ataollah kavian

Protection of soil resources is necessary the maintenance of world food security and the improvement of environmental quality. Soil structure is one of the physical and active characteristics of soil that it can be evaluated with the stability. Aggregate stability is important in the discussion of the physical quality of the soil, and its improvement leads to improvement of soil performance. Usage of different types of soil amendments in conditions where there is not the possiblity of biological management, it is a useful solution to conservation and improvement of soil structure. Biochar amendment is prepared from the various biological sources, and has been introduced as a non-structural conservation method in recent years. Therefore, the knowledge of its behaviors, reactions, and short-term and long-term changes in the soil is very important for sustainable management. The effect of biochar amendment on the physical characteristics of the soil under laboratory conditions has shown the positive changes in the criteria and physical indices of the soil. This aspect of biochar applications shows the study and its identification necessity in the natural resource fields with the focus on erosion control. Since the application of biochar amendment obtained from the Populus nigra branches in order to the soil conservation has not been reported in the field and in natural weather conditions, therefore, the current research has investigated the biochar effect on the soil structure in natural conditions in abandoned rain-fed and USLE plots for two continuous years.

In the present study, the effect of biochar amendment on soil structure changes in the area of ​​Noruzlu dam, Miandoab city, West Azarbaijan province was evaluated at the scale of six USLE plots. Biochar is prepared by the pyrolysis process from the branches of Populus nigra species. To the experiment performance, two treatments of control and biochar were considered each with three replications. After preparing and transferring biochar to the region, it was applied and spread on the plots with the rate of 32.5 t ha-1. Plots sample was conducted to changes the investigation of the soil structure due to the biochar application in four continuous times at intervals of six months after the biochar. Particle size distribution and aggregate stability were measured using the dry sieve series method at these time intervals. The results of dry sieving were used to the measurement of the aggregate stability and for the determination of the particles size, and distinction of the stability level of particles were calculated from two indicators of the mean weight diameter (MWD) and the geometric mean diameter (GMD). Then, homogeneity of variances tests as one of the basic requirements of data analysis, the GLM test to investigate the separate and interactive effects of treatments and time, and the independent T-test to averages comparison of the investigated components between treatments were performed.

In order to investigate the aggregate stability under biochar treatment in natural weather conditions at USLE plots, the mean weight diameter (MWD) and the geometric mean diameter (GMD) were measured for the control and biochar treatments in four continuous times. The MWD and GMD indices in control plots have the average values ​​of 0.85, 0.68, 0.64, and 0.81, and 0.8, 0.69, 0.7, and 0.76 mm, and in biochar plots with rates of 0.86, 0.82, 0.75, and 0.84, and 0.79, 0.78, 0.75, and 0.77 mm, respectively. The changes trend in the variables D10, D50, and D90 related to the distribution particle size in the second time period were the rates of 43.8, 26.7 and 15.2 percent, and in the third time period also were with the rates of 14.2, 14.2, and 16.8 percent, respectively, which showed in the mentioned time periods, the changes trend of these variables increased in biochar treatment compared to the control treatment.  Biochar amendment in combination with the soil of USLE plots had an effect on the aggregate stability indicators so that the separate effect of biochar and time and the interactive effect of biochar and time on the GMD index were significant at the level of 95 percent. In comparing the average of the investigated components between the treatments in each time period, both MWD and GMD variables in the second time period showed the significant difference at the level of five percent. Therefore, it can be said that the biochar is the useful and effective for improving soil stability after one year.

The findings of this study indicated the biochar amendment had the positive effect on aggregate stability indicators, which has caused a limited increase in the weight and geometric mean of the aggregate diameter and changes of 40 percent in the particle size components. In general, the examination of MWD and GMD indices in the control and biochar treatments in four continuous times at six-month intervals indicated the separate effect of biochar and time for both indicators and the interactive effect of biochar and time for the GMD index were significance at level of 95 percent. The second period had the maximum percentage of changes in the component of particle size distribution. Also, in the second period in both indicators, there was the significant difference between the averages of control and biochar treatment. Therefore, Therefore, based on the observed results in the current research, it can be stated that the best biochar performance to improve the aggregate stability and soil structure was after one year of biochar application on soil surface. According to the results of this research, the aggregate stability is affected by the time passage and seasonal climate changes., Due to the field scale of the experiment and also the exposure of the plots to the natural weather added to the complexities governing such processes, and in order to obtain more accurate results, it is necessary to design detailed studies with a more appropriate time scale and smaller time intervals.

Soil is the basis of biological resources and life on the earth. Soil stability is one of the key indicators that it used to performance evaluation of soil structure against soil erosion. In fact, the aggregates stability indicates the resistance of the soil structure against external forces such as the raindrops impact and splash erosion. The raindrops energy is one of the main factors in the disintegration of soil aggregates in water erosion. The usage of different conditioners on the surface or inside soil is closely related to various processes such as surface sealing, infiltration, runoff, evaporation and finally soil erosion. Considering the importance of the aggregates stability soil erosion control, increasing the particles diameter on the soil surface can be one of the ways to prevent their movement and by erosive factors. The literatures review showed that the bentonite conditioner as a mineral conditioner can play the effective role in stability changes of aggregates, especially in degraded soils. Therefore, the purpose of present research is to the usage of bentonite conditioner on the changes of soil surface aggregates.

