Introduction: Yardangs due to intensive wind erosion are exclusive landforms on the earth's desert and possibly occur on Mars and Venus. The recent advances in the remote sensing technique and easily available of high resolution satellite data e.g. QuickBird provide useful information of remote area. Hence the mega-yardangs with tens meter high and hundred meters long are easily identifiable on satellite images and their global distribution and properties can be mapped.The Lut desert (Dasht-e Lut) in the south east of Iran is described as the “thermal pole of the Earth” (Mildrexler et al., 2006). With an area of about 80, 000 square km it is regarded to the hottest and the driest desert in the world (Alavi Panah et al., 2007; Gabriel, 1938; Mildrexler et al., 2006).Yardangs are streamlined forms up to 150 km long and 75 m in height resulting from a number of formative processes, including wind abrasion, deflation, fluvial incision, desiccation cracks, slumping, weathering and mass movement (Goudie, 2007; McCauley et al., 1977; Ward and Greeley, 1984). A limited number of morphometric investigations have been done on yardangs. Goudie (2007) identified mega-yardangs in hyper-arid environments with total rainfall less than 50 mm including central Asia, the Lut desert in Iran, northern Saudi Arabia, Bahrain, the Libyan Desert in Egypt, the central Sahara, the Namib desert, the high Andes and Peruvian desert. According to Goudie, these features develop in a wide range of rock types e.g. sandstones, ignimbrites, limestones and basement rocks by a relatively unimodal wind direction.Materials and Methods: In this study 3 arc second DEM of version 3.0 SRTM data (~90 m) with geographic projection acquired was used. That was re-projected to UTM grid with WGS 84 Datum.We used 90 m DEM produced from version 3 SRTM 3 arc second data and the SOM algorithm for identification of yardangs in the western part of Lut desert. Self-Organizing Map (SOM) is an unsupervised and nonparametric artificial neural network algorithm that clusters high dimensional input vectors into low dimensional (usually two dimensional) output map which preserve topology of the input data. In geomorphic studies of landscapes, the first and second order derivatives of DEM are the basic components for morphometric analysis (Evans, 1972). The second order derivatives of DEM are affected by geomorphological processes (Evans, 1972; Wood, 1996 b). To calculate the morphometric features, a local window is passed over the SRTM DEM and the change in gradient of a central point in relation to its neighbors is derived by a bivariate quadratic function. Wood (1996 a) defined a set of criteria to classify DEMs into morphometric classes. Yardang identification and analysis in the study area was performed using the parameters proposed by Wood (1996 a). A local window of 5x5 is passed over the DEM and slope, cross- sectional curvature, maximum and minimum curvatures are derived by fitting a bivariate quadratic approximation surface. The derived morphometric parameters were used as an input to SOM.Frequency histograms and average quantization error of the results are compared. Two dimensional plots of mean values of morphometric parameters (feature space), oblique views of map units draped over the DEM, Landsat ETM+ data and high resolution Quick Bird images were used to study the mega yardangs in other places than Iran.Results and Discussion: Learning of the SOM was performed with four morphometric parameters as the inputs and a two-dimensional output of 10 neurons. The map with initial radius of 3, final neighborhood radius of 0.01 and 1000 iterations shows the best performance for yardang identification. The output map units from SOM are just numbers and need to be analyzed and interpreted. Studying the spatial relationship between different map units along with their morphometric parameters using feature space analysis allowed us to interpret and label them corresponding to morphometric features e.g. yardangs. Major morphometric features (corridor, planar and yardang) are identified in two-dimensional feature space plots of mean values of maximum curvature (x-axis) and minimum one (y-axis). The analysis of the results and corresponding satellite images shows the effectiveness of the method to identify the overall pattern of the morphometric features in the Lut desert. It is clear that the pattern of yardangs and their corridors running from NNW to SSE direction is parallel to the prevailing wind known as “wind of 120 days or Bad-i-sad-o-bist rooz-e Systan.Conclusion: The results show that digital terrain analysis methods applied on SRTM in the proposed way in this study could extract morphotectonic features from SRTM along Dehshir fault and they contributed to the tectonic interpretation of the study area. According to the evidences extracted from SRTM along Dehshir fault, for example: fault traces, deflected and beheaded drainages, pattern of network drainages, erosion surfaces of uplifted and back erosion of drainages because of the location (situated in quaternary landforms), they are neotectonic evidences for activity of Dehshir fault during quaternary. Our results reveal that the morphometric analysis and feature space analysis of the first and second order derivatives of DEM such as slope, cross-sectional curvature, maximum curvature and minimum curvature led to the description of SOM outputs as yardangs, corridors and planar. Slope allows distinguishing among morphometric features in sub levels.The optimal self organizing map with suitable learning parameters should be selected for feature identification. The lowest average quantization error of 0.1040 was achieved with an initial radius of 3, a final neighborhood radius of 0.01 and 1000 iterations. Result of this method revealed that from the total 6481 km2 coverage of the study area, about 2035 km2 (34%) are classified as yardang while corridors, in total cover 2732 km2 (43%)

