hamidreza karimzadeh

Accurate measurement of wind erosion and dust intensity requires precise sediment traps. However, traps with varying geometric and aerodynamic properties differ in their efficiency for collecting, retaining, and selecting wind-blown particles. This study evaluates the collection efficiency, retention capacity, and particle selectivity of two widely used wind erosion sediment traps—the Cox Sand Catcher (CSC) and the Modified Wilson and Cooke (MWAC)—in Iran, where they have recently been implemented for wind erosion monitoring.

Tests were conducted using soils from two wind erosion hotspots in Iran: God-e-Govar (Bafq) and Gavkhuni (Sajzi). A suction-type wind tunnel was equipped with custom-designed bases for the traps and soil trays. Experiments were performed in a controlled laboratory setting at wind speeds of 6.1, 7.88, 9.35, and 10.62 m/s. Collection efficiency, retention capacity, and particle selectivity were measured for both traps.

For loamy sand soil, the CSC trap’s collection efficiency at wind speeds of 6.1, 7.88, 9.35, and 10.62 m/s was 20.61 ± 1.11%, 43.06 ± 2.47%, 35.90 ± 5.12%, and 29.41 ± 1.78%, respectively. For sandy soil from Bafq, efficiencies were 25.35 ± 3.35%, 47.33 ± 4.00%, 41.68 ± 5.19%, and 33.11 ± 3.83%. In contrast, the MWAC trap’s efficiencies for loamy sand were 29.75 ± 4.02%, 31.95 ± 7.18%, 57.57 ± 5.21%, and 62.84 ± 5.82%, and for sandy soil, 43.92 ± 8.83%, 44.23 ± 4.34%, and 47.19 ± 2.97% at the respective wind speeds. Both traps exhibited retention efficiencies exceeding 95% for both soil textures. Selectivity was lower for very fine particles (<100 µm) and very coarse particles (>1 mm), but the CSC trap showed greater selectivity for sand particles due to its design.

The MWAC trap’s collection efficiency increased with wind speed for both loamy sand and sandy soils, whereas the CSC trap’s efficiency peaked at approximately 8 m/s before declining. These differences stem from the traps’ geometric and aerodynamic designs. Both traps showed reduced selectivity for very fine (<100 µm) and very coarse (>1 mm) particles, with the CSC trap being more selective for sand particles. Collection efficiency, retention, and selectivity depend on soil particle size distribution, wind speed, and trap design.

in addition to pasture grazing, animals are fed on such sources as manual forage, farm straw, etc. Therefore, due to various socio-economic reasons, overgrazing and forage shortage exert adverse effects on rangelands, leading to their degradation. On the other hand, excessive exploitation of rangelands and changes in their use has led to the expansion of invasive species, altering the rangelands’ species composition and influencing the relevant ecosystem’s functions and services, which, consequently, ends in the destruction of ecosystems worldwide. In this regard, in cases where the invaluable and important species are overgrazed, the improvement of the rangelands containing perennial, high-yielding, and palatable species is recommended to restore the rangeland’s production capacity, reduce the competitiveness of invasive species, and increase the vegetation both quantitatively and qualitatively. Thus, it could be argued that identifying the factors involved in the germination and growth of invaluable species in rangeland ecosystems is required for the management, improvement, and restoration of rangelands.

This study sought to investigate the effect of irrigation interval, water salinity, and the soil’s clay content on the seed germination and the height of germinated seedling of Hedyasrum criniferum which is an endangered, palatable species indigenous to Iran’s rangelands, under greenhouse and natural habitat conditions. To this end, a factorial experiment was performed in terms of irrigation interval at three levels of 7, 10, and 14 days, water salinity at three levels of <1 (0.4), 2, and 4 dS m-1, and added clay contents at three levels of 0, 10, and 20% under greenhouse conditions with three replications, using a random sampling method. Moreover, the GLM method was applied to examine the factors affecting the herbal parameters of the Hedyasrum criniferum species.

