جستجوی مقالات مرتبط با کلیدواژه « soil erosion » در نشریات گروه « آب و خاک »

Gully erosion is one of the most important and destructive forms of water erosion, and there are ambiguities regarding its initiation and development. The study aimed to identify the soil properties and other factors affecting gullies of South Nazar Abad in 2021. After the field survey, based on the Google Earth images, gullied area boundary draw, 32 gullies were selected, and their location was recorded with the GPS. A surface soil sample was taken from head cut wall of each gully and general analyses were done. The gullies watershed boundaries and morphological characteristics including area, perimeter, and slope were extracted from the DM obtained from unmanned aerial vehicle (UAV) images. The general characteristics of the soil surface in the watershed of the gullies including canopy, bare soil, and residual percent were determined by 1 m x1 m plot. The gully length, width, and depth were measured and volumes were calculated. Modeling of factors affecting gullies was done using a multivariable linear regression model (step-by-step method) in MINITAB on 70% of observations. The relationship between the volume of gullies with gullies soil properties and watershed characteristics were investigated and a suitable gully development model (soil loss) was introduced. Also, in this research, 30% of the measured samples that were not used in the model construction were used for model validation. Percentage, RMSE, CRM, NSE, CD, MAE and drel statistics were used to determine model efficiency. Principal component analysis showed that EC, Na+, Cl-, K+, Erodibility, Mg++, canopy, bare soil, and SP characteristics had noticeable effect on gullies volume. Based on the results of the research and especially based on the Nash-Shutcliffe efficiency coefficient, no reliable model has been developed. Also, the presented model is valid based on the regression at the five percent significant level and according to the validation coefficients. The model with a correlation coefficient of 0.59 and four factors K+, bulk density, crop residues, and percent bare soil could explain 35% of the changes.Strengthening and restoring crop cover in the area is recommended.

Soil conservation requires a suitable model and framework to assess soil erosion and sediment yield based on land use scenarios. Therefore, the present study was conducted with the aim of investigating the sensitivity of the G2 model to the soil erodibility factor in the Kasilian representative watershed in the period of 2001-2021. Points such as the use of global soilgrid database and comparison with soil sampling data, removal of soil erodibility in rocky areas, and removal of outlier data created by systematic error were included in the current research. The results showed that qualitatively, the rate of soil erosion estimated based on each of the mentioned points was completely in the minimum category. The initial results of the soil erosion rate obtained from the global soilgrid database and the IDW method were 4.31 and 4.33 t ha-1 y-1, respectively, which were not significantly different based on the independent t test. But the effect of other changes, including removal of soil erodibility in rocky areas and removal of outlier data on the change of soil erosion estimates using one-way ANOVA and Duncan's tests were significant (P<0.01). The estimated average rate of soil erosion in the watershed after following the mentioned points was reduced by more than 65% compared to the initial results and became closer to the data of erosion plot.

Soil erosion in upstream areas has an important role in sediment entry to dams. Sediment accumulation result in decreases of dam service life, environmental problems, and acceleration of floods. In addition to climate, topography, vegetation cover and land management, soil erosion amount depends on soil characteristics and its erodibility.  In this research, soil erodibility factor and its special distribution was assessed by using of various pedotransfer functions including KUSLE, KEPIC and KDg in a part of Aliabad watershed of Roodbar, located at upstream of Sefidrood dam. The soil samples were collected from 0-10 cm depth and size distribution of soil primary particles, organic carbon content, and aggregates stability were measured. The KUSLE was calculated in two ways without codes of soil structure and permeability, and with respective codes, named as KUSLEi, and KUSLEf, respectively. The results showed that studied soils generally had coarse texture, and KUSLEi was estimated low to moderate in range of 0.11 to 0.040 ton h MJ-1 mm-1. The least soil erodibility factor belongs to KDg, which was significantly lower than the soil erodibility factors calculated by other pedotransfer functions. All of the calculated erodibility factors had significant negative correlation with mean weight diameter of aggregates which KUSLEi and KDg showed the most and least correlation with MWD, respectively. All of the erodibility factors had moderate spatial dependence, however KUSLEi showed strong spatial dependence. Therfore, it generally can be concluded that zoning map of KUSLEi  generated via kriging can be a suitable indicator of the studied soils erodibility.

