Journal of Water and Soil Conservation
Year:2021 | Volume:28 | Issue:1|Papers Count:13

Background and Objectives: Nowadays the dust phenomenon is one of the biggest environmental problems in the world, causing major damage to sectors such as industry, transportation, agriculture, tourism and human health each year. The dust storm, which commonly occurs in arid and semi-arid regions such as the central and southern parts of Iran, carries a large amount of dust and reduces daily human activities and horizontal visibility. According to the World Meteorological Organization (WMO), when the wind speed exceeds 15 meters per second and a large amount of dust enters the atmosphere so that the horizontal visibility reaches less than 1000 meters, dust storms are reported. The creation of dust is caused by natural and man-made factors, the human component of which is mainly a response to changes in soil cover and land use. One of the objectives of the present study is to monitor the location and source of dust (origin and destination of dust) and the movement of dust storms and streams/trajectories containing dust. Materials and Methods: In this study, meteorological data including temperature, relative humidity, rainfall, evaporation, wind speed and number of dusty days from 3 meteorological stations of Qom province were obtained from Meteorological Organization and analyzed. Also in this study, to determine the potential dust sources by the maximum likelihood and minimum distances classification methods was done to determine the land use and soil type of different areas with Landsat images. This process was completed using time series images of Qom province in 30 years, from 1989 to 2019 with 5-year steps and monitoring the changes of this period with in 11 different classes. Next, according to the recorded dust data (horizontal visibility) at Shokouhieh/Qom Meteorological Station showing the occurrence of dust storms as defined by the World Meteorological Organization, backward tracking of air trajectories using the HYSPLIT meteorological model. The backward trajectory, if it is close to the surface of the earth and the area potentially capable of spreading dust from the surface into the air, can be considered as the source of the dust phenomenon. Results: The results identified 30 areas with different soils and cover as the source of dust. There were 20 spots of bare land, 5 spots of salt land and 5 spots of sandy land. The main sources of dust events studied in this province (Codes 06 and 07) are located in the eastern half of the province adjacent to the Namak Lake and the Dasht-e Lut. In the final part of the present study, meteorological data that directly report the occurrence of dust storms were first analyzed. Then, based on the recorded data and some restrictive conditions, the target dates that the dust storm defined by the World Meteorological Organization at that time were selected. Codes w=06 and w=07 are related to the dust phenomenon, and both codes are used in this study. These events are mostly local and regional (within the country) and mostly include small events. One of the innovations of this research is the combined view of soil cover and land use in the study area and also the investigation of dust events. Conclusion: The results of HYSPLIT model show that the main sources of dust events studied in this study are from neighboring eastern regions such as Semnan, around the Namak lake, Lut plain, and etc. These storms are ultimately considered as a domestic dust event. About 15 percent of the total dust storm events in the studied dates are likely to have been foreign dust. These events are mainly of foreign source and have been imported from western and southwestern Iran countries such as Iraq, Saudi Arabia and perhaps Syria and are modeled as foreign dust and generally considered as sever dust storms.

Background and Objectives: One of the most important issues for mankind in the present century is access to water resources. Increasing population growth and expanding industry have made agricultural development in arid and semi-arid regions a major challenge. The depletion of water resources and the critical situation in the drinking, agricultural, industrial and environmental sectors are a major problem. An essential principle is the relative balance of water supply and demand that emerges with the creation of a comprehensive water management system. Materials and Methods: The present study was carried out in Hirmand catchment in Sistan area, focusing on the issue of Hirmand river flow and the volume of Chah Nimeh. In order to control the alignment of Chah Nimeh, modeling steps were developed and the basis of the problem was investigated in the process of forming flow-storage diagrams. Using Vensim software, the effect of each variable was simulated on the problem and the calibration and model validation were fitted to different methods such as statistical tests. Results: The results of the tests show that the model corresponds to reality and the model behavior is consistent with the behavior of the system in reality. According to the statistical tests performed, between the observed and simulated values for the well reserves variable, the coefficient of determination is equal to 0. 84, the root mean square error (RSME) is equal to 0. 25 and the Nash-Sutcliffe criterion is equal to It is 0. 77 in 2019. According to the findings, the demand for various agricultural, drinking and environmental needs will increase in the coming years. The total demand in 1410 will increase from 1350. 01 to 1515. 93 million cubic meters, which will be impossible to meet the needs despite the reduction of system resources. The largest increase in demand will be in the agricultural and drinking sectors. Conclusion: The results show that the irrigation efficiency policies of 70% in the agricultural sector and the reduction of water losses (reduction of evaporation by 50%) based on the proposed scenarios were implemented by the model. Examining the results of these scenarios, it is seen that each of these solutions will reduce water shortage in the coming years, but the best result has been achieved in the first scenario (70% irrigation efficiency in the agricultural sector). In general, the findings show that the continuation of the current consumption trend and, consequently, the continued withdrawal of water resources with the same trend, will have irreparable effects. In this situation, modeling optimal consumption in different sectors, observing limit conditions and creating a culture based on non-extravagance is one of the key issues in crisis management and is one of the most basic foundations of consumption management.

