نشریه پژوهش های حفاظت آب و خاک
سال بیست و هفتم شماره 2 (خرداد و تیر 1399)

Soil contamination with heavy metals has become a global concern because of its adverse effects on ecosystem health and food security. Soil amendments including biochar can reduce the bioavailability of heavy metals in contaminated soils and reduce their risk of entering the food chain. Biochar is a carbon-rich material obtained by pyrolysis of biomass, such as agricultural residues and manures under conditions with little or no oxygen. Recent studies have shown that biochar also has great potential for immobilizing heavy metals in soil, because of its highly porous structure, active functional groups, and generally high pH and cation exchange capacity (CEC). In the country, most of the studies on biochar are related to calcareous soils or aqueous solutions and biochar has received little attention as an efficient adsorbent for the adsorption of heavy metals in acidic soils. The goal of this study was to investigate the effect of biochar derived from carrot pulp on properties of acidic soil and adsorption of lead and cadmium in soil.

In this study, biochar derived from carrot pulp was produced through pyrolysis at 550 °C with a heating rate of 25 °C min-1. Carrot pulp biochar was added to acidic soil at 0, 4 and 8% application rates and was incubated for 60 days. After the incubation period, to investigate the effects of time on Cd and Pb adsorption, 25 mL of 400 mg L−1 of Cd and Pb were added to 1gr of soil samples, and then samples were shaken for different times (4, 8, 12, 16, 20, 24, 28, 32, 36 and 40 h). Then, the concentration of Cd and Pb were measured. The results were fitted to pseudo-first-order, pseudo-second-order, and Elovich kinetic models. To determine the adsorption isotherms of Cd and Pb, 25 mL of heavy metals solution with concentrations ranging from 0 to 400 mg L−1 were added to 1gr of soil samples, and then samples were shaken for 24 h, and finally the adsorption data were fitted to Langmuir, Freundlich, and Temkin isotherm models.

The application of biochar significantly increased the pH, cation exchange capacity and electrical conductivity of the soil, although the 8% application rate more effective than the 4% application rate in increasing the pH, cation exchange capacity and electrical conductivity of the soil. The results of fitting the data to the Langmuir, Freundlich and Temkin isotherm models showed that Cd and Pb adsorption on the control soil and soil treated with biochar matches with the Langmuir isotherm model. The pseudo-second-order kinetic model was introduced as the best kinetic model of adsorption of Cd and Pb. The maximum adsorption capacity of Cd and Pb increased from 647.25 mg kg-1 and 855.71 mg kg-1 (in control soil) to 2078.29 mg kg-1 and 3182.72 mg kg-1 (in soil treated with 8% biochar), respectively.

This study showed that carrot pulp biochar increased the adsorption of Cd and Pb in acidic soil by increasing the pH and cationic exchange capacity of the soil. Therefore, carrot pulp biochar can be used as an effective and inexpensive adsorbent to improve acidic soil properties and increase the adsorption of Cd and Pb in soil. Keywords: Biochar, Adsorption, Kinetic, Cadmium, Lead

Petroleum products are one of the most widely used chemicals in today's modern world. Petroleum hydrocarbons have become a global problem for the environment. These compounds are highly resistant to the environment and are harmful to human health. Application of bioremediation process to remove polyaromatic hydrocarbons from contaminated soils is one of the most economical and desirable options.The purpose of this experiment was to investigate the percentage of hydrocarbon pollution remove of polluted soil with hydrocarbons (crud oil) by sorghum, barely and bermudagrass with and wihout Psudomonas putida and Azosprillum brasilense.

In this study, simultaneous efficiency of phytoremediation and bioremediation in removing crude oil from soil was investigated. For this purpose, a factorial experiment was conducted in a completely randomized design with three replications. The treatments consisted of 3 levels of soil pollution to oil (0, 4 and 8% oil), 4 treatments of plant (no plant, bermudagrass (Cynodon dactylon), sorghum (bicolor Sorghum) and barely (Hordeum vulgare() and 3 treatments of bacteria (no bacteria, Psudomonas putida and Azosprillum brasilense). To do the experiment, samples of five kilograms of soil were polluted with different amounts of crude oil and poured into plastic pots. After 6 weeks and the equilibrium of polluted soils, these soils were inoculated with Pseudomonas putida and Azospirillium brasilense bacteria, then in polluted soils of inoculated with bacteria and no inoculated three gramineae species were planted. Ninty days after planting, plants were harvested.

