صلاح الدین زاهدی

The amount of sediment and suspended materials, along with flowing water, is one of the important concerns in the design of hydraulic structures, such as channels, valves, and turbines of dams. This issue is very important from other aspects, such as maintaining the quality of soil in agricultural lands, addressing environmental issues, and managing water resources for drinking and industry. Satellite images, are used to estimate and monitor the water quality of rivers (especially the concentration of suspended load), the sources of pollution, and their movement. They cover a large area of the study area simultaneously, and they also record the spectral reflection of terrestrial phenomena. They have high efficiency. In general, research conducted in the field of the relationship between the spectral reflectance of water (recorded in satellite images) and the concentration of suspended load shows that there is a correlation between the red and infrared wavelengths with the concentration of suspended load. This correlation can be used as an indicator in the evaluation of these bands and to estimate the amount of suspended load concentration. The proper method to find the local model of suspended sediment concentration is to use field data collected during satellite imaging. In this article, the estimation of suspended sediment using Sentinel-2 satellite images in a narrow river has been discussed.

In this research, the estimation of suspended sediment concentration using Sentinel-2 satellite images in low latitude rivers has been investigated. In order to investigate the correlation between the spectral reflectance of the Sentinel-2 image bands and the concentration of suspended sediment, the statistics of the concentration of suspended sediments at the Polchehr station, located in the Gamasiab River of Kermanshah province, in a five-year period (1394 to 1398) were used simultaneously with them. For this purpose, a range of different amounts of sediment has been used, from a concentration of 0.44 mg/liter to 118.86 mg/liter. Out of the total of 24 images suitable for the days of measurement of suspended sediment concentration, four images were removed due to cloudiness, and two images with abnormal reflection higher than the others. Finally, 18 satellite images related to floods were used, of which 12 images (70% of the data) were used in the calibration stage, and 6 images (30%) were used in the validation stage. In this study, the pixel values of the images corresponding to the hydrometry data of Polchehr were extracted in two modes: single band and band ratio. Suitable regression models (linear, exponential, and polynomial) were fitted, and the accuracy of these models has been checked. Finally, the type of algorithm governing the concentration of suspended sediment in Gamasiab River was determined.

In this research, 8 bands of the Sentinel-2 satellite were used as single bands and band ratios. The results showed that the concentration of suspended sediment in the Polchehr station varied from 0.44 mg/liter to 118.86 mg/liter. Based on the results, it was found that dates with higher reflectance values had higher measured suspended sediment concentrations. The highest amount of reflection from the water surface was observed in band five (703 nm) and B8A. Also, from the obtained models, it was found that in the case of a single band, better results were obtained than when the band ratio was used. The exponential model related to band 5, which had a higher correlation with all sediment values, and the coefficient of determination was obtained as 0.83. To evaluate the results of the current research, the root mean square error of the evaluation index was used, and its value was 33.95 for the 5-fold band. It was found that the modeling of the suspended sediment parameter was done with proper accuracy. The results of the present study showed that satellite images can be useful for evaluating water quality monitoring. In addition, this study showed that Sentinel-2 can be used as a suitable tool for estimating suspended sediment concentration with acceptable accuracy in small-scale watersheds and flood conditions.

The results showed that the Sentinel-2 satellite images and the equations obtained in the present research are suitable for calculating the suspended sediment concentration in the Gamasiab watershed of Kermanshah province. Based on the results, it was found that nine models for the studied area had acceptable and suitable coefficients of determination and error values. Among the obtained models, it was found that better results were obtained in the single-band mode than in the mode where the band ratio was used. Also, the results showed that the exponential model related to Band 5, which had a higher correlation with all the sediment values, can be used to estimate the suspended sediment concentration from Sentinel-2 satellite images in the Gamasiab watershed of Kermanshah province when it is possible to collect no field data. The present study will be useful as a reference for future research in investigating and estimating suspended sediments using satellite data. In addition, considering the importance of suspended sediment in water quality and its effects on the environment and economy of the region, the use of suspended sediment estimation methods using satellite data can be used as a fast and efficient way to monitor water quality in narrow rivers.