Background and Objectives: The large-scale computational network of planetary models are not able to predict climatic variables on a regional scale. In other words, these models are affected by processes with a smaller scale than the model network in providing predictions of regional precipitation. Therefore, the model outputs should convert into a regional scale. The research purpose is to investigate the different configurations of the WRF model in the simulation of 5-days rainfall in March 17 to 22 March 2019 in Golestan province, which has caused devastating floods and heavy damage in the province. Materials and Methods: The observation and quality control precipitation data was analyzed in 13 synoptic stations of Golestan province for a 5-days period from March 17 to 22 March 2019 in the form of 24 Hours (From 06 UTC the day before to 06 UTC the next day) and 6 hours (00, 06, 12 and 18 UTC are 3: 30, 9: 30, 15: 30 and 21: 30 local time, respectively). Also, two types of input data including initial condition data and boundary condition data were used in the WRF model. The boundary condition data was GFS data with 0. 5-degree resolution. Furthermore, two domains were used in WRF model, 1) the large (mother) with a horizontal resolution of 18 km and 2) internal domain, which is the main domain and has 6 km horizontal resolution. Results: Two configuration was selected which showed better output results. The 5-days cumulative precipitation data which caused the flood show that the maximum 24-hour precipitation during the 5-days period is 06: 00 UTC on March 18 to 06: 00 UTC March 19 and the maximum cumulative rainfall of 6 hours is related to 06 to 12 UTC on March 18, 2019. Subsequently, by study similar research in Iran, different configurations for precipitation prediction were extracted and modeled. Then, in order to determine the accuracy of the model, the values obtained from the model in different configurations were compared with the values of synoptic stations. To ensure this comparison, MAE, d, R and ENS test statistics were used. Conclusion: The results showed that the WRF model overestimate the precipitation data in most stations. In both configurations, results convey the precipitation cores well illustrated and the model accuracy was good enough in predicting precipitation. In maximum values of precipitation, the configuration of the first type show better results. Overall, the first type configuration performed more accurate than the second type configuration.

Background and Objectives: Soil erosion is of the main global challenges for agricultural and food production. The indiscriminate intervention of man in the nature is of the main reasons for erosion. The success of any conservation program requires an understanding of the various aspects of human behavior. Behaviors are mainly emerge from the people’ s knowledge and attitudes. Farmers' attitudes can influence their behavior to adopt conservation practices. Studying the attitude and behavior of farmers towards conservation practices can play a crucial role to help managers and decision makers in understanding the reason for farmers' conservation behavior and to modify and improve it. Several studies have been conducted worldwide on the adoption and application of soil and water conservation methods. Many of them have focused on the purely socioeconomic aspects of the adoption. While the current study examined the attitude of farmers towards conservation practices, access to facilities for and barriers to the application of these practices. The study also examined the perceptual-attitudinal and socioeconomic aspects affecting the implementation of conservation practices. Therefore, the conservation behavior of farmers in Talkhehrood basin in Harris County, East Azarbaijan province has been studied from different aspects. Materials and Methods: The aim of this study was to investigate the attitude towards conservation practices and the application of these practices. Survey research method was used in this study. A sample of 220 farmers was selected using Cochran's sampling formula and the necessary data were collected using a face to face interviewing procedure. The random multistage sampling method was used to select the sample farmers. The instrument of the study was a questionnaire. Most sections of the questionnaire was in the form of 5-points Likert items. It was validated by a panel of university staffs and field experts of agricultural and natural resources. A pilot study was conducted using 30 farmers from out of the sample villages for reliability and correction of the questionnaire. The calculated values of Cronbach’ s alpha showed that the questionnaire has sufficient reliability. Results: The results showed that farmers had a positive attitude towards conservation practices. Among the 12 selected conservation practices, compost application, dredging of irrigation canals, weeding and retaining crop residues were at the above-average level. The use of other methods was below the average. Creating windbreaks and flood dam was very weak. Respondents perceived that land fragmentation and lack of financial ability were the most important obstacles to the application of conservation practices. Significant correlations were found between the implementation of most conservation practices. Based on the regression analyses, attitude and access to facilities were the most important perceptual-attitudinal factors, as well as education and farming experiences were the most important socio-economic factors explaining the implementation of conservation methods. Conclusion: The results showed that while farmers had a relatively positive attitude towards soil and water conservation practices, they implemented low-cost and quick-return practices using available facilities. Due to the lack of financial abilities, the use of practices that required financial investment was not much common among them. Removing barriers and restrictions, providing the necessary facilities and providing educational and extension programs can be effective in promoting the implementation of these practices.