In the present research, the conditioner of bentonite mineral used in amounts of 30, 15 and 45% of soil surface coverage and in three replications. At the first, collected soil from rangeland land to depth of 20 cm transferred to laboratory and was exposed to air-dry and passed through sieve of 4-mm. Then the soil was poured into the splash cups and placed under rainfall simulator with a rainfall intensity of 90 mm h-1 and a duration of 10 min. Surface soil before and after application of rainfall simulator was collected with depth of 2-mm with amount of about 50 g of the surface of splash cups and the aggregates stability was calculated using the method of wet sieve. In the method of wet sieve, the remaining soil on each sieve was drained into marked containers using washing method and then and was put to rest for 24 h. After draining the excess water of samples, the remaining sediment was transferred the appropriate containers with specific weight. Finally dried for 24 h at oven with temperature of 105˚C. Finally, the application effect of the bentonite conditioner on the variables of aggregation and aggregates stability was calculated using SPSS software.

According to the conservation function and the average diameter of the soil aggregates using bentonite conditioner in three values of 15, 30 and 45 percent and based on diameter classes >500, 250-500, 125-250, 100-125, 100- 53, 38-53 and <38 micrometer, the results showed that the average diameter of soil aggregates significantly changed under the effect of bentonite conditioner. The average mass of the aggregates in the control treatment was with rates of 0.82, 1.88, 6.82, 3.37, 9.53, 4.62 and 20.36 g respectively, in the mentioned diameters, and with bentonite conditioner in the amount of 15% was with rates of 1.16, 2.63, 8.17, 4.46, 10.81, 4.02 and 17.68 g, respectively. Also, in the conditioner with the amount of 30%, this variable was the rates of 0.84, 2.42, 93. 7, 4.32, 11.03, 3.46 and 17.38 g and in the amount of 45% was the amounts of 0.81, 1.96, 6.95, 3.53, 10.01, 3.51 and 31 It was 19 g, respectively. The results of GLM test showed that the effect of bentonite conditioner on the variables D10, D10/ D90 and sorting was significant in level of 95% and on the variables D50, D90, D90- D10, D75- D25 and skewness was significant in level of 99%. But the bentonite effect was not significant on the variable D75/ D25 and kurtosis. Also, the results of Duncan test showed that the bentonite conditioner with rates of 15 and 30% had the better effects on the stability of soil aggregates and increasing the average aggregates diameter.

The obtained results from this research showed that bentonite conditioner can act as a protector against the raindrops and reducing soil erosion with creating adhesion on the soil surface. According to the results of the present research, it is suggested that the first, the more researches be conducted due to the soil conditions and natural rainfall and then the optimal values of bentonite be determined by erosion management and runoff.

Introduction and Goal:

The implementation of watershed management practices in the country and the evaluation the conducted activities and effects investigation of these projects are essential on the governing processes at watershed. However, such an important approach has to be adequately considered.

Accordingly, the present study was planned with the simulation aim of the impact of watershed management practices on hydrological parameters using the SWAT model in the Kan Watershed in Tehran Province, Iran. Therefore, the first of the initial implementation of the model was carried out, and then it was calibrated and validated. In this research, SWAT-CUP software was used to usage of various instructions and objective functions and also to test and the model calibration and validation. In order to determination and comparison of the simulation conditions with the governing conditions on watershed applied the evaluation criteria such as the coefficient of explanation and the coefficient of efficiency.

The research results showed that the model efficiency was acceptable for the hydrological simulation of the studied watershed. So, the explanation coefficient for calibration and validation was with rates of 0.69 and 0.86 respectively. Also, the Nash-Sutcliffe index for the calibration and validation obtained with rates of 0.85 and 0.93, respectively. Then, watershed management practices simulated at the level of studied watershed. The simulated results showed that the surface runoff decreased with the practices of watershed management in the form of gabion, masonry check dam, counter trench and loose- stone check dam with the values of 25, 23, 21, and 11 percent, respectively. Also, the available water was more after the practices of watershed management in the form of gabion, masonry check dam, counter trench and loose- stone check dam with rates of 19.0, 21.3, 20.5 and 10.75 percent, respectively, compared to the absence conditions of these practices at the watershed level. Also, the maximum amount of flow changes observed in the practices conditions of masonry check dams. In addition, the evapotranspiration increased with implementation of gabion. masonry check dams, counter trench and loose- stone check dams with rates of 20.19, 20.86, 19.0 and 10.87 percent, respectively.

Conclusion and Suggestions:

Based on the results of this research in the Kan watershed, the flood possibility and the flood damages can be reduced by practices of the watershed management, management and biological programs.

Changes in soil moisture and aggregates stability both in the short term and in the long term after fire are important because of their important role in plant growth and nutrition and soil erosion. On the other hand, the conditioners usage in soil and water conservation is necessary for the sustainable usage of water and soil resources. The soil and water conservation requires the determining the optimal amount of soil conditioners in order to prevent water pollution with the application of chemical fertilizers. Nevertheless, determining the optimal amount of various soil conditioners less has been note with the quantification aim of their effect on the runoff and soil loss components. The present study was conducted in order to determination of the optimal amount of zeolite in fire soil under laboratory conditions.

In the current research, zeolite additive with amounts of 250, 500 and 750 g m-2 was used in the collected soil from the rangeland. The preliminary results on the soil showed that the soil texture, organic matter, organic carbon and pH, EC were clay, 0.47 percent, 0.27 percent, 7.86, respectively. After preparing the soil and placing inside plots (with scale of 0.5 m2), fire treatment applied to the soil surface. For this purpose, the remains of air-dried rangeland species with amounts about 250 g m-2 were poured and then fire was applied. The plots were placed under rainfall simulator system for a rainfall intensity of 50 mm h-1. Then, the runoff and sediment samples were collected in control and conserved plots with zeolite in three replicates. The total volume of the runoff sample and its sediment concentration were take constant for 24 h and the excess water volume of the samples was drained and finally the samples were placed in an oven at a temperature of 105˚c for 24 h.