Heavy soil erosion and sedimentation at the watershed level can trigger intense environmental consequences. This research proposes a modeling technique to estimate changes in incremental soil erosion over time and evaluate the effect of vegetation cover on soil erosion in critical areas. For this, the study employed the Water World Policy Support System (WWPSS) for simultaneous modeling of changes in vegetation cover and soil erosion. Changes in vegetation cover from 2000 to 2020 were studied by extracting data from the model databases received from MODIS VCF satellite images. The study further used maps and calculations of the run model to measure the amount of net soil erosion (erosion minus sedimentation in the same place) and subsequent change in its level under two baseline (before loss of vegetation cover) and current (post-vegetation loss) situations. It was found that the average percentage of grass-pasture cover in the studied watershed has declined from 78.36% (under the baseline situation in 2000) to about 47% (under the current situation). The average amount of net soil erosion in the two sub-watersheds of Aji Chai and Marduq Chai has increased by more than 277% and 33%, respectively, signifying them to be the most vulnerable sub-watersheds (among all the four studied sub-watersheds) to soil erosion at critical areas. Overall as expected, a 40% loss of vegetation in the studied watershed has provoked adversely hazardous consequences during the studied period while cumulatively leading to over 8 million tons of soil deterioration in 15 years. The proposed method is assumed to be advantageous by providing quantitative and rapid environmental assessments that entail precise quantification of environmental consequences like soil erosion.

The effects of weathering and erosion on Quaternary rocks and deposits depend on several factors, some of which are related to the nature of the rock and other factors are related to the external environment. Investigating all of the erosive factors is difficult and complex, therefore, the effective factors should be prioritized and taken into account in order to be able to determine a statistical relationship between the erosive factors and sediment statistics. Investigating the weathering and erodability of rock units is very important because of scientific and experimental knowledge of the rock's erodability in the region and as a result, their ranking and also their resistance to erosive factors can be a great help in evaluating the erodibility of rocks and for decision-making about the erosion control project in the region. For this reason, this study was conducted with the aim of investigating the weathering and rating of the rock mass resistance of geological formations to erosion in the West Islamabad region.

In this research, the role of weathering was investigated with the Lewis Peltier method using isotemperature and isohyetal maps that were produced in the ArcGIS environment using climatic data. Various parameters can be effective in weathering processes, the most important of which are average temperature and annual precipitation, and Peltier models are also created based on these two parameters. For analyzing the resistance of stone units, the inherent characteristics of the parent materials which include mineralogical composition and texture were used. The types of stones and formations in the region were identified using geological maps and Google Earth. In the last stage, the analysis and interpretation of the results and finally the classification of rocks and formations in the study area were done using a qualitative method.

According to the Peltier diagram and the precipitation and temperature of the study area, the results showed that the prevailing regime in the area is moderate chemical weathering. Also, out of the nine morphogenetic states in the Peltier model, two semi-arid and savanna states occur in the climatic conditions of the region. The study area is diverse in terms of rainfall due to its topography condition. The highest rainfall and the lowest temperature belong to the northern part of the region, and the highest annual rainfall is about 700 mm, which is considered one of the Savan regions in terms of morphogenetic regions. The dominant feature of the Savan region can be called the activity of runoff and the moderate influence of the prevailing winds in the region. Other parts of the study area are considered as part of the semi-arid region due to rainfall and average temperature. The most important geomorphodynamic features of these areas are the influence of wind and moderate to intense running water activity. Water erosion occurs due to heavy rainfall in an area. So, if the amount of runoff is high, water and river processes can be intensive, but this situation in the diagram may be somewhat misleading because in areas with high rainfall and high temperature, this type of erosion is weak. Pelletier probably drew this diagram based on the vegetation, precipitation, and temperature condition, because in areas with high temperature and high precipitation, rich vegetation is formed, which prevents soil erosion due to the presence of foliage and an extensive root system. The erodibility of rock and sedimentary units has been divided into six classes considering lithological factors. Each of the sedimentary units that have the highest level of sensitivity and erodibility is classified in the sixth class, that is, very weak, and according to the degree of sensitivity of the units located in the next classes, it decreases with the decrease of the class number, so that the facies located in the first class has the lowest sensitivity. According to the evaluation carried out in the study area, the least erosivity is related to limestone outcrops. Dolomite sensitivity changes from one to four in different areas, and the most sensitivity is related to discontinuous debris deposits, including The types of alluvial sediments of river beds and floodplains, the alluvium and alluvial cones are related to Qt2 and have a level of sensitivity of 6. The comparison of the results of the classification method presented in this research with the amount of observed sediment yield indicated that considering other effective parameters on erosion, it can be trusted with a high and acceptable level of confidence and it can be used to rate the stone units and formations susceptibility to erosion.