Background and Objectives: The accurate estimation of the dimensions of the wetting pattern is one of the important parameters in the design of drip irrigation systems, which reduce deep water losses and additional costs of irrigation system design. The wetting dimensions of moisture bulb are affected by the pattern of moisture distribution in the two phases (distribution and redistribution). Various studies have been conducted on the pattern of moisture distribution in sloping lands, but few studies have been carried out or not reported on the pattern of moisture redistribution in these lands. Therefore, the main purpose of this study is to investigate and simulate the pattern of moisture redistribution in sloping lands. Also, in similar studies, the dimensions of the wetting pattern have been usually simulated on the soil surface, but in this research, in addition to the dimensions and wetting area, the full shape of the moisture bulb has been simulated. Materials and Methods: In this research, two physical rectangular cubic models with dimensions of 1. 2 * 1. 2 * 0. 6 m and 1. 4 * 1. 2 * 0. 7 m were constructed to monitor the soil moisture advance front. These experiments were carried out for four different slopes (0, 10, 20 and 30%), three soil types with different textures (coarse, medium, fine) and three emitter discharges (2, 4, and 6 lit/hour). This study was aimed to simulate the wetting area in a drip irrigation system on slope land. The duration of irrigation was 4 hours and the redistribution wetting front was recorded for different times (e. g., 3, 6, 18, 42, and 66 h) on the Polycarbonate plate. Then, using the nonlinear regression analysis several equations were proposed to predict the redistribution pattern in slopping lands. In the proposed models, emitter flow rate, the volume of applied water, irrigation time, saturated hydraulic conductivity, the soil bulk density, the land slope, the percentage of sand, silt, and clay were utilized. Also, using an enhanced proposed model, the full shape of wetting bulb was estimated. Results: The suggested models had the high accuracy in heavy soils with the average values of RMSE and MAE for the wetted radius equal to 0. 34 and 0. 28 cm, respectively. RMSE and MAE values for the wetted area were 0. 0018 and 0. 0014 m 2, respectively. The suggested models had the low accuracy in light soils and RMSE and MAE statistical indices for wetting radius were 0. 44 and 0. 37 cm and for wetting area were 0. 0029 and 0. 0022, respectively. The values of calculated statistical indices for the wetted depth of the moisture redistribution front were similar for all the studied treatments and the values of RMSE and MAE varied between 0. 43-0. 5 and 0. 31-0. 39 cm, respectively. Also, the CRM values of the models are mostly positive and their NS is about 0. 99 for all the studied treatments. Conclusion: The results of this research showed that the suggested models have higher precision in heavy soils than light soils. Also, the suggested models have acceptable ability to estimate the wetting radius, upstream and downstream area of the emitter, the wetting depth as well as the full shape of the moisture bulb. The prediction values of the models were mostly underestimated. Therefore, the use of these models recommended for determining the exact location of the emitters in sloping lands, to reduce deep percolation losses and optimal use of water via the plant.