Accurate information about the amount of moisture and its fluctuations can provide a suitable solution for preparing soil surface moisture maps, predicting the occurrence of soil storms and dust, forecasting floods, droughts, and other climatic phenomena, determining the irrigation time table and the grazing season. In this study, the Perpendicular Soil Moisture Index (PSMI) extracted from Landsat 8 images was used to estimate and determine surface soil moisture. Using field data, the relationship between this index and soil moisture was determined. After radiometric and geometric corrections of images and normalization of field data, processing of satellite images and extraction of PSMI index were performed. Simple regression analysis between field data and index values ​​was performed at different times. Then, the accuracy of produced maps was determined with statistical indicators including coefficient of correlation (R2), root mean square error (RMSE), mean absolute error (MAE) and Nash Sutcliffe efficiency coefficient. The results showed that estimated values with the PSMI index are completely dependent on the season and vegetation status. In the growing season and with high greenness coefficient, the accuracy of estimation was high. In dormant seasons, vegetation had a weak and moderate correlation with field data. The average coefficient of R2 in all sampling times was about 0.65. From the findings of this study, it can be concluded that this index can be used to monitor soil moisture in areas with suitable vegetation, irrigation planning in agricultural areas, and the beginning and end of the livestock grazing season.

Nine accessions of Elymus libanoticus was planted at Baharestan Agricultural Research Station and evaluated in order to nominate of the best accessions in terms of adaptability and establishment. The experiment started in 2010 and continued to 2015. For each accession adequate seed of different stocks in whole of the province was reaped. In reproduction phase (2010 autumn) and after soil preparation, all accessions were planted on plots with 5*6 m2, with 50cm spacing of planting line and planting points and 3cm of planting depth. At this stage weeding, and three irrigation times were performed. In the summer of 2011 mature seeds of grown accessions harvested and re-cultivation of seeds that were not green in the first stage was carried out. In 2011 and 2012autumn, the accession of each species based on complete randomized block design with 3 replications and 2 meter intervals on 2*4 m2 plots and 4 lines with 4-meter length and 50 cm intervals (In order to elimination of marginal effects) and 3 cm of planting depth planted as rainfed. The measured traits for plant selection were 1) growing 2) flowering 3) seeding 4) Yield 5) canopy cover 6) height and 7) regrowing, all data were statistically compound analyzed by SPSS and averages were compared using Duncan method. Results showed that there were significant differences among the measured traits and accessions (P≤0.05) in all studied years (2012-2015). In terms of measured parameters for all accessions of Elymus libanoticus, Iranshah and Chakhelo accession, respectively showed superiority and minority in the Baharestan research station conditions. In addition to the difference in genotypic power and the amount of precipitation that mentioned in previous studies as the only limiting factors of growth and propagation, Variable factors such as altitude from sea level, depth of soil and geographic direction of collecting areas of different accessions are factors influencing the establishment and adaptation of rangeland species in the site of cultivation and have the most effect on the performance of different accessions. So, it seems that zoning of areas is necessary for seed reproduction in order to improve the rangelands, and the use of extras in each area is necessary for replanting and planting in the same area.

Snow cover has a significant role in management and supply of water resources in mountainous basins. In this order, this study aimed at estimating of contribution the snowmelt runoff in Chehelgazi Sub-basin at Kurdistan Province in supplying water requirements of its farmlands during 2012 and 2014. To do so, SRM model and MODIS satellite images were applied to estimate runoff from the snowmelt and CROPWAT model was implemented to determine water requirements of farmlands. Through the findings, it was found that SRM model with coefficient of determination (R2) of 0.97 and volume difference percentage of 0.14 for the calibration year (2012-2013) and coefficient of determination of 0.96 and volume difference percentage of 0.66 for validation year (2013-2014) was able to estimate snowmelt runoff. Moreover, the result from CROPWAT model showed that water requirement for farmlands in Chehelgazi Sub-basin was 1939371 m3yr-1. Ultimately, it was shown through the model that runoff from the snowmelt has 100 % potential in supplying water requirements in the basin. The result from this study can be used to provide a model for water planning in Chehelgazi Sub-basin.

Global warming due to increasing concentrations of greenhouse gases, especially carbon dioxide, has led to drastic climate change in recent decades. This has intensified the process of degradation of natural resources, soil and water, especially in arid and semi-arid regions. One of the most important tools for adapting or modifying the consequences of this crisis is the sequestration and storage of carbon by natural ecosystems with the help of efficient management tools such as rangeland and watershed management. This study was conducted to evaluate and quantify carbon storage in various types of biological remediation and rehabilitation operations, including pit-seeding and exclosure in the Gavdareh watershed of Kurdistan province. Sampling was performed in soil and plant units using a systematic random sampling method of aerial parts, roots, litter, and soil. Samples were analyzed in vitro. The results of the statistical analysis of the data indicated that the amount of vegetation carbon storage in the experimental treatments had a significant difference (p≤ 0.05). The least significant difference in this level of probability is 334.35 kg/ha (p≤ 0.05), and also the results of comparing the mean yield of these treatments showed that the amount of carbon storage in the exclosure was higher than other treatments, and compared to the experimental control in the upper and higher class. The average total carbon stored per unit area was 8809 kg/ha, 67% of which was related to carbon storage in the soil. In general, it is concluded that biological remediation operations, especially exclosure, have a high capacity for carbon storage, and the soil is the most important carbon reservoir in this operation.