As a result of weathering processes, the connected rocks will change to large and small separated materials. These materials rarely remain fixed on the slopes and they move on the slopes due to the gravity and the weight of the mass of materials or under the influence of the transport processes and are transferred to the foot of the mountain in different forms. In the West Islamabad region, due to the heavy rainfalls, mostly moderate chemical weathering occurs. Chemical weathering includes a set of chemical processes and interactions as a result of which substances in the atmosphere such as water, carbon dioxide, and oxygen show a chemical reaction against the minerals in nature, and as a result, new materials and minerals with different characteristics from the primary minerals will be created. Based on field observations and studies, dissolution is one of the most important chemical reactions common in the region. Considering that the dominant regime in the study area is chemical weathering and more than 90% of the area is in the semi-arid area, which is affected by the moderate to the severe activity of running water, as well as the inherent sensitivity of the rocks in the area to erosion, various types of erosion can be seen in the area, which makes it necessary to have suitable soil conservation programs in the region.

Soil erosion followed by sediment production is the most important phenomenon that causes soil and environment degradation in many areas and is increasing. Sediment fingerprinting is a method to identify sediment sources and determine the contribution of each source to sediment production. The present research was carried out to evaluate the relative erosion sensitivity of lithological units and to determine the contribution of each unit in bed sediment production using geochemical properties in the Vaz River located in Mazandaran province. The 33 soil samples were taken from the whole watershed and one sediment sample at the outlet of the watershed. Then, five tracers of B, Al, Sc, Mo, and Sn were selected as the optimal combination using three statistical tests range tests, Kruskal-Wallis, and discriminant function analysis. Finally, using optimal tracers and a combined multivariate model, the contribution of lithological units with very high (A), high (B), medium to high (C), and medium (D) sensitivity in bed sediment production were obtained using FingerPro statistical package and R software. The results showed that the contribution of lithological units with very high (A), high (B), medium to high (C), and medium (D) sensitivity in bed sediment production were 24.23, 50.77, 15.62, and 9.36%, respectively. Then, the specific contribution of each sensitivity class was also calculated to remove the effect of area on the results. The Qal lithological unit including the Quaternary sediments in the river bed and banks with very high sensitivity to erosion (A) and a specific contribution of 0.0807 % per hectare had the maximum contribution in bed sediment production in Vaz River.

Changing land use may have a major influence on physical, chemical, and biological soil properties with a consequence for soil functioning and productivity. Abandonment of agricultural lands is actually a kind of restoration of these lands to their original natural conditions, which is often done through human intervention. Soil restoration after land abandonment is a complex phenomenon. The pastures of our country are typically cultivated in rainfed methods, and the use of agricultural inputs such as animal manure, poisons, and chemical fertilizers is not very common. Therefore the continuous cultivation of a product and the lack of use of agricultural inputs causes a gradual decrease in fertility and increase erosion. Hence, after years of cultivation, the production potential decreases, and the land is abandoned.
This study was conducted to determine the effects of land abandonment on some physical, chemical, and biological soil properties in the 0-20 and 20-40 cm depth at three different sites including Lal Abad, Qaleh Kohneh and Chalab-e Pain, using 2×2 factorial layout arranged in a completely randomized design (CRD) with three replications. The physical, chemical, and biological characteristics of the soil were measured by conventional laboratory methods. Electrical conductivity of saturated paste extract (ECe) with electrical conductivity meter device in saturated paste extract, pH of saturated paste with pH meter device, and bulk density by cylinder method were determined in the samples. The amount of dispersible clay (DC) was determined by the method of Gee and Bauder and the Mean Weight Diameter (MWD) was determined by the method of the wet sieve. The amount of absorbable phosphorus by extraction method and total soil nitrogen by Keldahl method were measured in the samples. The amount of soil organic carbon (OC) in the samples was determined by the method of Walkley and Black. Mineralization of organic carbon (soil respiration) (Cmin) and metabolic quotient (qCO2) were obtained by validated and conventional methods.
 The results showed that the abandonment of agricultural lands significantly increased the MWD and reduced the amount of dispersible clay. Bulk density also decreased due to the abandonment of agricultural land in all areas except the Qaleh Kohneh area. The results of the analysis of the chemical characteristics of the soil indicated a decrease in soil pH in all areas and depths, except in the Qaleh Kohneh area. The biological results also showed that the abandonment of agricultural lands caused the change in biological characteristics. Abandonment of agricultural lands in all three regions led to an increase in microbial biomass carbon and soil microbial respiration. High microbial respiration in abandoned lands is probably related to more organic carbon in these soils. Loss of soil organic matter due to cultivation and improper soil management is often the main reason for reducing soil respiration in agricultural lands compared to abandoned lands.
Changing land use from agriculture to abandonment improved the physical, chemical, and biological indicators of soil quality, especially the surface layer of the soil, which ultimately led to the improvement of soil quality in all the studied areas. It can be concluded that the release of agricultural lands has increased soil health by increasing the carbon input into the soil, improving the soil aggregates, and improving the microbial activity of the soil.

