فصلنامه پژوهش های ژئومورفولوژی کمی
سال هشتم شماره 1 (پیاپی 28، بهار 1398)

The runoff response from arid and semi-arid catchments is a problem that is difficult to approach and is not satisfactorily nswered yet. One of the reasons is that runoff events in dry regions are rare, and difficult to observe and to monitor. Another reason is the fact that overland flow, which plays a crucial role in dry watersheds, is difficult and complicated to quantify Channel incision is part of  denudation,  drainge -network development and landscape evolution. The causes of river channel are numerous. It is generally agreed that runoff generation in drylands is caused by infiltration excess or Hortonian overland flow. Partial area contribution and variably contributing areas are a phenomenon in drylands as well The focuses on time factors is very important in practical study and its bring in modeling is fundamental. Slope erosion by runoff  can be investigating in related to time scale . Disturbance  of  slope surface by runoff can be  explanation in during time. When  flow water on slope is faster and  time concentration is short ,surface  potential for erosion is very high. In this conditions is shaping liner erosion  forms  on slopes, such as ,  Ravin , Gully and Rill. In these slopes also is occurred flash flood . Ojhan  Chay  catchament located in the eastern slopes of  Sahand   mountain .Load sediments is very high in this catchement .The purpose of this paper  therefore is measurement of runoff concentration time and is estimated  flow velocity on slopes.   Ojan Chay  catchament is one sub-basin  that located on  eastern slopes of  Shand  mountain .This basin is located  at  37° 54'  N to 37° 44 ' and from 46° 50' to 46° 31'.Ochan  River is one reach of  Achy Chay that it at western site adjacent to Saaied Abad Sub-basin, and at eastern site is adjacent to other sub-basin. Ojan basin is experience intensive  liner  erosion  and  all forms of liner erosion is created  on  foot and sharp slope .Geology and lithology of this basin is  various .Sediment and Igneous rocks formed base of this basin. Thickness of these rocks is high .Diorit ,Volcano sediments  ,Ash ,Igenberits  are sample  of  these  rocks in Ojan basin. Miocence  sediment rocks are contained of Marl-Gyps  and Sandstone. Quaternery sediments as trase and alluvial fans  is  in  northern site of basin. This formation is made of lay ,clay and sand .  In order to estimation  of  runoff  time  concentration on  slope  surface  in  Ojan Chay  basin ,is  divided to 140 parts and all accounts is made  in  these parts . Many data  is obtained  from  these sub-basin properties .Some data is obtained from  digit maps and others data is obtained from field studies.In this paper, we focused on time concentration estimation by used of Tc1,Tti  and Tc. Tci ,Tti and Tc is defined in terms of  channel Lengths ,storm and slope .Where l is channel length ,S is slope ,p is storm  and  n  is  Maning Index. We  used in Tl1 , maning index table .  Velocity of flow is estimated by used of V1, V,Tt,T1,... V1,V are defined in term of  slope ,channel length,storm ,k (is constant that related to flow type ).The results are show that on maps . Surface flow that on slope is concentrating and is flowing  in single channel ,have very high power for erosion .When surface material are suitable to erosion ,is created liner erosion forms ,such as ,Rill,Gully ,...,on slope by flow . River Ojan  have very high bar load in water .All parts of these sediments are due to slope erosion by rill and gully erosion on slope and footslopes. Ojan Basin is a mountainous basin ,for this reason ,slope factor play main role in erosion .Central  and northwestern site of Ojan slope is high because  erosion in these sites is intensive . In study area  time concentration is related to many factors .slope ,length of channel ,storm are affects factors on slope erosion. In this study these factors is considered .The results of investigation on time concentration show that rate of time concentration is high  in central   and northwestern site of Ojan slope.In this site surface of slope is disturbance by rills and gullies .In these  areas  lengths of channel is short ,such as , rills. Water flow due to shower is moving quick. Basins these single channel are not big and these shapes are  round that water is flow into channel that is located  at foot slope.    Investigation  on velocity of runoff in Ojan (by  V1) show that flow  velocity is under 10 second in all parts of basin .In this method ,channel length play very important role in velocity  of  flow on slope ,therefore  short rills is made on slope . Velocity of flow is quick on slope that rills is created . Runoff on slope is creating  initial channels and then is disturbance surface and delivered sediment to foot slope channels. Sensitiveness of surfaces for intensive erosion is high when flow velocity is high and time concentration is low. In these  slope we can seen vary forms of liner erosion ,such as ,rills, gullies,....Also in these slope is experience flash floods. Some parts of rain water is not influences into soils ,because many parts of water is reduced to runoff. Investigation is suggested that surface materials and topographical factors are suitable to liner erosion ,short channels are made by concentrated water . Channels have high depth in foot slope in Ojan Chay. At upslope  area of basin is not vast. Length of channel have short in these site. Due to , time  concentration is short .When area at upslope is vast , rill is not created ,but gully is created ,in foot slopes. In  these condition ,slopes is gentle and velocity of flow is slow. Bcause  area is vast and therefore amount of water is high ,gullies big and deep.