ABSTRACT The geomorphology of the Zanjanroud basin is affected by the active tectonic zones resulting from the interaction of the Soltanieh, Zanjan, Tarem, and Manjil faults and the faults that have been investigated more closely in this research. The interaction of these faults has made this basin in the form of a small high plateau, heterogeneous compared to the surrounding areas and a suitable place for the establishment of human settlements. In this research, remote sensing and geomorphometric techniques have been used to identify the lineaments and tectonic evidence in order to discover the tectonic effect on the geomorphology of the basin. The contour lines have been converted into a map after checking with the help of telemetry, Geomorphometry and field techniques. Then, by analyzing and interpreting the evidence, the relationship between the dynamic pattern of the faults and its effects on the morphology of different landforms is presented with an emphasis on the interactive reconstruction of drainage networks and faults. The results show that the active tectonics of the faults are concentrated towards the centre of the basin and Zanjanroud area. On the other hand, the compliance of the morphology and topographical trends of the basin, as well as the Zanjan River canal and many drainages with the extraction lines with the help of geomorphometric techniques, clearly shows the effectiveness of Geomorphometry to evaluate and prove the impact of terraforming on the geomorphology of the basins. Although no destructive earthquake has been reported in the region, But the presence of morphological evidence and the interruption of Quaternary to Holocene deposits indicate the active deformation of the region. Therefore, it seems that the fault systems of the basin have the potential to create earthquakes with a much higher magnitude than what has happened so far, which indicates the necessity of planning based on a detailed study of the faults in the region Extended Abstract Introduction Understanding the geological conditions of each region and basin, along with other influencing factors, has a significant role in understanding the governing processes. Zanjanrud basin stands out as a small local plateau and in a heterogeneous manner with the topographic alignment of the surrounding area. In this research, an attempt was made to evaluate the tectonic effect on the geomorphology of the Zanjanrud basin using remote-sensing and geomorphometric techniques. The main objective of the research was to investigate the morphological pattern of the Zanjanrud bed and its relationship with active fault tectonics.   Methodology In this research, remote sensing and geomorphometric techniques, along with field observations, were main tools of investigating and evaluating the effects of faulting on the geomorphology of Zanjanrud basin. The data used were Sentinel-2, Landsat- 8 & 9, Quick-bird data, SRTM-DEM 90 & 30-meter, and the DEM 10-meter. The data were used to extract geomorphometric indicators and enhancement of the morphotectonic elements and geomorphometric analyzes and evaluation of the effect of faults on the landscape and landforms of Zanjanrud basin. In addition, in this regard, field surveys have been conducted to validate remote sensing and geomorphometric findings and prepare ground truth data for comparison and accuracy evaluation. Different software (ENVI, SAGA, MicroDEM, ArcGIS, GRASS) are used to geomorphometric analysis of morphometric parameters, extraction of geomorphometric indices and characterization of morphotectonic elements. In this research, by extracting the basic parameters of the earth's surface, the elements and parameters of the topographic surface have been identified and, based on them, the anomalies of the topographic surface have been detected. Neotectonic and faulting are among the most important factors causing anomalies in topographical surfaces.   Results and Discussion In this research, we tried to enhancment of the fault maps and the topographic, hydrological and structural trends of the basin that are used to enhancement and documenting the anomalies of the topographic surface including the effect of faults and fracture systems in the area. The map of hill-shade parameters and indicators, profile and plan curvature, and topographic surface roughness index have clearly enhanced the effect of basin faults. In the meantime, two fault systems have been confirmed in the basin with high certainty. Geomorphological analysis based on high-resolution images, digital elevation models and field observations made it possible to estimate the evolutionary pattern in the form of these active structures. Although the focus of the current research is on Zanjanrud, which almost follows the extension of the Zanjan Fault, but in order to understand the dynamic pattern of faults and their effects on Zanjanrud, neotectonic evidence based on basin Geomorphometry has also been discussed.   Conclusion In general, the results of this research are: - Neotectonic evidences: Examining the neotectonic evidences show that the faults in the region are active faults and have a high potential for seismic activity by cutting Quaternary sediments. - Deformation of Zanjanrud Basin: This study showed that Zanjanrud Basin has been affected by four main fault systems and several sub-faults with different scales. These changes have forced the formation of mountain, foothills, plains and changing the course of Zanjanrud. - Tectonic patterns of the basin: Zanjanrud basin is exposed to complex tectonic stress patterns due to its geographical location and location at the meeting points of Alborz (western), Talash and Central Iran morphotectonic units. These tectonic stress patterns include north-south convergent movement in the direction of Arabia-Eurasia. Also, the performance of regional-district-local units has also played a role in the formation of the Zanjanrud basin. - Zanjan is a fault plain: it seems that the subsidence resulted from the intersection and interaction of two northwest-southeast fault zones and north-south have a role in the formation of the plain. Zanjan. Also, the simultaneous and active action of the faults have caused morphological anomalies in the topographical level in the Zanjan river basin. - Anomaly of Zanjanrud channel and heterogeneous topography in Zanjan plain and basin: The northern part of Zanjanrud basin has two main lines that continue towards the south. These lines have caused the interruption and displacement of Quaternary sediments on the level of the plain, barracks, beaches and Zanjan river channel. This research shows that the morphotectonic evidence of Zanjanrud basin indicates the presence of faults and active fracture systems in the region, which has a significant effect on the formation of morphological and topographic anomalies in Zanjanrud basin.   Funding There is no funding support.   Authors’ Contribution All of the authors approved the content of the manuscript and agreed on all aspects of the work.   Conflict of Interest Authors declared no conflict of interest.   Acknowledgments We are grateful to all the scientific consultants of this paper.