The results showed that interaction effects of treatments were significant on crude oil removal percentage of soil in probability level of 1%. Removal percentage of crude oil by plant cultivation alone, inoculation of bacteria alone and combined application of plant and bacteria significantly increased compared to control. Cultivation of plants was more effective than soil inoculation with bacteria in removal oil pollution and plant increased bacteria function significantly so that, there were significant difference among treatments of plant alone, inoculation with bacteria alone and plant+ bacteria. The highest removal percentage was observed in combined application of plant and bacteria. At all treatments of soil inoculation with bacteria, with increasing levels of oil pollution, dry weight of plants decreased but, at each level of crude oil pollution, inoculation of soil with bacteria, the dry weight of shoot increased. Incubated soil with bacteria improved dry weight of shoot through removal of oil pollution in soil. With increasing level of crude oil pollution, concentration of leaf chlorophyll decrease significantly but, incubation of soil with bacteria increased it in fresh leaves of plants due to reduce the negative effects of oil pollution and supply nitrogen. With increasing levels of oil pollution, the mean of proline concentration in fresh leaves of plants was significantly higher than that of control. Its highest concentration (in each plant) was obtained at 8% of crude oil pollution. Inoculation of soil with bacteria in polluted soils and non-polluted soils increases the amount of proline in the leaves of plants. In each level of crude oil pollution, inoculation of soil with bacteria, the proline concentration of leaf of plants increased. The highest concentration of proline in the treatment of the highest oil pollution level (8% crude oil pollution) and inoculation with Pseudomonas putida was measured.

Establishment of plant with microorganisms can be considered as a key component of the strategy to remove hydrocarbons. Consequently, these bacterial and plant species can be used for the biodegradation of soils contaminated with crude oil.

The occurrence of climate change and its impact on surface water and groundwater resources, along with inappropriate management of water resources have led to an increase in the social and environmental vulnerability of river systems. Assessing the vulnerability of river basins, especially in developing countries such as Iran is essential and is considered as one of the main priorities of the water resources planners for the sustainable management of these resources and for the formulating of policies consistent with the regional conditions. In this line, this paper focuses on the assessment of the vulnerability of the Jarahi River Basin.

The study area of this research, the Jarahi River Basin, with an area of about 24000 square kilometers is located in southwest of Iran with a population of about 870000 people. In this research, the River Basin Vulnerability (RBV) method was used to assess the vulnerability of the Jarahi River Basin. This method examines the vulnerability of ecosystem and human simultaneously and consists of a total of six main indicators including ‘governance’, ‘economic status’, ‘social condition’, ‘environment’, ‘water stress’, and ‘natural hazards’ indicators. In this method, data are evaluated quantitatively. The combination of these indicators is based on a raster summation algorithm which can be carried out in the ArcGIS platform.

The anlysis shows that the vulnerability of the Jarahi River Basin corresponding to each of the indicators of governance, enconomic status, social condition, environment, hazards and water stress are 0.76, 0.41, 0.061, 0.43, 0.44 and 0. 84, respectively. The results exhibit that the Jarahi River Basin is severely threatened by natural hazards, and in particular, the flood hazard threatens all parts of the river basin. It is also exposed to high water stress. The highest water stress (0.76) associated with Shadegan sub-basin that is located in the southern part of the basin. In addition, Saiddon sub basin has the lowest literacy rate among the sub basin of the Jarahi River Basin with the rate of 79%. A significant part of the Shadeghan sub-basin exhibits considerable environmental impacts, interpreted as a discernible sign of human footprints in the area.