The study’s results revealed that out of the three treatments mentioned above, only the irrigation interval had a significant effect on the H. criniferum species’ germinated seedling height and its germination percentage (α = 5%), with the greatest amount of germination (77.77%) and the highest germinated seedling’s height (4.93 cm) being observed in the seven-day irrigation interval based on the comparison of means. According to the species’ response curves, while the species’ height showed an ascending trend in proportionate to the precipitation rate, it had a reverse trend in proportionate to salinity. As for the clay content, it was found that the species’ height decreased up to 25% with an increase in the clay content. However, the trend was increasing for over 25% clay content.On the other hand, the analysis of the species’ response curve in terms of the amount of germination density indicated that while the number of germinated seeds increased with an increase in the precipitation rate, it decreased with an increase in salinity. Moreover, the number of germinated seeds responded to clay content the same as it reacted to the species’ height, getting decreased with up to a 25% increase in the clay content.

as found in this study, irrigation interval is a more important factor than the other two treatments. The tolerance level of germination and seedling growth was found to be at a 14-day irrigation interval, 4 dS m-1 salinity level, and 20% added clay content. Therefore, it could be argued that lowering the irrigation intervals may help the root growth. Furthermore, maintaining the moisture at 40-0 cm away from the soil profile can facilitate root growth and thereby increase photosynthesis. However, increasing the irrigation intervals may disrupt photosynthesis by creating a shortage in the soil’s moisture and decreasing the production of photosynthate materials to be transformed into the plant’s growing parts, checking the growth of the plant’s height. Considering the fact that Hedyasrum criniferum is regarded as a very high-quality forage in Iranian rangelands based on the rangeland classification indices in terms of forage quality, and that the species contains more protein and metabolic energy and higher nutritional value than alfalfa, and also its desirable ability to stabilize the soil’s nitrogen, the species can be used to convert the abandoned rain-fed lands in semi-arid areas to forage-planted lands and restore the destroyed rangelands in natural habitats. On the other hand, it was revealed that in natural habitats, the chances for the growth of the aforementioned species increased with an increase in precipitation rate, reaching its highest points in areas with average annual 650 mm precipitation. It should be noted that the precipitation range of the species’ habitats indicates the possibility of  H. criniferum growth in different climatic regions, including arid, semi-arid, and semi-humid regions. Therefore, it was found that the chances for the species' growth increased with an increase in precipitation rate from arid to semi-arid and finally, to semi-humid regions. Moreover, the study found that based on its optimal precipitation rate, the species prefers semi-humid climates.

Sediment accumulation is one of the major factors that reduce the beneficial life span of artificial reservoirs. Conservation and improving vegetative cover conditions may reduce sediment accumulation. A framework for implementing the PES was proposed assuming that the cost of soil and vegetation cover conservation may be considered as an investment in water supply through economic incentives, consisting of vegetative cover change projection, erosion and sediment transport modeling, reservoir sedimentation estimation, and the PES scheme design. Based on the results of increasing the amount of total sediment production from 486637.6 m3/yr in the current situation to 564217.5 and 658925.4 m3/yr, respectively over the next 20 years, and reduction of the useful lifespan of the Shirin Darreh reservoir (17.3%), the minimum payment for ecosystem services was considered 104 million Rials/yr. Furthermore, the volume and the total value of sediment control services provided by the vegetative cover was also determined by considering a complete degradation of the vegetative cover scenario and opportunity cost of 740535.5 m3/yr and 3.7 billion Riyals. Furthermore, the maximum payment was also estimated by considering the total value of the sediment control services and the estimated net present value of range conservation to be about 3.9 billion Rials/yr.

Cover-management factor (C) is one of the most important influential factor on soil erosion using the Revised Universal Soil Loss Equation (RUSLE) model. C-factor is challenging to determine based on the proposed procedures due to lack of accurate information. Vegetation cover map can be used to estimate C-factor, but preparing a suitable mapping of vegetation cover is challenging in many situations. Therefore, in this study vegetation cover map was prepared and compared using the k Nearest Neighbor (k-NN) algorithm, linear regression (LR) and linear stepwise regression (LSR) in the study area. In regression methods, 17 vegetation and environmental indices were prepared and their relationships were investigated. The results of comparing the three methods showed that the k-NN method has better results than other regression methods due to its highest overall accuracy (83.3%) and kappa coefficient (75.9%) therefore, it was used to produce C-factor map. Results showed that the k-NN was very promising for mapping vegetation canopy cover in the arid and semi-arid areas. The results showed that among vegetation indices NDVI had the highest correlation (0.82) with percentage vegetation cover. Also, in the k-NN method, the Euclidean distance metrics in k = 9 has better results than the other two Fuzzy and Mahalanobis distances and can be used to estimation of vegetation cover map.

