate the tectonic forces in the region .This index is obtained from the equation (3):

VF =      (3)

VF, represents the relationship of the valley floor width to valley height, VFW: the valley, Eld and Erd to the height of the left and right and Esc is valley floor elevation valley.

- The ratio of the area ratio of the area and the equation (4) is obtained:

BS= Bl / BW      (4)

-BS; the shape of the watershed; Bl; length dividers watershed of water to the bottom of the watershed outlet and BW:  width of the flat portion of the watershed.

-The longitudinal gradient index (SL) for a range of drainage path is calculated and determined by the relationship: SL = (ΔH / Δ L) * L. In this regard, SL: the longitudinal gradient index, ΔH: height difference between two points measured, ΔL: during the interval and L: total length of the specified channel to assess where the index to the highest point of the canal.

The classification provided for indicators Sl, Smf, Vf, Bs, Af by Homduni et al (2008), this indicator is obtained based on the amount of 1, 2, 3 classified in three classes. Index of active tectonic (Iat) Geomorphic indicators by means of different classes Calculated based on the value of (S /n) is divided into four classes, That the division are characterized by class 1 with very high activity Neotectonic, Class 2 with high Neotectonic activity, Class 3 with medium Neotectonic activities and and Class 4 with low Neotectonic activity. In this classification of Class1 have the highest and Class 3 have the lowest Neotectonic activities (Table11).

On the basis of Iat indicator Neotectonic activities in the under studied area were assessment and results were is in table (13). Based on the data in Table (13) , watersheds of Kan and Darband hava a high Neotectonic activities and located in Class 2 and watersheds of Vesk, Frahzad, Darakeh, Velenjak and Darabad  have a medium Neotectonics activities and and located in Class 2, and Neotectonic activities are a high relative tectonic activity in all watersheds. Geomorphic indicators are reflecting activities in the metropolitan Tehran watersheds can say that tectonically active watershed has not yet reached stability and tectonic activity are relatively high. Geomorphologic indicators drainage watershed asymmetry, the main river sinuosity, the valley floor width to height ratio of density of rivers and valleys, structural geology and tectonic activity in the7watersheds of Tehran metropolis better show it.

The results show that Tehran metropolis Watersheds have a high relative tectonic activity in all watersheds, because of the proximity to the major faults (such as Mosha- Fasham and North Tehran faults) and minor faults, tectonic activity exists. Finally it can be stated that, due to the presence of multiple faults and background seismicity and tectonic activity in Tehran metropolis and its watersheds, occurrence of earthquakes in the study area is not unexpected and this issue requires serious consideration and management.

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 Quantitative assessment of landslide sedimentation in the ILAM dam Basin

Information on the accurate volume of landslides and sedimentation in landslides is a research necessity, with the assumption that the bulk of sediment accumulated in the ILAM Dam (located between , E and , N) is related to the surface landslides of the basin. Although the role of landslides in erosion, sediment transport and sedimentation of slippery basins is confirmed and different experts understand and determine the relationship between the fluctuation of slopes and the fluctuation system in many respects more important than other areas. Because according to the results they can assess the widespread environmental changes, but comprehensive research on the scale of catchment basins has done very little (Harvey 2002). So far, the study of wet landscapes in Iran has been more sensitive to the factors, their sensitivity and their hazards, and there has been no study on the sedimentation of landslides.

