مریم ممبنی

Flood spreading is one of the most important soil protection and improvement measures, which both prevent flood waste and help fight desertification. This research aimed to investigate the effect of flood spreading and plant type on the activity of some physicochemical and biological properties of the soil in pasture fields with and without flood spreading in the Garbayegan, Fasa in 2019-2020. Soil sampling was carried out in spring and autumn to a depth of 20 cm in three repetitions around the rhizosphere of plants and modified according to the materials and methods section. The averages were compared with Duncan's test at the level of 1.5% and using R software. The results showed that the amount of usable phosphorus and potassium in the flood spreading conditions and the control area was without significant difference, but the amount of carbon and nitrogen in all the studied species in the flood spreading area was significantly different. It was more significant than the witness was. However, the amount of respiration in the flood spreading area was the highest, while the respiration and microbial biomass in the control area showed the highest amount. However, the amount of basal heat and microbial biomass in flood spreading areas showed a lower amount, which can be the result of the low amount of organic matter in the soil as a result of excessive livestock grazing in these areas. Finally, it is recommended to implement flood-spreading projects in arid and semi-arid areas to increase the productivity of soil characteristics.

The rangeland ecosystems of arid and semi-arid regions play the most important role in the distribution and density of vegetation in these areas due to the specific environmental conditions governing the soil, which is the bridge between living and non-living parts of ecosystems. Soil enzymes play important biochemical roles in the decomposition of organic matter at all stages in the soil system. These enzymes play an important role in the stability of the soil structure, the decomposition and formation of organic matter, the cycle of elements and the activity of soil microorganisms. Environmental stresses, such as drought, have negative impact on plant growth and soil microorganism's activity. Therefore, evaluating the effect of flood spreading on soil quality indicators can be a useful step in improving knowledge in this field. Therefore, this research was conducted during 2018 and 2019 to investigate the effect of flood spreading, plant types and characteristics on biological soil in the Kowsar floodplains located in Gareh-Bygone, Fasa.

Sampling of the soil around the roots of Artemisia sieberi Besser, Dendrostellera lessertii (Wikstr) Van Tiegh. and Heliantemum lippii (L) Pers, in two situations: with flood spreading and without flood spreading (control area) in spring and autumn from a depth of 0-20 cm and in three repetitions. After ensuring the normality and homogeneity of the variance of the data by the Shapiro–Wilk and Levene tests, the data were analyzed using the two-way variance method and mean comparison were made using Duncan's test at the 1% and 5% level and using the R software.

The results of soil fertility characteristics showed that there was no significant difference in the amount of phosphorus and potassium in the three pasture species studied under flood spreading and the control areas. However, the amount of carbon and nitrogen in all studied species was significantly higher in the flood spreading area (containing 0.3% organic matter) than the control area (with 0.15% organic matter). In addition, the results of this research indicated that the highest activity of acid phosphatase enzyme was observed in the rhizosphere of D. lessertii species and in the spring season, and on the contrary the lowest activity was observed in the rhizosphere of H. lippii species under the flood spreading condition. Alkaline phosphatase activity in all species was significantly higher in spring than in autumn season. The highest activity of this enzyme was observed for A. sieberi in the spring season with an average of 186 (µg p-nitrophenol g-1 soil h-1) in the flood spreading area and the lowest level was observed for H. lippii in the control area with an average of 57 (µg p-nitrophenol g-1 soil h-1) in the autumn season. In general, the level of phosphatase enzyme activity for the A. sieberi species in the spring season was approximately 89% higher in the flood spreading area than in the control area. The dehydrogenase enzyme activity was higher in spring than in autumn. Also, the highest activity of this enzyme was observed in the spring season for the D. lessertii  species with an average of 8.5 (µg TPFg-1 soil 24 h-1 ) in the control area, and the lowest level was observed in the autumn season for the A. sieberi species in the flood spreading area with an average amount of triphenol formazan was 1 (µg TPFg-1 soil 24 h-1 ) .In other words, the amount of dehydrogenase enzyme activity in the spring season was approximately 66% higher than that in the fall season in both areas (control and flood spreading). The results of this research showed that the activity of urease enzyme under flood spreading conditions in both seasons (autumn and spring), with an average of 270 and 300 (µg N/g.dm.2h) is more than the control area with an average of 173 and 250 (µg N/g.dm.2h). Also, the soil quality indices in all three studied species in the two (control and flood spreading) areas have a significant difference, so that the flood spreading operation has upgraded the value of these indices for the H. lippii species and the A. sieberi, while which has reduced the soil quality index of D. lessertii.

