1 Introduction Nabkhas are sand dunes that form around vegetation. They have been reported in many parts of the world. Nabkhas are often associated with areas having degraded soil and vegetation. In these landscapes, information on the formation, structure and growth of coppice dunes can provide distinct clues about environmental changes. Therefore, to evaluate and control desertifi cation resulting from vegetation change it is critical to understand the coppice dune dynamics. Many studies have showed the importance of aeolian processes, including the erosion of sediments and their deposition under the shrub canopies. This study focused on evaluation of morphoscopy and Granulometry characteristics of nebkha sediments in Shahdad-Kerman. 2 Materials and Methods The study was conducted in the Southwest Lut playa, Shahdad, Kerman province. A coppice dune was selected. The height of the selected dune was measured from the base of the dune to the center of the mesquite canopy, which typically protrudes about 15m. Sediment sampling was conducted on the top 10cm of the sediment. Sediments were sampled every 0. 5m coppice dune. The samples were transported to laboratory for determining morphoscopy and Granulometry characteristics such as sorting and skewness and sediments physiochemical properties such as EC, pH, SAR, particle size distribution (sand, silt and clay). 3 Results and Discussion The samples belonging to lower part of nebkha had higher EC than those of the upper parts. Average pH of the samples was 4. 23. Mean grain size for sediments on the upper and lower parts of the dune was 208μ m and 115μ m, respectively. Mean sorting was 1. 29. The lower samples are generally better sorted compared with the upper samples. Skewness of grain-size distribution was 0. 16-0. 82. Mean kurtosis of all the samples was 1. 74. The results of kurtosis showed that the upper samples exhibited the lowest kurtosis. The results of morphoscopy showed distance of deposited sediments around Nebkha from their source area was approximately 20-50 km exhibiting their short distance from source area.

Rip current is one of the most important phenomena in coastal areas. Due to the importance of rip currents, which are directly related to human lives, they have been studied and evaluated from different approaches. This research aimed to determine rip currents' effect on the sediments' Granulometry through sampling of the sediments in the rip channel and its surrounding area on the Caspian Sea coast. In this study, one station was selected in Noor city, Mazandaran province. Various factors such as lack of private property, easy access, lack of human manipulation, and knowledge of drowning rescuers about the location of the drowned were considered in the selection of the station. Then, in two seasons, winter (December and March) and spring (May and June), with the help of lifeguards and existing signs, the location of the rip canal was identified in the station and at least three sediment samples were taken from the channel and three samples from the environment around the channel using Grab. In addition, the water depths were estimated in the sediment sampling points using Echo sounder. The sediment samples were transferred to the laboratory and sediment particles were separated based on grain size using a shaker and multiple sieves (with a network mesh of 30, 50, 60, 80, 100, 140, 200, and 230). The data obtained from the shaker were entered into the excel page of GRADISTAT software and the characteristics of sediment samples including mean diameter (D50), mean degree of sorting, skewness, and kurtosis were calculated by Folk and Ward method. All sediment particle characteristics were compared between the rip channels and surrounding areas using an unpaired t-test. The results showed that among the sedimentation characteristics, no significant difference was observed between the channel and surrounding areas in the degree of sorting and kurtosis neither in the winter nor in the spring. In addition, the results of Granulometry showed that D50, mean particle size, and skewness of grain distribution of sediment particles were significantly different between the rip channel and the surrounding areas in the spring. The highest amount of D50 (with an average of 185. 8 mm), mean (with an average of 202. 7 mm) and skewness (0. 48) of sediment particles were observed in the rip channel. These significant differences in particle characteristics were not observed in the winter samples probably due to the turbulent weather and sea currents. In addition, the average water depth of the rip channel was obtained at ca. 120 cm, while the average water depth of surrounding areas was estimated at ca. 85 cm. Therefore, we can state that some of the channel sediments have been removed by water flow in the channel. The higher energy and velocity of the flow in the channel than the surrounding environment has caused the transfer of sediments. On the other hand, sediment transport is directly related to other parameters such as sediment grain size. The present study showed that rip channels have sediments with significantly different characteristics than the surrounding sediments. The higher flow rate in the rip channel probably causes the removal of some fine-grained sediments and is not able to remove coarse-grained sediments. Removal of fine-grained sediments causes a change in the texture of the remaining sediments towards larger grains and these changes have caused a significant granulometric change between the rip channel and the surrounding environment, especially in the spring.