Data and Method
First, using a geomorphologic system methodology with topographic maps of 1: 50000, geological map of 1: 100000, aerial photography1: 20000, Landsat TM1988 ETM2002,2013 satellite imagery, and Google Earth in the GIS environment in the following sub-basins and landslide events at the following levels The basin was drawn. The discharge data of the water and sediment flow of three hydrometric stations GOLGOL,CHAVIZ and MALEKSHAHI Station were provided from the waters of the ILAM province. Two models of estimated MPSIAC and EPM models have been used to estimate soil erosion and subsoil sedimentation. The Moran spatial correlation model was used to introduce the spatial pattern of landslides, and the fuzzy logic model was used to determine the relationship between the dependent landslide to the independent variables and the potential risk of landslide hazard in the basin. In order to elucidate the quantitative results of landslide sedimentation, empirical models of estimation of sediment erosion, hydrological model of discharge curve and sediment, observational statistics of sediment during statistical period, landfall time occurrence in compliance with the hydrometric station sediment peak during the statistical period of computation Estimated a small amount of sedimentation of the landslides of the ILAM dam basin.
Result and Discussion
The spatial correlation model of Moran showed that the data have spatial correlation and cluster pattern. The average total sediment production in the MPSIAC model in the GOLGOL basin was estimated to be 13.3 tons per hectare per year under the CHAVIZ basin of 10.3 tons per hectare for one year and 4.00 tons per hectare in the sub-basin MALEKSHAHI. Using hydrological model of discharge-sediment curve, the mean sediment was calculated during the statistical period at the hydrometric station of the sub-basin of GOLGOL 18.8 ton per hectare, the station CHAVIZ 10.4 tons and the station MALEKSHAHI 0.9 tons of sediment per hectare per year was calculated. According to the results of the research methodology, the observation of the sediment in the two stations of GOLGOL and CHAVIZ compared to estimated sediment is related to the events occurring in these two sub-basins.
The data of 16 active landslides were recorded. Under the GOLGOL basin, 9 landslide events occurred, and in the CHAVIZ basin, 7 landslide events, the time of landfall occurrence recorded with sedimentary peaks, the length of the statistical period, the precipitate in the sub-basins was almost synchronized. Average relationship between suspended period of the statistical period - average of the peak delayed flight time of the statistical period coinciding with the occurrence of landslide = the amount of suspended load of landfall occurrence in the basin.
The amount of suspended land slip under the GOLGOL 75088.19 - 315.85=74772.34
Landing slope under the Chavez Basin 19907.30 - 20.24=19887
The area of the sub-basin is about 29,000 hectares and the active landslide area is about 100 hectares. According to the calculations, 77772.34 tons of suspended sediment is a sedimentary passage passing at the GOLGOL hydrometric station, which shows with a coefficient of 1.4 times the suspended sediment load of approximately 104681 tons of landslide sedimentation in this sub-basin, which shows the amount of sediment yield 100 hectares of landslide, so each landslide hectare had an average of 1046. 81 tons of sediment deposited at the GOLGOL hydrometric station. The area under the Chavez Basin is about 14000 hectares and the active landslide area of this sub-basin is about 65 hectares. According to the data of the discharge data, the sedimentation of the Chavez hydrometric station is 19887 tons of suspended sediment load, which shows a 1.4 equivalent of 27842 tons of landslide sedimentation in this sub-basin, equivalent to a slope of 428.33 tons per hectare.
Conclusion
According to the calculations, it is concluded that in the sub-basin of flowering GOLGOL, 37.35% is equivalent to 4.9 tons per hectare per year, the increase of sediment is related to landslide events. As a result, 28.2 tons of sediment per hectare were introduced in one year Dam reaches ILAM. The results showed that in the CHAVIZ sub basin, 38.2 percent is equivalent to 4.6 tons per hectare per year for the increase of sediment related to landslide events. As a result, an amount of 14.5 tons of sediment per hectare has entered ILAM dam in one year. In the sub-basin MALEKSHAHI, there was no increase in sediment during the period without active landslide occurrence. A total of 1237314 tons of landslide deposition have entered the ILAM Dam. To control this threat, the appropriate action by the executive office for sustainable development should be applied.

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 Investigation of morphometric indices of Assaluyeh, Varavi and Kangan anticlines in Fars Zagros and their relationship with tectonic activity
 