Generally, in the Jarahi River Basin, the vulnerability of three indicators, namely "governance", "water stress", and "natural hazards"are quite significant. In particular, flood assessment analysis shows that almost all the river basin is highly susceptible to flood hazard. Also, seismic hazard threatens a considerable portion of Behbahan and Takht-E Deraz sub-basins. The results regarding the water stress show that almost half of the basin (mostly Shadegan sub-basin) suffers from high water stress. Through controlling corruption, improving Iran’s political stability status and reducing the government fragility index, an improvement in the governence indicator can be achieved. Concerning the water stress indicator, given that the excessive use of water in the agriculture sector is mostly responsible for the high vulnerability state, changing the current land-use and accordingly the cropping pattern in the Jarahi River Basin will potentially have a positive impact on water stress indicator.Moreover, regarding the natural hazards, given the high potential of drought, flood, and earthquake occurrences in the research area,it is possible to somewhat reduce the incurred damages caused by these phenomena in the river basin by means of paying due attention to knowledge, awareness, planning and efficient management.

Environmental stresses are a major obstacle to world food supply. There is relatively little stress-free arable land where crops reach their potential yields. For example, about 45 percent of the world's agricultural lands, with 38 percent of the world's population, are experiencing temporary or permanent drought (Bot et al., 2000). Sesamum indicum L., due to its tolerance to drought and heat, is very important in the development of arid and semi-arid regions as summer crop (Aien, 2013). In one study, sesame cultivar Darab 14 based on MP, TOL, SSI, HARM and STI indices was introduced as superior cultivar under normal conditions and moisture stress (Amani et al., 2012). Due to the importance of sesame as one of the most important edible oil products supplier in Iran, deficit irrigation can be adapted to water shortage during drought. Due to its high content of sesame oil (42-52%) and its good quality (low cholesterol and some antioxidants), it plays an important role in human health and on the other hand, it is tolerant and drought tolerant (Afshari et al., 2014). The purpose of this study was to investigate the effect of drought stress by applying different levels of surface irrigation and identifying superior cultivar based on stress indices.

Study and evaluation of drought stress indices in surface irrigation on sesame seed yield and its components, seed oil yield, seed oil percentage and water use efficiency of experimental seed were conducted at Behbahan Agricultural Research Station in 2014. The experiment was conducted as split plot in a randomized complete block design with 3 replications. Irrigation at two levels (irrigation after 100 and 200 mm evaporation from Class A pan, respectively) was evaluated as main factor and cultivar at 5 levels (local of Behbahan, SG37-92138, SG51-92138, SG53-92138 and SG55-92138) as sub-factor.

Comparison of mean water use efficiency in irrigation and cultivar interactions showed that 100 mm evaporation from Class A pan and V5 (SG55-92138) evaporation with water use efficiency of 0.272 kg/m3 sesame seed was superior. The mean water consumption in one year of experiment in 100 and 200 mm evaporation from Class A pan was 547.5 and 438.6 mm, respectively. The results of Pearson correlation coefficient showed the highest correlation of 1000 kernel weight after number of kernels per capsule with grain yield was r = 0.9616 which indicates the effective role of 1000 kernel weight gain in enhancing grain yield. The highest values of STI, MP, GMP, HM and YI were calculated with V5 (SG55-92138) with values of 1.538, 1037.1, 1024.7, 1011.5 and 1.548, respectively. Increasing of the above indices in cultivar V5 (SG55-92138) compared to other cultivars caused it to be introduced as superior treatment for drought stress. The decreasing trend of sesame yield caused by dehydration stress decreased SSI, MP and TOL indices and, on the contrary, decreased sesame yield, and led to bullish changes in STI, GMP, HM, YI and YSI indices.

Comparison of mean interaction effects between irrigation and cultivar in terms of water use efficiency showed that water use reduction in stress treatment decreased water yield in these treatments compared to non-stress treatment. The effect of reducing water use was even to the extent that it failed to cover the continuous decrease in yield in return for water consumption and continued to treat 100 mm evaporation of Class A pan despite more water consumption than the 200 mm evaporation treatment of Class A pan. The highest water use efficiency among treatments was due to increased yield.

Evaluation of watershed operation performance is always done by comparing watershed responses before and after operations. This process causes the effect of the operation to spread over time and not to see its true effect and consequently, the weakness of that series of operations will remain unknown over time. Therefore, considering the importance of check dams in watershed management programs in Iran, the goal of this study is determination of real-time impact or life span of check dams in controlling discharge and sediment load and evaluating of their impacts in Kand’s watershed in Tehran province. .