This study was conducted to evaluate the capability of the DHSVM model to simulate hydrological processes in a mountainous watershed with a minimum agricultural land use. The required climatic parameters were set for the daily time step. The inverse distance method was used to interpolate the climatic variables from the stations to the network cells. Time inputs to the model were prepared for the years 2008 to 2013. The land cover map was prepared using the supervised classification method of Landsat TM data. The stream network map was generated using the DEM map in ArcGIS software. The soil texture map was prepared using field sampling and in the laboratory. Primary tests to the determine sensitivity of input parameters showed that this model is sensitive to lateral hydraulic conductivity, exponential coefficient of hydraulic conductivity, porosity, field capacity, and minimum stomatal resistance. In this study, except for the lateral hydraulic conductivity and exponential decrease coefficient, all other parameters (soil and vegetation) were determined based on previous studies and field measurements in a similar way for both categories of data.  The time series of the data were divided into three, warm- up or preparation periods (2008-2009), calibration (2009-2011) and validation (2011-2013). The model was calibrated using stream flow data from 2008 to 2010. Different efficiency criteria were calculated between simulated and observed flows. NSE value for calibrating was 0.59 and for validation was 0.606. In general, the results of this model implementation in the studied basin with the quality and quantity of input data to the model are satisfactory.

The evaluation of Elymus hispidus var. hispidus ecotypes in different ecological zones of Kurdistan province was carried out at Baharestan Agricultural Research Station in order to nomination of the best ecotypes in terms of adaptability and establishment. The experiment started in 2010 and continued to 2015. For each Ecotype adequate seed of different stocks in whole of the province was reaped. In reproduction phase (2010 autumn) and after soil preparation, all ecotypes were planted on plots with 5*6 m2. In 2011 and 2012autumn, the Ecotype of each Species based on complete randomized block design with 3 replications and 2 meter intervals on 2*4 m2 plots and 4 lines with 4-meter length and 50 cm intervals (In order to elimination of marginal effects) planted. The measured traits for plant selection were 1) growing 2) flowering 3) seeding 4) Yield 5) canopy cover 6) height and 7) regrowing, all data were statistically compound analyzed by SPSS and averages were compared using Duncan method. Results showed that there were significant differences among the measured traits and ecotypes (P≤0.05) in all studied years (2012-2015). In terms of measured parameters for all ecotypes of Elymus hispidus var. hispidus, Dolab Ecotype, showed superiority in the Baharestan research station conditions. it seems that altitude, soil properties and aspect factors have had most efficacy on different ecotypes operation of this specie in this study.

The global warming due to increased greenhouse gas concentrations, especially carbon dioxide has led to severe climate change over the past decade. This has aggravated the destruction of natural resources, soil and water, especially in arid and semi-arid regions. One of the most important tools for adaptation or correction of the consequences of this crisis is the carbon sequestration using natural ecosystems through efficient management tools such as watershed management. This research was carried out in order to evaluation and quantitative of carbon sequestration by checkdams and banquette in Kurdistan representative site of Gav-dareh. Sampling was done at work units using a systematic random sampling method. And then transferred to the laboratory for analysis. The results of statistical analysis of the data indicate that the amount of carbon dioxide in vegetation cover in treatments has a significant difference at 5% level. Also, the results of total carbon sequestration, including vegetation and soil, indicate that the amount of carbon sequestration has increased due to watershed mechanical management. This increase in banquette and gabion checkdam is significantly higher than the control and in comparison with it, they are in the class of superiority. The mean of total carbon sequestration is 7266 kg/ha which 65 % of that is related to soil sequestration. It is generally concluded that watershed operation, especially banquette as a mechanical operation has high potential in sequestration, and soil is the most important reservoir in this kinds of operations.