Extended Abstract
Introduction
Anticlines are the most prominent surface landforms whose geometry and morphology reflect mechanism of their formation and are keys to assessing the existence of deep faults that are effective in their formation and are among the most important seismic sources.
Detachment folds are formed by buckling of the rock units in response to shortening and are typically symmetric folds. Alternatively, asymmetric folds at the surface may be forced by the propagation of thrust faults at depth (fault propagation folds) or result from thrust movements along footwall ramps in the sedimentary pile (fault-ramp folds).The Zagros folds have often been interpreted as completely detached along the Hormuz salt.
Structurally, the study area is a part of the folded and coastal Zagros whose geological structure is simple and gentle and comprises a series of near-compact anticlines with a near-vertical axial surface and a northwest-southeast trend.
Outcrops of lithological formations in the study area include Surmeh, Fahliyan, Gadvan, Dariyan, Kazhdumi, Sarvak, Ilam, Gurpi, Pabdeh, Gachsaran, Mishan, Aghajari and Bakhtiari. In the northwestern part of the Kangan anticline, uplift of salt diapir along the Darang Fault has led to the exposure of limestone, shale, dolomite and anhydrite units of the Khami Group.
Assaluyeh is one of the most important economic bases in Iran and also one of the largest energy production areas in the world. With the rapid development of Assaluyeh region and increase of residential, urban and industrial constructions and refinery facilities, without attention to environmental hazards and especially earthquakes, it seems necessary to conduct this research.
The aim of this study was to investigate the morphometric characteristics of the Assaluyeh, Veravi and Kangan anticlines and its relationship with active tectonics in the region.
Methodology
At first, topographic, drainage network, slope, slope direction and tectonic maps of the anticlines were prepared using digital elevation model data, Landsat imagery and field surveys. Then, the geomorphic quantitative indices of the fold front sinuosity, aspect ratio, fold symmetry index, fold surface symmetry index, anticline crestline index, fold elevation index and spacing ratio were calculated. Qualitative studies were carried out on drainage pattern indices, triangular facets, wineglass valleys, linear valleys, fault scarps, springs, alluvial fans, etc. Finally, the relationship between all geomorphic and tectonic parameters was analyzed.
Results and discussion
Fold symmetry index is one of the most important parameters that show the degree of inequality of the two limbs of the anticline and thus the intensity of tectonic activity. In a completely symmetric anticline, the value of this index is 1, while in an asymmetric anticline the value of this index is less than 1. The index values for all three anticlines are less than one, but the Asalouyeh anticline shows more asymmetry, indicating a high tectonic activity on the anticline.
The fold front sinuosity index indicates the degree of tectonic activity or age of the folding system. The values obtained for this index in the three anticlines indicate that the anticlines are young and the tectonic forces are dominating the erosion.
The high value of the aspect ratios indicates the elliptical shape of the anticline, which is caused by the high stress perpendicular to the axis of the anticline. The index for Varai, Kangan, and Asalouyeh Anticlines are 0.7, 0.5 and 0.5, respectively, which again indicates nearly high tectonic activity in all three anticlines.
The spacing ratio index at the northern flank of Varavi and Assalouyeh anticlines and the southern flank of  Kagan anticline indicate a high value. Quantitative index of surface symmetry of folds also shows that all three anticlines are asymmetric and the asymmetry of Asalouyeh anticline is greater than Kangan and Varavi anticlines.
The drainage pattern is another indicator that, in the absence of tectonic evidence, can be a key to identifying tectonic activity.
The existence of asymmetric fork drainage networks is evidence of active tectonic evidence indicating lateral growth of anticlines. According to this criterion, Varavi anticline has grown to the northwest.
Comparison of the valleys shows that most of the valleys in Kagan anticline are of wineglass type whereas in Asalouyeh and Kangan anticlines linear valleys are more abundant. Some of these valleys are formed along transverse faults. The presence of numerous alluvial fans in the slopes of the Varavi anticline, indicates rapid erosion of the valley bed due to the rapid uplift and increasing valley slope. The presence of elongated and narrow V-shaped valleys is another evidence of the high tectonic activity of this anticline.
Conclusion
In seismicity studies and identification of hidden or blind fault studies, geophysical and geotechnical methods are expensive, time-consuming and require special equipment and are performed on a small scale. With the availability of landforms and features, risk assessment will be done at a lower cost, faster, and on a larger scale, if a relationship between landscapes and earthquakes can be established.
The geometry of the folds reflects the mechanism of their formation. Asymmetrical folds are associated with deep faulting and a detachment horizon, where the movement of sedimentary layers on the detachment horizon or at the tip of the hidden faults can cause an earthquake. The three anticlines of Assaluyeh, Varavi and Kangan are also part of the folded Zagros and have the characteristics of the folded Zagros.
In this study we defined a new index related to fold morphology, called fold surface symmetry index. Also we used fold morphology to detect the presence of detachment horizons and faults in the core of anticlines and their relationship to seismic hazard risk.
The results of this study show the transverse profile asymmetry of all three anticlines due to the association of these anticlines with the longitudinal faults in the anticline core and along their axes. The results of measurements of aspect ratios, fold front sinusitis, anticline ridge, and study of drainage patterns and tectonic landforms such as fault scarps, triangular facets, linear valleys also confirm the high tectonic activity of all three anticlines and the potential for earthquake hazard due to the movement of deep faults or any segments of them.

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Analysis of the behavior changes of hydrological response units due to Residential development
(Case Study: Cheshmeh Killeh Tonekabon Basin)

Ezatollah Ghanavati ^*[1]
Ali Ahmadabadi^[2]
Amir Saffari^[3]
Masoud Rajaei^[4]


Abstract                                                                                                                                          
Land use and vegetation changes directly lead to changes in the hydrological regime, especially runoff coefficient and maximum instantaneous discharge changes. Much of the land use change has occurred due to residential development, which has led to a decrease in residential and rangeland lands and agricultural lands in the northern regions of the country; This has led to an increased risk of flooding in these areas and downstream urban areas. Cheshmeh Killeh basin as one of the catchments in the north of the country in the last decade has witnessed the occurrence of various floods; Therefore, in this study, by extracting the hydrological response units of Cheshmeh Killeh catchment in order to identify changes in vegetation and land use of these units and the effect of these changes on the hydrological behavior of the basin, the runoff coefficient is one of these behaviors in this period of 29 years (1991-2018). paid. Therefore, in this research, hydrological response units have been identified and extracted as a working unit to determine the runoff production potential of Cheshmeh Killeh catchment. In order to monitor changes in density and vegetation cover using satellite images of the study area in 1991 and 2018, the normalized plant difference index was used; Then, by combining the layers of hydrological groups and land use, the amount of curve number was determined for each of the hydrological response units. According to the values ​​of the obtained curve number for each hydrological response unit, the amount of soil moisture holding capacity was extracted. Finally, by calculating the average monthly values, the amount of runoff from rainfall for 1991 and 2018 was estimated. The results of the study indicate a decrease in the amount and density of vegetation, an increase in the number of curves, a decrease in soil permeability and also an increase in runoff height during a period of 29 years (1991-2018) in Cheshmeh Killeh catchment (especially the northern parts of the catchment); In other words, settlement development, land use change and weakening of vegetation have intensified flooding in the basin; Therefore, it is necessary to carry out watershed management operations upstream to increase permeability.

 Keywords: Hydrologica response unit, Cheshmeh killeh, Runoff, Normalized vegetation difference index, SCS-CN model.
 

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