The statistical results indicated the zeolite conditioner with rates of 250, 50, and 750 g m-2 on the surface of fire soil had the significant effect on the increasing the time to runoff (in confidence level of 99 percent) and decreasing the runoff volume (in confidence level of 99 percent), soil loss (in confidence level of 99 percent) and sediment concentration (in confidence level of 99 percent). Also, the results showed that the conservation percentage of time to runoff in zeolite treatment with rates of 250, 500 and 750 g s-2 was 1.61, 17.30 and 20.04 percent, respectively. The changes percent of the runoff volume in the fire soil with the zeolite application with different amounts was 8.00, 10.66 and 22.66 percent, respectively. The results of soil loss indicated that the conservation percent of zeolite conditioner in fire soil after the zeolite application with the used amounts was 14.24, 32.03 and 38.33 percent, respectively.Finally, the changes percent of zeolite conditioner in the fire soil on sediment concentration were 21.13, 24.90 and 21.41 percent, respectively.

The fire phenomenon in the control treatment caused the decreasing the soil porosity and the creation of the hydrophobic layer, which also decreased the infiltration amount of soil and also caused to drying of the soil, especially in the surface layer, and significantly increased the runoff and sediment transportation. The subgrouping results of the different zeolite treatments on the time to runoff showed that zeolite with the amount of 750 g m-2 was placed in the third subgroup, which it was selected as the optimal amount to increasing the time to runoff and reducing the runoff volume in the post-fire soil conditions. Also, the investigation of the conservation effect and grouping the different zeolite amounts showed that the zeolite with the amount of 250 and 500 g m-2 were the better for sediment concentration and soil loss, respectively, its same effect with other amounts and also its discussion of the economic efficiency. Therefore, they are suggested as optimal and practical values for changes study of sediment concentration and soil loss components.

Soil loss is a phenomenon that it causes the land degradation and due to the low productivity of agriculture, it has a negative impact not only on natural resources but also on people's livelihood. From an economic point of view, soil is one of the natural resources that is effective on the national power of a country and is evaluated as a major axis in economic power. The average annual soil erosion in Iran is about 24 t.ha-1 year-1. This figure is very significant and includes the economic value of more than hundreds of billions of Rials. Economic, social and political tensions, especially the tensions resulting from the migrations of villagers and nomads, are also largely related to this issue. On the other hand, the ever-increasing growth of the population in Iran, followed by the consumption of more food, has forced the farmers to use sloping lands that are sensitive to erosion, and this is one of the main reasons for the destruction of natural resources. Therefore, before any action, it is important to predict the intensity of soil erosion, to plan in determining land use, to examine the risks of erosion and to evaluate the effects of changes in land use. Changing land cover and land use affects many natural processes such as soil erosion and sediment production, floods, and physical and chemical properties of soil. The purpose of the present study is the investigating the different scenarios of biological operations on the amount of soil loss in Margav watershed of Mazandaran province.

The watershed area of Mergav is in the range of east longitude 53° 9′ 6″ to 53° 14′ 41″ and north latitude 36° 6′ 25″ to 36° 12′ 34″, with an area of 4401.7 hectares, upstream of Shahid Rajaei Sari Dam and in the functions of the city of Frame, Dodangeh The average annual rainfall of the basin is equal to 1.580 mm, and December and autumn are the rainiest months and seasons respectively, and August and summer are the least rainy months and seasons. The average temperature is also calculated as 11.7°c. Also, the physiographic parameters the minimum and maximum height above the sea level are 779 and 1787 meters respectively, the weighted average height is 1204.2 m, the weighted average slope is 35.79% and the concentration time is 2.7 hours. In the end, the climate of the area has been wet, cold and semi-humid according to Amberje and Dumartin methods. In order to implement the scenarios of changing the current land use of the basin to the use of pasture and medicinal plants, first, the current land use map of Mergao watershed, was drawn using field visits and Google Earth software in the GIS environment. Then, using the RUSLE model, the erosion of the entire basin was calculated. Since it was not logical to change the use of forest, residential and dam lands to other uses in the basin, a scenario with an area of 561.54 hectares was proposed to be removed from the simulation process and applied to other uses.

The obtained results from present study showed that the average soil loss in agricultural lands, gardens and degraded forest areas of Margav watershed using the RUSLE model was the rate of 25.4 t.ha-1.year-1. Also, the simulation results of the scenarios of biological operations and soil conservation using the RUSLE model showed that scenarios Pasture (first scenario), pasture and horticulture (second scenario) and cultivation of medicinal plants (third scenario), decreased the soil erosion with rates of 18.9, 8.9, 5.4 t.ha-1.year-1, respectively. According to the role of rain erosion, its amount increases from the north of the basin to the west and southwest of the basin, which is related to the decrease in rainfall and uneven spatial distribution of rainfall in the basin. The index of soil erodibility (K) in the use of destroyed forest and agriculture was more than other uses. Areas with higher slopes were more eroded, which shows the role of LS factor in this matter. In other words, the agricultural lands that were placed in the medium to high section for the LS factor make this section more sensitive to soil erosion. According to the map of the vegetation factor on the amount of erosion, the most sensitive areas to the erosion of degraded forest lands and then agriculture are those that increase or decrease the amount of erosion by considering the increase or decrease of the slope. Therefore, the most important factor that can reduce the negative effect of slope on erosion in the basin is vegetation.