Spatial modeling of the groundwater springs occurrences allowed the identification of new springs for drinking, agriculture and industry. The objective of this study was spatial modeling of the groundwater springs occurrences using the Geomorphometry indexes affecting the groundwater springs occurrences and Weights-of-evidence control model and evaluating this model in Central Alborz. Generally, 584 springs were identified in the study area that 409 (70%) of them were utilized for training and 175 (30%) springs for validation of Weights-of-evidence control model. 14 important Geomorphometry indexes includin elevation, degree of slope, aspect, plan curvature, profile curvature, topographic wetnes index, stream power index, slope length, topography position index, lithology, distance of faults, fault density, distance from rivers and drainage density were chosen in the form of Weights-of-evidence control model for spatial modeling of the groundwater springs occurrences. According to Weights-of-evidence control model, aspect and topographic wetness index had the lowest and the highest impact on the ground water springs occurrences respectively. The map resulted from spatial modeling of groundwater springs occurrences were classified into 4 classes including the low, middle, high, and very high potential occurrences. The model was validated using ROC method, which the area under the curve was 0. 866. This means the weights-of-evidence control model was accurate enough for estimating the spatial modeling of groundwater springs occurrences in Central Alborz.

Geomorphological map is one of the main information layers in natural resources studies. So far, various methods have been proposed for the classification and separation of various units and Geomorphological types, most of which are based on qualitative and descriptive information. In this study, the ability of Geomorphometry parameters in separation of mountains from pediment and also separation of different types of pediments was investigated. First, ground truth map was prepared using visual interpretation of satellite data and topographic maps. Then the 1000-point sampling grid was designed randomly. Parameters including profile curvature, plan curvature, tangential curvature, cross-sectional curvature, longitudinal curvature, and general curvature were prepared from digital elevation model in the GIS software. Then, their values were extracted at all points of the sampling network. Then, artificial neural network with structure of 13_6_ 4 was used to separate the units. The results showed that the erosion pediment could be separated from epandage using artificial neural network; however, the separation of epandage pediment from covered pediment was not well. For this purpose, to improve network performance, the digital value of Landsat 7 data was added to the previous values. The resolution accuracy of mountain, erosion pediment, epandage pediment, and covered pediment was calculated to be 90, 79, 80, and 76%, respectively.