The river route has different patterns, such as straight, meandering and braided, and these changes have always been of interest to geomorphologists. A river along its path can have different patterns; the Meandering rivers are part of a single-channel river, the river has only one flow. One of the important issues in geomorphology is to consider changes in the shape and pattern of flow channels in the course of the river. The morphology of the rivers depends on several factors such as water flow changes, bed slopes, river cross section, geology, tectonics or morphotectonics of the area, as well as the time needed for formation and change of river plan forms. The spatial displacements of the meanders cause changes in the dimensions of the bedding stream and the flood plain. Due to their many dynamics, this phenomenon also causes major problems. In many parts of the world, numerous studies have been done on the phenomenon of rivers 'meandering, and more than 30 theories have been presented on the process of rivers' meandering. [Maghsoudi et al., 2010, 276]. The meanders can be sinusoid, regular or compact, very irregular, crumpled, and even other forms. The shape of the meander is a function of the characteristics such as slope and flow rate, river width, and the material of the bed [Rezaei Moghadam et al., 2012, p. 86].
The Mahneshan County with a total area of 2,786 square kilometers is located at 47 degrees and 15 minutes to 48 degrees and 10 minutes of Greenwich and 36 degrees and 20 minutes to 37 degrees and 10 minutes north latitude, northwest of the province Zanjan. The entire length of the Ghezel Ozan route is from the Chehel Cheshme mountains of Kurdistan to the Manjil Dam Lake, 550 km, about 91 km lies within the Mahanshan county. The Mahanshan area comprises mountain ranges stretches the northwest-southeast that lies between them, plains and valleys. In this study, topographic maps or scale of 1.50000 and geology of 1.100000 were investigated for the study of drainage network and geological formations of the region. A geological map was used to investigate the relationship between meanders with formations and geological structures. Using the GPS during fieldworks, probable meanders were positioned. IRIS satellite images with a resolution of 2.5 m in 2007, 1389, 1394 and Google Earth in 1373 were used to study and investigate the process of changing the direction of the Ghezel Ozan. By digitizing the route, the amount and position of the river changes were detected. Based on data on length of arc, valley length and radius of circles on the river arch, bending coefficient, central angle and sinusoid index, were calculated. Then, according to the calculation of the bending coefficient of each arch and the central angle of the arches, and the Korins classification, the percent of frequency of the central angle of the meander arches were determined. According to calculations of the bending coefficient and the central angle of the arches of the Ghezel Ozan River in the Mahneshan County, the dominant river pattern over the course of four years is meandering and their coefficient is between 1.25 and 2. While the sinuosity of 55% of the meanders was more than 1.5, the bending coefficient of the arches 1 to 10 is high, indicating that they are in the category of highly developed meanders and the rest are underdeveloped to advanced meanders.
Using the Korins central angle index), the development rate of meandering was calculated for four periods. Calculated values shows that in 1996, about 60% of the course of the river had a developed meandering pattern. The central angles of the arch were in 1373, 136, which illustrates the highly developed meandering pattern. This amount was reduced to 131, 96.5, and 106.5 in 1386, 1389, 1394, respectively, reflecting a developed meandering pattern. The decline in the highly developed meandering pattern and the increase in the developed and undeveloped meandering pattern show that the numbers of arch rivets have gradually decreased.
The mean radius of arches in the studied boundary was calculated for four years 1994, 2007, 2010, 2015, respectively, 506, 254.5, 166, 229 m. It is seen that the mean radius of the circles of 1994 is higher than in other years, which is often due to erodibility of the river banks, which causes the radial development of meandering rings. The geometric parameters of the studied sections were analyzed in four periods of 1994, 2007, 2010, and 2015. The distance between the two alternating meanders in 1994 is much higher than in 2007, 2010, and 2015. The increase in the longitudinal distance of two successive meanders is somehow indicative of an increase in the meandering conditions.
After plotting the longitudinal profile of the Ghezel Ozan in the Mahneshan County, the mean slope of the river was 0.07 percent. The longitudinal profile of Ghezel Ozen shows that the river at first has a slight slope and the meanders are formed. Down the river, increasing the number of effective faults, increases the slope of the bed at the end of the stream Meanders are the main causes of erosion and changes in flood plains, and if these changes are high and severe, it leads to lateral erosion. Findings of the research indicate that in four periods, there is a large variation in the course of the river; by examining the parameters and field observations, it can be said that the Gezel Ozan River is a developed meander. The bending coefficient of years 1994, 2007, 2010, and 1394 was calculated between 2-1.25. Also, with respect to the values obtained, the center angle is in the range of 158-85 degrees, is related to the developed meanders. In this study, there was no evidence that tectonics affected the river route directly and, and thus led to a redirection of the river. Mahnashan County is active tectonically. The right part (look in the direction of the Gezel Ozan stream) is more uplifting. Consequently, the behavior of the small streams affects through the formation of alluvial fans and rapids in the Gezel Ozan River.

Soil salinity is a limiting factor for plant growth and a serious cause of land degradation cognition change space and time every impressible in the study agrology, geomorphology, hydrology, Estimating soil salinity by using of remote sensing data and spatial statistic showed possible resolution parameter high accuracy obtain and indexes the every coefficient. goal of this research application program and access is base away and out access soil salinity in the arid and semi-arid zone by using of remote sensing techniques. sabzevar zone in the west khorasan Razavi have arid and semi-arid climate conditions and soil salinity problem and acceleration rend that is one of the greatest challenges of this zone in the resent years, so that recognizing salinity in this condition have specific important. In this research The 48 sample soil sampled which correspond with work unit map(geomorphology) the zone, After ward, acted to consider relation correlation between value electrical conductivity(EC) and variable obtain of Landsat satellite imagery included salinity indexes, vegetation indexes, brightness index, imagery bands TM, ETM+, OLI, Principal component analysis, Tasseled Cap Transformation. In SPSS, multivariate regression method was used in the form of five regression methods, step wise multiple regression, Back ward elimination, Forward multiple regression, Enter multiple regression, Stepwise multiple regression.In the Arc.GIS.10.2.2 by using spatial statistic models, Moran’s Index and High-Low clustering did consider related correlation. The most correlation determined by calculation variance Inflation factor and Pearson coefficient. The result showed pattern correlation is positive and models of have suitable correlation coefficient. In this research, remote sensing methods and anticipated models have suitable ability for estimating surface soil salinity.