The results of this research showed that the flood spreading system is a desirable method for improving soil organic carbon, and its efficiency increases with the plant planting. The increase in moisture and the amount of organic matter in the flood spreading area can be a reason for increasing the activity of enzymes in the flood spreading area, so that in both autumn and spring, the activity of soil enzymes is more in the region. Considering the important role of organic matter in improving biological indicators and soil quality and health, the restoration of floodplains with native species can play an important role in providing these conditions. In addition, it is recommended that these tests be repeated with more samples and in different areas and the nitrogen, carbon, sulfur and phosphorus cycles and its relationship with the activity of other soil enzymes related to this cycle should be investigated.

 as one of the most critical environmental challenges in recent decades which has engendered environmental pollution worldwide (33, 3, 2), wind erosion occurs due to increased velocity and turbulence of the wind when blown on a cover-free surface (11), inflicting lots of economic and social damage on various sectors.There are several methods used to reduce wind erosion, including biological methods (seeding and planting), mechanical methods, and the methods used for strengthening the surface cover such as the application of different types of mulch (oil, polymer, biological, and mineral mulches) (21). In this regard, mulching should, as a last resort, be able to pass rainwater, penetrate into the ground, and maintain moisture while having sufficient required adhesive strength.Non-petroleum materials have increasingly been used in recent years to improve the stability of buildings, aggrandize the diameter of soil aggregates, and stabilize the soil against wind erosion. However, choosing a material as a soil stabilizer against wind erosion, replacing new mulch instead of oil mulch while considering the aforementioned factors, and taking the biodegradability of the non-petroleum materials into account are other crucially important factors to note in this regard. Therefore, this study sought to investigate the effect of mineral mulch (a combination of CaCl2 and MgCl2) on soil properties.

 The study area covered the sand dunes of the Rigboland desert located in Aran and Bidgol city, Isfahan. The mineral mulch used in the study was a stabilizing solution obtained from the evaporation of the brine of Iran’s central desert in the Khorobiabank region, known as the SS400 soil stabilizing solution (27). Chemical analysis of the solution indicated that it contained 30% CaCl2, 15% MgCl2, 5% NaCl, KCl, Ca (NO3) 2, and 50% water whose pH ranged between 5 and 6, with an average specific gravity of 1.5 g / cm3.On the other hand, in March 2012, mulch was sprayed directly to the natural field with three replications on three mounds of incomplete Barkhan-type sand dunes in Rigboland Aran and Bidgol regions to evaluate the influence of mineral mulch on soil’s chemical properties (Figure 4). To this end, samples of aeolian deposits were collected from three different depths of the hills in the study area with three replications (0-5 cm for the first replication with and without mulch; 5-10 cm for the second replication; and 10-20 cm for the third replication) prior to performing mulching. Finally, some samples were collected once more at the end of the experiment in May 2014 from the same three depths. It should be noted that 15,000 liters of mulch were applied per hectare.

 The results of paired T-test performed on the characteristics of different soil depths suggested that the mulched aeolian deposits did not differ significantly in both control and treatment groups in terms of N, CaSO4.2H2O, P, Cl, and OM characteristics in at all the depths studies (P> 0.01). However, the application of mineral mulch significantly increased the EC, pH, Ca, K, and CaCO3 at all depths, and N and Mg at the first and second depths (P <0.01).Mulches with different compositions and origins may increase or decrease the root's ability to absorb elements. In this regard, the current study found that mineral mulch significantly increased the soil’s pH (P <0.01), which could be justified if the Na and CaCO3 added to aeolian deposits as a result of applying such a mulch are taken into account.Furthermore, hydrolysis of Na and the dissolution of CaCO3 which eventually lead to the formation of hydroxyl anions could be regarded as the main cause of such an increase in the aeolian deposits’ pH under treatment mulch. Moreover, the comparison of the deposits’ pH made as a result of sampling with and without mulch revealed that the deposits’ pH would be higher if they are sampled with mulch, which can be justified according to the explanations provided above. On the other hand, some studies have reported that the aeolian deposits’ PH increased when treated with mulch (17), which is consistent with the results obtained in this study. However, the finding does not correspond with the results reported by some researchers (20 and 4).The significant increase in EC capability at different depths of the treatment group compared to those of the control group clearly confirms the influence of mulch on increasing the soil’s EC. Moreover, examining the soil’s EC capability at the evaluated depths showed a decreasing trend caused by the washing and transfer of the mulch-included solutes to lower depths, where the rate of ion transfer decreased with an increase in the soil’s depth.Also, mineral mulching significantly increased the soil’s K (P <0.01), which could be justified by considering the type and the origin of the mulch used, taking into account the fact that the initial solution was prepared by using the materials collected from the study area contained high amount potassium, a limited portion of which still remained active even after it was extracted from the solution (what remained from the solution afterward was used as mulch), causing a significant change in the amount of potassium in the soil. This finding is consistent with the results reported by some researchers (10, 13, and 14) who argued that mulch increased P and K in the soil.