At the first, life span of check dams has obtained based on Double-Mass curve, and field surveys . Then, the study period (1999-2015) is divided into three periods: before the construction of the check dams (first period), the life span of the check dams (second period) and the end of the life span of the check dams (third period) and the discharge and sediment load changes at the outlet of watershed are investigated and compared with the common approach. Sedimentation rate curve methods were also used to estimate the sediment load in each period.

The time points of occurrence of slope fractures in double mass curves as well as field observations indicate that the duration of impact (life span) of check dams in the Kond’s watershed was on average four years (from 1999 to early 2003). The results of the evaluation of the impacts of the check dams in the case study indicate that despite the constant precipitation conditions, the outflow discharge and the maximum, minimum and average characteristic discharges in the second period, compared to the first period, has decreased by 43, 49.66, 53.28 and 100, respectively. The amount of sediment load reduction in the second period is much more noticeable than the first period and is 92.47%. However, at the end of the life span of check dams (third period), the amount of discharge and sediment load has increased, returning to the level of the first. Comparison of the results of this evaluation approach (determine the life span) with the common approach (before and after project implementation) also shows that in the common approach, due to the distribution of the effects of operations over time, the performance of check dams will be measured at half their actual performance.

The results of this study show that considering the life span in the evaluation process will provide more realistic results. Actually the efficiency of check dams in Kond’s watershed is considerable during their life span, but their shorter life span is a significant weakness of this type of watershed operation. Actually relying on check dams to stabilize watersheds has not been a successful solution and only prevent to exit sediment production from the watershed and, for this reason, in the third period, the watershed response has returned to the pre-operation conditions (temporary effect). Therefore, the benefits of watershed management operations in the Kond’s watershed were off-site impacts and the on-site impacts were limited to reducing the slope of the main stream.In fact, in order to increase the life span of check dams, watershed management operations with on-site impacts should be prioritized, which this in itself requires erosion control at the source, ie the slopes

Amarantuse farming is a way to increase biodiversity. It has high photosynthetic efficiency and is resistant to drought conditions, so it is suitable for cultivation in arid regions and reducing irrigation costs. The desirable agronomic traits (high vegetative growth rate in hot months of the year, drought tolerance and water productivity) and its qualitative (high levels of protein in seed and forage) make this plant a valuable forage plant.

This experiment was conducted to investigate the quantitative and qualitative yield and water use of forage amarantuse in Golestan province. The experiment was conducted as split plot in a randomized complete block design with three replications. The amount of water consumed (including full irrigation, 75%, 50% and 25% of total irrigation) were in the main plots and the amarantuse varieties (including two cultivars Cim and Loura) were sub-plots..

Analysis of variance showed that the simple effect of cultivar and the simple effect of irrigation on plant height, fresh forage weight, fresh and dry stem weight, total dry matter weight, water productivity (based on forage fresh weight yield), insoluble fiber yield were significant. The effect of irrigation on all studied traits was significant at 1% level and two traits of protein yield and water productivity (based on dry matter) were only affected by irrigation regime. Interaction effects of cultivar irrigation on leaf traits, fresh and dry weight of leaves, leaf to stem ratio, insoluble fiber (NDF), percentage of crude fat, lignin, calcium and phosphorus were significant. Results of mean comparison showed that dry matter yield in Cim (6 ton / ha-1) was higher than Loura (5.5 ton / ha-1). The highest water productivity based on fresh and dry weight was 17.1 and 2.2 kg / m-3, respectively, with 75% of total irrigation. The highest protein yield was obtained in the complete irrigation treatment, and by reducing the amount of irrigation by 25%, the total amount of protein decreased. The highest and the lowest protein content in irrigation treatments were 947 and 433 kg ha-1, respectively.

According to the results of this study, Cim was superior to Loura for most of the agronomic and qualitative traits of forage, so that in terms of leaf and stem weight, leaf to stem ratio, phosphorus and especially water productivity. Repeating these results in similar experiments and considering the results, it is advisable to obtain high quality forage Cim in Gorgan climate conditions and to save water (increase productivity), Irrigation can be adjusted to 75% of the water requirement.