Zagros forests play an essential role in providing groundwater resources, air conditioning, soil protection and preventing erosion, and providing wildlife habitat. Today, the ecosystem of these forests has become completely fragile due to improper exploitation and destruction. This study was conducted in areas of Zagros forest in Kermanshah province that were included in the implementation of the protection plan, including Sorkhak and Tappeh Goleh in Islamabad and Qeshlaq in Ravansar. The main purpose of this study was to evaluate the implementation of the forest conservation plan on soil properties.

For this purpose, composite soil samples were collected by random-systematic method from the mentioned area and their respective control area, and their physical, chemical, and biological properties were measured. Soil characteristics in Tappeh Goleh, Sorkhak and control sites were analyzed by one-way analysis of variance and Qeshlaq soil characteristics were analyzed by T-test. The soil samples collected from the forest were air-dried in the laboratory environment and sieved (2 mm). Then their physical and chemical properties (pH, EC, bulk density, and soil organic carbon content) were measured. Soil samples were collected with sterile equipment and sieved through a 4 mm sieve. Fresh and moist soil was kept at a temperature of 4 °C for soil biological tests (basal soil respiration, metabolic quotient, and microbial biomass carbon).

The results showed that no statistically significant changes in soil EC and pH were observed in all study areas. The amount of organic carbon in Sorkhak was significantly higher. Among the measured biological properties of soil, no significant change was observed in organic carbon mineralization in all study areas. However, microbial biomass carbon and soil metabolic quotient in Sorkhak were significantly higher than those in control and Tappeh Goleh areas.

The results of this study showed that the forest protection plan if properly implemented in the field (Sorkhak area) will be able to revive some soil quality indicators. The provisions of forest protection management and the process of soil regeneration in these forest lands should be investigated. Among the studied indicators, soil organic carbon and microbial biomass carbon were among the indicators that responded well to the correct and complete implementation of the forest protection plan, and we have witnessed the improvement of these parameters in managed lands. This suggests that biological soil quality indicators are more sensitive to responding to land management and respond more quickly to these changes.

One of the most significant environmental crises in arid, semi-arid, sub-humid, and even humid regions is the destructive phenomenon of desertification and in the arid and semi-arid regions is wind erosion. These problems exist in large areas of Iran and it is necessary to use an environmentally friendly and economic method to solve this problem. In this study, calcium bentonite clay was used for the first time in Iran and perhaps in the worlds in the critical region of Sajzi, which covers an area of 65 hectares. Experiments were performed on the crusts after one year of mulching with bentonite clay. The results showed that wind erosion has a negative and significant correlation with the mean weight diameter and geometric weight diameter of aggregate, aggregates with diameters greater than 0.25 mm, shear strength, and penetration resistance. On the other hand, the results of the permeability test using double-ring and by three models (Kostiakov, Horton, and Philip) showed that the lowest mean square error (SSE) and the highest coefficient of determination (R2) belonged to the Kostiakov model in the mulch-applied and control samples. This result indicated the superiority of the Kostiakov model compared to Horton and Philip's models. Wind erosion intensity was also measured in situ using a portable wind tunnel at 20 points in the Sajzi region. The findings showed that mulch application has controlled more than 95% of soil erosion.

Soil erosion is one of the main phenomena related to soil degradation that threatens environmental sustainability and soil productivity. It has always been a major environmental challenge worldwide. Soil erosion and its harmful consequences are a serious obstacle to the development and progress of countries and have adverse effects on agricultural production, water quality, and ecosystem health. Soil erosion control intends to promote innovative land management approaches. Soil conservation methods reduce soil erosion, improve soil structure and water uptake, and maintain soil moisture. Therefore, it is necessary to study soil erosion factors and provide management strategies to mitigate it. This study identifies and prioritizes soil erosion factors and strategies to prevent soil erosion in Fars, Iran.

This research is applied in terms of purpose, with a descriptive-survey nature. This study presents a combined approach based on Grey SWARA and Grey ARAS methods to identify soil erosion factors and prioritize methods to prevent soil erosion. After literature review and interviewing an expert panel, the soil erosion factors in Fars were identified and classified into technical, chemical, social, environmental, and climatic. The weight of the criteria was calculated by the Grey SWARA method. Then, the suggested methods and strategies were identified and provided to the panel to evaluate based on the criteria by completing a questionnaire. Then, they were finally prioritized using the Grey ARAS approach. In order to consider the uncertainty and indeterminacy of opinions, grey numbers were used in the calculations.

The results indicated the following as the most important factors affecting soil erosion, respectively: "soil erodibility," "low aggregate stability," "deforestation and ecosystem degradation," "cultivation on slopes and plowing of sloping lands," "loss of vegetation," and "reduced organic matter." The most important preventative measures were prioritized as follows: "ratifying and implementing regulations to preserve soil and natural resources and the developing training and promoting workshops, promoting conservation tillage and smart agriculture, adding organic matter to the soil, mulching the soil with organic or artificial material, and adopting bioengineering methods, such as soil stabilizing bacteria" and "rangeland enclosure and fencing and promotion of industrial livestock.