 Considering the findings of this study in terms of the influence of mulch on the aeolian deposits’ componential elements and important chemical properties, including the deposits’ response, electrical conductivity, sodium absorption ratio, and the percentage of the exchanged sodium, all of which showed an increasing trend that led to salinization and alkalization of the deposits, and consequently to physiological dryness, and taking into account the fact that the mulch exerted no influence on the percentage of the aeolian deposits’ organic matter as the most important and effective factor in improving the physical, chemical, and biological conditions of the deposits, it could be argued that the mulch used in this study had no positive effect on the aeolian deposits studied. Therefore, this mulch is not recommended for stabilizing sand dunes and controlling dust.

 Considered the habitat of a large number of living organisms, the soil is regarded as one of the most significant resources for fulfilling the essential needs of human beings, whose destruction brings about lots of damage to various aspects of the organisms’ life. As a natural phenomenon occurring in soils with sparse vegetation where the wind blows at high speed, wind erosion is a highly influential contributing factor to soil degradation, covering one-third of the world’s lands. On the other hand, wind erosion-induced detachment of the surface soil and the movement of quicksand causes enormous damage to various aspects of human life.  Meanwhile, arid and desert areas are more subject to the damage incurred by wind erosion and the influx of quicksand. Various methods have already been used to contain wind erosion and prevent its damage, including biological, mechanical, and soil fixation methods. However, in some areas where biological operations are difficult to perform, mulching is initially used to temporarily stabilize the region. In this regard, petroleum mulching has been the most commonly used method in Iran since 50 years ago.  Nonetheless, some experts believe that petroleum mulching increases soil temperature, raises heavy metals and hydrocarbons, intensifies groundwater and environmental pollution, decreases permeability, and inflicts harm on plants and animals. On the contrary, some other scholars argue that not only does petroleum mulching pollute the soil but also increases vegetation, animal population, and consequently the soil’s microbial population by raising the soil’s temperature and increasing its moisture. However, adding petroleum mulch to soil raises concerns about polluting the soil with petroleum materials and altering the soil’s physicochemical properties.

 This study used the soil samples collected in three replications from the 0-5 cm and 5-10 cm depths of both the control area and Hamidiyeh city’s sand dunes, Khuzestan province, that had been mulched for short-term (less than 5 years), medium-term (5-20 years), and long-term (more than 20 years) to investigate the physicochemical properties of the soil. The samples were then transferred to a laboratory where the soil’s physical properties, including the texture, true specific gravity, temperature, and humidity, and its chemical properties, including EC, pH, chlorine, carbonate, bicarbonate, calcium, magnesium, lime, phosphorus, sodium, potassium, and the sodium adsorption ratio were examined and analyzed using the SAS software.

 The results revealed that while petroleum mulching caused significant changes in the soil’s temperature, moisture, chlorine, bicarbonate, potassium, EC, and pH, it exerted no influence on the soil’s texture, calcium, lime, and sodium absorption ratio. It was also found that due to its black color, petroleum mulch absorbs sunlight and increases the soil’s surface temperature, decreasing the soil’s permeability and moisture with its greasy hydrophobic nature. Moreover, the study found that compared to the control area, petroleum mulching increased the amounts of the soil’s EC, bicarbonate, phosphorus, and potassium, and reduced its magnesium, chlorine, true specific gravity, and sodium in some areas. Taking the above-mentioned results into consideration, it could generally be argued that in addition to influencing the soil’s physicochemical properties, petroleum mulching makes significant changes in the moisture, temperature, true specific gravity, pH, EC, bicarbonate, chlorine, potassium, and phosphorus of the soil. Furthermore, the investigation of the effects of petroleum mulching in the region suggested that most of the restrictive changes made in the region occurred during the short term, with the changes turned towards the improvement of the soil’s quality and fertility and the increase in the soil’s temperature by the establishment, improvement, and growth of vegetation over time. Therefore, if mulching does not helps improve vegetation due to the special conditions of the region (for instance, non-exclosure of the region and preserving it throughout the first mulching years), petroleum mulching is not recommended as it increases the temperature, decrease the moisture, and restricts some properties of the soil in the short-term. However, should there be any chances for the improvement of vegetation, petroleum mulching will increase the soil’s quality.