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Although a better understanding and quantitative knowledge of digital elevation model scale will help to improve soil predictions, the influence of pixel size has not been investigated in detail. The aim of this study was to investigate the role of spatial scale on soil clay content prediction by empirically testing the interaction between pixel resolution and window size with regression tree model. In two different areas in terms of their geomorphology and soil (area 1, Maybod located in Yazd province covered 400 km2; area 2, Iasokand located in Kurdistan province covered 400km2), 120 surface soil samples (0-30 cm) were taken and their clay contents were measured. From 121 digital elevation models representing different scales, 22 attribute were extracted and used for soil clay content prediction. Results showed that Maybod area had the minimum RMSE (9. 0%) and maximum R2 (0. 47) and dependence of tree model on pixel size was significant for clay prediction[H1]; however, in Iasokand area, the minimum RMSE (5. 65%) and maximum R2 (0. 77) were obtained and window size was significant for clay prediction.

One of the goals of geomorphologists in working with the models of different landforms is to obtain better relations in realizing the physical realities of environment. In this study, to evaluate the performance of geomorphometric parameters to increase accuracy of zoning landslide susceptibility map has been studied. As the first step by the application of nine initial conditioning factors including slope, aspect, elevation, land use, lithology, distance from roads, rivers and vegetation index (NDVI) the zoning map was provided. In the next step geomorphometric parameters influential on the occurrence of landslide including topographic location index (TPI), surface curvature, curved sections, slope length (LS), Topographic wetness index (TWI), stream flow power (SPI), surface area ration index (SAR), was added to the model and then the zoning map was obtained. In the final step, the zoning maps was evaluated by using ROC curve. To provide zoning maps a new mixed model was applied, so, for determination of criteria weights multivariate regression and to determine weight of the classes' frequency ratio method was utilized. The findings of this research indicated that geomorphometric factors have a considerable influence on the increase of identification of regions that are susceptible to the landslides and enhance the accuracy of zoning maps from 0. 731 to 0. 938. These factors have also increased the resolution of the slip classes. According to the results, topography position index, plan curvature and surface area ratio have the highest influence on the accuracy of zoning maps. Based on superior approach, 8. 68% (6737 ha) of the region are at very high risk and 15. 3% (11906 ha) have been identified as high risk areas. According to the high ability of geomorphologic parameters in the identification of susceptible areas to the landslide, the application of these parameters is recommended in landslide hazard zonation.

Awareness of sedimentation and erosion rates in catchment areas and effective factors. The most important concerns and challenges for geoscientists, especially geomorphologists. Morphometric parameters of drainage network have yery determinant role in the rate of sediment uield in catchment. In this research, in order to evaluate the correlation of morphometric indices of drainage network at annual sedimentation rate, a digital elevation model (DEM), digital topographic maps, geological maps, and statistics and information on the discharge of 15 drainage basins in northeastern Iran were used. And calculated the geomorphometric indices such as: Drainage density (Dd), drainage frequency (FD), drainage (T), fault density (Df), length of drains (BL), branching ratio (Rb), number of hierarchical anomalies (Ha), hierarchical anomalous index (Δ a ), The density of the hierarchical anomalies (Ga), concentration time (Tc) and erosion-sensitive units (E) for each of the basins were calculated in the software Arc GIS 10. 5. The annual sedimentation rate was calculated using the Ciccacci et al. 1987 method for each basin. The model was validated with sediment data (regional water organization) and the gauge-sediment curve. Then the Pearson correlation coefficient and the relationship of the mentioned indices were calculated using SPSS 17 software, with annual sedimentation rate in ton / km2. According to the results, the Tc, A, E, Ha, BL, Δ a indices have a significant correlation with annual sedimentation rate of 0. 274, 0. 286, 0. 118, 0. 179 and 0. 177 respectively, respectively. There was no significant relationship in other indices. The results of the research show that the method of Ciccacci et al. 1987 is not a suitable method for estimating annual sedimentation rates in research basins. And other factors have the greatest impact on the annual precipitation rate, precipitation intensity, soil condition and land use in annual sedimentation rates of these basins, which should be considered.

Understanding of landforms and their distribution are basic needs of applied geomorphology and other Earth sciences to understand and evaluate of landforms development, slope stability studies and regional planning. Landforms have at least two features: the first they are result of last geomorphologic and geologic processes and second to determine the borders now geomorphologic processes.In this study assess the Performance of Wood’s method for detection and classification of landforms in Maranjab dry region. After extraction morphometric parameters; slope, cross-sectional curvature, minimum and maximum curvatures from DEM overlay indices with slope tolerance value 1and curvature tolerance value 0.01. Result show flat and plain areas with 49/8% are majority with ridge and channel. This study focused to automate extraction of elements morphometric of land surface using Wood method. Result showed wood method is efficient in general Geomorphometry on Marajnab region and could to extract main classess using DEM. But in spicific Geomorphometry and ectrcat discret landform is required to develop and improve performance.