Spatial distribution of erosion phenomena and susceptibility analysis of different parts of watersheds to their types, plays an important role in environmental planning, so that the preparation of susceptibility maps to types of erosion and identification of factors affecting it, can Reducing the risk of various erosive phenomena will lead to providing the necessary management measures for the relevant areas. In this research, a bivariate statistical method was investigated for analyzing the susceptibility of Surface, Rill, Channel and Riverbank erosion phenomena using eight factors of rock resistance, land use and land cover, slope percentage, slope aspect, plan curvature, slope length, stream power index and soil hydrologic group in Omarabad watershed of Urmia. The results showed that regarding the effect of various factors predisposing to the occurrence of Surface, Rill, Channel and Streambank erosion, acceptable results with a clear trend in surface and rill erosion were not obtained, However, in the case of channel and streambank erosion, each of the factors, according to the relevant classes, has a positive or negative effect on the occurrence of this type of erosion and the effect of one factor cannot be considered as complete, positive or negative. factors such as lithology, slope length, slope percentage, slope aspect and SPI have the most positive effect on the occurrence of Channel and Streambank erosion. On the other hand, according to the calibration of the susceptibility map to Channel and Streambank erosion, only 20% of the area with Channel and Streambank erosion related to calibration were in the range of areas with very high to severe sensitivity in the susceptibility map. This indicates the inefficiency of the susceptibility map produced using the above eight predisposing factors and emphasizes the research on other more important and effective factors in creating the desired erosion phenomena in the study area.

Marls produce the highest deposits in the catchment areas among lithological units. This property of marls can cause the reduced useful life of dams, river, and sedimentation of water channels, the destruction of road, utilities, and ultimately desertification phenomenon. Hence, understanding the characteristics influencing the erodibility and marls divergence can be a priority. In this thesis, marls located in the south of Tehran (south of Hassan Abad- Varamin) were evaluated in terms of shape and intensity of erosion, physical, chemical, engineering and divergence features. Marl unit studied includes the onshore marl of Upper Red Formation unit M3 and Pliocene marl of unit Plm. Sampling in the unit of red upper geology and Pliocene was conducted in slopes 5%, 20% and 40%. Tests such as gradation, Atterberg limits, chemical analysis such as cations and anions, SAR, TDS, EC and dual Hydrometry and pinhole were carried out to achieve the predetermined goals. Granulation distribution showed no significant difference in different slopes. Comparing the plasticity index among the different forms of erosion, it can be seen that the surface erosion plasticity index is greater than other forms of erosion .it is a factor in the postponement of erosion. But overall, it's not much different from many other forms of erosion. The cation exchange capacity in the samples is between 14/2 to 25/88 meq per liter. The mean of this variable is further in the stream erosion .the range of this variable in samples is between 0.9 to 2.17 meq per liter. The mean of this variable in the erosion of stream and ditch is more than the rest of upper red formation units. The results of the double hydrometer tests on 20 samples indicate the high non-divergence. The sample collected from Station 1 (in the form of gully erosion) and station 5 with a gradient of 5% (with stream erosion) shows the average divergence. According to the pinhole experiment conducted at different stations, station 5 (with single stream erosion M3) and station 7 (with a form of gully erosion M3) showed a moderate divergence.

river erosion is always one of the main factors in the risk of energy transmission lines and oil and gas pipelines. In this paper, using the Pipeline Risk Screening Matrix (PRSM) and the ANP model, stream pipelines in the Iran gas trunk – line 9 (IGAT 9), in the province of Khuzestan with a length of 170 km were investigated. For this purpose, using the ANP model, four main categories of criteria were included: the criteria "pipeline situation to the streams", "Hydrogeomorphology", "geomorphology" and "other environmental factors", with 36 sub-criteria, then using the PRSM model and the questionnaire were sub-criteria scoring in the Super decision software, as well as a pipeline hazard risk classification map. The results showed that the "pipeline situation to the streams" criterion has the highest risk and response to pipeline hazards among the four criteria. The most important sub-criteria with the highest risk profile are construction method, mountain, drainage and geology. Risk map is also in the range of Shushtar and km 150+ to 170+ in east of Dezful. The 9th gas pipeline has the highest risk situation and increased stream and rivers response in mountain geomorphology unit.