Background and Objectives: Detailed soil maps are an essential tool for achieving sustainable management. Despite advances in digital soil mapping and efforts to produce accurate maps, insufficient reliability of soil maps on many scales remains. Recent studies have focused primarily on remote sensing, which takes into account the characteristics of the subsurface of the soil. This study used a new interpolation method between subsurface characteristics and soil diagnostic properties to increase the accuracy of the prepared maps. In this study, the production of soil maps with two approaches including use of geomorphic surfaces as well as the interpolation of subsurface characteristics of the soil in the Chalous region were examined. Materials and Methods: The study area with an area of 100 hectares in Bandar village is one of the functions of Kelardasht section of Chalous city in Mazandaran province. The thickness or depth of the upper / lower boundary of characteristic horizons or characteristic soil characteristics was used as a criterion for distinguishing soil map units. According to the Comprehensive American Soil Classification System, there are six influential characteristics in the division of regional soils at the family level (Upper Combine horizon boundary, argillic horizon upper boundary, calcic horizon upper boundary, Malic horizon thickness, limestone or limestone thickness or the numerical interpolation of these features was used to generate thematic maps. The final soil map of the region was obtained by combining these six thematic maps. After mapping each of the soil properties separately, all the prepared maps were crossed and a map of homogeneous units was obtained. In order to study and describe the spatial structure of the variables, a semivariogram was used. The existence of data trend and heterogeneity was also examined. After preparing the change curves, the selection of the best models was done using cross-validation method and RMSS index. Results: In order to prepare the soil map using the geomorphic surface method, out of 20 soil units identified, 12 soil units were of the same type and 8 units were of the community type. However, all 20 map units obtained by interpolation of subsurface features were of the same type. This method had high accuracy in drawing the boundary between soil units. The main differences between this method and traditional methods are in the production of detailed soil maps, the use of supervised automatic interpolation instead of manual interpolation, and the use of a set of quantitative indicators. Conclusion: One of the major advantages of this method is the use of internal characteristics of the soil as an auxiliary variable along with other climatic factors, topography, living organisms, parent material and time. This study underscored the importance of the role of factor s in the SCORPAN model and showed that the internal properties of the soil, which are directly involved in soil classification, can be effectively used to separate soil units.

Background and Objectives: Human activities such as deforestation, conversion of natural ecosystems to farming, biomass burning, tillage and cultivation, grazing, fertilizer use have a significant and negative impact on soil organic carbon pool. In particular, the conversion of natural ecosystems to agriculture reduces soil organic carbon pools. Understanding the spatial distribution of organic carbon in soil is particularly important for understanding the role of soil in the global carbon system. Therefore, the purpose of the present study was to investigate the changes of total carbon and its components in different sizes of aggregates of a forest soil after conversion to paddy. Materials and Methods: For this study, Poplar Research Station in Guilan province was selected. Soil samples were collected from two uses of forest and adjacent paddy fields at two depths (0-20 and 20-40 cm). The factors included land use type at two levels and soil depth at two levels that were studied in three replications. Therefore, the number of experimental treatments was 4, and by applying 3 replications, there were a total of 12 experimental units. In the soil samples, aggregates of different sizes (>2 mm, 2-0. 25 mm, 0. 25-0. 053 mm and <0. 053 mm) were separated and the amount of organic carbon in these aggregates was measured. Organic carbon was then densified based on density in different sizes of these aggregates. Results: Investigation of organic carbon distribution in relation to aggregate size in two land uses showed that with increasing aggregate size, organic carbon content increase. The amount of organic carbon is 4. 5 and 3. 3 times higher in Populus natural forest and rice fields (average of two depths per use) in aggregates larger than 2 mm (larger aggregates) than smaller aggregates 0. 053 mm, respectively. The amount of organic carbon in the aggregates decreased with the change from natural forest to paddy fields. However, the decrease was greater in aggregates larger than 2 mm and lowest in aggregates (0. 25– 0. 