The negative consequences of the erosion of the entire watershed of Mergav can be a gradual decrease in the fertility of the surface soil and arable agricultural lands and endanger people's livelihood and food security. In fact, considering the effective role of vegetation on soil erosion, the implementation and development of garden lands or the cultivation of medicinal plants according to the principles of strip cultivation in sloping lands in this basin is suggested. In fact, in line with conservation targeting, economic targeting can be considered in choosing the type of vegetation and choosing a plant species that can both prevent soil erosion and generate income from its cultivation. Therefore, according to the instructions for building a garden and cultivating rainfed medicinal plants in sloping lands in 2016 and considering the economic aspects, three scenarios were proposed for this basin, the best scenario is the conversion of agricultural lands to rainfed medicinal plants, which reduces erosion from 4 25.4 to 5.4 tons per hectare per year (scenario 3) because the cultivation of medicinal plants does not require tillage every year and compared to crops such as wheat, it can be cultivated according to the soil conservation model, which reduces soil erosion and cultivation costs.Therefore, the considering the social and economic issues based on sustainable development in the implementation of watershed operations can be an important factor in the better management of country watersheds.

Watershed management practices by biological, biomechanical and mechanical operations are not only trying to solving watershed problems, but also in line with the sustainable development through improving the economic condition and living standards of stakeholders. Therefore, the present study was conducted to impact evaluation of the soil and water conservation practices on the sediment yield of Kan watershed in Tehran province using the data of the period of 1998-2018. The initial results from the practices simulation using the SWAT model showed that there was the large difference between the simulated and observed values, the model was recalibrated and validated after steps performance of the sensitivity analysis with the 2-SUFI algorithm. Based on the obtained results, the coefficient value of explanation in the calibration and validation stage of model obtained equal to 0.74 and 0.86, respectively, and the Nash-Sutcliffe index value was equal to 0.74 and 0.77, respectively, that these values showed the model had the high efficiency for simulation. Then the simulation of watershed management practices investigated on the watershed level and the results indicated if the management practices implement the sediment values will reduce. In such away that the sediment yield in the watershed reduced using practices simulation of terracing, masonry check dams, gabion check dams, loose stone dams, seeding and planting decreased with rates of 44.65, 26.72, 26.70, 8.03, 4.97 and 9.73 percent, respectively.

The aim of this study is to identify the areas prone to gully erosion and landslide as a two-hazard map in the form of a single map in Gorganrood watershed. In addition, the use of two machine learning models such as RF and SVM to establishing the spatial relationship between these hazards and the GEFs and any hazard susceptibility mapping separately. In addition, the validation of the hazards susceptibility maps was conducted based on the ROC curve method, and the best model was chosen with the highest predictive performances. Finally, by combining the susceptibility landslides and gully maps, the two-hazard probability maps were produced, which were a combination of different models and the best model. The results showed a RF model with (AUC = 82.9) for landslide and (AUC = 96.9) for gully erosion have higher accuracy compared to the SVM model with a value of (AUC = 0.76) for landslide and (AUC = 93.9) for gully erosion. Finally, a single and comprehensive map was obtained by combining of the each hazard susceptibility map for identification the areas prone to both hazards based on both models. The final two-hazard map can be used as a valuable tool for sustainable land use planning in multi-hazard prone areas.

The sudden increase in population growth, followed by the restriction and scarcity of the world's supply of freshwater resources, has created new conditions for countries in the arid and semi-arid belts. To conserve, enhance and make the best use of these valuable resources, several projects have been implemented, including irrigation and drainage, flood control and dam construction. Meanwhile, dams are a very important tool to manage the river water for socio-economic development and also to improve the deteriorated ecological status of the river system and its services. Depending on place and time, dams play both negative and positive roles in environmental flows, with significant environmental costs. According to the results of the documents and reports, the construction of the dam has brought about environmental changes from various aspects of invasion and increase in invasive species to improving access to spawning habitats for migratory fish. The challenge for managers and scientists today is to better understand and manage the consequences of dam decommissioning. For this reason, the purpose of this study is to present the approaches of removing the dam on ecological changes. The results of this research can provide stakeholders in the responsible departments with valuable information about the changes in the behavior of dams on the environmental properties.

Land use changes are one of the important factors in changing the hydrological status of the watershed and soil erosion, so the type of land use is one of the important and determining factors in the production of surface runoff. By knowing the process of land use changes, it is possible to manage the effects of land use changes in the hydrology of the affected areas and led the natural ecosystems towards balance. The following research was carried out with the aim of revealing land use changes using satellite data and analyzing its role in changing the hydrological situation.

The study area is the upstream part of the Siahroud river basin located in the south of Qaemshahr city. In this research, to extract land use maps of different time periods, integrated pixel-based and object-oriented methods, unsupervised and supervised classification of TM sensor images of Landsat 5 satellite related to 1998 and 2009 and OLI sensor images of Landsat 8 satellite related to 2015 and 2019 were used. After preparing the land use maps for each time period, the CN values for each land use were determined based on the standard instructions of the SCS method and the weighted average CN was estimated for the entire study area. At the end, the amounts of runoff production and depth of runoff resulting from rainfall are calculated.

The land use changes of the studied area in the period of 22 years showed that 281%, equivalent to 657 hectares, was added to the area of citrus orchards. About 5% of the area of deciduous forest has decreased and the area of residential areas has increased by 57%. Due to the changes in land use during this 22-year period, the weighted average value of CN has decreased from 63.01 to 62.73. Also, the estimation of the amount of runoff for rainfall equal to 59.8 mm (average maximum rainfall of 24 hours during the period of 22 years) showed that the depth of runoff has decreased from 4.83 mm in the 1988 situation to 4.73 mm in the condition of 2019.

Considering the changes in land use and its effect on watershed runoff production, it seems that these effects have been moderated and land use changes have played a role in reducing runoff production over a period of 22 years. Therefore, it is expected that with the continuation of this process of land use changes, the production of runoff in the upstream of the Siahroud River watershed will decrease.

Landslide classification using a fractal model at the Tajan river basin in northern Iran is the study intended as a new approach based on 142 landslide information data set.

The obtained results were interpreted using the Depth–Number (Dp–N) fractal model and a fairly wide set of information available for each landslide class, consisting of Digital Elevation Model (DEM), rainfall, landuse, geology (lithology and fault) and drainage network data.