Soil salinization and its development in arid and semi-arid zone are one of the environmental hazards that have been take into consideration in recent years and the range is creasing day by day. The main objective of this study is: To understand the spectral reflectance characteristics of saline soil in sabzevar plain, to explore the potential of Landsat satellite imagery to detect and map the soil salinity and to analysis the correlation between field and Landsat imagery. The finally, produce the soil salinity.  

In analysis, Landsat satellite imagery in three different dates (3 April1995, 27 June 2006, 19 November2017) are used as a first step. Landsat satellite imagery TM, ETM+, OLI, provided by the United States Geological survey. Acquired from Atmospheric and radiometer correction was applied images and the flat field method, which is a relative correction method, was used for atmospheric correction of images. In the next stage, spectral indexes were used. These indices include three vegetation indices(SAVI,EVI,NDVI),four salinity indices (EC,SI1,SI2,SI3),a one brightness index(BI),three main Principal component analysis(PCA1-PCA2-PCA3),Tasseled Cap Transformation(Tasseled cap1-2-3),coincide transferred 48soil sample to soil laboratory. Finally, salinity data of the soil horizons in the ArcGIS environment, on individual variables, overlapping and cutting off given. The descriptive tables resulting from the previous step in the Excel environment were then transferred SPSS and analyzed. In the spatial spatial method were used moran’s index and High-Low clustering.  

 One the methods for extracting information, analyzing and evaluating satellite imagery is to create a regression between the desired land parcel and its corresponding image. In all correlation models, R (Pearson correlation coefficient) is strong. The resulting (sig) value is less than 0.05. All models are meaningful and their correlation is positive. Moran’s index and High-Low clustering, validate spatial correlation and clustering of data, In addition, maps and charts show increased salinity from1995to2017.In 1995, more than 70percent of the area of the salinity area was low, while the land area would reach less than 10 percent 2017.  

 All models have acceptable calibration and the accuracy of the extracted function, Back ward elimination regression method is more than the order models. The use of spatial statistics, in addition to having the proper accuracy due to the presentation of the distribution map of the points, the error map and the lack of the need for information exchange between the soft different is superior to the classical statistical models. Landsat satellite imagery useful in detecting and monitoring the saline soil. Identify areas at risk for soil salinity is very important in the shortest possible time and with high precision for proper management practices

Alluvial fans are considered as one of the geomorphical features of dry and semi-dry areas which is the result of intense runoffs in the past and present. Thus, it can be considered as a Quaternary climate heritages. However, it is now visible in all climate conditions across the globe such as arid regions, Alpine environments, humid climates, and even tropical environments. Several studies have been done on their structure, morphology and hydrology. These studies have shown that cone-shaped characterization is associated with various and different parameters and factors which can be classified into six major groups including climatic factors and changes, geometric Properties of upper catchments, Lithological conditions, Tectonic variations, in particular in base level, land-use changes and geographic directions of slopes. The main goal of this study is to investigate the morphometric role of catchments in the volume of alluvial fans in the different slopes of Shirkouh Mountain in the south of Yazd with emphasis on geographical orientation. Since Shirkooh is a granite mass relatively cone-shaped that has created a number of alluvial fans in all its aspects, and in terms of lithology, its various directions are similar, the orientation of slopes against the air masses can play a major role in the volume of alluvial fans. To do this project, we used satellite images, a digital elevation model with a resolution of 5 meters and topographic maps of 1: 50000 . Initially, using these data, the boundary of alluvial fans and their upstream watersheds were determined.So, 24 significant alluvial fans and their watersheds were identified that there were 9 of them in the eastern slopes with the southern direction, 6 of them in the same range with the northern direction, 5 in the western slopes and 4 in the northern slopes of the mountain. Using the quantitative model in the geographical information system, the volume of alluvial fans was calculated. Then, the boundary of the upstream watershed of each alluvial fan determined in ArcGIS 10.3 software and ArcHydro add-ons and their geometric characteristics include area, environment, average height, average slope, the length of the basin, and the Gravilius coefficient were measured individually. In fact, by converting the information layers into the Raster's format, quantitative geomorphic characteristics and morphometric parameters of the catchment were calculated in four directions. Then, the correlation between the volume of alluvial fans and watershed morphometric parameters were calculated in SPSS software for 4 geographic directions and is also shown in the graph.Finally, to illustrate the effectiveness watershed morphometric parameters on the volume of the alluvial fans,  We calculated multivariate regression between alluvial fans volume and morphometric basins in SPSS in four geographical orientations. Eastern slopes with southern and northern directions extend to the vast plain of Ebrahimabad in the eastern slopes of Shirkouh and west of Mehriz city. Alluvial fans in this range are more numerous than in other slopes of Shirkouh and they have created bajada. However, in the slopes with northern direction, the watersheds are much wider compared to the opposite slopes. Therefore, the size and volume of the alluvial fans in the section are bigger and wider. While the correlation between the volume of alluvial fans and geometric characteristics of the upstream watershed is very high in the eastern slopes with the southern direction. So that the area, the environment and the length of the river show correlation above 95%. But the correlation for the slopes with the northern direction is very low in the range and the significant level between them is unacceptable.In the western slopes of Shirkouh, the geometric factors of the upstream watersheds are the main controllers of the volume of alluvial fans. The correlation between the volume of alluvial fans and geometric parameters of watersheds showed that among the eight parameters studied, only two of them includes Gravilius coefficient and drainage density played a small role in the formation and volume of alluvial fans, and other factors including form factor, area, environment, basin length, average elevation and slope Respectively played a major role in the volume of alluvial fans. But this case is different for the northern slopes of Shirkouh, So that there are the lowest correlations between geometric factors of catchment and volume of alluvial fans Relative to other geographic directions. The results indicate that there is a high correlation between alluvial fans volumes and geometric factors especially area (0.99), environment (0.98), and the length of watersheds (0.95), in the eastern slopes with southern direction with a significant level of zero and close to zero. This applies to the western slopes and geometric factors includes area, environment and coefficient of form (with correlation 0.99), length of the catchments(0.94), average slope and elevation(0.85) have been the most important factors effect on the volume of the alluvial fans in the slopes. But the correlation between the volume of alluvial fans for the eastern slopes with northern direction includes only slope (0.64) and form factor (0.59) and for the northern slopes of includes Gravilius coefficient (0.43) and watersheds length (0.37) that have low significant levels. Therefore, in these slopes, geometric factors of watersheds played the least role in the volume of alluvial fans.