053 mm). Results of soil organic carbon fractionation showed that percentage of soil weight in fractions increased with increasing density in two land use. This situation was visible in two depths and in all the aggregate sizes. By increasing the density of fractions, the concentration of organic carbon in the fractions decreased. The organic carbon content of the fractions as a percentage of organic carbon content of whole soil, in all the aggregate sizes, and in the fractions with density < 2 g cm-3 was smaller than those of fractions with density > 2 g cm-3. In all of the aggregates, with increasing depth, organic carbon content of the fractions with density < 2 g cm-3 as a percentage of organic carbon content of whole soil decreased while those of the fractions with density of > 2 g cm-3 increased. By increasing the density of fractions, the C/N ratio of the fractions decreased. In all of the aggregate, due to the change of land use from natural forests to rice field, organic carbon content of the fractions as a percentage of organic carbon content of whole soil, reduced in the fractions with density < 2 g cm-3 and increased in the fractions with density > 2 g cm-3 and this was more pronounced in aggregates of larger size. The most sensitive and resistant fractions to land use change were fraction <1. 6 g cm-3 (free particulate organic matter and occluded particulate organic matter) and fraction > 2 g/cm 3 respectively. The ratio of carbon to nitrogen decreased as a result of land use change from natural forest to the rice field. Conclusion: The change of land use and long-term cultivation in virgin forests and its transformation in rice field has changed organic carbon content of the fractions. The amount of free and occluded particulate organic matter in the aggregate (light fraction), which plays a very important role in the nutrition of the crop, was greatly reduced. This reduces the soil's health and the potential for carbon sequestration in the soil.

Background and Objectives: In the northern provinces of Iran, in many areas, the relative humidity reaches more than 60% and in some cases even more than 80%. On hot days of the year, gas coolers in these areas, produce large amounts of water by condensing the moisture in the air, which in most cases becomes unavailable regardless of its quantitative and qualitative management. Identification of new water resources will lead to the use of various uses and protection of existing resources in order to sustainable management of water resources. Therefore, in this study, with a managerial approach, the quantitative, qualitative and economic potential of water produced from gas coolers in Gorgan as a new source of water was investigated. So far, no comprehensive study has been conducted to estimate the quantity and quality of water produced from condensate of gas coolers in Gorgan and to estimate the existing potential by considering the energy consumption. In this research, the management of water obtained from condensate of gas coolers in Gorgan has been studied. Materials and Methods: In this study, Gorgan was divided into four main regions. In these areas, the quantitative and qualitative conditions of produced water, the effect of cooler power on the amount of water produced, and the influence of various parameters on the choice of cooler power to be purchased by users, were studied over a six-month period. Also, with the average power of 21, 000Wh and the tariff of electricity consumption, the price of water produced was calculated. For statistical analysis, t-test and ANOVA were used and the level of P<0. 05 was selected as the significance level. Results: The results showed that obtained water had a neutral acidity, low turbidity and alkalinity and hardness. The mean water produced were 25. 5, 29. 8 and 22. 67 for split and 13. 79, 18. 13 and 13 liters per day for window coolers, respectively, in the first to third periods (Two-month time intervals). The water produced in the splits (Double coolers) was more than the window type and with the increase of air conditioner power, the water produced in both types of air conditioners increased. Also, two factors of area covered by coolers and building insulation had the most influence on the choice of air conditioner. Conclusion: According to the results, accumulation of cars and overcrowding affect the quality of produced water. In this city, on average, a considerable amount of 3542 m 3 of water is produced daily through condensate water coolers, which can also be used for sensitive applications (such as washing the body and face and contact with the skin and eyes) due to its high quality. Applying some assumptions and considering 50% of the cost of consumed electricity, the cost of water production per liter will be 3173 Rials, which is approximately 25% of the final cost per liter of market drinking water. So according to the results of this research, by creating a network of water outlet aggregation of home air conditioners using a simple piping in apartments and towns and considering the storage source, a considerable volume of water can be used for different purposes in each apartment or even different towns. Therefore, solutions such as forcing the creation of water collection network of gas coolers for buildings under construction in cities with high relative humidity and creating sites for the use of water production devices from the atmosphere can be an appropriate solution.