The influx of quicksand in the desert areas of Iran causes damage to various aspects of life of the inhabitants of these areas. Oil mulching is one of the measures that has been used for many years to stabilize quicksands. Because oil mulch is made up of heavy petroleum products, it can contaminate water resources in these areas with heavy elements and hydrocarbons by entering water sources. To investigate the effect of heavy elements and hydrocarbons on water resources, samples of oil mulch in short-term, medium-term and long-term periods from Hamidiyeh sands of Khuzestan province and also samples of oil mulch of Abadan refinery in laboratory conditions with Simulations of natural conditions and 24-hour residence time in contact with water were investigated. The results of this study showed that the amount of pollution of heavy metals other than elemental, which in the long-term, medium-term, short-term and control area increased by 95%, 115%, 123% and 129%, respectively, than the allowable limit. Oil mulch does not have a significant effect on increasing the pollution of water resources in terms of heavy elements. Examination of oil mulch on the amount of hydrocarbons in water showed that with the exception of Naphtalene and Benzo (g, h, i) Perylene, which decreased in the medium and short term compared to the control area, the difference of other hydrocarbons compared to the control area increased. Been; But in general, the amount of all hydrocarbons studied in the studied treatments was less than their allowable limit.

As one of the most significant environmental problems in recent decades, wind erosion has caused environmental pollution throughout the world (Shojaei et al., 2019; Aliabad et al., 2019; Alipour et al., 2016).), inflicting damages to nearly 500 million hectares of land worldwide per year (equivalent to 46.4% of the world's degraded lands) (Rand et al., 2015). On the other hand, the presence of large areas of running sands, wind erosion-inflicted damages, and problems regarding the use of oil-based mulches, highlights the necessity of using nature- friendly mulches. This study, therefore, sought to investigate the effects of lignocellulosic nanomaterials and lignocellulosic micromaterials on shear strength of soft sands and to the positive and negative effects of such mulchs in that regard so that the most appropriate composition and extent of those mulchs could be identified in terms of increased shear strength of sand particles.   

To conduct this study, a sample of sandy soil with 89% sand particles was collected from the Isfahan’s sand dunes (Rig Boland of Kashan) in the central Iran. Bagasse paste is used to make lignocellulose materials. Using blade mills and super disk mills, bagasse paste is transformed into lignocellulosic micromaterials and nanomaterials. Moreover, the Black liqueur is a paper industry’s waste that is used as an adhesive element. To investigate the effect of lignocellulose nanomaterials and lignocellulose micromaterials on soft sands’ shear strength, nano and microparticles each with 0.3% concentration at three levels (2.5, 5 and 10 g/L in 0.3 m2 soil), Black liqueur with 1% concentration at the level of 10 g/L in 0.3 m2 soil, a combination of Nano lignocellulose (NL) and Black liqueur (BL) in three levels (2.5, 5 and 10 g/L at 0.3 m2  of soil), composition of Micro-lignocellulose (ML) and black liqueur at three levels (2.5, 5 and 10 g / L in 0.3 m2 soil), the control sample and all treatments in one-later and two-layer thickness were sprayed on the surface of the sand. Furthermore, shear blades were used to measure the adhesion of the mulches under saturated and dry conditions.   

In saturated mode, the maximum shear strength of the double-layer microlignocellulose was found to be 10 g/0.3m2, with the shear strength increased to 13.6 kN/m2 compared to the control sample (zero), followed by double layer- microlignocellulose at 5 g/0.3m2 (8 kN/m2) level, double layer- nanolignocellulose at 10 g/0.3m2 (7 kN/m2) level, and the combination of single-layer microlignocellulose plus Black liqueur at 10 g/0.3m2 level (7 kN/m2). It was also found that the lowest shear strengths belonged to single-layer treatments of NL (at all levels), ML (2.5 and 5 g/0.3m2), and the combination ML + BL (2.5 g/0.3m2), as well as double-layer treatments of the combination of NL + BL (at all levels), and 2.5 g/0.3m2 ML + BL. In the dry mode, the maximum shear strength belonged to double- layer NL + BL mulch at 10 g/0.3m2 level, with its shear strength increased by 39 kN/m2 compared to the control sample (zero), followed by double-layer ML at 10 g/0.3m2 (36.33 kN/m2), and a combination of double- layer ML + BL (33.33 kN/m2), respectively. The study’s findings indicated that there was no significant difference between these three types of mulches in terms of shear strength at 5% confidence level, while the results of the mean comparison between these three types of mulches and the control sample showed a significant difference in terms of shear strength (P <0.05).   Table (7): Shear strength of different mulches in both saturated and dry conditions One Layer Double Layer   Black Liqueur control (water)  lignocellulose lignocellulose + Black Liqueur lignocellulose lignocellulose + Black Liqueur  Saturation level 2.5 5 10 2.5 5 10 2.5 5 10 2.5 5 10 One Layer Double Layer   Nano 0 0 0 1 4 3 1 6 7 0 0 0   3.3   0.3   0 Micro 0 0 0.66 0 3 7 1.33 8 13.6 0 3.6 6 Dry Nano 0 5 26 1 4 22 1 16 26 0 7 39   1   0   0 Micro 0 0 5 0 1 13 1 14 36 2 15 33.