The log–log plot shows five classes for depth (weakly, moderately, highly, strongly, and extremely magnitude) which shows that the extremely magnitude landslides have depths higher than 19.95 m in the NE, middle, western, and SE parts of the Tajan basin. The strong (5-19.95 m) and high (2.4-5 m) magnitude landslides happened in the northern, NE, western and NW parts. The results, which were matched up to landuse, drainage network, DEM, and fault allocation patterns revealed an affirmative correlation between landslide classes and the particulars in the area. In addition, the coefficient of determination, R2, for each population shows that the classification has been done correctly using the Dp-N fractal model. Amounts of P-value obtained from paired samples t-test and ANOVA showed that the separated categories are in incongruity with each other and are significantly different (sig=0.000).

Results show that separating the populations of landslides based on a parameter as magnitude and the difference between the populations’ magnitude of landslides should be considered in landslide susceptibility zonation.

Accurate information about the source of suspended sediment in river systems is necessary because supply enhancement of fine-grained sediments to a river system through human activities leads to overloading of suspended sediment, which affects water quality and the ecosystem. In addition, quantifying the relative contribution of different sources is vital to determine the best methods for suspended sediment control. Therefore, reliable information needs about the origin of transported fine-grained sediments by rivers. The purpose of this study is the fingerprint of suspended sediments using geochemical characteristics using the R software Fingerpro package in various land uses/covers of the Vaz watershed in Mazandaran province. In this research, 30 soil samples were collected from different land use, including forest, rangeland, agricultural land, and the streambank as sources of sediment yield, and one sample of suspended sediment at the outlet watershed. Geochemical characteristics of the soil and 59 sediment samples were measured using the ICP-OES GBC Integra device. Then, suitable tracers were identified for the fingerprint of suspended sediments using range tests, Kruskal-Wallis, and discriminant function analysis, in the Fingerpro package of R software including K, Li, P, V, Cr, Fe, Cu, Ga, Ge, Rb, Sb, Ba, Nd, Ta, and W. The separation results of the land use/covers contribution in the yield of suspended sediment with the GoF index showed with the rate of 80.68 that the contribution of agricultural, rangeland, forest, and streambank was with rates of 0.18, 7.90, 5.69, and 86.21 percent, respectively. Finally, the contribution of each source to the yield of suspended sediment per hectare was calculated. Results showed that the streambanks and forests had the highest and lowest participation in the yield of suspended sediment per hectare with rates of 0.513 and 0.0007 percent, respectively. The results also showed that the special contribution of stream bank lands at land uses for agricultural, rangeland, and the forest was the rates of 320.62, 394.61, and 732.85, respectively. The fingerprint results using the geochemical method for managers and planners provide valuable information about the resource contribution of suspended sediment yield to implement management programs for soil and water conservation.

Identification of sediment resources and their associated pollutants and contribution separation of land uses / land cover in sediment production is a valuable tool in spatial prioritization of soil conservation practices at watersheds. The present study was conducted with aim of bed sediment Fingerprinting using the geochemical method in Vaz watershed in Mazandaran Province. Thirty soil samples from different land covers were collected as sediment sources, and a sample of bed sediment at the basin outlet was measured. The geochemical characteristics including 59 elements were measured using ICP-OES. Then, using the combination of range tests, Kruskal-Valis and DFA test in FingerPro package at R software, 15 elements including K, Li, P, V, Cr, Fe, Cu, Ga, Ge, Rb, Sb, Ba, Nd, Ta, and W were selected as the optimal tracers. The results with a goodness index of fit of 78.31 showed that the contributions of agricultural, rangeland, forest, and stream bank lands in the bed sediment yield were with rates of 2.77, 3.61, 12.14, and 73.84 %, respectively. Finally, the relative contribution of each source in sediment yield for each hectare was calculated and the results showed that stream bank and rangeland with the relative contribution of 0.43 and 0.0008 percent for each hectare have the highest and lowest participation in sediment yield, respectively.

Slope instability and landslides are important hazards to human activities that often result in the loss of economic resources, property damage and facilities. These hazards occur in the natural or man-made slopes. In the current study, the maximum entropy model was used which is one of the progressive data mining models, in order to modelling landslide susceptibility map for Gorganrood watershed. In the first step, the landslide inventory map was prepared consiste of 351 landslides. 18 geo-environmental factors were selected as predictors, such as: Digital elevation model, slope percent, aspect, distance from fault, distance from river, distance from road, rainfall, landuse, drainage density, lithology, soil texture, plan curvature, profil curvature, lithological formation, Topographic wetness index, LS factor, stream power index, Relative Slope Position and Surface roughness index. Three different sample data sets (S1, S2, and S3) including 70% for training and 30% for validation were randomly prepared to evaluate the robustness of the model. The accuracy of the predictive model was evaluated by drawing receiver operating characteristic (ROC) curves and by calculating the area under the ROC curve (AUC). The ME model performed excellently both in the degree of fitting and in predictive performance (AUC values well above 0.8), which resulted in accurate predictions. Furthermore, In this study the importance of variables was evaluated by the model. Dem (digital elevation model) (32.4% importance), lithology (22.9% importance) and distance from fault (14.8% importance) were identified respectively the main controlling factor among all other variables.