Soil salinity is one of the most important characteristics of the soil. Salinity accumulation is strong in arid areas and it has become a serious environmental problem. Identification and mapping of saline soils often due to temporal and spatial variability and the need for sampling and laboratory work is difficult. In recent decades using geostatistic and remote sensing have been developed for mapping salinity and sodicy of surface soil and monitoring it heir changes. The objective of this research was soil salinity zonation and comparing the capability of geostatistic and remote sensing for mapping soil salinity- in Segzi plain, Esfehan province. For this purpose, 29 soil samples from the study area were randomly sampled and measured the electrical conductivity. TM LandSat 7 images from August 1997 at the same time field sampling were applies to prepare for mapping soil salinity. Then Image processing like image enhancement and PCA were applied on the data. The results indicated that the ordinary kriging (OK) with exponential semivariogram the best method for modeling and interpolating soil salinity. With a significance level analysis and measure study between ground data and output of models, best salinity method selected and extraction soil salinity map. The results showed that the PCA234 method has the highest correlation with the sampling point.  With the results of two periods of 1997 and 2018, it was found that the salinity levels of medium and high classes were reduced in 1997, then in 2018, respectively. Added to the Very high and extreme salinity classes in 2018.

Rangelands provide a diverse array of vital services that pertain to human life. But market failure to consider the value of these ecosystem services has disturbed provision of many ecosystem services. In this study the economic value of water conservation functions by Arnaveh basin located in northwestern Iran was estimated. Rainfall-runoff simulation was carried out by using Curve Number (CN) method. Also by means of Replacement Cost method the value of the hydrological services were quantified. The role of vegetation cover in water conservation was estimated by comparing the surface runoff under current condition and uncovered soil conditions. Moreover the role of rangelands on water retention and surface runoff reduction by devising three more hypothetical scenarios and then the effects of land use changes associated with these scenarios on rainfall-runoff rate of the region were compared. Results showed that the role of rangelands vegetation cover in water conservation and surface runoff reduction was 7.19×106 m3, with the economic value of 123×109 IRR. Also, the results of a comparing between 3 hypothetical scenarios and current conditions showed that, under the case of scenario one which assumes that the entire of rangelands area is becoming to rain-fed farming, total outflow would be in the maximum amount and the most negative effects will accrue. Also the scenarios of improvement of vegetation cover to 25-50 percent has the most positive effects (1.95×106 m3 yr-1 decrease) on water retention. The results of this study could help decision-makers in selecting appropriate and economically feasible development strategies.

Considering the role and importance of grazing on vegetation structural changes, thisstudy aimed to assess the effects of various grazing intensities on vegetation parameters in semi-steppe rangelands of Alavigeh, Isfahan. Three rangeland locations with relatively homogeneous ecological conditions and various long-term grazing intensities (light, moderate and heavy) were selected. Four perpendicular transects with 100 meters length (two parallel transects and tow transects perpendicular to the general slope of the area) were established in each site and vegetation parameters including vegetation cover, density and palatability class of the species were recorded in 10 plots. The Margalef richness index and Shannon-Vainer diversity and evenness indices of the plots were calculated. A one way ANOVA was used to compare the vegetation parameters in sites with various long term grazing intensities. According to the results, the sites with low and moderate grazing intensities had higher plant density and vegetation cover compared with site grazed heavily and these vegetation indices varied significantly between the sites (P< 0.05). The species composition of the light and moderate grazing areas mainly included class II species with 72% and 54%, respectively. The heavily grazed site was dominated by the species with low grazing palatability (69%). The plant diversity, richness and evenness indices of the sites with low and moderate grazing intensities varied significantly (p < 0.05). The log normal was the best fitted parametric model among species abundance models for the low and moderate grazed sites, indicating a stable vegetation community. Log series were fitted to diversity data in the heavy grazed site, indicating an unstable vegetation community. RDA analysis revealed that there was a distinct grazing gradient and three vegetation zones could be clearly separated with various vegetation compositions. Although vegetation condition is appropriate in the sites with low grazing intensity, also the vegetation regeneration can benefit from moderate grazing intensity. Biological considerations are required in the management of rangeland ecosystems in arid and semi-arid ecosystems due to the fragile nature of these ecosystems. 