Soil organic carbon (SOC) is a principal component in soil quality assessment. Knowledge of SOC and total nitrogen (TN) stocks are important keys to understand the role of SOC in the global carbon cycle and, as a result, in the mitigation of global greenhouse effects. SOC and TN stocks are functions of the SOC concentration and the bulk density of the soil that are prone to changes, influenced by land use changes, and soil erosion processes. This study has evaluated SOC and TN stock under different land use types and soil erosion types at catchment scale.SOC and TN stocks were measured in 112 different sampling sites of four main groups of land use/soil erosion: rangeland/surface erosion, orchard/surface erosion, dry-farming land/surface erosion, and rangeland/streambank erosion at Hiv and Zidasht catchments, Iran. The results showed that SOC and TN stock under all land use and erosion groups was significantly different. SOC and TN stock was greatest in the orchard land use and the total SOC stock for the 20 cm soil layer under different land uses and erosion types varied for Hiv in order of orchard/surface erosion (46), rangeland/surface erosion (31), and rangeland/streambank erosion Mg/ha (p<0.005). For Zidasht, the variance was, in order:orchard/surface erosion (43), dry-farming land/surface erosion (23), rangeland/surface erosion (23), and rangeland/streambank erosion 22 Ton/Hector (p<0.005). The TN stock has the same trend in all studied land use and erosional groups. Therefore it was concluded that rangelands were affected by erosion, with a subsequent decreasein productivity level. These results can be useful as a scientific basis for selecting the proper soil erosion control methods as a simple, low-cost approach to mitigate SOC and TN loss.

Flooding is a natural hazard events and Survey data from the annual losses due to flood in Iran and the world show the extent of the flood damage caused on natural and human resources. To estimate height of the runoff and discharge maximum in basins and stream erosion، there are various experimental methods and mathematical models that one of these models، SCS model is. Thus، the aim of this study was to estimate the Runoff coefficient and Maximum discharge by Curve Number method with different units forming the Fyruzkla Kojoor basin and zoning maps of potential runoff and stream erosion in the drainage basin is. After mapping the watershed CN and S، to calculate the volume of runoff produced in the region، short-term rainfall for different return periods were calculated using Pearson distribution of type III. According to the map of potential runoff in the basin، forest land has the lowest runoff potential and pasture lands have the greatest potential to generate runoff and erosion is occurring and also has the lowest penetration. The middle part of the basin، the most prone to runoff and erosion and gully formation in the region are. After determining the height of the basin surface runoff، peak discharge was calculated for various hydrological. The highest values of maximum flow rate are based on rangeland with hydrologic group D.

Soil is one of the most vital issues for the sustainability of the environment, which provides human needs and livelihood on the surface of the earth. Therefore, reducing the phenomenon of land degradation is one of the leading challenges for the sustainable development of the environment and economic activities, which is why comprehensive planning and management against erosion is essential. Today, several methods have been developed for preparing soil erosion maps, which can be mentioned using experimental methods; that these methods include equal weights for all parameters in calculating the average erosion; While each criterion has a point value that is affected by environmental, geomorphological and physical factors related to soil erosion. Among other methods, we can mention machine learning, which is an advanced method that requires high-performance computing systems. However, it is necessary to use statistical methods for fast, understandable and accurate modeling, and there is no requirement for high-performance systems in these methods and Among these methods, Entropy Index, Frequency Ratio, Information Value, Certainty Factor, and Witness Weight methods can be mentioned. Therefore, the aim of the current research is to identify the most important criteria and sub-criteria that are effective in preparing the erosion sensitivity map of the watershed upstream of the Tajen River using the Integration of two data mining models Entropy - Information Value.