River geomorphology is one of the determining factors and an important step in mathematical modeling of landform variations. Investigating the pattern of flow in warping intervals and geomorphic units of the Aras river, the formation processes and the process of their change are important for river geomorphology studies and make river engineers better acquainted with the trend of changes. The main objective of this research is to implement fractal dimension of geomorphological changes in the Aras River route. Using the method of controlled classification and maximum probability algorithm, the layer of geomorphologic landforms of the Aras River environment for two periods was prepared in four channels of Channelform Channel, Point Bar, Flood plain, Riverside, and Coniferous; Then, the fractal models of the environment - area and cumulative number - were used to describe the mathematical behavior of these landforms. Changes in the amount of DAP (environment-area) for the landforms in the Aras River environment in the two years of 1987 and 2018 showed that the DAP values of all landforms (other than point load) in 2018 were smaller than the DAP Landforms in 1987. Therefore, the geometric pattern of the Aral River landforms in 1987 is more irregular and more complicated than in 2018. In the case of Land Point, this figure increased in 2018 than in 1987, indicating a more regular pattern of this landform. Changes in the amount of D (cumulative area - area) for the landforms studied in the Aras River environment showed that its magnitude increased in 2018 compared to 1987, which can be D, or represents small components of a large size Or more components with small size. Regarding the survey of Landsat satellite images used in this study to extract river geomorphological landforms in the Aras River in 1987 and 2018, pixel behavior of landforms is typical of the large There is a tendency to study the landforms. Of course, in the case of the river channel, it should be noted that due to the decrease in the discharge and hence the reduction of the channel width, it can be commented on the reduction of its area.