Soil is one of the most important production factors that has a great impact on human socio-economic life and the process of soil erosion is one of the environmental issues that threatens the environment, natural resources and agriculture. Spatial and temporal information of the soil loss and soil erosion on the land has a significant role in influencing management practices, soil erosion control and watershed management. Therefore, this study was conducted with the aim of studying the spatial and temporal estimation of soil erosion during 1994, 1999, 2008 and 2015 in the sub-basin of Menderjan with an area of 21100 hectares located in the west of Isfahan province using RS and GIS. In the present study, while conducting field studies, various data and information including the digital elevation model, satellite images, soil, and statistics on rain gauge stations were used as a research tool. Estimation of soil erosion in the study area was carried out using RUSLE Model. The results of this study showed that the amount of soil erosion in 1994, 1999, 2008 and 2015 was 0.001 to 233, 0.001 to 297, 0.001 to 231 and 0.001 to 215 "ton/”ha.year”. The topography factor in the study area with the correlation coefficient of 80% had the greatest effect on the estimation of annual soil erosion by the RUSLE model. This research corroborate the effectiveness of modern GIS technologies and remote sensing in temporal simulation for quantitative, exact, and point-to-point estimates in the whole area to obtain soil erosion content.

     Soil serves as an important rangeland ecosystem component and evaluating the effects of management practices on structure and function of range ecosystems can assist managers to select the best option in their reclamation plans. This study aimed to compare the effects of long-term exclosure (33 years) and rest-rotation grazing system on some soil physicochemical properties in semi-arid rangelands of Hamzavi research station, Hanna- Semirom in Isfahan province. Six transects were established in each area and three plots of 2m2 were placed along each transect randomly and 72 soil samples were collected from five points of the plot at the soil depth of 0-10 and 10-30 cm. Soil properties such as pH, EC, CaCO3, organic carbon, absorbable phosphor, total nitrogen, K, Ca, Mg, soil saturated percentage, cation exchange capacity, soil clay, silt, sand, and fine sand contents were measured in the soil laboratory. Independent t-test was used to compare soil properties in both areas. Results revealed that soil properties were more appropriate in areas under long-term rest-rotation grazing system compared with exclosure area. According to the results, most soil properties were differed significantly (α = 5%) due to rest-rotation grazing system in both areas, except pH, Mg, soil saturated percentage, silt, sand, and fine sand contents. This study showed that rest-rotational grazing systems can maintain ecosystem health condition in semi-arid area as well as decrease the costs of animal husbandry and is a more appropriate management option for ranchers compared with long-term grazing exclosure.

Soil erosion is one of the most important issues that human is facing now. The purpose of this research is to estimate the soil erosion in Iran using the RUSLE model and use of geographic information systems (GIS) and remote sensing data (RS). In the present study, after collecting and gathering various information including the digital elevation model (DEM) layers, Statistics on weather stations and rain gauges, satellite images and soil characteristics were used as research tools and Soil erosion was estimated using the RUSLE model. The average annual values of P, K, C, LS and R factors are 0.65, 0.04 (t h MJ-1 mm-1), 0.46, 3.6 and 195 (MJ mm ha-1 y-1 h- 1), respectively. The results of this study showed that the average annual soil erosion in Iran is about 24 tons per hectare per year. Also, the results of the study showed that about 4 billion tons from soil the country eroded and partial entered the system of water in the stream and the sea which reduces the quality, water pollution, reduces of soil fertility and reduces the amount of cultivated land and ultimately leads to soil degradation.