Rivers under different hydro-morphological regimes, demonstrate different flow behavior as normal, debris, mud and flood flows. Spatial and temporal differentiation of these flows according to granulometric characteristics of remainder sediments is of high importance in implementation of watershed management projects especially in river flood plains. The Ziarat watershed contains debris and mud flows in summer that threat the water reserviors of the Gorgan city and touristic sites along the main stream as flash and periodically. In this study for the differentiation of flood flows, after three flow events in 26/27 July 1999, 26 August 2000, and 15/16 October 2000, 37 sediment samples have been selected randomly along the suitable reach of main stream. Then, after granulometric tests by wet sieving and hydrometry, and related curves, key granulometric indices including Trask, Symmetry, Inclusive graphic standard deviation and Krumbein index have been calculated. The sedimentology studies showed that those three flow events were high sediment flows; the first one is determined debris flow and the other two events are known as mud flow. The statistical analysis of variance resulted that, there are significant differences between first and other two flow events at 0.05 levels. The analysis of variance also showed that for particles sizes of less than 50% frequency, the difference between three flood types is not significant but for particles of higher than 50% frequency, the differences are highly significant

Precise study of geophysical and ecological characteristics of benthic habitats is very important, because the seabed type of these habitats has close relationship with presence or absence of particular benthic species as well as with their distribution in the benthic communities. The aim of this study was Investigation of Relationship between Ecogeomorphology and Granulometry of Bed Sediments and evaluates the ecological macrobenthos stations sampled, study of environmental factors temperature, electrical conductivity, salinity, acidity (pH) and dissolved oxygen (DO) in River Bahmanshir respectively. This project was during two seasons in the winter of 2011 and summer of 2011 and in the three parts elementary, middle and end of Bahmanshir River. Samples were transported to the environmental laboratory in Khorramshahr University of Marine Science and Technology. After the laboratory tests, the results were analyzed using the SPSS statistical software. Overall in this study, six species belonging to the class Polychaeta (Nephtys sp. Nereis sp. Capitellacapitata), crustaceans (Sphaeroma sp. ), Gastropod (Triphora sp. ) And nematodes (Nematode sp. ) were observed. Fine-grained sediments in the study area forming particles (mμ 063 / 0>). With increasing depth (200 meters) grading scale is finer and more organic substrate. study also suggests that the aggregation of clay-silt particles were deposited. The results also show that the percentage of coarse particles of silt and clay in the summer has increased, which can cause it to flow from the river in the summer Bahmanshir.

The particle size distribution of the resultant cobalt ferrite samples was determined from Scanning Electron Microscopy (SEM) images using the Granulometry image analysis method. The results showed the nanosized particles of the samples. The X-Ray Diffraction (XRD) patterns of samples were also analyzed by Rietveld refinement method. The results indicated that the precipitated sample at 95 oC had cubic cobalt ferrite structure with F3dm: 3 space group and high crystallinity. The lattice parameters, microstrain and crystallite size of samples were also calculated from the XRD pattern. With increasing the precipitation temperature, the crystallite and particle sizes were increased while the lattice parameter and microstrain were decreased. Regarding the results, it can be concluded that the lattice parrameter of cobalt ferrite has a diverse relationship with crystallite size.

Source identification of sand dunes is of particular importance in projects of wind erosion control. In this study, the map of geomorphology and inventory map of sand dunes were prepared for five regions of Baluchestan under wind erosion using aerial photos, satellite images and Arc-View and Arc-GIS soft wares. Then, 28 samples were collected based on the form of sand dunes and geomorphological facies. The samples were analyzed for Granulometry, morphoscopy and mineralogy in the laboratory.Granulometric analysis was performed using dry-sieving technique and the curves and statistics were drawn and calculated using Gradistat software. The morphoscopic and mineralogic investigation were performed using binocular microscope. Granulometric analyses show that the sediments are well sorted, having better sorting than fluvial sediments, with standard deviation of less than 0.5. Morphoscopic analyses mostly show the effect of Aeolian transport on the grains. Mineralogical studies show that the most abundant particles in the sediments are rock fragments consisting of limestone, quartzite and granodiorite (%84), and the rest are minerals such as quartz, feldspat and calcite. About 94.5 percent of the particles have been transported in saltation. The results of differentiation of sediments according to sedimentary processes indicate that about %71.43 of sediments are transported and deposited by Aeolian processes, %21.42 by fluvial processes and %7.15 by overlapping of Aeolian and fluvial processes.