The erosion inventory map with 252 erosion points for the upper watershed of Tejn River was identified using Google Earth images, and 70% of these erosion points were classified for training and validation of the model. Then, to evaluate the sensitivity of erosion and also to identify the most important driving factors in the occurrence of erosion, the criteria of elevation, slope direction, soil type, land use, Rainfall Erosivity, distance to stream and Topographic Wetness Index were used and The erosion sensitivity map of the studied area was obtained from the integrated entropy-information value model. In order to evaluate the success rate and predict the model, Receiver Operating Characteristics and Area Under the Curve were used.

The results of the present study showed that the effect of elevation on soil erosion is increasing, so that this effect reaches its maximum value in the elevation class of 2745-3742 meters with an Information Value of 1.65. The influence of the slope directions on soil erosion showed that the south-west slope direction with an Information Value of 1.04 has the greatest effect on the erosion of the region. The results of overlapping the distance to stream layer with the erosion map of the region indicate that the distance layer of 0-456 meters has the highest Information Value of 0.63. The barren land use class with an Information Value of 2.74 has the greatest effect on the erosion potential of the region. The results of the overlap between the Rainfall Erosivity map and the regional erosion map showed that the 302-325 layer of rain erosion has the highest Information Value of 1.28. Examining the relationship between types of soil groups with regional erosion showed that the Inceptisols soil group with an Information Value of 0.66 has the greatest effect on soil erosion in the region. The results of the overlap between the Topographic Wetness Index layer and soil erosion in the region indicated that the 6.2-8.6 layer of the Topographic Wetness Index with an information value of 0.25 has the highest erosion potential. According to the curve (ROC-AUC), the success and prediction rate of the combined model of Entropy Index - Information Value was obtained as 0.831 and 0.837, respectively which indicates the good performance of the model for training and validation courses.

Soil erosion is one of the most important issues of land destruction on a global scale, which causes muddying of waters and lakes, loss of fertile agricultural topsoil and biodiversity; Therefore, it is essential to evaluate the sensitivity of soil erosion. The current research was conducted with the aim of identifying the most important criteria and sub-criteria effective in soil erosion with the integrated model of Entropy - Information Value in the upper watershed of Tajen River. The results of the present study showed that out of the total area of 693.23 square kilometers of the study area, 156.75 and 94.71 square kilometers are in the high and very high categories, respectively. The prepared soil erosion sensitivity map in the studied area can be a useful tool for management and planning in line with soil protection measures.

In recent years, valuable experiences have been gained in relation to environmental challenges, as well as pipeline risk management in the United States and Europe, in relation to the design and stabilization of pipelines, including the knowledge of geomorphological hazards, in particular the erosion hazards of the stream. It has helped to reduce the risk, and identify the response and response of the stream and rivers. In this paper, Pipeline Risk Screening Matrix studies the hazards of the geomorphology of the stream pipelines in the Iran gas trunk – line 9 (IGAT 9), in Khuzestan province. For this purpose, seven hydro-geomorphological data including scale, landscape sensitivity, stream type, riparian corridor, bank characteristics, bed characteristics and hydrologic regime were used. In the pipeline risk axis, three nominal scales include:

Low risk, medium risk, and high risk were used to estimate the risk profile of the pipeline in relation to the increase or decrease of response and river responses. The results of this study showed that from the seven classes of the studied, the type stream is low-intermediate risk stream response and three classes, the riparian corridor, bed characteristics and hydrological regime are Medium risk. Bed characteristics and scale are medium-high risk and the landscape sensitivity high risk stream response. Overall, the class of risk stream response in IGAT 9, is medium – high risk stream response class.