Water quality indicators are a standard for classifying surface water based on the use of standard parameters and is a mathematical tool that converts a large amount of data used to describe water properties into a number and obtains a water quality level. The aim of this study was to assess and compare the sensitivity of NSFWQI and IRWQISC water quality indicators to quality parameters using variance-based methods on Haraz River with monthly sampling in 2022 in 7 selected stations in the range of Panjab to Haraz reservoir Dam in the province Mazandaran. The results of the present study have shown that the water quality in S1 (upstream) and S2-1 stations are relatively good at best, and bad at worst. Water quality in stations of S2, S3, S4, S5-1 and S5 (downstream), in the best case is moderate and in the worst case in September have poor quality. SRC method was used to analyze the uncertainty and sensitivity of the NSFWQI index and FAST and SOBOL methodologies were used for the IRWQISC index. The results of sensitivity analysis based on Factor Prioritization approach showed that in NSFWQI index, DO, BOD, CF, T and P parameters respectively and in IRWQISC index after DO parameter, BOD, P and N parameters had the most impact on output. In the uncertainty analysis, the results of applying SOBOL methodology for different stations of Haraz River were consistent with FAST method, but the results of sensitivity analysis obtained from these two methods were different from each other. Considering the obtained results and despite the similarity of the results of the two methods, it can be said that SOBOL methodology has been more successful than FAST methodology in this study due to unconditional convergence.

 Nowadays, ths soil erosion is a serious threat for most societies and it causes the loss of water and soil. One of the most important factors of control of runoff and soil erosion is the application of soil conditioners. Therefore, the current research was conducted in order to performance evaluation of individually and combined effect of the bean straw mulch in three levels of 25, 50 and 75 percent and polyvinyl acetate in level of 3 percent on changes of runoff and soil erosion.

 the used soil at present study collected from rangelands at depth of 20 cm and after transportation to laboratory for relative stability of aggregates passed from sieve of 4 mm. For performance of the present study of the treatments of bean straw mulch as an organic soil conditioner and polyvinyl acetate as an inorganic conditioner used in individually and combined form. The conservation treatments applied at laboratory conditions using rainfall simulator for time priodes of 24 h, 2 and 4 months.

The results showed that the bean straw mulch and polyvinyl acetate at individually and combined various levels and applied time intervals could increase the time to runoff and end runoff and also decrease the runoff coefficient, soil erosion and sediemt concentration. The most affect on time to runoff related to combined treatment of bean straw mulch with level of 75 percent + polyvinyl acetate (MSP3) at time interval of 2 month (with rate of 74.68 percent). Also, the maximum changes of reduction of soil erosion related the application of bean straw mulch with level of 75 percent (MS3) at time level of 2 month with rate of 67.54 percent. The results showed that the bean straw mulch and polyvinyl acetate had significant effect on studied variables at level of 99 percent.

In general, it can be stated that the usage of bean straw mulch and polyvinyl acetate with form of individually and combined with other conditioners in order to investigation their effects on soil and water conservation can be a useful method. Finally, the usage of bean straw mulch and polyvinyl acetate in eroding or eroded lands and performance of new researches with other soil conditioners and in different conditions recommended with aim of soil and water conservation. Also Due to the different performance of individually and combined application of bean straw mulch and polyvinyl acetate, the correct usage of conditioners is necessity at the resources management of water and soil.

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.

Given the importance of soil and its significant role in the countries evolution, numerous methods are presented to preserve this national capital and to combat the soil erosion consequences. In recent years, Iran like other countries, has taken an effective step to protect soil using organic and inorganic soil preservatives. Therefore, the aim of this study was to investigate the effect of corn mulch on rate and changes runoff and sediment.

This study was in loam – sandy soil in scale small plots laboratory and using a rain simulation with an intensity of 50 mm / h with a10-minute duration has been done. For this purpose, three levels of protective cover of 25, 50 and 75% of corn mulch one control treatment (without conservation cover) with four levels of moisture, air dry, 15, 20 and 30% were considered in three replications.

The results of this study showed that application of corn mulch has a significant effect on runoff and sediment reduction at 99% level. Considering the moisture levels, the amount of runoff and sediment yield in uncoated (control) and 25, 50 and 75% plots were 4422, 4290, 3943 and 3619 ml and 296, 136, 62 and 33 g, respectively. The results of percentage change of runoff, sediment and start time of them showed that the cover at 25, 50 and 75 percent protective cover and different moisture levels were 3.14, 11.25 and 19.29 percent, respectively. Sediment reduction was 62.06%, 77.09% and 88.85%, respectively, compared to the control treatment (without protective cover). The percentage of changes in runoff and sediment of them increased by 32.23%, 73.38% and 136.82%, respectively.

Based on the changes in hydrograph and sediment graph, it was found that 75% corn mulch at 15, 20, and 30% moisture content at 645, 452, 215 and 99 seconds, respectively, was more effective in increasing runoff and sediment time to runoff compared to the control treatment other cover surfaces have been used. However, two more (25 and 50%) were also effective in increasing production time to runoff and sediment. knowledge the trends of runoff and sediment changes and their time by applying conservation cover can be a useful tool and effective solution for soil and water conservation.

The aim of this study was to investigate the effect of land use age on dynamic of different forms of soil organic carbon in Chahar Dangeh region of Kiasar, Mazandaran province. In this area, the studied habitats include pastures conversion to agricultural lands (barley) and orchards (apples and walnuts) in three different ages (more than 30 years, more than 20 years and less than 10 years) in Era, Erost and Vavsar villages. In each land use, soil sampling was performed systematic- randomly from 0-15 and 15-30 cm depths. In total, ten soil samples from land uses were transferred to the laboratory for analysis of soil organic carbon, particulate organic carbon, microbial biomass carbon, labile organic carbon. The variance analysis results indicated that the higher values of soil organic carbon, particulate organic carbon, microbial biomass carbon, labile organic carbon found in orchard use during 30 years old, which was located at a depth of 0-15 cm. Due to the conversion of rangeland to orchard use (age more than 30 years), soil organic carbon, particulate organic carbon, microbial biomass carbon, labile organic carbon increased in 86.18%, 68.42%, 61.13% and 66.94% respectively. Also, the highest amount of EC was found in orchard use older than 30 years. But pH in barley land use older than 30 years at a depth of 15-30 cm had the highest value. In general, the results of this study indicated that the effects of the studied factors on different forms of soil organic carbon depend on the time. Therefore, soil organic carbon management strategies should be adjusted according to the time period.