Background and Objectives: The drying up of Hur al-Azim wetland has caused turn in it to Sabkha. The increase in Sabkhas has caused the salinization of the fertile lands of Karkheh and the destruction of agricultural lands in this region, It also creates puffy soils that act as a fine dust center. Sabkhas changes rate of Hur al-Azim wetland margins have not been studied so far. Because of the socioeconomic and environmental importance of this wetland, such research is severely needed. The aim of this study is to evaluate the changes rate of Sabkhas that caused by the drying of Hur al-Azim wetland in a period of 20 years, which is the first research of its kind. In this paper, for the first time, the rate of change of the Sabkhas in different classes was examined and determined. Also, the rate of increase of the Sabkhas has been compared with long-term climate change. Monitoring the changing process of wetlands and their surrounding lands can be helpful in managing these ecosystems, and preparing sabkhas Destitution maps and their changes maps can help environmental and natural resource managers in making more sensible decisions, better land use planning, and improving resource management. Materials and Methods: In this study, Landsat 8 images in 2017 and Landstat 5 in 1997 were used to study the Sabkhas changes and mapping caused by Hur al-Azim Wetland over a 20-year period. The study area was divided into 8 classes, which include: wetland, forming Sabkhas, dried wetland, salt ponds, dark Sabkhas, light Sabkhas, abandoned agricultural lands and agricultural lands. Then, the supervised classification method and the support vector machine method were used to prepare the map of the area. The post-classification comparison method has also been used to investigate changes in the 20-year period. Also, to check the changes in the 20-year period, comparison after classification method was used. Results: The results of classification accuracy showed that the backup vector machine method was obtained in Landsat 8 image with kappa coefficient of 0. 79 and overall accuracy of 84. 70 and in Landsat 5 image with kappa coefficient of 0. 74 and overall accuracy of 81. 42. It turns out that the support vector machine algorithm is a good way to classify this area. Also, the results of the 20-year period changing review, using the comparison after classification methods were showed that classes of dried-up wetlands, salt ponds, and abandoned agricultural land have changed dramatically over the past 20 years. Decreased changes were observed in classes of wetland, agricultural fields, dark Sabkhas and light Sabkhas. Examination of the average long-term rainfall-temperature data in the region shows that the temperature has increased and the amount of rainfall has decreased in the region, which has been one of the affective factors on the region changes. The only class that has not changed during the period of this study was the class of forming Sabkhas. Conclusion: The results show that the change rate is high in the study area during this 20-year period. One of the reasons is the changes in the wetlands area in recent years. The results also show that by using remote sensing methods with fewer number of points, in addition to saving time and money relatively accurate maps can be prepared and a useful method for examining changes in the amount of Sabkhas is to compare past and present classified maps.

Background and Objectives: In the oil-rich country of Iran, pollution of soil with petroleum compounds is a very important factor for pollution. Gasoil is one of the major products of crude oil and is a major source of environmental pollution. Currently, there is an urgent need to prevent the expansion and distribution of oil pollutions as well as their derivatives. Organic carbon has gained attention as an effective compound in applied management programs of environment conservation. The present study aimed to evaluate the refining of total petroleum hydrocarbon content, determining its kinetic model during the application of refiner and quantitative investigation of the effect of active carbon weight and grain size on the attenuation rate of total petroleum hydrocarbon. Materials and Methods: The soil polluted with gasoil was collected from the vicinity of the gasoil tanker located in Shiraz refinery. Then, after measurement of the amount initial total petroleum hydrocarbon content and physical and chemical properties of the polluted soil, 700 gram soil samples containing active carbon at 0. 05 and 2. 05 mm sizes and 20, 40, 60, 80 and 100 g kg-1 weight doses were prepared as pilot. The samples were then rested in a 50% constant humidity for four weeks at 28 ± 2 ° C and were aerated and incubated two times a week. Finally, the results of the changes in the total petroleum hydrocarbon and microbial activity over time were reported after statistical analysis. Results: The results showed that the application of active carbon had a significant effect on the reduction of gasoil pollution of the soil. The results related to determination of the kinetic model for the reduction of pollution during the biochar application process showed that the kinetic of reduction in total petroleum hydrocarbon was of first order equation; so that in 100 g kg-1 active carbon treatment, the lowest half-life was 21. 13 days, and the half-life of control soil was 78. 76. The results of total petroleum hydrocarbon showed that there was a significant reduction of total petroleum hydrocarbon content in all active carbon treatments. Investigation of bio-respiration (activity index of degrading microorganisms) showed that the application of active carbon in smaller sizes and amount higher weights led to improved hydrocarbon degradation. The biological efficiency of active carbon was calculated 38 percent at the end of the 60 day period. Conclusion: Application of active carbon refiner in the gasoil-polluted soil is a cheap, effective and environment-compatible method which provides a suitable environment for the plants and soil microorganisms if utilized properly in the polluted soil. This method may be utilized in remediation of the polluted soils as a pre-refining method alone or along with other biological methods (depending on the extent of the pollution and the required remediation).