Coastal zones are dynamic parts of the Earth. They and arid lands are the most favorable areas for wind processes (Mahmoodi, 2002). The coast is a zone where land, sea and air (the lithosphere, hydrosphere and atmosphere) meet and interact (Bird, 2008). It is a region of very high physical energy and biological diversity (Murthy et al., 2002). They are the basis of important ecosystems, supporting valuable communities of plants and animals (Kidd, 2001, 1). Coastal species are more widely distributed; they predominate in habitats with sand movement and the herbaceous component prevails (Castillo and Moreno-Casasola, 1996).
Sphaerocoma auchri Boiss belongs to Caryophyllaceae family and paronychioidae subfamily. According to Asadpour & Soltanipour research (2017), this species distributed in coast of Sudan, Egypt, west of Pakistan, south east of Arabia and south and south east of Iran including Hormozgan province (Gheshm, Bandar Abbas, Charak, Larak, Kish, Bandare Lengeh, Jask and Minab) and Sistan-O-Baluchestan province (Chabahar and Konarak). This plant is one of important spicies on coastal sand dunes of Hormozgan province that play a magnificent role in soil conservation.
The study areas contain 7 sites throughout east to west of coast belt in hormozgan province. They are located at 25o 36’-26o 58’N, 54o 22’-58o 59’E, in south of Iran at the north of Oman Sea and Persian Gulf. In general the region under research could be assumed a dry land with very low rain and its remarkable nature is windy, sand storm, torrent shower, thunder-storm, higher humidity and hazy down(Akbarian et al., 2006). In order to investigating on Sphaerocoma aucheri vegetative condition, 7 sites have been selected. Different vegetative parameters as canopy cover, long and small diameters, density and height of each individual plant were studied. In order to do soil characteristics measuring (for 16 physical and chemical soil factors), in each of the identified sites, 9 profiles are established and 3 samples (0-25, 25-50 and 50-75 cm depths) were taken from each one. According to the comparison between soil parameters of Sphaeroma aucheri habitats and adjacent areas, apart from temperature, soil texture, Ec, ph, total Ca+Mg, Caso4, Na content, SAR, potassium soluble content are most important factors on stablishing of Sphaeroma aucheri habitats; saturated moisture percentage and potassium content are in second importance.
The saturated moisture percentage, Ec, pH and lime content ranges as 25.67-34.79, 0.43-5.93, 7.61-8.75, 26.43-60.69, 0-28 respectively. Sand and SAR contents ranges from 52 to 94 and 0.5 to 29.52 respectively. The soil pH is alkaline and lime is found in all soil profiles. The electric conductivity is below 4 in all of the areas and below 2.5 in most areas. This plant spreads in non-salty and ordinary soils. Maximum elevations in all of the sites do not reach 100 meters.
Results showed plant density has negative relation to saturated moisture percentage and positively relation to lime content. Also there are a negative relation between silt and K contents of first depth of profiles, clay of second and third depth with plant density and a positive relation between sand content of first and second depth with density. Canopy cover of this plant has negative relation with saturated moisture and clay content of all depths and positive relation with sand of first depth. There is a negative relation between mean diameter of the plants and height saturated moisture percent. These results indicate the effect of soil particle (texture) on vegetative parameters.
Generally it would be concluded, there is the relation between soil particles (soil texture) with the vegetative parameters of the studied species. Sandy texture leads to drainage and clay texture, causes soil moisture. (Bybourdi 1993; Foth, 2011; Sadeghi, 2016). Particle size windows (PSWs) are interpreted as reflecting different modes of sediment transport and deposition (Clarke et al., 2014). Sand dunes occur in two distinct habitats: along the coasts of seas and rivers, on the one hand, and on the barren waterless floors of deserts, on the other (Bagnold, 1954). Based on the sedimentology of sand mass grains and in relation to sediment sources, coastal plain sand masses can be divided into interior sand masses, resulting from the erosion of the coastal plain surface, and coastal sand masses, that originate from the tidal zone (Akbarian; 1393). In coastal sand masses, sand is removed from tidal foreshores and deposited onto backshores by sea breezes (Akbarian, 2014; Shayan et al., 2014 and Shayan et al., 2016). These with interior sand masses which are mainly located on the upper reaches of the plain are different from genesis aspect. (Akbarian, 2014). Based on results Sphaerocoma aucheri grows on coastal sand dunes, which have lost their clay and silt during the sea processes and are mainly composed of sand and high levels of lime (Oyster lime shells' particles). It does not inhabit on the internal sand masses which are formed as a result of the coastal plain surface erosion, which have high silt and clay percentages. Hence, it can be used as an indicator for differentiating coastal masses from internal sands (desert dunes).

Alluvial rivers react quickly and consistently to active tectonic deformation and by studying the relation of river with tectonics; the recent activity can be shown. Geomorphological analyses allow the study of modifications that affect river basins, particularly modifications due to active tectonics, and investigate the morphotectonic evidence of the area such as, bisected alluvial fans deflected streams basin and cut Quaternary deposits. Morphometric indices are useful to analyze the influence of active tectonics in large areas. Considering that the study area is extensive and has numerous rivers and main faults, the study of Morphometric indices is useful. The aim of this paper is to extract information on tectonic activity and landscape evolution of the study area. This study focuses on the morphotectonic indices of the west Alborz and includes three principle streams the polrud, safarud and chalkrud. The study area is located in the west Alborz. Alborz, a part of Himalaya-Alp mountain range, has formed by convergence between Iranian microplate and Eurasia since Triassic Period and it is divided into West, Central and East Alborz. The study area comprised of a series of active faults and the mostly faults are reverse and thrust type with few normal faults. Main faults of study area include Khazar fault, samamus fault, kashachal fault, soheil fault, deylaman fault, zarinraje fault, lahijan fault. The DEM data of 30 m have been used to generate the drainage basins of all the catchments. The seven indices: Hierarchical anomalies (Δa), Bifurcation (R), Drainage density (Dd), Stream length–gradient index (SL) Form factor (Ff), Relative relief (Bh), and hypermetric integral (Hi) for each subbasin were measured and a unit index obtained as index of active tectonics (Iat). Afterwards the relationship between indices with morphotectonic characteristics and active faults of the area was investigated. In this study we use of survey satellite image1:100,000 geological maps of Geological Survey of Iran, digital elevation model. The field observations show that this study area has been active tectonic and the Basin morphometric indices to evaluate the active tectonic activity of river basins. In order to evaluate the active tectonic seven morphometric indices were used as follow: Hierarchical anomalies (Δa), Bifurcation (R), Drainage density (Dd), Stream length–gradient index (SL) Form factor (Ff), Relative relief (Bh), and hypermetric integral (Hi) and finally tectonic activity Index (Iat) was measured in 38 sub basins in the study area. Anomalies of the stream length gradient are associated with the faults Including Khazar fault, samamus fault, noosha fault, soheil fault. The drastic increase in SL occurs at the subbasin 35 related to kashachal fault. The High hypsometric integral and convex hypsometric curves indicate younger stage of landscapes and relate to neotectonic rejuvenation. The hypsometric Integral (Hi) index is calculated in range between 0 and 0.6, high values of the hypsometric integral are convex, and these values are generally greater than 0.35. The results of our study indicate that the highest mean value of Hi in subbasin 35 has undergone the highest intensity of neotectonic activity of kashachal fault. By using relative tectonic activity Index (Iat) the area was divided into 4 classes of tectonic activites as very high, high, medium and low. In the study area, about two thirds of the total area, Iat is classified as 1, meaning high to very high active tectonics In this research Various geomorphic features and landforms were observed in the study area where fault scarps ، unpaired terraces،V-shape valleys. Triangular facets, hanging valleys, deformed alluvial fan deposits, and deep gorges incised near mountain fronts exist. Results obtained show that central and south portion has the highest rate of tectonic activity and moderate relative tectonic activities level, has been found in the Nw and Sw part of the study area. While in the northern parts of the coast the value of this indicator is very low and tectonic activity is low.The results indicate the recent tectonic activity by movements of several faults such as Khazar fault, samamus fault, noosha fault, soheil fault, deylaman fault, zarinraje fault and lahijan fault of the study area.