An optimized land management and the planning requires updating information on the land use changes over time. The application of remote sensing capabilities and land use change modeler (LCM) may provide a suitable platform for simulating land use changes. The LCM, land use changes in the upstream area of the Siahrud River Basin were evaluated in the 1977-2015 period and simulated for 2030. The land use maps of 1977, 1988, 1998, 2009 and 2015 were prepared, using the unsupervised and supervised classification methods of the Landsat satellite images, and the LCM, for the 1977-1988, 1988-1998 and 1998-2009 periods were implemented in the form of three models. After evaluation the performance of these models, the most appropriate one was selected. Using the data for the 2009-2015 periods a prediction was made for the year 2030. The results indicate that the use of appropriate inputs for the LCM, the application of the combined methods in classification, and utilizing expert knowledge, can be effective in improving the classification results and increasing the efficiency of the LCM. (Kappa coefficient 0.82 to 0.91). Predicting land use changes in the Siahroud River Basin during the 1977 to 2030 period indicates a 67% decrease in paddy fields and 12% decrease in forest area and a 34-fold increase in the extent of the mixed agricultural and orchards, and threefold increase in the extent of the residential areas.

Destruction of the riverbed and activities in the river area, including mining activities, road construction, non-standard bridges, etc., often increase the risk of floods. Due to importance of this issue in the present study, the effect of mining activities on determination of channel boundary of Haraz River, (Noorrud junction to Kelerd forest area as a given reach) has been investigated with a length of 40 km. In this regard, to study changes in river mineral activity levels during the years 1985 to 2021 from satellite images, to simulate the hydraulic behavior of the river from the HEC-RAS hydraulic model and to compare changes in river area during the study period the DLSRS model were used. Thus, satellite data with visual interpretation techniques were used to determine the level of mining activities. Then, a 1: 2000 scale topographic map of the riverbed in the HEC-GeoRAS (GIS) extension and the HEC-RAS model was used to simulate the hydraulic behavior of the river. Finally, by estimating the five parameters of the DLSRS model, the quantitative values ​​of the river at 10-year intervals were determined in the period 1300-1399. The results of changes in the levels of mining activities indicate geometric changes of the bed of the given reach such as displacement and narrowing process. The results of the study of the factors of channel boundary changes also showed that increasing human activities and changing the river flow regime increase the quantitative boundary of the channel. The results also showed that during the last century, the level of mines in the study area has increased from 3.35 to 13.57 ha in 2021, the maximum development of which has been since 2011. As a result, the quantitative area of the river has increased from 9 m in 1922 to 17 m in 2021.

The aim of this study was to investigate the effect of converting natural lands to agricultural lands in Vavsar village of Kiasar city. For this purpose, a rangeland use, along with three other uses, including lentil, wheat, and potato cultivation, were selected as the study area. Soil sampling was performed at a depth of 30-0 cm from each soil surface. A total of 40 soil samples were collected. Then the physical and chemical factors of the soil were measured including soil texture, aggregate stability, bulk density, total organic matter, total nitrogen, potassium, absorbable phosphorus, calcium carbonate, pH and EC. The results of variance analysis showed that the conversion of rangeland to the three mentioned uses had no effect on the overall soil texture and the soil texture in all four uses was Lummi. However, in the comparison of the average of the three factors that make up the soil texture (silt, clay and sand), it was found that there is a significant difference between the percentage of sand and silt at the level of 0.05. The results also showed that other factors such as aggregate stability, total organic matter, total nitrogen, calcium carbonate were significantly reduced as a result of this conversion. So that in the use of lentils, potatoes and wheat, the stability of the soil is 50.95, 20.44 and 8.86 percent, respectively, the total organic matter is 41.94, 24.73 and 22.44 percent, respectively, the total nitrogen is 42.86, respectively. 21.43% and 7.14% and calcium carbonate levels decreased by 72%, 62% and 88%, respectively. While phosphorus increased by 55.91, 86.39 and 24.39, respectively, and potassium increased by 44.05, 71.88 and 8.45%, respectively. But this conversion did not have a significant effect on pH, EC and bulk density. The results of this study showed that land use change can have different effects on soil quality characteristics. Therefore, it is suggested that continuous monitoring and evaluation of the fertility status and quality of the cultivated lands be done.

One of the most important consequences increased radiative forcing due to anthropogenic activities is global warming, that created varied and challenging changes such as climate change on ecosystems. Predictions show that the increased radiative forcing will continue. Regarding to the existence of several climate models and error correction methods, selection of the right model is one of the key challenges. In this study, the accuracy and efficiency of the fifth report on regional climate models including CanESM2, CSIRO Mk3, EC- EARTH, IPSL, MIROC51, HadGEM2, MPI, NorESM1 and GFDL and statistical downscaling error correction methods including Linear Scaling (LS), Change Factor (CF), Distribution Mapping (DM),  Local Intensity Scaling(LI), Power Transformation (PT) and Variance Scaling (VS) Using T and F tests, the Taylor diagram and 10 statistical indices during two control (1956-2005) and validation (2006-2015) periods were assessed in Birjand station. The results show that; comparing the average of monthly period increases the efficiency of models and methods exaggeratedly. The best model is different based on statistical indicators and time series period. CF downscaling method is not accurate in validation period. LS and VS downscaling methods are appropriate selection for precipitation and temperature parameters respectively. Also, average accuracy of all models for both precipitation and temperature parameters is better than a single model. MPI and Earth climate models have good performance in simulating precipitation and temperature data.