As mentioned above, the amount of shear strength increased in the dry mode compared to the saturation one. Therefore, it seems that the passage of time and dryness of the sandy bed have increased the efficiency and strength of the mulch. While the findings of some studies have indicated a significant correlation between the soil’s shear strength and time, other studies have proven the opposite. Moreover, this study found that the paper layer created by the spray of NL on the sand’s surface increased the resistance to sand retardation as well as surface resistance to sinking. Therefore, it appears that the morphologic structure of NL which is comprised of long hole-less nano strings increased both abrasion and strengths. According to the study’s findings, the minimum amounts of shear strength belonged to the treatments of 2.5 gr/0.3m2 NL, ML, ML+BL, 5 gr/0.3m2 of single-layer ML, the combination of NL+BL, and double-layer BL, with the results of the mean comparison between these treatments (minimum shear strength) and the control sample proving no significant difference between them in terms of shear strength (P <0.05). The results of the study also showed that while a seemingly integrated layer had been created on the sand surface via the addition of those mulchs, limited suspensions may have prevented proper adhesion of the sand particles, leading to the easy disintegration of the particles. Therefore, it is recommended that these types of mulches be tested in the natural field first, and should they produced favorable results, be used for the stabilization of the running sands.

Rangeland ecosystems cover a large area of the world and are of special economic and environmental importance, so considering the expansion of the use of exclosure to improve rangelands and carbon sequestration, its effects on soil properties and value calculation the economics of precipitated carbon are important. This study was carried out by investigating the effect of exclosure on some soil properties and carbon sequestration in Dozalum dry rangelands of Golestan province. In this study, soil sampling was performed using systematic-random method and the establishment of three transects with a length of 100 meters, points were identified along each transect. Soil samples were taken at each point. Soil samples were taken at each point. A total of 30 samples of topsoil (from a depth of 0-15 cm) were taken in each area. Then in the laboratory, soil properties, bulk density, soil porosity, soil moisture, acidity, electrical conductivity, sodium, potassium, calcium, magnesium, lime, nitrogen, sodium uptake ratio, and soil carbon were measured. An independent t-test was used to compare the control and exclusion zones for homogeneous data and Mann-Whitney nonparametric test was used for the carbon variable. The data obtained from the experimental results were analyzed using SPSS software. To evaluate the performance of carbon sequestration, carbon tax policy and carbon emission costs were used as the shadow value of carbon. The results of the analysis of changes in soil parameters at the two sites show that rangeland confinement for 15 years in the study areas had little effect on soil properties and only the ratio of sodium uptake was statistically significant. The results also showed that the rangeland confinement operation in comparison with the control area had no significant effect on the amount of deposited carbon and the confined area has an economic value of 255909.5 Tomans in terms of carbon sequestration function.

The use of environmentally friendly mulch is one of the methods used to reduce wind erosion and stabilize the sand. To prepare the bed for the treatments in the laboratory, windy sand of the Kashan desert was used. For experiments, metal trays with dimensions of 2 × 30 × 100 cm and for spraying bentonite clay, zeolite, molasses, and lignocellulose treatments were used. Complete randomized examinations were performed. Finally, based on the experimental results and after creating a regression model between the mixed design variables and the response, the optimal value of each mulch in the Design of Expert software was obtained. According to the obtained results, the presence of zeolite, lignocellulose, and molasses as a combination in each mulch creates a significant difference in terms of compressive, shear, impact, abrasion and ridge formation characteristics with other mulches and control samples. The study performed in the maximum and medium state showed that the amount of bentonite and molasses are equal to each other (15 g) and differ in the amount of zeolite and lignocellulose, so that the amount of zeolite and lignocellulose in the maximum state is 5 and 15 g. And in the middle state are 15 and 0 grams. Each material alone shows different responses to different resistances, but what the results of this study show us that the combination of these materials together has improved soil stability indices. So that the amount of compressive strength is 3.2 kg/cm2, the shear strength is 7.9 N/cm2, the impact is 0.8, the wear is 45 and the thickness is 20 mm. Increased compared to the control sample.