Arsenic contamination is one of the serious environmental challenges in developing countries. Contaminated water is the main source of human and animal exposure to inorganic arsenic. There are various physicochemical and biological methods used for arsenic removal from aquatic environments. Compared to all the advantages and disadvantages of arsenic removal methods, adsorption processes considered as an effective method due to its low cost and ease of application. Iron - rich materials have a high capacity to sorption of arsenic in aqueous solutions. The objective of this study is an assessment of arsenate removal from water using biochar modification by iron salt, which can be used for the recovery of arsenate contaminated water resources for drinking water supply and reuse of industrial effluents.

In order to preparation of iron modified biochar 0.1 (0.1FeBC) and 0.4 (0.4FeBC) ratios of FeCl3.6H2O were added to apple pruning residues powder and pyrolized in the furnace for an hour at 300 °C under limited oxygen condition as well as a control sample without iron. SEM images were used for characterization of the morphology of the adsorbents. The isotherm experiment was carried out at initial concentrations of 0, 1, 2, 4, 6, 8, and 10 mg arsenate/L and remaining arsenate in solution was determined using hydride generation atomic absorption spectroscopy (HG-AAS). Experimental data were fitted to Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models, and parameters such as apparent energy of adsorption (E), adsorption efficiency, Gibb’s free energy (ΔG) and separation factor were calculated.

Iron modified the surface properties of biochar and increased the amount of the granular compounds on the adsorbents surface. The results showed that by increasing of the adsorbent iron content, the removal of arsenate from solution increased and the highest removal efficiency (86%) was obtained for the 0.4FeBC adsorbent at 1 mg Arsenate/L. The ability of the Freundlich model to simulate the process of arsenate adsorption by iron-modified adsorbents was higher than the Langmuir, Dubinin–Radushkevich and Temkin models. By increasing the iron content in the adsorbents Freundlich (KF and n), Temkin (KT and A), Langmuir (KL and qmax) coefficients increased, while the Dubinin–Radushkevich (KDR) coefficient and separation factor (RL) decreased. The highest value for the maximum absorption capacity (qmax) was obtained for 0.4FeBC in the amount of 7.66 mg of arsenate per gram of adsorbent. According to the values of apparent energy of adsorption (E), adsorption process for unmodified biochar is physical (less than 8 kJ / mol) and for the modified biochar is chemisorption. Based on Gibbs free energy (ΔG) values, the adsorption process of arsenate by adsorbents is spontaneous.

According to the results of this study, modification of biochar by iron salt can be considered as an inexpensive absorbent due to local accessibility and easy application for removal of arsenate from water.

Iran is in a warm and dry area and optimal use of water in a way that does not damage the plant is very important. Chicory is located in the dark of vascular plants, its height is 120 cm and has a thick root. One of the ways to optimize water use is to use bentonite and superabsorbent polymer. In this study, the effect of these two substances on chicory growth has been investigated.

The experiment was conducted in a research farm of Agricultural faculty of Agriculture of Birjand University located 5 km from Birjand-Kerman road with latitude 32 degrees and 56 minutes north and longitude 59 degrees and 13 minutes east. Drought stress was applied in a completely randomized design with two irrigation treatments (100 and 50%) in three replications with 6 bedding. In general, drought stress has a significant effect on yield and yield of chicory plants.

In general, drought stress has a significant effect on yield and plant characteristics of chicory. Also, the highest average leaf dry weight was observed in interactions between irrigation levels of 100 and 50% and different levels of cultivation respectively 3686.66 and 2453.33 kg / ha. The highest intermediate interaction between irrigation levels of 100% and 50% and different levels of culture on root fresh weight was 3626.66 and 2526.66 kg / ha, respectively. The highest mean root dry weight was observed in interactions between irrigation levels of 100 and 50% and levels Different cultivars are 1276.6 and 903.3 kg ha-1 respectively. According to the data obtained from this study, the lowest amount in the control treatment and the highest amount of the obtained values are related to the combination of 4.5 kg bentonite and super absorbent polymer, and can be affected The combination of these two treatments was observed on the plant.

Therefore, the results show that the application of bentonite and superabsorbent polymer will have a positive effect on plant growth and can increase the plant's resistance to water stress and the highest yield of chicory plants in Birjand region was observed. absorbent polymer, and can be affected The combination of these two treatments was observed on the plant.