Background and Objectives: Evapotranspiration is one of the most critical components in the land branch of the hydrological cycle, which, as the link between water and energy cycles, plays an essential role in the interaction of the atmosphere and surface. Getting access to remote sensing images has made it possible to study evapotranspiration spatially and temporally, including actual evapotranspiration (AET) and potential evapotranspiration (PET). Evapotranspiration of the MOD16A2 MODIS sensor can be very useful among remote sensing images due to its very appropriate spatial (500 m) and temporal (8 daily) resolutions in regional studies in areas without data. Materials and Methods: This study evaluated the MODIS global terrestrial potential evapotranspiration product (MOD16A2) using two reference evapotranspiration methods of Penman-Monteith FAO 56 and Priestley-Taylor in meteorological stations from 2001 to 2018. The study area is located in the southwestern provinces of Iran (Khuzestan and Bushehr), west of Iran (Hamedan and Kermanshah provinces), and north of Iran (Guilan and Mazandaran provinces), which is classified from arid to hyper humid according to the UNESCO method. Then, Penman-Monteith FAO 56 and Priestley-Taylor reference evapotranspiration was prepared using meteorological data with the Evapotranspiration package R software, and the potential evapotranspiration data of the MOD16A2 product was provided using the Google Earth Engine system. Then, these data were compared based on evaluation metrics in different climates. Results: Compared to both the Penman-Monteith FAO 56 and Priestley-Taylor methods, the MOD16A2 product overestimates evapotranspiration in all climate types and has a greater variance in data. The statistical properties of the MOD16A2 include: the first and third quarters in arid and semi-arid climates with Penman-Monteith FAO 56 evapotranspiration is less different than the Priestley-Taylor method. In contrast, the first and third quarters of the MOD16A2 are more similar to the Priestley-Taylor evapotranspiration in semi-humid, humid, and perhumid climates. MOD16A2 also estimates the seasonal evapotranspiration cycles well, but the date of the MOD16A2 peaks in all climate types occur mostly with one-week precedence. The evapotranspiration of the MOD16A2 is successful in estimating the PenmanMonteith (Priestley-Taylor) evapotranspiration in arid and semi-arid climates (semi-humid to perhumid climates), particularly semi-arid with cold winters and hot summers climate (per humid climate), due to the small errors of the model, including PBIAS and RMSE respectively in the range of 40. 3-46. 5% and 14. 19-6. 6 (the range of 72. 5-97% and 6-24. 5 ), the high coefficient of the modified agreement index in the range of 0. 5-0. 61 (0. 37-0. 5), weighted determination in the range of 0. 55-0. 63 (0. 44-0. 51). Moreover, there is a strong positive linear relationship among MOD16A2, Priestley-Taylor, and Penman-Monteith in most climate types, because of their high correlation coefficients (more than 0. 85). Conclusion: The results of this study indicate less uncertainty in evapotranspiration of the MOD16A2 product with the Penman-Monteith FAO 56 method in the semi-arid and arid climates, especially semi-arid climates. In contrast, in the semi-humid to perhumid climates, MOD16A2 product has less uncertainty with the Priestley-Taylor method. Also, the MOD16A2 product has the least uncertainty in the semi-arid climates due to the least errors. Therefore, considering the recent climate change in terms of increasing temperature and consequently increasing evapotranspiration, particularly in arid and semi-arid regions around the world, and proposing the Penman-Monteith FAO 56 as the standard method of estimating evapotranspiration by FAO, the MOD16A2 evapotranspiration can play a crucial role in irrigation planning, water resources management, and monitoring drought in the arid and semiarid climates without any observed dataset, especially semi-arid climates.