One of the main challenges of land degradation management in arid and desert areas of Iran is the stabilization of sand as well as the control of dust; therefore the use of mulches, particularly eco-friendly mulch, is one of the ways to stabilize sand used. The purpose of this study was to investigate the possibility of using residues such as black liqueur and malass as mulch to stabilize the sand. To prepare the substrate for treatments in the laboratory environment, Rig Boland sandy of Kashan was used. Metal trays with dimensions of 100 × 30 × 2 cm were used for the experiments. For spraying of malass, black liquor and control treatments in a single layer and double layer of 2.5-liter sprinkler were applied and a completely randomized design with three replications was performed. To evaluate the performance of these materials, the shear strength, saturation, and dry strength and water permeability were measured and the data were analyzed by appropriate statistical software. In vitro results showed that the penetration resistance of molasses and black liqueur mulches were 9.8 and 7.8 kN/m2, respectively. These two types of mulch have significant differences with each other and with control (water) treatment. The highest penetration and shear strength were related to Malass treatment, which increased the penetration resistance by 9.8 times and the shear resistance by 14 times. The infiltration rate in one-layer liqueur mulch was significantly different compared to Malass and control (water) mulches, while the infiltration rate decreased with increasing thickness.

Determining the sediment delivery rate and watershed delineation is among the first stage in environmental research, especially in water erosion estimation. The determining the accurate boundary of watershed is important for the hydrological and morphologic characteristics of watersheds. The study aims to present an automatic extraction model of watershed delineation and calculate sediment delivery rate. The traditional method of determining the watershed delineation, and subsequently, calculating sediment delivery rate is performed manually that using a topographic map, the boundary of the watershed is determined and main flow length is calculated. However, nowadays due to the advancement of digital analytical spatial-based methods in GIS software, automatic delineation of watershed is feasible. For this purpose, the errors of digital elevation model are removed. After calculating the flow direction, and flow accumulation, watershed boundaries can be determined having pourpoints. Then, sediment delivery rate is calculated by local height of watershed, its perimeter, and flow length. In this research, the digital elevation models of ASTER-DEM and SRTM-DEM are utilized to design watershed delineation model and to evaluate the overall accuracy and the correspondence of them, so the border of watershed is delineated using Google map, which is used as a ground truth. The findings of this study show the automatic extraction of watershed boundary and calculation of sediment delivery rate do not have significant differences with traditional mothed. So that, the overall accuracy and Kappa index of the watershed boundary based on ASTER-DEM are 93 percent and 0.92, respectively, and their values for the watershed boundary based on SRTM-DEM are 94.3 percent and 0.94, respectively. The correlation coefficient (r2) of calculated sediment delivery rate based on SRTM-DEM is 0.98 and its value based on ASTER-DEM is 0.95.

Abstract: Wind erosion phenomenon is considered as one of the main processes of land degradation in arid and semi-arid regions. The emission of dust and motion of sand by wind power is known as one of the main causes of the desertification process, resulting in the conversion of agricultural areas to landfills and the creation of sand coverage on them. The sand dunes, due to insufficient moisture and lack of appropriate plant cover, have little adhesion and are susceptible to erosion of the wind, thus stabilizing and preventing their development is necessary. One of the common methods of controlling sand is mulching on a surface of sandy hills, where mulch is divided into two groups of oil and non-oil. Recently, paying attention to the problem of environmental degradation by the oil mulch and the high cost of using this type of mulch, has enabled the country's scientific and research centers to investigate the changes in the type and methods of mulching. In the present study, mulches have been introduced from the point of view of their mechanism of action in stabilizing sandy soils and recognizing the disadvantages and the benefits of using mulches. The results of this study indicate that although the traditional use of oil mulch has been an important step in the implementation of sand stabilization over the years, due to its many disadvantages and problems, including the high cost of using this type of mulch and the necessity of using the machine Heavy machinery in field operations, environmental and health problems with this type of mulch and, ultimately, the huge losses that our economic resources each year suffer from wind erosion, Today, it is suggested that, while using oil mulch in very urgent cases, research and promotion of the use of biodegradable mulch using various titles should be used in order to improve the properties and the quality of these biohazardous mulches in the future, production costs It was reduced to an acceptable level.

Remote sensing is the main technology to assess the expansion and rate of land cover changes. Knowledge of these changes in different parts has particular importance as the base information for different planning. The aim of the present study was the comparison of the maximum likelihood and fuzzy Artmap methods to prepare land use map using Landsat satellite images. In this study, changes in land cover were evaluated over the past 24 years in Omidiyeh. Sensor images of TM Landsat 4, ETM+ Landsat 7 and OLI Landsat 8 for the years 1990, 2000 and 2014, respectively, and topographic and land cover maps of the area also were used. Images of all three periods were classified into four land uses including rangelands, agriculture, saline lands, and residential areas. The overall accuracy of the classification results showed that the fuzzy classification method with a kappa coefficient of 93% had more accuracy in comparison with the maximum likelihood algorithm with a kappa coefficient of 81%. According to the obtained results, the most dynamic land use in the region was the agricultural area, whose extent increased from 1990 to 2014, and 32703.32 hectares (32.2%) was added to this land use. An increasing trend was also obtained for the residential land use with an area about 1325.1 hectares (0.94%). On the other hand, rangelands (13.4% of the study area) showed the highest reduction in area (18857.63 hectares).