Changes in plot size can be determine its effects on parameters changes of runoff and soil loss. On the other hand, the generated runoff in eroded soils is one of the most important obstacles and challenges of human in conservation of water and soil resources and it is also a threat to well-being and life. One of the most important of controlled factors of surface runoff and increasing soil infiltration is the application of conditioners or amendment materials on soil. But it should be noted that the size change can also control the runoff and soil loss variations. Therefore, the present study was carried for the effect investigating of size change in laboratory plots in two sizes of 0.5 × 0.25 and 1 × 0.5 m2 using application of organic manure with rates of zero (control treatment) and 62.5 and 125 g m-2 (conservation treatment) on changing time to runoff, runoff coefficient, soil loss and sediment concentration. The obtained results showed that the plots with size of 0.5 × 0.25 m2 and the application of organic manure with rate of 62.5 g m-2 had the little effect on the increasing time to runoff compared to control treatment. But, time to runoff increased with increasing plot size and also rate of organic manure. The effect of plot size on parameters of runoff coefficient, soil loss and sediment concentration, organic manure on parameters of time to runoff, runoff coefficient and soil loss and interaction effect of size change and organic manure on parameter of soil loss was significant at level of 99 percent. Also, in plot with area of 1.0 × 0.5 m2, the changes of time to runoff and runoff coefficient, soil loss and sediment concentration for organic manure with rate of 125 g m-2 toward 62.5 g m-2 were 72.83, 53.52, -212.27 and -142.92 2.12 percent, respectively. While, the changes of studied parameters for plot of 0.5 × 0.25 m2 were 594.24, -212.63, 4.06 and 13.70 percent, respectively.

Management practices such as land use change is one of the main components of global change that affects the process, structure and function of ecosystems by changing microbial communities (due to their role in the decomposition of organic matter and food mineralization(.Changes in soil biological characteristics due to land use change and management practices may lead to significant changes in soil organic carbon dynamics, soil microbial respiration and affect nutrient cycle and plant growth. Therefore, to better understand human management on carbon cycle, it seems necessary to understand the correlation between soil microbial properties during land use change.

The aim of this study was to investigate the temporal dynamics of soil microbial characteristics during land use change in rangelands around Kiasar Chahardangeh city of Mazandaran. For this purpose, in this basin, the studied habitats were including Erost village with pastures turned into agricultural lands (barley) and orchards (apples and walnuts) with an age of more than 30 years, with a control pasture, Vavsar village with pastures turned into lands. Agriculture (barley) and orchard (apple and walnut) with an age of more than 20 years and also rangelands converted to garden use (apple and walnut) less than 10 years, with a control rangeland and Ara village with rangelands converted into agricultural land (Barley) less than 10 years old with a pasture. Soil sampling in each land use was done systematically randomly from two depths of 0-15 and 15-30 cm.In total, nine soil samples from landuses were transferred to the laboratory for analysis of soil physico-chemical characteristics including texture, bulk density, moisture content, organic carbon, total nitrogen, pH and microbial characteristics including Basal respiration, Substrate induced respiration, Microbial biomass carbon, Microbial biomass nitrogen and Microbial biomass phosphorus, qCO2, microbial ratio and carbon capability index.

The results showed that the highest amount of physicochemical characteristics (except sand and silt percentage and bulk density, pH and C/N) and soil microbial characteristics (qCO2, microbial ratio and carbon capability index and MBC/MBN) at both depths and mean depths belonged to orchard land uses older than 20 and 30 years. Principal Component Analysis (PCA) indicates that over time, higher values of microbial activity and soil fertility in the orchard uses are older than 20 and 30 years with a completely different location on the axis. In general, the results of this study showed that the variability of organic carbon, total nitrogen, acidity and soil moisture content in the long run caused an increase in microbial respiration rate (Basal respiration and Substrate induced respiration), While the qCO2 in the orchard less than 10 years old and control rangeland for lands older than 20 years, also the microbial ratio in the control rangeland for lands less than ten years old had the highest value, while the carbon capability index showed no significant difference between users of different ages.

In general, the results of this study showed that soil characteristics in orchard uses with older ages were in a better condition. Also, variability in soil physicochemical properties changed the microbial characteristics of the soil over time. Therefore, it is suggested that long-term studies and management strategies to reduce uncertainty and estimate the rate of organic carbon pool of ecosystems, which are not unrelated to soil microbial characteristics, are considered necessary during land use change.

Soil hydrophobicity is an effective characteristic on plants growth, surface and subsurface hydrology and soil erosion. The application of soil conditioners can be have the various effects on hydrophobicity phenomenon. Therefore, the present study was conducted with study aim of effect of zeolite, compost and combination of these two conditioners on changing soil hydrophobicity and different time periods. For study of changing soil hydrophobicity used from two types of organic conditioner (compost) and mineral conditioner (zeolite) in laboratory conditions. The experiments performed at before and after application of rainfall simulator and the applied values for compost and zeolite were with rates of 7.1 and 5.8 g, respectively. Also in the present study, the phenomenon study of hydrophobicity was conducted using time periods of 24 hour, two, four, eight, 16 and 32 weeks. The results showed that the zeolite as an organic conditioner had the maximum effect before and after application of rainfall simulator on hydrophobicity changes with changes percentage -93.7, 18.9, 71.72, 57.24, -3.10 and 78.28% (before rain simulator) and -22.7, 56.8, 60.9, 54.5 , -54.9 and 78.1percent (after rain simulator). Also, the separation effect of conservation treatment, time and rainfall simulator had positive an effect on changing hydrophobicity was significant at level of 99 percent.  Also, the results showed that the hydrophobicity rates decreased after simulator application toward before simulator application.