As unfortunately, in Iran, soil erosion is several times the global average, and a large volume of good soil becomes out of reach per year, it requires serious management measures. More specifically, an extensive management plan should address soil erosion in Fars. It can be expected that findings in this research will help water, soil, and agriculture decision-makers make the most appropriate decisions and solutions to solve soil erosion problems.

Awareness of erosion and its spatial changes is a guide for managers and planners in the important matter of water and soil protection in watersheds. In the present study water flow and sediment data of 40 hydrometric stations in the Middle Alborz region and in the statistical period between the wateAwareness of erosion and its spatial changes is a guide for managers and planners in the important matter of water and soil protection in watersheds. In the present study, with the aim of presenting a map of soil water erosion, water flow and sediment data of 40 hydrometric stations in the Middle Alborz region and in the statistical period between the water years of 1980-1981 to 2020-2021 were used. First, the most important factors affecting erosion and sedimentation in the studied sub-basins including 30 hydrological, physiographic, geomorphological, geological and soil characteristics, climate, land use and vegetation as independent variables and two sediment characteristics; including total yield and specific deposition as dependent variables were identified. Using factor analysis and principal component analysis methods, the most important characteristics of effective basins in sedimentation were identified. In the next stage, the study area basins are divided into six homogeneous groups based on selected characteristics and cluster analysis and multivariate regression stepwise method was used to model between specific sedimentation and basin characteristics. According to the selected regression models, it is determined that the amount of special sediment in the Middle Alborz region to five factors of agricultural land area (rainfed, irrigated and orchards), the area of sub-basins, the total area of erosion-sensitive and Quaternary structures, the average annual discharge and the form factor of the basin depend on the fact that these five factors control 92% of the sediment production changes in the selected sub-basins. Then, considering the sediment transfer coefficient of the sub-basins, the amount of soil erosion was determined and the soil erosion map was drawn for the Middle Alborz region. The results showed that the average sedimentation rate and the average weight of soil erosion in the study area were 3.84 and 13.56 tons per hectare per year, respectively. In general, the factors affecting erosion and sedimentation of the Middle Alborz region can be divided into three groups: land use change due to human activities, geology and physiography.r years 1980-1981 to 2020-2021 were used. First, the most important factors include 30 hydrological, physiographic, geomorphological, geological and soil characteristics climate land use and vegetation as independent variables and two sediment characteristics. The most important characteristics of effective basins in sedimentation were identified. In the next stage, the study area basins are divided into six homogeneous groups based on selected characteristics and cluster analysis and using multivariate regression by stepwise method to model between specific sedimentation and basin characteristics. According to the selected regression models, it is determined that the amount of special sediment in the Middle Alborz region to five factors of agricultural land area (rainfed, irrigated and orchards), the area of sub-basins, the total area of erosion-sensitive and Quaternary structures, The average annual discharge and the form factor of the basin depend on the fact that these five factors control 92% of the sediment production changes in the selected sub-basins. Then, considering the sediment transfer coefficient of the sub-basins, the amount of soil erosion was determined and the soil erosion map was drawn for the Middle Alborz region. The results showed that the average sedimentation rate and the average weight of soil erosion in the study area were 3.84 and 13.56 tons per hectare per year, respectively. In general, the factors affecting erosion and sedimentation of the Middle Alborz region can be divided into three groups: land use change due to human activities, geology and physiography.