In recent years, the growth of urbanization in Iran and the increase of migration to the major cities have led to the sudden and abnormal expansion of these cities, degradation of fertile lands and natural resources, and irreparable damages to the nature. As the population of the city of Shushtar has increased, there has been a lot of growth in the built lands in the region, causing a large change in the use of the lands around the city and the degradation of the fertile lands in the suburbs; so that, the continuation of this process could cause irreparable damages to the environmental resources of the region. Land-use prediction models are essential in planning for sustainable use of the lands (Kamusoko et al., 2009: 435, Mas et al., 2004: 94, Sohl and Claggett, 2013: 235). In addition, predicting land use changes and creating a relation between these changes and their socio-economic consequences is very important for sustainable land management (Whitford et al., 2008: 340). So far, the Markov-genetic model has been used in
several studies. Wu et al. (2006) studied the monitoring and forecasting of the Beijing region of China over a 16-year period and used the Markov chain model and regression to predict the land use. Therefore, the purpose of this study was to investigate the trend of land use changes over the past years and predicting the land use and land use changes
using the Markov chain model in the city of Shushtar in Khuzestan province. By predicting land use variations, the development and degradation of the resources can be identified and it can be led to managing the changes in the appropriate pathways (Brown et al. 2000: 247, Hathout, 2002: 229 and Jenerette et al., 2001).
The study area of this research is Shushtar city with an area of 340645.2 hectares located in the North of Khuzestan province. The software packages used in this research include ArcGIS 10.2, ENVI 4.8 and IDRISI Selva 17.0. The images used to extract ground cover classes include Landsat series satellite images; these images were used in this
research due to having a long time series, having an appropriate spatiotemporal resolution to study the land cover changes, and being free. Regarding the existing land uses in the region, the research objectives, and the capabilities of the images used to extract useful information, especially the land use mapping, four land uses including rangeland,
irrigated agricultural lands, rainfed agricultural lands and residential lands were considered. In the analysis of the Markov chain, the cover classes are used as the states of the chain. To determine the possibility of a change, the chain needs two land use maps (model inputs), which are usually obtained by processing the satellite images (Mitsova et al., 2011: 141). Markov chain analysis was performed using Markov chain order in the Idrisi Selva software. Markov chain analysis is provided for two purposes, the first matrix is used for calibration and the second one is used to simulate the possible changes occurring in the future. The output of the model also includes the possibility of transforming the state, transition area matrix for each class, and at the end of the conditional probability images for converting different uses (Gilks et al., 1996: 19 and Weng, 2002: 273).
Regarding the trend of changes during these three periods, the irrigated and residential lands classes had an increasing state, but on the contrary, rainfed lands and rangelands classes had been decreasing. The accuracy of classifications is generally more than 77%, and suitable for use in the Markov model. The results of the detection of changes in 2030 are such that if the current trend continues in the region, 20.33% will be added to the area of the irrigated agricultural land use, so that irrigated agricultural land use constitutes 60.95% of the area in 2030. This increase is due to the changes of the land uses of rangeland and rainfed to the irrigated agriculture. The decrease in the rangeland and rainfed classes will be 21.12% and 0/21% respectively which will be added to the area of the irrigated agricultural lands. These changes are more pronounced around the rural areas in the region.
During the research period, irrigated agriculture has been the most dynamic land use in the region. The area of these lands has increased from 1989 to 2015, so that, 1350131.69 ha has been added to the area of this land use during the three study periods. In the first period, the annual rate of increase was 3650 hectares and in the second period the annual rate increase was 3998 hectares. Considering the lack of change in regional governance and planning, the trend is such, that more than 60 percent of the plain area will be covered by this class in 2030 which can be led to changes in the ecosystem conditions. This result is consistent with the results of Gholamali Fard et al. (2014) in the middle coasts of Bushehr province and is not consistent with the results of Ali Mohammadi et al (2010), Dejkam et al. (2015), and
Ramezani and Jafari (2014).
In general, the results of this study indicate an increase in the area of irrigated agriculture, as well as development of the Shushtar, which has occurred through the disappearance of rangelands and rainfed lands. As it is well known, if the current strategy of land use in this area continues to reduce natural lands and increase urban lands, regardless of sustainable development considerations until 2030, significant environmental problems, including degradation of rangeland, decline in production of the major agricultural products of the region, decrease in the fertility, and increase in the deserts, will be a serious threat to the future ecosystem of the region. Also, considering the current productivity status, the region's economy which is based on the agricultural and livestock production will face a serious threat in 2030. Therefore, this research recommends the use of resulting maps to identify the sensitive areas for better planning
and management of the executive organizations.