Water and tillage-induced soil erosion on steep slopes farmlands are primary causes of land degradation process that gradually change land morphology. Measurement of soil erosion and sedimentation in most watersheds are nearly impossible. So soil erosion modelling and simulation to understand the processes of soil erosion, to predict runoff and soil erosion and also to determine the best management practices of soil conservation is highly important.

Area of study (Sample sub- catchment) is a sub-watershed of the Kachik watershed in Golestan province, which is one of the sub-basins of the Gorganroud basin. This area is around 197 ha which completely covered with fertile and erosive loess deposits and is a part of Iranian Loess Plateau (ILP). In this study, WaTEM / SEDEM version 2004 used to estimate water and tillage erosion. After soil sampling in 20 different location respected to the model based sampling method on minimax approach, 137Cs activity determined, and all three distinct erosion phases prepared. Finally, erosion map using 137Cs by considering conversion models including Mass Balance II for farmland and Diffusion and Migration for other land uses produced. Then the erosion and sediment point map produced separately for model evaluation.

Using 137Cs radionuclide, 90 % of the soil measurement locations devoted to erosion. Mean annual soil erosion using radionuclide conversion models was 21.1 ton ha-1. This rate of soil erosion regards to 97% SDR (Sediment Delivery Ratio) illustrates high potential for sediment production in the area of interest. Mean of water and tillage erosion by WaTEM/SEDEM were 8.28 and 4.87 ton ha-1 year-1 respectively in erosion locations and this rate for sediment was 18.14 and 7.89 ton ha-1 year-1 for sediment zones as well. Soil erosion and sedimentation rate using WaTEM/SEDEM model was estimated to be 1.46 and 0.85 ton ha-1 year-1 in turn. SDR for WaTEM/SEDEM in this study was around 58 %.

Given that the entire study area covered with sensitive and fertile loess deposits, and a significant percentage of area devoted to farmland, so water and tillage induced soil erosion is of great importance. The results of this research indicate a low estimation (under-estimation) of the WaTEM / SEDEM model compared to the actual values (measured 137Cs). As a result, WaTEM / SEDEM erosion model is not effective in the loess deposits of the northeast of Golestan province. On one hand spatial pattern of water and tillage induced soil erosion can be used in soil and water conservation practices. On the other hand, pertaining to large vast area devoted to farmland in Gorganrood Basin, tillage erosion should be taken by decision maker. Although for higher certainty, it is necessary to calibrate the model and repeat its implementation in other watersheds.

Water as the most scare input in the production of agricultural products is not only a limiting factor for agricultural activities, but also is obstacle to other economic and social activities. Water supply of different sectors faces a lot of constraints with increasing population and development in different dimensions and rising standards of living. Therefore, appropriate policies should be used to manage water demand. One of these policies is the pricing of water resources in different ways in the agricultural sector. Investigation of internal studies on water valuation shows that there is a great difference between the economic value of water and paying farmers for water. Water pricing policies based on the economic value of water can be effective in allocation and optimal use of water. Therefore, it is necessary to do various studies in order to apply appropriate policies to the climatic conditions of different regions. Pricing policies in different parts of the country in most cases are used only by area pricing. Due to the problem of water crisis, the growing demand, and the gap between water supply and demand, area-based pricing method does not provide sufficient incentives for optimal use of agricultural water. Therefore, this study examines the different methods of water pricing such as area pricing, volumetric pricing and combination of both. Therefore, this study examines the optimal consumption of water resources for the purpose of water and soil conservation in Gonbad-e-Kavous County, Golestan province. This syudy considered the volumetric pricing and composition of volumetric with area-based methods in addition to area-based pricing method that is the innovation of this study. Since different agricultural policies can not be investigated and analyzed in the laboratory environment, so the potential effects of these policies should be investigated by appropriate instruments of policy before, during and after the implementing of policy. Therefore, due to the importance of the subject, in this study, the Positive Mathematical Programming (PMP) model is used to simulate farmers' behavior in the downstream lands of Golestan Dam (1) in Gonbad-e-Kavous County, in the implementation of various water pricing methods such as Area-based, volumetric and mi combined of them. In this study, data were collected using random sampling method and 20 scenarios were investigated. The GAMS software package is also used to analyze the information in this study.The results of this study show that water demand in all three methods (area-based, volumetric and combined) will decrease from 22.6 to 48.8% as water price rises in different scenarios. The highest and lowest water demand reduction is related to the area-based and combined water pricing method, respectively.Applying appropriate water pricing methods makes water be distributed optimally between users based on the value of marginal product and provides incentives to save and prevent loss. Therefore, based on the results of this study, it is recommended to use a volumetric and area-based pricing method in combination.