Desertification means land degradation in arid, semi-arid and dry sub-humid regions as a result of various factors, including climatic variations and human activities. In this research, the study area with an area of 136 thousand hectares located 20 kilometers far away from east Isfahan was selected. Due to the proximity of this area to Isfahan city and the impact that desertification phenomenon on the city, studying the desertification in this region is of great importance. To assess the current status of desertification, the multi criteria Analysis and MEDALUS model was used. For this purpose, in the first step and based on the local situation, six qualitative criteria, including climate, soil, groundwater, vegetation, soil erosion, desertification management and policy evaluation were considered. These indices have been standardized and quantified based on their effect on desertification in the frame by scoring 100 to 200. The qualitative value of each criterion has been obtained by multiplying the weight of the Analytic Hierarchy Process (AHP) and integration of layers based on the weighted linear combination. Finally, the desertification status map has been acquired through multiplying weight to the layer value of each criterion and integrating layers according to the method of weighted linear combination in Geographic Information System (GIS). According to the results, 35.49% of the area of the region falls in a severe class and 64.5% falls in very severe class of desertification. Besides, the climate criterion with a weight of 0.29 has the greatest impact on the phenomenon of desertification and then it goes to the management and soil criteria with weights of soil 0.23 and 0.21, respectively. Therefore, to assess desertification and executive programs to deal with it in the region, considering these criteria are of great importance.

The present study aims to improve the assessment, soil salinity accuracy, using of OLI Landsat satellite image dated to 26 May 2015 and topographic parameters in the eastern region of Isfahan. Ground data were collected in date second half May by using the random sampling method from 29 sampling sites from the depth of 0-30cm. Spectrum indexes include OLI sensor bands, salinity indexes SI1, SI2 and SI3, soil indexes SBI and SCI, and vegetation indexes NDVI and RVI were obtained from processing referenced ground images. Also, topographic feature including slope percent, orientation of slope and elevation from sea level were extracted from Digital Elevation Model (DEM), then to estimate the salinity linear regression the stepwise method model was used. From analysis, regression indicated that on 99% statistical level, there is a meaningful correlation between EC of topsoil samples, elevation from sea level and band 4 (R2=0.68). The salinity map acquired from the regression model indicates the salinity is very high in the region so that more than 70% of the area has a salt concentration of more than 60 ds/m. Finally, the reliability of the model was evaluated using 20 percent of the samples. Results indicated that the model can estimate soil salinity by an RMSE=6.54 ds/m. According to the research results, Conclusion They are using elevation from sea level parameter with satellite data is Beneficial in the soil salinity research and causes improve the accuracy of the assessment.

The aim of this study is evaluation the effect of soil, sludge and wastewater on growth characteristics (height, number of leaves and fresh weight) of and plant. For this purpose, 3 sludge treatment, 2 type of soil and 4 levels of irrigation and SPSS 18 were used. The results showed that in all three characteristics of plant growth, increasing height in crop soil is more than the Sejzy soil. In the Haloxylon pp plant, with increasing levels of waste water and sludge, reduced height. And in plant varies according to soil type. Some of branches in the Haloxylon pp plant by increasing sewage sludge levels is decreasing and it shows different effect in different wastewater levels. But in the Nitraria schoberi plant different wastewater levels in both of soil type hadnt significant impact. Increase sludge levels in crop soil; increase the number of branches and Sjzy soil showed an insignificant effect. Effect of different sludge on fresh weight in Haloxylon pp plant is decreasing and different effect in different wastewater levels. But in the Nitraria schoberi plant, effluent impact is not significant. In the Sejzy soil, increasing of sludge levels due to decreasing of fresh water and in crop soil is opposite

More than two thirds of Iran is located in arid and semi-arid regions facing water shortages challenges. This emphasizes the need to reduce water consumption and the use of other unconventional water resources. Based on this fact, the present study deals with the effect of sewage and wastewater on some vegetative traits of Nitraria schuberi as a species adapted to arid and semiarid areas. Its design was a split plot design with six replications in desert Research Station, Segzy plain, Isfahan. In this study, irrigation with wastewater treatment at five levels ( 0 , 25 , 50 , 75 and 100 % ) , sludge at two levels ( presence or absence of sludge ) and two soil types (agronomical soil and Segzy plain soil) were used and morphological characteristic analyses of the plant using a SPSS software was done. Results showed that the highest rate of increase in height and canopy, basal diameter and canopy in Segzy plain soil is in 100% sludge and non- sludge treatments, whereas the same increase is for agronomical soil in sludge treatment with 100% Sludge and non- sludge treatments for plant height of wastewater level of 50%, basal diameter level of 100% and canopy cover of 75%. level for height, basal area and canopy diameter was 100, 50 and75%, respectively. The results showed that the lowest height, basal diameter and canopy cover for Segzy soil under non-sludge treatment for height, basal diameter and canopy cover was 0, 25 and 25%. Also, as for soils under non-sludge treatment for height, basal diameter and canopy cover wastewater levels were 0, 25 and 50% respectively, and for sludge application treatment 75% for basal diameter and 0% height and canopy cover, respectively.