Soil erosion has been one of the most important problems of watersheds in the world and is considered one of the main obstacles to achieving sustainable development in agriculture and natural resources. Identifying and prioritizing regions sensitive to soil erosion is essential for water and soil conservation and natural resource management in watersheds. The present research was performed in 2021 year to prioritize the soil erosion susceptibility in 12 sub-watersheds of the Roudzard watershed in Khouzestan province using morphometric analysis and multiple criteria decision-making (MCDM) methods. In this regard, 11 morphometric parameters including shape parameters such as compactness constant (Cc), circularity ratio (Rc), form factor (Rf), elongation ratio (Re), linear parameters such as drainage density (Dd), stream frequency (Fs), drainage texture (Dt), bifurcation ratio (Rb), Basin length (L), Length of overland flow (Lg), and topographic parameter including Ruggedness number (Rn) were extracted and their relative weights were calculated using Analytic Hierarchy Process (AHP). The prioritization sub-watershed to soil erosion was performed using TOPSIS, VIKOR, and SAW methods, and the results were combined using rank mean, Copeland, and Borda methods. The final prioritization was compared with the amount of specific erosion in the MPSIAC model by determining Spearman's correlation coefficient. The result of the evaluation of morphometric parameters by using the AHP model showed that drainage density (0.161), drainage texture (0.158), and stream frequency (0.146) had the greatest effect on the erodability of the sub-watersheds. In contrast, the form factor (0.049), Elongation Ratio (0.036), and shape factor (0.026) had the least effects on erodability of the study area. In this research, the Spearman correlation coefficient between the final result of prioritizing the sub-watershed and the MPSIAC model was obtained as 0.8 in p-value<0.01. The results of prioritization of the sub-watersheds in terms of their sensitivity to soil erosion showed that sub-watersheds 11, 12, and 10 with an area of 191.83 km2 are categorized as very sensitive to soil erosion due to high value of linear parameters, low value of shape parameters, sensitive geology formation, and poor vegetation cover and located in rank 1 to 3, respectively. According to the results sub-watersheds 11, 12, and 10 have the highest amount of specific erosion equal to 16.03, 12.48, and 11.6 tons per hectare per year, respectively. Therefore, these sub-watersheds are a priority for watershed management operations. The results of the present study showed that MCDM methods and morphometric analysis are suitable tools for identifying areas sensitive to soil erosion and using the combined methods of the results and it is possible to take advantage of each of the different multi-criteria decision-making methods.

Soil erosion is a kind of land degradation that is one of the world's environmental issues. One of the most common causes of land degradation is soil erosion. Various additives and amendments are being employed in order to safeguard the country's water and land. As a result, understanding diverse soil additives and their roles in the conservation of soil and water resources, as well as complete watershed management, is critical. As a result, the purpose of this study was to provide comprehensive information on the background and recent studies on the use of organic, inorganic, and biological soil additives, as well as to evaluate various effects and determine their performance and application in erosion control and soil and water conservation.

All studies and research on the application of amendments in soil and water conservation in different conditions on various components of soil erosion and conservation in Iran were documented in databases and extracted from journal articles, conferences, executive reports, and related research, and theses and dissertations were investigated. The relevant 75 documents were then chronologically evaluated, analyzed, and summarized in order to assess the usage of various amendments in many areas, including the kind of amendments, the scope of use, the experimental setting, and the research variables. The necessary conclusions were ultimately drawn qualitatively.

The use of soil stabilizers and amendments such as organic, inorganic, and biological elements to enhance the erodibility threshold and prevent soil water erosion has been widely documented based on the findings of this study. According to research findings, the performance of amendments varied depending on the kind, manner of application, scale, and soil type. In addition, the findings on the usage of amendments revealed that various additions are used and work well in soil and water conservation. However, adopting any of the customary changes has been noted as a considerable difficulty due to economic, environmental, health, administrative, functional, and technical restrictions. The use of biologically and ecologically friendly alternatives to boost the efficiency of the conditions for balancing and stabilizing the soil environment has been stressed due to the aforementioned constraints for the use of amendments.

Because of the widespread use of amendments, the feasibility of using environmentally friendly amendments, and emphasizing waste management in the primary industry through additional studies and research, there is a need for proper and appropriate measures that are naturally environmentally friendly in the long term. Nevertheless, additional research on the application of various amendments resulting from the direct or modified use of significant industrial wastes with respect to various aspects of environmental, economic, ecological, and even aesthetic and at different scales is necessary to summarize and develop appropriate executive instructions.

Splash erosion is the first stage of water erosion process, which results of the particles detachment of soil surface cause by raindrops. One of the efficient methods for reducing splash erosion is the usage of soil conditioners. Soil conservation at splash stage can play an effective role in reducing detachment of soil particles, increasing infiltration and ultimately reducing soil loss. The general purpose of the present study was to changes investigation of the total, net, upstream and downstream splash using conditioners of compost, zeolite and their composition. Zeolite with suitable granolometery cause the improvement of hydrophysical characteristics of soil. In addition, the compost can cause the improvement the structural characteristics of soil. Therefore, in this study used from two conditioners of zeolite and compost with amounts of 5.8 and 7.1 g cm-2, respectively, and their combination for changes investigation of total splash, net splash, upstream and downstream splash with soil texture of loamy-sandy.

The used soil was collected from the depth of 0 to 20 cm and was transferred to the laboratory. The study was performed on scale of splash cups and laboratory conditions using the rainfall simulator at rainfall intensity of 80 mm h-1. Also changes of time periods evaluated for durations of 24 h, two, four, eight, 16 and 32 week. Splash erosion measured by collecting the splash particles during each rainfall and then drying at temperature of 105° C. Physical and chemical characteristics of soil determined using current methods of laboratory. Data of splash erosion analyzed using SPSS software, Duncan test and GLM.