Soil erosion is a major global challenge that its control by appropriate and proportionate methods is necessary. In recent years, various studies have been carried out using amendments and chemical stabilizers to reduce the detrimental effects of runoff and soil erosion. Environmental problems, low efficacy and time-consuming, low availability and high volume requirements have challenged the use of amendments in the usual form. Therefore, due to the proper performance of the amendments to reduce runoff and soil loss, improving the quality of the amendment is inevitable. Nowadays, various wastes are currently produced in important industries, including wood and papermill. In this regard, the fine corrugated and small particles in the effluent of paper mills can be mentioned. Residual fine amendments is a part of fibers that are unavoidably crushed in paper production and recycling processes. Therefore, due to the problems caused by the excessive amount of fines in the process of paper production and the ability to store water in the soil, it seems that it can be used as a natural amendment to reduce runoff and soil loss.

The present study was carried out to investigate the effectability of runoff generation and soil loss from fine corrugated amendments at small experimental plots. To conduct the study, the soil carried out from the marginal area of the Marzanabad-Kandalous region located in the west of Mazandaran Province. The soil was air-dried and then crossing a 3 mm sieve to put into 50×50 cm plots with a height of 30 cm was filled from the bottom to a depth of 18 cm of mineral pumices as a drainage layer and for the top layer of soil 2 and 8 mm. Treatments were studied at three levels of 0.5, 1 and 1.5 )L m-2 ( and each with three replications in liquid form and uniform spraying on 18 plots with pure water additive and control (dry) and in laboratory scale under rainfall simulation was performed with intensity of some 70 )mm h -1 ( and duration of 30 minutes.

The results showed that use of fine amendment with three levels of 0.5, 1 and 1.5 )L m-2 ( decreased runoff volumes (P>0.05) and soil losses (P<0.05) of -35, -5 and +15; 47, 84 and 71% compared to those of the treated plots by fine, respectively.

The results of this study show that the application of biocompatible amendment from wastewater of papermills is recommended to prevent entering into the water and soil resources in order to reduce runoff generation and soil losses in sensitive areas of the country facilitating sustainable development. It further leads to reduce runoff generation and soil losses in sensitive areas of the country facilitating sustainable development.

Knowledge about land uses and their changes over time is a significant factor in land-use planning and management. This could be used to predict future changes and to take appropriate preventive actions. Public participation approach for land use planning and preventing improper land uses are important practical tools for optimizing water, soil and plant management. In this research, public perception on land use modification in Chehel-Chai Watershed, Golestan Province (Iran), was investigated through field surveys.

A questionnaire was prepared and its validity and reliability was confirmed by expert elicitation from academics and experts and Cronbach's alpha test (α = 0.87), respectively. The statistical population of this study includes villagers in Chehelchai watershed. The total population of this catchment area is 13,017 people, 373 of whom were randomly selected from among the total population. Descriptive techniques within SPSS software was used for data analysis. At first, factors that hinder the improvement and optimization of land use owned by the villagers and farmers were identified and scored. Then, the factors that promote the acceptance of land use improvement and optimization operations by farmers and villagers were investigated.

The results indicated that the most important factors hindering land use optimization are the lack of financial power of the villagers, lack of support from banks and government institutions, farmers' lack of awareness and low value of agricultural land in terms of production per unit area. The most important factors that could improve land use modification are involvement of people in the formulation of solutions and planning, assurance of ownership of cropland, providing financial and spiritual incentives, farmers' convenient access to engineers and experts and organizing extension and training courses and classes. Finally, by comparing popular acceptance of land use optimization strategies, it has been shown that villagers are in agreement with the option of permanent crop cultivation to optimize landslide slopes, as well as the conversion of sloping croplands to gardens, and, if performed, and Land use improvement program The villagers are prepared to implement land reform programs and, if they plan, plan more than three quarters of their land for implementation of operations and programs.