The Study of Morphological Change and Speed of Landslide Displacement. The extent of instability can be determined., The extent of instability can be determined. The aim of this study was to model the speed of displacement and change the morphology of the marshland landslide in the northern slopes of Alvand, Hamadan, using morphometric indices, the GAMBIT pre-processor model, and the FLUENT computing model. First, The coefficient of transverse, longitudinal and deformation of landslides was investigated. Then the fluid properties were measured and calculated based on the slope and Reynolds numbers, speed and how to change the landslide morphology for 0, 50 and 100 seconds. The results of morphometric indices showed that the slope and water angle has a significant effect on lateral expansion and transverse Landslide shape variation. Studies on Landslide morphology evolution show that the Landslide of the longitudinal deformation is very weak and then a weak transverse deformation has occurred. Results of calculation of Reynolds equations. In the Fluent model, it shows that the initial motion and deceleration of the Landslide mass under the influence of the gravity and the velocity of the first seconds of motion in the longitudinal shape and in seconds 50 in the form of not too transverse and after the time and with the reduction of the gravity and the effect of 100 in the shape of It is completely transverse and lateral. The results show that the higher the viscosity of the Landslide mass, the more intense the formation of fungal fossils forms, and with increasing the flow rate of the fluid volume and the change in its morphology, the increase of the lateral mass also in the pine increase. Also, the results of the Fluent and Field model and the results of the indicators are completely consistent with the results.

aaIntroduction Iran has natural potential for creating a wide range of landslides; Because of different climatic zones, Topography, tectonic activity and seismicity, geology and natural condition. The basin of Komeh is located in southern Isfahan province. This research studies the factors affecting the occurrence of landslides and makes draw a hazard zonation map to identify sensitive areas with potential hazards.in order to, an appropriate solution could be used to the crisis and the risk of landslides to reduce damage and improve the environmental situation. Now a day Landslide and mass movements have been studied in scientific and international contexts Introduction Iran has natural potential for creating a wide range of landslides; Because of different climatic zones, Topography, tectonic activity and seismicity, geology and natural condition. The basin of Komeh is located in southern Isfahan province. This research studies the factors affecting the occurrence of landslides and makes draw a hazard zonation map to identify sensitive areas with potential hazards.in order to, an appropriate solution could be used to the crisis and the risk of landslides to reduce damage and improve the environmental situation. Now a day Landslide and mass movements have been studied in scientific and international contexts Methodology In this research, the zoning and preparation of hazard maps are based on the combination of landslides in the region with effective criteria. The recorded landslide points of the Komeh basin have been identified by field studies, satellite images with high spatial resolution, geological and topographic maps and converted to Landslide zones. Then, effective independent variables (such as slope, direction of amplitude, elevation, lithology or geology, land use, fault, waterway, rainfall and communication path network) were identified in the occurrence of landslide phenomenon and Using relative frequency method, the relative weight of each floor was calculated from each variable. Finally, by comparing and overlapping the mapping of landslides and hazard zonation maps in GIS, to evaluate and compare the fuzzy landslide risk zoning operators using two methods, of quality Sum (Qs) and method ( P). so appropriate operator with survey area and different classes of risk of landslide occurrence in the Komeh basin. Results Fuzzy maps were created after recognizing the factors affecting landslide and zoning as effective factors in the area. Using fuzzy functions and fuzzy maps were created. Considering the relative weights calculated the geological variable as the most effective and then gradient variable occurrence of slopes of the basin of Komeh was based on specialist's idea. After weighing each variable Based on the relative weights obtained from the hierarchical analysis, Landslide hazard zonation map of Komeh basin was provided by five fuzzy logic overlapping operators, Sum, Product, Gamma 0.7, Gamma 0.8 and Gamma 0.9. Results Fuzzy maps were created after recognizing the factors affecting landslide and zoning as effective factors in the area. Using fuzzy functions and fuzzy maps were created. Considering the relative weights calculated the geological variable as the most effective and then gradient variable occurrence of slopes of the basin of Komeh was based on specialist's idea. After weighing each variable Based on the relative weights obtained from the hierarchical analysis, Landslide hazard zonation map of Komeh basin was provided by five fuzzy logic overlapping operators, Sum, Product, Gamma 0.7, Gamma 0.8 and Gamma 0.9. - Discussion & Conclusions Generally, in this region a quantitative fuzzy method is Able to find and recognize landslides zone. Landslide is one of the most dangerous natural disasters, and some important factor such as slope, elevation range, lithology, geology... in landslide creation. Factors were identified in the region and using weight ratio model. Fuzzy weighting and weight of the criteria were determined using hierarchical analysis method. The results show that the elevation 1775-2000 with a rainfall of 500 mm, slop more 30 to 40 degrees, slopes in the northern direction due to rainfall and humidity, marn zones, intervals of 0-100 m from the rivers, distance between 0-100 m from road, 0-100 m from fault, garden and agricultural lands, they have the Most landslides allocate themselves. The value of the index (Qs) shows that the fuzzy gamma0.8 operator is with 7.09. The most appropriate method of overlapping fuzzy logic was to obtain a gamma value of 0.8 for the landslide hazard map of basin komeh. Discussion & Conclusions Generally, in this region a quantitative fuzzy method is Able to find and recognize landslides zone. Landslide is one of the most dangerous natural disasters, and some important factor such as slope, elevation range, lithology, geology... in landslide creation. Factors were identified in the region and using weight ratio model. Fuzzy weighting and weight of the criteria were determined using hierarchical analysis method. The results show that the elevation 1775-2000 with a rainfall of 500 mm, slop more 30 to 40 degrees, slopes in the northern direction due to rainfall and humidity, marn zones, intervals of 0-100 m from the rivers, distance between 0-100 m from road, 0-100 m from fault, garden and agricultural lands, they have the Most landslides allocate themselves. The value of the index (Qs) shows that the fuzzy gamma0.8 operator is with 7.09. The most appropriate method of overlapping fuzzy logic was to obtain a gamma value of 0.8 for the landslide hazard map of basin komeh. Key Words: Zoning; Landslide; komeh basin; Fuzzy Logic.