The experiments showed that the application of the combination of compost and zeolite on changing the soil splash was the more than their separation effects. The results showed that the combination of compost and zeolite of total splash was with rates of 68.93, 15.53, 49.51, 38.83, 38.83 and 77.66%, respectively, and net splash of 67.27, 10.9, 56.36, 32.72, 47.27 and 72.72% at time periods of 24 h, two, four, eight, 16 and 32 week, respectively. Also, the changes percent of splash changes for the composition of compost and zeolite at the upstream of splash cup observed with amounts of 70.83, 20.83, 83.66, 45.41, 29.16 and 83.33%, respectively, and downstream was amounts of 68.35, 13.92, 51.89, 36.70, 41.77 and 75.94% , respectively. The effect study of time periods showed that the time periods of 32 and eight week had the more reduce at the amount of splash erosion. The statistical results showed that the effect of time period and treatment and their interaction on reducing the total splash and net splash was significant at the level of 99%. Also, the effect of time period and the interaction effect of time period and treatment on reducing the upstream and downstream splash was significant at level of 99%.

Adding these conditioners to the soil cause the reducing the soil splash erosion. The time effect also caused the more effect of the conditioners for reducing the amount of slash erosion. Among the used conditioners, the effect of compost conditioner was more than two other conditioners on reducing splash erosion, because this conditioner by increasing the stability and porosity of soil can bind the soil particles and thus the resistance of soil particles increase against the rainfall energy. Finally, it can be stated that the conditioners application separately and combination can be have the positive effects on decreasing soil splash that will lead to reducing soil loss at the long term.

Sediment Production in catchment area subject to very much factors, the one of these factors are not correct use of the lands. Environmental characteristics such as amount and intensity of precipitation, the degree of slope and accumulation of aqueducts in production of runoff and sediment is effective. Sediment production in a watershed depends on several factors, one of the most important of which is inappropriate and unprincipled use of lands. Different environmental issues also have different effects on sediment production. Aghajari formation consists of gray and brown calcareous sandstone, gypsum red marl, and siltstone. Its main section spreads from Omidiyeh to the Aghajari oil field and it has a thickness of 2965 meters. Gahsaran formation has a thickness of about 1600 meters. A viewpoint of lithology is consisting. Statistical studies in the mentioned regions show that the absolute maximum air temperature is 46 °C, the absolute minimum temperature is -6.7 °C and the annual temperature average is 20.8 °C. The annual rainfall average is 636 mm.

In order to investigate sensitivity to the erosion and sediment yield the various land uses of Aghajari and Gachsaran deposits, part of Margha and Kuhe Gach watersheds areas in Izeh Township was elected. This investigation to determine productivity runoff and sediment in 6 points and three times replicates in Gachsaran formation and in 7 points and with three times replicates in Aghajari in the various intensities of precipitation 0.75, 1, and 1.25 mm in minute in three land uses range, the residential and agricultural lands to help kamphorst rain simulator do. These experiments were carried out in Aghajari and Gachsaran formations at the end of spring and after harvesting in agricultural lands, and in order to create homogeneous conditions for rainfall simulation, there was no vegetation at plot level in Aghajari and Gachsaran formations. In this study, samples were randomly identified and harvested. Also, all information related to different studies in the studied watershed including climate and geology were used in this study. Spss and Excel software were used to perform all statistical analysis.

Comparing runoff and sediment in two formations showed that in the low intensities of precipitation formation type in runoff and sediment has more interference. Whatever precipitation increases, the difference to at least it seems. It is also recommended that due to the high erosion and sedimentation of these two formations, reservoir of large dams is not located in these two formations because at a very short distance or the reservoirs of these dams are filled with sediment. Or they become so salty that they cause huge damage to downstream areas or cause dangerous landslides in the dam reservoir, which will eventually lead to dam breakage and ultimately devastating floods by pushing large volumes of water into the dam body.

In addition, research results showed that erosion and sediment rates in land uses of Gachsaran formation is more than Aghajari formation land uses due to Ec and more distance gypsum hardpan than soil surface. However, two formation of viewpoint run off rates proximately had similar trend. The results also showed that due to high erosion and sedimentation of these two formations, reservoir of small and large dams is not located in these two formations.