Overall, the most important action to be taken before implementing the watershed programs in the villages is to increase the villagers' awareness of such programs and involve them in the early stages of the program implementation. Public acceptance of participatory programs are much higher.

Flooding occurrence with rare return periods in most regions of the country, and its harmful human and financial effects which are intensifying often due to human actionshas brought the issue of flood management under more attention. Numerous numerical models have been developed to simulate flooding. These hydraulic models are three types, i.e., one-dimensional, two-dimensional and three-dimensional. Due to the fact that it is necessary to simulate inundation accurately with low cost, a two-dimensional horizontal hydraulic model called Nays 2D Flood was used in the present study.

aforementioned model was used for a short period of time, it's before joining the Gorganrood River for the flood event occurred on March 20, 2019, as this phenomenon is one of the rare floods for region. For this purpose, a DEM with one meter resolution and flood hourly hydrograph were given to the model. Then an appropriate grid was determined and the roughness of the channel and flood plain were mapped using the Google Earth images in the model software environment.

The results of this simulation include maps of depth and flood zone and flow rate. The results were evaluated by computing the F coefficient and comparing the area calculated by the model with the images recorded by Sentinel2 satellite on the same date. The F statistic was calculated to be 0.78 in the present study. This number indicates that there is an acceptable match between the area calculated by the model and the area observed by the satellite. The flood area is 13.95ha in the satellite image, while the simulated area was estimated 14.30ha by the model. To evaluate depth results, from rating curve data were used. The depth calculated by the model is 6.22 m on 5 April 2019. At that date, the depth of water was observed according to the rating curve measuring 6.63 meters. The error rate in this evaluation was calculated 6.18%.

These results suggest that the Nays 2D flood model has an acceptable function and it can also be used in future research. Since the flood movement in the flood plain is in length and width, two-dimensional models that take into account this fact are preferred one-dimensional models. The results of this study and similar research indicate the good accuracy of these models in simulating the flood zone outside the river channel. Having a high resolution DEM, the model can be used successfully without channel sections data when the flood has spread out of the channel bed.

River water temperature has both economic and ecological significance when considering issues such as water quality and biotic conditions in rivers. This parameter affects directly other water quality parameters and plays a major role in the quality of aquatic life and habitats. Consequently, with wide application of water temperature for conducting environmental impact assessments as well as for effective fisheries management, it is important to understand the thermal behavior of rivers and related heat exchange processes. Numerous deterministic and statistical models have been used for prediction of river water temperature by researchers. These modeling were generally based on the air temperature, yet. However, the river hydraulics and metrological parameters may have their special effects on river water temperature. Furthermore, there are limited researches undertaken by novel and intelligent algorithms. Hence, in this study, gene expression programming has been used for estimation of the water temperature of the MohammadAbad river located in Golestan province. In addition to the air temperature, the river hydraulics and metrological parameters were also accounted for modeling river temperature.

Gene Expression Programming (GEP) is an evolutionary algorithm that uses a population of individuals and selects individuals according to fitness, and introduces genetic variation using one or more genetic operators. For the water temperature modeling, the river hydraulics and meteorological parameters including river flow discharge, flow velocity, air temperature, humidity, wind speed and cloud cover during 7-year statistical period (2006-2012) were considered as input parameters and river water temperature was selected as output parameter.

Based on the comparison of the results of different GEP models with 1 to 6 input variables, it was concluded that the GEP model with 6-parameters has the highest accuracy in terms of the coefficient of determination and the root-mean-square error. These values were obtained 0.92 and 1.8˚C for training data and 0.90 and 2.3˚C for the testing data. The mean absolute errors of this model were obtained as 14.67% and 12.80% for training and testing phases, respectively, while the error of linear regression model was obtained greater than 38%. Results showed that in comparison with the multiple-linear regression model, the GEP model has better performance for river water temperature estimation.

According to the results obtained in this paper, one can use the GEP model for prediction of river water temperature with acceptable accuracy. It is concluded that in addition to the air temperature which has the highest impact on the river temperature, the river flow discharge also has considerable impact.