Dust emission and sand mobilization are the common natural hazards in desert roads of Iran, which originate from geomorphological facies of road margin. In this study, the geomorphological units of Yazd-Meybod road margin were distinguished, and the samples were taken from these facies as origin area while roads sediment as the transition area of sediments. The samples were analyzed using morphometric indices and microscopic mineralogy; then, its results were compared using cluster analysis method. The results showed that the median and mean of road sediment grain is 208 and 224 μm, respectively which according to the relationship between transportation distance and diameter of grains in deposition area prove that the origin area could be close to sedimentation area. The skewness index of grain size distribution tends to show coarser grains and poor sorting for road sediments which revealed the local transportation area of sediment particles. The results of mineralogy between road sediments and geomorphological facies around the road showed that the aeolian sediments crossing the road were more similar to sand sheets and sand dunes which can be introduced as the source area of aeolian sediments on the Yazd- Meybod road.

Loess sediments among of the most widespread forms of eolian glacial sediments. These sediments are usually yellow but grizzly with approximately 70 to 90 percent of their formation consisting of silt materials. Iran losses are mainly located in northeast regions. The purpose of this research is to investigate sediment logical properties of loesses in Ghapan (semiarid climate) and Naharkhoran valley (humid climate) regions in Golestan province. Loesses in mentioned sections were described based on soil taxonomy and from non-developed horizons of parent materials (C horizon). Grain Granulometry at the 2 stages of measuring sand components, with the help of wet sieve, and also, a determination of silt and clay components, with the help of pipette method, where completed. The gained conclusions indicated that, in studied sediments median and mean diameters stand between 4 to 11 and 3 to 8 microns respectively. Also in these sediments, sorting, skewness and kurtosis are very poorly differenced, frneskewed and platy kurtic respectively. These sediments are not equable, the fine grains being abundant and sedimentation having occurred in quiet environments. The main part of inequality is related to particles with the medium size. The statistic conclusions indicate that the sediments found in Ghapan as compared with the ones found in southern Gorgan are significantly different in median and mean diameters, but these sediments are similar from the view point of skewness and kurtosis. Ghapan region loesses are coarser and with a better sorting. A comparison of the studied loesses sedimentary properties with those in a few other countries' losses indicated that there nearly exists a harmony between them from sorting and skewness aspects, but from the view points of median and mean diameters and kurtosis they are different. Weak sorting and Granulometry curve bimodality, in these sediments, indicate that Iran loesses are of 2 origins of different distances. Also, the finer being of southern Gorgan section sediments as compared with Ghapan section, shows that, north and northeast winds (northeast - southwest) play an important role in forming Iran northeast losses.

In general, Loess sediments are one of the most widespread forms of eolian sediments. These sediments are usually yellow but grizzly and approximately 70 to 90 percent of their formation is silt materials. Iran loesses often are located in northeast region and in this research, sedimentology properties of loesses in Ghapan (semiarid climate) and Naharkhoran valley (humid climate) regions have been studied. The stages of this research consist of field operations, brief identification of loess components in sand part, morphoscopy study of Quartz grains and Granulometry operations. In our reading concerning Granulometry, the different components of sand with using wet sieve method and silt and clay components with the help of pipette method were separated and their weight percent were measured. The conclusions of this research concerning sediments indicated that, median diameters is between 4 to 11 microns and mean diameter is between 3 to 8 microns. Their sorting, skewness and kurtosis are very poorly sorted, fine skewed and platy kurtic respectively. The statistical conclusions indicate that the sediments which are found in Ghapan and the ones, which are found in southern Gorgan, have significant difference in median and mean diameters and sorting. Consequently the Ghapan loesses are coarser and their sorting is better, but they are equal from sight of skewness and kurtosis. Our investigation concerning the components of loesses in Ghapan region indicates that gypsy-clayey aggregates and some of the primary minerals are abundant, whereas in the southern Gorgan regions, secondary calcareous-clayey aggregates are great. Morphoscopy research concerning quartz mineral indicates that these samples are located in angular to semi angular class and they have not been moved much distance from their source locations. From the point of surface texture, quartz grains are mainly aureole and partially blur. The form of their aureole indicates that they have been taken from ancient rivers bed and have been deposited in eolian sedimentary environment and their blurring shows wind abrasion, color blending by Sesquioxids and secondary calcareous effect.