Karst lands provide water for 25% of the world's population. Karst's economic resources, the importance of karst lands in agriculture for identify geomorphic developments is determined. On the other hand, the study of karsts in arid areas is very important due to the suitable areas for water storage. Recently, numerous studies have been conducted on karst with different models (Bai et al., 2013; Febles-González et al., 2012; Wang et al., 2004; Xu et al., 2015). Considering the importance of the subject, the aim of this study was to determine the karstic regions using a new algorithm called Dempster–Shafer theory and comparing it with fuzzy method. In order to determine the susceptible areas of karst, geological data, distance from fault, rainfall, elevation, temperature, distance from the river, slope in GIS environment were used.
Dempster–Shafer theory
The Dempster–Shafer theory is based on two non-additive evidential measures: belief and plausibility, which can be estimated from basic probability assignment. The value of the basic probability assignment, also called mass, for a set Xi, represented as m(Xi), expresses the amount of evidence supporting the claim that an element of the universal set X belongs to the set Xi. The basic probability assignment is defined on a universal set X as a function of the power set (PX) in the interval [0,1] that satisfies two conditions: and =: Sets with nonzero mass are called focal elements. Measurement of belief for a set Xi, Bel (Xi), represents the minimum belief in the claim that an element of the universal set X belongs to the set Xi. It satisfies the following conditions: and Bel (x)=1
Fuzzy-AHP The term fuzzy logic was introduced with the 1965 proposal of fuzzy set theory by Lotfi Zadeh. Zadeh, in his theory of fuzzy sets, proposed using a membership function (with a range covering the interval (0,1) operating on the domain of all possible values. For any set X a membership function on X is any function from X to the real unit interval [0,1].
For preparing the fuzzy map for each parameters should definite membership function. A membership function assigns to each object a grade ranging between 0 and 1. The value 0 means that x is not a member of the fuzzy set, while the value 1 means that x is a full member of the fuzzy set. (Mc Bratney and Odeh, 1997): A fuzzy set is an extension of a classical set. If X is the universe of discourse and its elements are denoted by x, then a fuzzy set A in X is defined as a set of ordered pairs:µA(x) is called the membership function (or MF) of x in A. The membership function maps each element of X to a membership value between 0 and 1.
The Analytic Hierarchy Process (AHP) is a theory of measurement by pairwise comparisons and relies on the judgments of experts to derive priority scales (Saaty, 2008). The first step in the AHP is the estimation of the pertinent data. That is, the estimation of the aij and Wj values of the decision matrix. This is described in the next sub-section.
The weights of importance of the criteria are also determined by using pairwise comparisons.

The results of the Dempsstrapher method showed that by increasing the level of reliability and reducing the riskiness of the karstic areas, it decreases. Also, the results of the Dempsstrapher model have better results and better dispersion than the fuzzy method. Finally the results showed that the likelihood of karst in the west of the study area was higher than the other parts. According to the results of DST method, it can be generated karst map with different levels of confidence, which according to the conditions of economic and importance of the subject in the study area can be from one of these maps for management and planning.