The aim of this study was assessed desertification potential of the Dashte Abbas in the semiarid region of Ilam provience18028.8 hectares by using the Iranian model of desertification potential assessment (IMDPA) on soil and vegetation cover indicators. The geometric average for each index including effective soil depth, soil texture, electrical conductivity of soil, percent of gravel, the operation of the plant, the revitalization of vegetation and vegetation condition was obtained using ArcGIS®9.3 and the status map of each criteria was prepared. Finally, by combining and determination of geometric mean desertification intensity map was obtained. The desertification intensity map based on soil criteria demonstrated that over 4843 hectares (28.86% of the total area) and 13185 hectares (73.13% of the total area) has been taken in low and moderate classes, respectively. Also the obtained results from geometric average of vegetation cover criteria indices showed that 7005.99 hectares (38.86% of the total area) in the lower classes and 407.45 hectares (2.26% of the total area) and 10615.35 hectares (58.88% of the total area) has been taken in moderation and Severe classes, respectively. The results of the assessment the considered Catteries indicating that vegetation cover criteria with values of 2.6 is the most influential criteria in the severity of desertification in the study area. Accordingly, it can be said that the quantitative value of the desertification intensity of the total area has been taken in moderate class.

Desertification is currently a big problem in many countries, especially in developing countries, and includes natural processes and improper human activities. The present study was conducted to evaluate the potential of desertification with an emphasis on water, climate and soil criteria using IMDPA Model in Abbas plain, Ilam province with an area about 18028.8 hectare. Geometric averages for indices including water table fluctuations, EC of water, SAR, irrigation system, annual precipitation, aridity index, drought continuity index, soil texture, soil thickness and Ec of soil were obtained using ArcGIS 9.3 and the status map of each criterion was prepared. The results of climate indicated that 100% of the area is in severe class. The desertification intensity map based on soil criteria demonstrated that over 4843 hectare (28.86 percent of total area) and 13185 hectare (73.13 percent of total area) are in low and moderate classes, respectively. Also, the obtained results from geometric average of water criteria indices showed that 10861.4 hectare (60.2 percent of total area) and 7166.6 hectare (39.75 percent of total area) are in low and moderate classes, respectively. The results also indicated that climate with the value of 2.81 is the most influential criterion in the severity of desertification in the study area. Accordingly, it can be said that the quantitative value of desertification intensity of total area is in moderate class.

Desertification means Land degradation in arid, dry sub-humid due to various factors such as climate change and human activity which is one of the considerable problems. Soil Salinity also is one of the main causes of desertification. One of the dynamic properties of soil is the soil salinity; this characteristic is one of the main problems in arid and semi-arid areas which much of the territory of Iran is in these areas. Khuzestan is one of the provinces where the salinity problem is considered as the main problem for farming. Especially the southern part of the province, where the land has a heavy texture and underground water level is high, but they have capability to get reclamation. This study investigated changes in soil salinity in the area of about 11869.207 hectares of land in Khuzestan province, satellite images Landsat relating to the years of 1973, 1990 and 2000 were geometrically corrected and then were used as the main data. Images in the form of maps and tables were presented in four periods after correction of classification in GIS systems. Generally the results show a significant increase in the vast of saline soils in 28 years.

One of the direct methods of land use impacts on the hydrological conditions of each region is relation between land use changes and the groundwater table fluctuations that can assist managers in optimized management of natural resources. In this study، to evaluating the impacts of land use changes on groundwater level drop in Gilan-E gharb plain، satellite images from MSS، TM and ETM sensors in 1985، 2000، 2010 were used. After processing and analysis of images، the region were classified into six classes in terms of land use including forest، pastoral، gardening، dry and water farming، farming and residential areas. Quantitative data of piezometric wells that exist in the plain during 1999- 2010 was used to examining aquifer changes and the resulting layers were also classified. The results showed that pasture land has devoted the largest area (more than 50% of the total area)، as it formed 61. 8% (9927 ha) and 67. 15% (10782 ha) of the area in 1985 and 2000 respectively، its extent has decreased during the period from 1379-1389 and formed 50. 23% (8066 ha) of the region. Evaluation of dry and water farming was also showed that it has been faced with decreasing in the amount of the area 0. 84% (130 ha) during 1985-2000، but the changes in the period 2000 to 2010 has been increased 1429 ha which formed 8. 9% of the region. Assessment of groundwater drop showed that it has been increased through replacing pasture lands class with farming classes. This changes has caused to 83. 93% of the area in 2010 had a groundwater drop more than 50 cm per year، so that the area of this region was 43. 85% in 2000. Human intervention is undoubtedly the most important factor of the region degradation.