In the world, most of the research work on the hazards of pipelines (oil and gas pipelines) is in the United States, Canada and Russia, respectively. Also Western European countries, in particular the UK, have had research in this field. In Iran, pipeline failure or damage to the pipeline is eroded annually, for example, Rafsanjan-Naein-Esfahan oil pipeline (2013), Ray-Tabriz (2017). In Iran, there is no comprehensive study in which the geomorphological impact of the erosion damages to the pipelines unlike the long history (over 110 year records) of the oil and gas industry. In this paper, the purpose is to identify and assess of the risk stream response by using of pipeline risk screening axis relation to IGAT 9. Method and result In this paper we use of pipeline risk screening axis for estimate and identify of stream response risk class. This axis has seven criteria such as: scale, landscape sensitivity, stream type, riparian corridor, bank characteristics, bed characteristics and hydrologic regime. Pipeline risk screening axis classified into three categories, low risk, medium risk and high risk based on field data from seven criteria:

1) 50 river have point scale, 2 river reach scale, 4 rivers multi-reach and 4 rivers have watershed.

2) Landscape sensitivity have high risk reaction groups.

3) Stream type are two class include alluvial and bed rock.

4) Riparian corridor is 3 type of continuous – wide, semi continuous – wide and discontinuous – narrow.

5) bank characteristics have 3 type naturally non erodible, erosion resistant and highly erodible.

6) bed characteristics have 3 types boulder/cobble/clay bed, gravel /silt bed (dominate in case study) and sand bed.

7) hydrologic regime in our case study is rain and thunderstorm.

The results of this study showed that from the seven classes of the studied, the type stream is low-intermediate risk stream response and three classes, the riparian corridor, bed characteristics and hydrological regime are Medium risk. Bed characteristics and scale are medium-high risk, and the landscape sensitivity high risk stream response. Overall, the class of risk stream response in IGAT 9, is medium – high risk stream response class. For decrease of stream response risk, and improvement Iran gas trunk – line 9, it needs to tight management – engineering measurements, and Geomorphologically in case of erosion stream and restoration and review of project of rout line.

In this study, marls ofsouth of Hassan Abad and Varamin in Tehran Province, including the marls of Upper Red Formation unit M3 and Pliocene marls of unit Plm in slopes of five5, 20 and 40 percents were evaluated in terms of shape and intensity of erosion, physical, chemical, engineering and dispersion features. Accordingly, 20 samples were taken from mentioned marl formations. To achieve predetermined goals, granulometry, Atterberg limits, chemical analysis such as cations and anions, SAR, TDS, EC and double hydrometery and pinhole were tested. Results of double hydrometery tests on 18 samples indicated that only three have low dispersion degree Which are related to marls of unit M3 in undisturbed samples of station 1 with the form of gully erosion, station 2 with 40% slope and surface erosion and station 5 with 5% slope and channel erosion. According to the pinhole test, from 17 samples, 12 samples were classified as non dispersive and five samples as low to moderate dispersive classes. In this test, the majority of the samples with channel erosion and some samples with gully erosion showed low to moderate dispersion rate. Other erosion forms such as surface and rill erosion showed non-dispersive behavior. Based on chemical properties of the Total Dissolved Solids (TDS) and Sodium Percentage (PS), in Casagrande chemical graph, the majority of samples are clssified as dispersive soil, one sample with surface erosion in the boundary of dispersion and one sample with rill erosion as dispersive with the probability of 50%. In modified Sherard chemical method, all samples are classified as non dispersive soils. These results have no conformity with other physical and chemical methods so this classification is not acceptable. African chemical method showed better results compared to other chemical methods. In this method, half of the samples were classified as dispersive and the other half as non-dispersive. According to chemical and physicalstandards, dispersion phenomenon has been seen in all forms of surface, rill, gully and channel erosion. It has been concluded that marl soils are potentially dispersive under the influence of chemical and physical factors, even if they show surface and rill erosion forms, at the time of sampling. In other words, if the necessary conditions such as slope sleepness and runoff concentration occure in these soils, surface and rill erosion forms can be developed to dispersive forms such as channel and gully erosion types.