In land use planning and sustainable development strategy, the selection and arrangement of land use options, project design and environmental management practices with legal and technical requirements are based on capability mapping and zoning of the severity and type of environmental hazards such as landslide and land instability. Landslide can be defined by mass movement of massive materials influenced by gravity and environmental factors such as earthquakes, floods and flood rains .This phenomenon has an effective role in destroying communication roads, residential areas and creating erosion and sediment in catchment areas. By zoning the risk of occurrence of landslide, it is possible to identify sensitive areas with high risk of land slipping and, by presenting solutions, appropriate control and management methods to some extent prevent landslides from occurring or reduce the damage caused by their occurrence. Landslide hazard zonation is in fact the division of the land surface into separate areas and the ranking of these areas based on the potential risk of landslide occurrence. In this research, the zoning of landslide hazard in Kohgiluyeh and Boyerahmad province has been done using the empirical Haeri-Sami method and the integration of thematic maps of rocks, slope angle, fault length, road and river length, rainfall, rainfall intensity and earthquake on a scale of 1: 1,500,000. After preparing of landslide zoning map, by carefully examining the images of Google Earth, areas of the province that were expected to have more potential for landslides were identified. Then, during extensive field observations, the geographic coordinates of the observed landslides were recorded and by providing the coordinates of the landslides in the Arc Map software and transferring them to Google Earth images, the location of landslides was identified and the respective area was prepared as a polygon file and transferred to the Arc Map software environment, and a digital map of the landslide distribution of the province was prepared. The Density Index (DR) was used to assess landslide hazard zonation map. The results showed that only in term of geology about 40% of the area of Kohgiluyeh and Boyer Ahmad province has a high sensitivity to the occurrence of landslides, in the case of other factors such as slope angle, fault length, road and river length, rainfall, rainfall intensity and earthquake, about 95% of the area of Kohgiluyeh and Boyer Ahmad province has a small sensitivity to the occurrence of landslide. After integrating the numerical score of the thematic maps of the Haeri-Sami model, the landslide hazard map was prepared in four classes without danger, very low, low and moderate risk, with a distribution of area of 26.3, 33.8, 36.9 and 2 percent respectively. In relation to the evaluation of the performance of the model using the density ratio index, the results showed that the model has been able to distinguish between landslide hazard zones and are very accurate in the low risk class. Based on the results of zoning, it can be said that the occurrence of landslide hazard in Kohgiluyeh and Boyerahmad province in the current situation is almost negligible and can only be managed by management plans for risk control or the principle of prevention, the occurrence of landslides in the province were prevented in the future. In general, for land risk management, there should be two components of the management tool and management method. The preparation of a hazard zonation map, the acquisition and use of the necessary techniques and training and promotion can be used as management tools and risk prevention, control and risk reduction in areas susceptible to landslide, can be considered as management practices. The results of this study are an effective step in planning and managing the land in Kohgiluyeh and Boyerahmad province.

Salt domes of Hormoz Formation has outcropped in large areas in south and southwest of Iran, Persian Gulf, and Eastern Saudi Arabia, with their extension delimited by major faults such as Kazeroon, Zagros, Minab, and Oman-Ural axis. Today, these domes have found various industrial applications such as radioactive waste disposal, gas storage, and tourism. In the meantime, these contribute to such problems as increased salinity of water and soil resources. Even though researchers have referred to the faults and density difference between salt and overlying sediments as the reasons behind the outcrop of the salt domes of Hormoz Series, the domes are significantly different in terms of morphometric indices and outcrop location. The present research is aimed at identification of the effects of tectonics on the form of the salt domes by calculating some morphometric indices (roundness, elevation, area) and analyzing them in Zagros and Persian Gulf zones while detecting the trend along which the domes have outcropped. In this research, 1:250,000 geological maps, satellite images and digital elevation model (DEM) were used to identify locations of salt domes and digitize the areas where the domes outcropped followed by the calculation of morphometric indices (roundness, elevation, and area) using ArcGIS Software. Subsequently, through elevation-based classification of the outcrop area on the basis of elevation and physiographic similarities and separation of salt domes based on host fold and local outcrop surface (onshore or offshore), the morphometric indices were analyzed in each area. Moreover, trend diagram was utilized to identify trend of the salt domes. The results indicate that, the farther one moves from Persian Gulf region toward higher latitudes and higher onshore areas, the lower is the roundness of the salt domes while their elevation increases, so that the salt domes exhibit larger area and further roundness yet lower elevations in expansion zone of Zagros folds and synclines. This is while, the domes within the trust zone, contraction zone of folds, and high lands show higher elevation yet smaller area and lower roundness. Investigations based on the trend diagram and the researchers’ work show that, the domes outcropped at levels higher than Jahrum and Fasa and High-Zagros Faults follow the trend of the major faults, i.e. a northwest-southeast trend. However, the domes outcropped at levels below these faults tend to follow basement faults and form along a northeast-southwest trend.
All of the outcropped salt domes of Hormoz Formation within Oman, Persian Gulf, and Zagros zones have been developed along basement and major faults. However, the faults are not visible in Persian Gulf zone because of the presence of water bodies, and also the basement faults in Zagros-Fars and Hormozgan areas are commonly buried because of erosion of the respective anticlines. These have made it somewhat difficult to explore the relationship between the faults and salt domes. For the bare salt domes outcropped within the contraction and high zone of Zagros, it is easy to detect their connection to the faults. An investigation on the roles of height and volume of overburden sediments along with the role played by the faults show that, in general, the higher the elevation of the outcropped zone, the lower is the number of outcropped salt domes. In the Persian Gulf zone, sea dynamics effect and burial of the salt domes have contributed to lower number of outcropped domes. Increased volume of overburden sediments on top of Hormoz Formation have hindered the outcrop of salt domes within high lands and contraction zones in Zagros. However, the large fracture generated by major faults set the stage for outcrop of the domes onto the surface. Regarding roundness and area of salt domes, it can be stipulated that, the salt domes could better develop and grow within Zagros-Fars and Hormozgan zones because of the expansion of folds, where those exhibit not only more extensive area, but also further roundness. In high Zagros zone, however, the anticlines and areas where folds are in contraction mode, lack of adequate space for dome development has resulted in a situation where the domes have been mostly developed longitudinally. This has ended up with elongation and smaller area of the outcrops, as compared to those of Fars and Hormozgan zones as well as plain areas.