Soil depth is a major soil characteristic commonly used in distributed hydrological modeling in order to present watershed subsurface attributes. It strongly affects water infiltration and accordingly runoff generation, subsurface moisture storage, vertical and lateral moisture movement, saturation thickness and plant root depth in the soil. The objective of this study is to develop a statistical model that predicts the spatial pattern of soil depth over the watershed from topographic and land cover variables derived from DEM and satellite image, respectively. A 10 m resolution DEM was prepared using 1:25000 topographic maps. Landsat8 imagery, OLI sensor (May 06, 2015) was used to derive different land cover attributes. Soil depth, topographic curvature, land use and vegetation characteristics were surveyed at 426 profiles within the four sub-watersheds. Box Cox transformations were used to normalize the measured soil depth and each explanatory variable. Random Forest prediction model was used to predict soil depth using the explanatory variables. The model was run using 336 data points in the calibration dataset with all 31 explanatory variables (18 variables from DEM and 13 variables from remote sensing image), and soil depth as the response of the model. Prediction errors were computed for validation data set. Testing dataset was done with the model soil depth values at testing locations (93 points). The Nash-Sutcliffe Efficiency coefficient (NSE) for testing data set was 0.689. The results showed that land use, Specific Catchment Area (SCA), NDVI, Aspect, Slope and PCA1 are the most important explanatory variables in predicting soil depth.

The maxillofacial fractures have shown an increasing trend. Hence, in this study, the trend of maxillofacial fractures is studied and their corresponding etiologies are analyzed in patients referring to Imam Khomeini hospital.
In a descriptive cross-sectional design, 637 medical documents of patients with maxillofacial fractures who referred to Imam Khomeini Hospital between 2009- 2011 were evaluated and were analyzed using ANOVA and chi-square exams with SPSS software.
The mean age of maxillafacial trauma was 26.68 ±14.47 years. Falls and traffic accidents were the most common cause of fractures followed by assaults. The most common fracture sites were nasal and mandible areas with 66.4% and 7.1%, respectively.
It may be concluded that maxillofacial fractures are more common among males aging from 20 to 30 years old and are mainly due to falls and traffic accidents and are more common in nasal and mandible areas.

In the past decade, extensive changes have occurred in the land use and land cover of Qeshlaq dam watershed. The rangelands of the study area have undergone extensive changes, converted to other land uses, or lost their quality. The continuation of this process not only reduces the forage production and consequently livestock production but also increases unemployment and migration to the city, leading to increasing soil erosion and sediment yield as well as reduced size of the dam reservoir and reduced economic life. This research was aimed to detect and provide the map for the land-cover changes in the study area during 1987 and 2010 using TM Landsat 5 satellite images. In this regard, the available data of the study area and the data collected from field were used as ancillary data. Maximum land-use changes, with a reduction of 4857 ha in area, were related to the class II rangelands, followed by class III rangelands with an increase of 2983 ha, and agricultural irrigated lands with an increase of 1641 ha, respectively. Our results clearly confirm the heavy grazing in the study area and conversion of rangelands to agricultural lands.

For assessing clipping (simulated grazing) effects on Stipa barbata as an important species, a half hectare exclosure field was established before 2007 growing season in Majidabad paddock. Inside the exclosure area, 40 plants were selected of which 10 replications were allocated to each specific treatment of ocular-estimated hand clipping of 25, 50 and 75 percent of annual growth. Ten replications were assigned as control (unclipped) plants. Clippings were done monthly during the three months of current grazing season. Monthly-clipped plant materials were dried in free air to calculate the accurate clipping intensity. In addition, the residues of all plants (also controls) were clipped and dried simultaneously at the end of growth season. The study was done for four years. A split plot in time was used as the statistical design and analysis. The results showed that the main effect of year and different clipping intensities and interactions effect of different clipping intensity and years were significant on forage production but no significant difference was found on final height and number of reproductive branches. Most and least amount of production were related to the years of 2007 and 2008 with 508 and 167 mm of rainfall, respectively and 75% treatment (severe clipping). As the overall conclusion, regarding the environmental and management variations of this species, it is adapted with light clipping (25%) and maximum allowable use of one third of the annual yield growth.

To study the effect of different harvesting intensity on forage production of Bromus tomentellus was considered of Majid Abad Qorveh. Treatments included four harvested intensity 25, 50 and 75 percent and control (no harvest).Data were analyzed based on splitplot over time during four years(1386-1389) using SAS and IRRISTAT software. The results showed that the main effect of year, different harvesting intensity and interactions effect of different harvesting intensity and years are significant on forage production and vitality of Bromus tomentellus. Comparing the harvesting intensity of 50 and 25 percent indicated no significant difference between them. The highest intensity of production is harvest intensity of 25 percent with 390 mm perecipition in 1389 and the lowest harvest intensity is 50 and 75 percent with170 mm perecipition in 1387. Regarding to AMMI Analysis, the first interaction principal component(IPC1) had a significant effect and express a 93/6 percent of the interaction of the sum of squares. The first main component biplot interaction showed that the 25 percent treatments had a highest average production and stability is relatively good, control treatment had a lowest stability and 75 percent treatment had a highest stability. According to the results, to preserve the production and vitality of Bromus tomentellus the harvesting intensity of 25 percent is recommended.