Background and Objectives: The contaminant mass balance in a soil profile is highly necessary in long term agriculture management under different irrigation systems. The objective of this research was assessment of the preferential flow on the travel time and mass balance of NO3 under two irrigation systems. Materials and Methods: Nine PVC-columns were employed with a 60 cm length and 16 cm diameter. Each column included 50 cm height of clay loam soil and two cracks with 50 cm length and 1 cm diameter that filled by course sand. The treatments were based on two groups at three levels. The main group was crack: soil with blocked cracks (M); soil with remove lateral infiltration to cracks (MC-S); soil with lateraled and vertical correlation and infiltration with cracks (MC-C). The subgroup was irrigation systems: surface irrigation (SI) with 2 cm water constant height and surface drip irrigation system (DI4 & DI2) with 2 and 4 l/h flux, respectively. Each experiment column was irrigated for 6 hours (1 h with distilled water; 2h with solution consist of 176 (mg) of NO3 and 61. 8 (mg) of Cl in 1 liter distilled water and finally 3 h with distilled water). Before the start of experiment, each column was irrigated with distilled water for 5 h to reach saturation condition. The drainage water separately collected from soil and cracks every 15, 30 and 60 min. Results: The results showed the value of mass balance of NO3 and Cl in SI and DI4 irrigation systems were not significantly different. Based on the results, the mass of NO3 of drainage water in M inDI2 was approximately half that of SI and DI4. Whiles, this mass of transported Cl in DI2 irrigation system was higher than other irrigation systems. Also, the travel time of Cl in MC-C treatment, in crack section, was shorter than that of NO3. On the other hand, the results show the mass balance of these anions that transported from crack section was more than 1. 5 times that of other treatments, which emphasizes the role of the vertical flows in course paths of crack in the transport of contaminants such as NO3 and Cl toward groundwater. Conclusion: Over all, under high water velocity as SI, NO3 is transporting more rapidly but under condition with low water velocity like as DI2 with longer time of unsaturation condition, Cl is leaching more. The preferential flows in treatment with full interaction between soil matrix and cracks were happen more. Also, the preferential flow has stronger role to transport of Cl than NO3.

Background and Objectives: In religious sciences, it is believed that the beginning of the creation of man was from the earth, that God created the blessed and exalted man from the earth is itself a proof of its value and importance. Soil as the raw material of human creation is one of the elements that accommodate most of human needs. Soil is a valuable element in the continuity of the earth and the life of every living thing depends on it, in fact, saving the lives of all creatures is related to saving the lives of this vital substance. Materials and Methods: In conducting this research, the library method as well as authentic religious books and sources, especially Quranic verses, authentic and famous meanings and interpretations, and Islamic traditions have been used. In general, all its verses and translations from the site of the Islamic Encyclopedia, as well as the books of Nahj al-Balaghah, Baharalanvar, sample commentary, guide commentary, sufficient principles and the Holy Quran and about 60 verses of the Quran were used to extract data and analyze them. Results: The Qur'an considers the creation of man from dust. The meaning of soil is the same as mud (mud) which is a combination of water and soil. This issue also deserves attention; (Romans 20) Our environment, water, soil and air, which are the greatest divine blessings for humanity, are like a chain called the chain of interconnected and interdependent life, the removal of each of which is equal to the death and destruction of life. The soil is beautiful. The soil absorbs seeds and water: (that you see the earth barren, you see the earth dry (and lifeless), (Fossilat / 39). The living soil carries us and the dead bury us: (Have We not made the earth (as a place) to draw together, Did we not make the earth the center of human society, (Morsalat/25). This divine blessing is made in a way that is easy for agriculture and to build a rigid building. Conclusion: Soil is the place where plants grow and can be considered as the main element of life. The purpose of this study is to investigate the need for soil and land from the perspective of the Creator. Many verses of the Holy Qur'an address the importance of soil, which shows the high importance of soil and earth in the Qur'an. In verses of the Holy Qur'an, God has considered this life cycle to be interconnected and continuous; The word earth is used more than 40 times and the word mud is used 12 times in the Qur'an. In many cases, soil is mentioned as a place of human sustenance. It is understood from the teachings and beliefs that the soil is sacred and valuable (necessity), the Muslim man has rights, responsibilities and limitations against the soil, and he must protect this divine blessing well (conservation), and he must also preserve it. And its health to strive.