Different types of soil erosion including gully erosion occur in many parts of Iran. The west of Iran is further threatened by gully erosion due to its specific physical and climatic conditions. However, few studies have been carried out to study the sediment production of gully erosion in Iran. This research was therefore conducted to measure storm-wise sediment production of gully erosion in the west of Iran. To achieve the study objectives, 48 gullies located in three small watersheds viz. Darreh-Shahr, Abbas-Abad and Hollowsh in Ilam and Lorestan Provinces were monitored. The volumes of gullies were measured before and after 5 rainstorms for Darreh-Shahr and Abbas Abad watersheds and 6 rainstorms for Hollowsh watershed from 2005 to 2007. Sediment production was calculated on storm basis for each gully. The results revealed that the minimum and maximum volumes of gully erosion were 0.002 and 1.010 m3, respectively, for one millimeter of rainfall. The results indicated that soil moisture, percentage of silt and clay, amount and intensity of rainfall and drainage area were the most important factors on formation and sediment production of gully erosion.

Wind erosion and sedimentation include detachment, transportation and deposition of soil particles by wind. To increase stability of soil surface and for soil conservation against wind erosion, artificial covers can be used, along with vegetation cover. Among artificial covers, one can use industrial residuals. Steel slag is a by-product of iron and steel industries which is produced in massive amount in Isfahan and contains valuable combinations and material. The study area is Harand plain in east of Isfahan which is one of the most critical erosion sites in Isfahan province. The experiment treatments included thicknesses at 2 levels (1 & 2 layers), cover percentage at 4 levels (25, 50, 75 and 100 percent), graining at 3 diameter levels (15-30, 30-45& 45-60 mm), wind velocity at 7 levels and their reciprocal effects. Test took place with 4 factorial replications and by completely random design, and then data got analyzed with Duncan & ANOVA tests in SPSS 15 and Excel. The results showed that steel slag increased the surface coarseness and therefore can control the erosion. Increasing area cover, size and graining of mulch, decline the soil loss. However there was no significant difference between the numbers of applied layers. It is citable that simultaneous increase in area percentage, size and diameter of slag decline the soil loss as well. According to the results, slag mulch can be used for erodible sediments control with 50% density, 30-45 mm graining and in one layer.

Desertification is the ecologic and biologic reduction which may occur naturally or non naturally. Desertification process usually effects arid and semi arid region and reduce the land efficiency very rapidly. This study has been conducted to evaluate and classify desertification with the aim of geographic information system and remote sensing techniques. In this study, TM data of 25 shahriver 1369(16 October 1990) and ETM+ data of 16 shahrivar 1380 (7 October 2001) were used. Geometric, radiometric and sun height angle correction were carried out on the images. Supervised and unsupervised classification were used for both two images and 9 land uses were classified and compare quantitatively due to geomorphology and desertification attributes. Each main and partial desertification factor was input to geographic information database and scaled to make the map of desertification severity based on recommended method for Iran and FAO map of desertification vulnerability. The result of desertification severity which shows desertification condition, velocity and potentiality, showed that natural desertification occurs in 35 % of area with different medium, high and very high desertification severity. Anthropogenic desertification includes 65 % of study area with high and very high condition. But in desertification vulnerability map, very high desertification vulnerability was determined in 20 % of area with simultaneous human and animal effect and high desertification vulnerability was determined on 80 % area with only animal effect. According to the map, for arid region of north of isfahan, it was identified that range land use change to agriculture, improve agricultural patterns, over grazing, incident economic condition and ground water over exploitation are the most important anthropogenic factor, and drought and soil and water salinity are the most important natural factors. Desertification trend is enhancing to north west of the study area which will make trouble for rangelands, residential and industrial areas.