Soil loss can cause many intra-regional and extra-regional problems, on the other hand, the effect of soil moisture on processes of soil loss and sediment yield for the identification and simulation of soil hydrological response is necessary. Therefore, the application of soil conditioners is essential for soil and water conservation. The present study was conducted to investigate the effect of soil conditioners of vermicompost and nano-manure on variables of soil loss and sediment concentration at moistures of air-dried, 15 and 30%, and rainfall intensities of 50 and 90 mm h-1. The obtained results in addition to confirmation of the significant effect of each conservation treatment at the level of 99 percent on the intended components showed that the conservation treatment of vermicompost compared to nano-manure treatment had more effect on measured variables. Also, the conservation treatment of vermicompost could decrease the soil loss at soil moisture air-dried, 15, and 30 percent with rates of 72.15, 66.63, and 78.76 percent (50 mm h-1), respectively, and 45.01, 35.57, and 10.45 percent (of 90 mm h-1), respectively. The effect of conservation treatments, soil moistures, and rainfall intensity and the interaction effects of conservation treatments × rainfall intensity and rainfall intensity × soil moisture on changes of soil loss and sediment concentration were significant at the level of 99 percent. The application of vermicompost and nano-manure had acceptable results on studied parameters but the vermicompost effect was more than nano-manure. Therefore, due to the widespread use of different types of conditioners, nowadays, it is needed to move the application feasibility of conditioners such as vermicompost and nano-manure that these have not the adverse effects of environmental.

To control soil erosion, several measures can be conducted which information on their effects is very important in managing soil erosion. Therefore, this study was conducted to assess and model soil erodibility in two adjacent sites in Behbahan region (Khuzestan province). At one site afforestation and contour furrowing were conducted to control soil erosion and the other site without any controlling measures was considered as control. Totally 150 soil samples were collected from the surface layer (0-5 cm) and K was estimated using the methods introduced by Wischmeier and Smith (method A) and Vaezi et al. (method B). For spatial modelling of K, based on digital soil mapping (DSM) techniques, several environmental covariates were derived from a Landsat 8 image and a digital elevation model (DEM) and two models including random forests (RF) and artificial neural networks (ANN) were employed. The values of K for methods A and B varied from 0.025 to 0.087 and 0.002 to 0.008 t.ha.h/ha.Mj.mm with means of 0.067 and 0.006 t.ha.h/ha.Mj.mm, respectively. Results revealed good correlation between K and remotely sensed covariates. Although K (method B) had significant correlation with some of the covariates derived from DEM, but there was no significant correlation between K (method A) with all covariates derived from DEM. Results indicated a significant difference between two sites it terms of K estimated by method A, while there was no significant difference in case of K estimated by method B. Model validation showed that both RF and ANN models resulted in good and unbiased estimates of K (methods A and B). In general, the findings indicated, although the performance of DSM techniques in modeling K were high, performances of the models and the results of means compassion may significantly differ in terms of the method through which K is estimated.

The maximum value of soil detachment due to overland flow is the soil detachment capacity. The present study aimed to evaluate the effect of particle size classes on the rill detachment capacity (Dc) in Saravan watershed (North of Iran). For this purpose, the variations of Dc have been measured on soil samples with three particle size classes (0-1, 1-2 and 2-3 mm) under laboratory conditions through a flume experiment at five slope gradients (4.1 to 38.3%) and five flow rates (0.26 to 0.67 Lm-1 s-1) with five replications. The results showed that the Dc in 2-3 mm class was significantly higher than the other particle size classes (p < 0.05). The unit stream power was found to be very accurate predictor of the Dc in forestland of Saravan watershed. Rill erodibility, which calculated by relationship of the Dc and the water flow shear stress, had the lowest value in 0-1 mm class. Overall, this study has confirmed that the particles with size larger than 2 mm on steep slopes are more susceptible to erosion and separation by surface runoff in delicate environment ecosystems, such as the Saravan Forest Park in Northern part of Iran.

Soil erosion is one of the most serious environmental issues in the world, causing soil degradation, reduction of land productivity, increasing flood, water pollution and pollutions transportation; it is also a serious threat to sustainable development in the world. Therefore, the soil conservation and the prevention of soil erosion and use of conditioners as the nanoclay can be considered as a solution to improve   land productivity and protect environment. The present study was, therefore, conducted to address the effect of the application of montmorillonite nanoclay with three rates of 0.03, 0.06 and 0.09 t ha-1 on changing runoff and soil loss variables under laboratory conditions. The results showed that the nanoclay with the rate of 0.03 t ha-1 could decrease the runoff coefficient, soil loss and sediment concentration with the rate of 40.65, 88.38 and 82.19 percent, respectively. The average of soil loss in control treatment and conservation treatments of nanoclay with various rates was measured to be 3.76, 0.44, 1.33 and 3.16 g, respectively. Also, the results showed that the most sediment concentration was the control treatment with the rate of 5.84 g l-1 and the conservation treatments with nanoclay in the applied rates was 1.04, 3.47 and 2.96 g l-1, respectively. Also, the results showed that the nanoclay effect was significant on changing the soil loss and sediment concentration at the level of 99 percent. Finally, due to the effect, the use of this conditioner in natural conditions and investigation of the effects on environment and aggregates stability are recommended.